sign in sign up
<<
Home , Acacia acuminata, Acacia quadrimarginea, Australian Shield, Banksia dryandroides, Banksia verticillata, Barren vegetation

VEGETATION SURVEY OF WESTERN

SHEET 7 SWAN 1 : 1 000 000 Vegetation Series MAP AND EXPLANATORY NOTES

J.S.BEARD

I UNIVERSITY OF PRESS VEGETATION SURVEY OF WESTERN AUSTRALIA

I ,I .:i 1 : 1 000000 Vegetation Series I EXPLANATORY NOTES TO SHEET 7 I J I J. S. BEARD PROGRESS IN MAPPING AND PUBLICATION Jt! Published at 1:1 DOD DOD I ± I Published at 1:250 ODO low woodland near Reagan's Ford, Swan Coastal , with nitens in in the understory, and conspicuous Restionaceae. VEGETATION SURVEY OF WESTERN AUSTRALIA

SWAN

1: 1 000 000 Vegetation Series EXPLANATORY NOTES TO SHEET 7

THE VEGETATION OF THE SWAN AREA

J. S. Beard

UNIVERSITY OF WESTERN AUSTRALIA PRESS 1981 First published in 1981 by University of Western Australia Press Ned/ands, Western Australia

PUBLISHED WITH ASSISTANCE FROM CONTENTS THE INTERIM COUNCIL FOR THE AUSTRALIAN BIOLOGICAL RESOURCES STUDY PART I: DESCRIPTION OF THE AREA Introduction 1 History 1 Agents: Eastern States of Australia and New Zealand: Botanical exploration 1 Melbourne University Press, Carlton South, Vic. 3053; Settlement 7 U.K. and : Previous treatment of the vegetation 10 Antipodean Books, Methods of survey 17 79 Grosvenor Road, Muswell Hill, London NJ0, U.K.; Natvral 19 U.S.A. and Canada: Climate 24 International Scholarly Book Services Inc., Box 555, Forest Grove, Oregon 97116. 35 39 Physiography 40 Soils 43 Description of the natural regions 46 Formation of the landscape 60 This book is copyright. Apart frctm any fair dealing for the purposes of private study, research, 68 criticism or review, as permitted under the Copyright Act, no part may be reproduced by any Human influences process without written permission. Enquiries should be made to the publisher. Pre-settlement 1829 68 Post-settlement 73

© J. S. Beard 1981 PART II: DESCRIPTION OF THE VEGETATION Introduction 77 Beard, J. S. (John Stanley), 1916- Classification 77 Swan, I : 1,000,000 vegetation series. formation and association 81 87 (Vegetation survey of Western Australia). The flora Bibliography. Physiognomy 95 ISBN 0 85564 094 4 Vegetation series 115 Vegetation systems 122 1. Plant communities-Western Australia. Some problems in southwestern vegetation 130 2. -Western Australia. I. Title. (Series). The distribution of karri 130 135 581.5'264'099412 Some other eucalypt distributions The mallee 139 Kwongan 144 Acknowledgements 147 References 147 Photoset by University of Western Australia Press. APPENDIX: 179 Printed and bound by Alpha Print Pty Ltd, , Western Australia. Description of the vegetation systems

V PLATES in flower in the understory, and conspicuous Restiona- ceae 167 18 Low woodland of on coastal dune sand, Bremer Bay (understory of and Stipa) 167 19 Low forest of jarrah ( marginata). Denbarker area 168 PLATES 20 Thicket with Acacia neurophylla dominant, on dense laterite north of Beacon 168 21 Thicket of Mela/euca uncinata on sandy laterite soil north of Beacon 169 Frontispiece: Banksia low woodland near Reagan's Ford, , with Verticordia nitens in flower in the understory, and conspicu­ 22 Mature thicket of Acacia resinomarginea, 5 m tall, with heath under- ous Restionaceae story, on deep sand north of Bonnie Rock, on the vermin-proof fence 169 23 Mt Toolbrunup in the . Jarrah low woodland in fore­ Landscape in the inner wheatbelt (Meckering Upland). Dissected pene­ ground, grading to jarrah mallee-heath on slopes and mixed thicket on plain on granite, with tors. Relics of the original plant cover on fence the summits 170 lines, on rough ground, or as scattered in paddocks 159 24 Thicket on the heights of the Stirling Range, in flower iri October: 2 Wheatbelt scene. Relict trees of showing typical , Dryandra, Banksia, Sphenotoma. Bluff Knoll 170 form .._. 159 25 Acacia scrub on shallow granite soil along the vermin-proof fence, 100km 3 Granite rock outcrop 'The Humps', Hyden: mainly bare rock with some east of Bonnie Rock 171 Casuarina huegeliana 160 26 Mallee, typical form, with Mela/euca understory, Ravensthorpe- 4 Profile beneath woodland and mallee in the Hyden district, showing Norseman track southwest of Peak Charles 171 indurated upper horizon underlain by pallid zone 160 27 Mallee-heath, with and E. ca/ophylla dominant. 5 Breakaway marking the boundary between sandplain and valley, Stirling Range at the foot of Mondurup 172 Southern Cross district, with at the foot of the break- 28 Mallee-heath with Eucalyptus tetragona on plain adjacent to the Barren away 161 Ranges 172 6 Coastline in the Barren Ranges, looking east from Point Ann, with 29 Scrub-heath in early stage after fire: general cover re-established, mallee-heath in the foreground 161 of taller species beginning to rise above the general level. Hyden- 7 Effects of salinization: dead salmon gum trees in a bottom land (Moora Norseman road 173 district) 162 30 Scrub-heath in advanced pioneer stage. Grevi//ea excelsior and 8 Karri tall forest (Eucalyptus diversicolor). Pemberton 162 G. pterosperma rising above smaller heath . Great Eastern High- 9 Tuart tall woodland (). Ludlow 163 way, Koorarawalyee 173 10 Unlogged prime (Eur::alyptus marginata). Pemberton area 163 31 Scrub-heath in spring, near Newdegate: Grevil/ea hookerana, Verticordia 11 Lower-grade jarrah forest (Eucalyptus marginata) previously logged. acerosa and V. roei 174 North Bannister 164 32 Scrub-heath in the Barren Ranges, with victoriae, Eucalyptus 12 Low woodland: and E. flocktoniae, typical 'marlocks' sepu/cralis an.d floribunda 174 occurring in patches in the mallee southwest of Lake Magenta 164 33 Scrub-heath component of the Le Sueur vegetation system, on sand. 13 Woodland of wandoo (Eucalyptus wandoo) in state forest west of Bever- Jurien Bay road 175 ~ IM 34 Heath component of the Le Sueur vegetation system, on ironstone gravel. 14 Woodland of York gum (Eucalyptus loxophleba): an apparently undis- Badgingarra 175 turbed example near New Norcia 165 35 Low scrub on granite boss, Point Gordon, Bremer Bay 176 15 Woodland of salmon gum (Eucalyptus salmonoph/oia) north of Bonnie 36 Sedge swamps bordered by paperbarks Me/aleuca rhaphiophylla·, merging Rock 166 into jarrah low forest. Denmark-Mt Barker road 176 16 Low woodland, columel/aris and Acacia spp., Karroun System, 37 Sedgeland: reed swamp of Cyperaceae and Restionaceae with scattered along the vermin-proof fence 166 Xanthorrhoea and shrubs near Mt Chudalup 177 17 Banksia low woodland near Reagan's Ford, Swan Coastal Plain, with 38 Spinifex steppe: hummock grass of Triodia scariosa beneath mallee of

vi vii PLATES Eucalyptus sheathiana, on red sand. Jackson area near- the Die Hardy Range 177 39 Woocted succulent steppe: saltbush A triplex vesicaria with scattered Euca­ lyptus flocktoniae (adjacent to Lake Hope) 178 40 Succulent steppe, unwooded, eastern margin of Lake Moore, looking south 178 FIGURES J 1 Key to component 1 : 250 000 map-sheets of the Swan area xii 2 Botanical provinces and districts in the South-West according to Diels (1906) 12 3 Botanical provinces and districts in the South-West according to Gardner and Bennetts (1965) 15 4 Botanical provinces and districts in the South-West according to Beard (1980) 21 5 Comparison of the positions of the boundary of the South-West Botanical Province according to Diels, Gardner and Bennetts, and Beard 23 6 Rainfall map of the Swan area from Commonwealth Bureau of Meteoro- logy 1962 27 7 Ombrothermic diagrams for recording stations representative of the four major climatic zones: Albany, moderate mediterranean; Perth, dry medi- terranean; Kellerberrin, extra-dry mediterranean; Coolgardie, semi- mediterranean 28-9 8 .Climatic zones according to Bagnouls and Gaussen {1957) classification, based on the average number· of dry months per annum 31 9 Period (in months) during which average rainfall exceeds effective rain- fall, calculated with the Prescott fotmula 32 10 Relation of average annual rainfall to length of dry season in eastern and western climatic sectors 34 11 Natural regions (based on Clarke 1926) and their physiographic divisions 36 12 Drainage 41 13 Diagrammatic cross-section of landscape on the Yilgarn 64 14 Diagrammatic cross-section illustrating Jutson's theory of the Old and New Plateaux 65 15 Land occupation in the southwest at 1977, based on a map in Jarvis (1979) 74 16 Profile of Eucalyptus diversicolor (karri) tall forest from a measured

). strip 100 x 2m in the Pemberton area 97 17 Profile of Eucalyptus marginata-E. ca/ophyl/a forest (jarrah-marri) 98 18 Reconstructed profile of original Eucalyptus gomphocephala (tuart) woodland in King's Park, Perth 100 l9 Example of height and form of Eucalyptus loxoph!eba (York gum) wood- land 101

viii ix FIGURES 20 Profile diagram of Eucalyptus salmonoph/oia woodland from a measured strip 200 x 20 feet, 42km south of Hyden on the Hyden-Newdegate road 101 21 Profile diagram of Eucalyptus transcontinentalis woodland from a measured strip 200 x 20 feet 102 22 Profile diagram of Eucalyptus platypus low forest from a measured strip 50 x 10 feet near the southwest of Ravensthorpe 103 TABLES 23 Profile of Banksia low woodland from a measured strip 70 x 2m in the Pemberton area 104 24 Profile of Eucalyptus marginata low woodland from a measured strip I Summarized meteorological data recorded at Albany 25 60 x 2m in the Pemberton area 105 II Summarized meteorological data recorded at Perth 25 25 Profile diagrams of Acacia-Casuarina thicket (broombush thicket) 106 III Summarized meteorological data recorded at Kellerberrin 26 26 Profile diagram of low mallee from measured strip 50 x 10 feet, Hyden- IV Summarized meteorological data recorded at Coolgardie 26 Norseman road 109 V Nomenclature of vegetation units as used in the Vegetation Survey of 27 Profile diagram of tall mallee from measured strip 50 x 10 feet, Hyden- Western Australia 78-9 Norseman road 109 VI Mapping notation and formulae 85 28 Profile diagrams of two examples of mallee-heath 30m x 3 m measured-·· VII ' Species designated in mapping 86 between the Phillips and Hamersley Rivers on the access track 110 29 Profile diagrams of scrub-heath, XzSZc 50 x 10 feet, Hyden- VIII Distribution of species within Western Australia 88 Norseman road 111 IX Wider distribution of Western Australian plant species 90 30 Illustration of the catena of the Boorabbin vegetation system, Coolgardie X Life-form for five types of vegetation on the Swan Coastal Plain 94 Botanical District 123 XI Key to symbols in Figures 16-29 101 31 Vegetation systems in botanical districts and subdistricts of the Swan area 124-5 XII Major vegetation communities on acid and basic rocks in the three 32 Diagram showing topographic relationship of vegetation units in the climatic zones of the Kimberley 116 Stirling Range System 211 XIII Vegetation series related to soils a:rtd rainfall: western sector 126-7 ,· XIV Vegetation series related to soils and rainfall: eastern sector 128-9

X xi PART I

DESCRIPTION OF THE AREA

INTRODUCTION

Vegetation Map Sheet No. 7 in the 1: 1000000 series to which this memoir BENCUBBIN JACKSON relates, covers the southwestern portion of the State of Western Australia south of latitude 30 ° S. and west of longitude 121 ° 30' W. In the absence of a generally accepted name for the southwest of the state other than the 'Swan­

SOUTHERN land' of Griffith Taylor (1918) the sheet has been titled 'Swan' after the Swan BOORABBIN CROSS River. In the compilation of the map, 23 component sheets of the standard Austra­ lian 1 : 250 000 topographic series were incorporated by reduction. A key to these is given in Fig. 1. All of them have been previously published as vegeta­ LAKE tion maps at that scale either individually or as composites of more than one HYDEN JOHNSTON standard sheet as detailed in Fig. 1 . Adjacent sheets of the 1000000 series were published by Beard (1975a & 1976]). The Swan sheet no. Tis the last in the series to be completed. At the outset of the Vegetation Survey it was decided to deal with the most remote and least-known areas first, worl,<.ing back gradually towards Perth. This policy has given time for the more complex vegetation of the southwest to be examined piecemeal in detail and to be mapped and published at the 1: 250000 scale. It has also given time for much .related work in botany and other fields such as soils and geomorphology to appear. The volume of this has been in­ creasing rapidly in recent years and permits a much more coherent picture of the vegetation and its ecological relationships to be drawn than would have been possible a decade previously.

Fig. l Key to component 1 :250000 map-sheets of the Swan area. HISTORY All of these have been previously published as vege,tation maps with .explanatory memoirs, references: Boorabbin & Lake Johnston-Beard 1969; Bremer Bay, Newde­ gate, Hyden, Southern Cross, Jackson, Kalgoorlie-Beard 1972; Pemberton-F. G. Botanical exploration Smith 1972; Ravensthorpe-Beard 1973; Collie-F. G. Smith 1973; & Augusta-F. G. Smith 1974; Moora and Hill River, Perth, Pinjarra, Mt Barker & The first recorded landing by Europeans in Western Australia took place in Albany-Beard 1979; Bencubbin, Kellerberrin, Corrigin, Dumbleyung-Beard 1980. 1616 when the Dutch Captain Dirk Hartog in the Eendracht anchored off the island which now bears his name, but this event took place much further north, outside our Swan area. The first sighting of the south coast was made by another Dutch captain, Thyssen in the Gulde Zeepaerd in 1627, who

Xll VEGETATION SURVEY SWAN explored it east as far as the Bight and named it Nuytsland after the Dutch East and while anchored in Gage Roads awaiting his consort, Captain Hamelin of India Company's official aboard the vessel. the Naturaliste explored Rottnest, Carnac and Garden Islands and rowed up The first contact with the coast in,the vicinity of Perth did not occur till 1656 the Swan River like Vlamingh but further, almost to Guildford. Leschenault and then under unfortunate circumstances. The ship Vergulde Draeck (Gilt again collected. They examined the coast further north and named a number Dragon) strayed too far west and was wrecked near Ledge Point. During the of coastal features-Ronsard Bay, Jurien Bay-as well as Mts le Sueur and next two years several Dutch vessels visited the area in search of her, and a Peron which were sighted from the ships but not visited. The peaks were landing was made by Captain Bakels in the Goede Hoop in latitude 31 ° 45 ' S, named after two naturalists in the party. about half way between and Yanchep. Wreckage of the Gilt Dragon Matthew Flinders in the Investigator arrived at King George Sound at the was eventually found a little further north in 1658 by the ships Waekende Booy end of 1801 accompanied by the botanist Robert Brown, the scientific illus­ and Emeloort. This party landed on Rottnest. trator Ferdinand Bauer and the horticulturist P. Good. It was their first land­ In 1694 another ship disappeared on the Western Australian coast, the fall in Australia, and they spent three weeks while Brown collected, laying the Ridderschap van Holland, and in searching for her in 1697 W. de Vlamingh in basis for what eventually became a massive collection of Australian plants. the Gee/vinck (Goldfinch) named both and the Swan River. He Bauer's illustrations, now housed at the British Museum, are among the most landed on Rottnest which was named ('Rat Nest'). from the multitude of beautiful and accurate paintings of Australian plants ever made. The French seen there, and travelled in the ship's boats some distance up the ships Geographe and Casuarina entered King George Sound in February 1803 Swan River which in those days was home to a multitude of the black'"swans acCOQJpanied by Leschenault de Ia Tour. Further round the coast they encoun­ which seemed so strange to Europeans. Although William Dampier. made the tered an American sealing vessel and named the spot Two People's Bay in first Australian botanical collections about that time on the northwest coast, consequence. This shows that there were already vessels visiting the coast at Vlamingh was not a collector, and it was to be over a century before botanical that time other than official explorers. Convict ships making for exploration began at the Swan. passed that way and may often have called for water and repairs. There were no other visitors for nearly 100 years until French and British Lieut. King in the Bathurst charted the western coast in 1821-22 and touched vessels began a more systematic survey of the coast. Expeditions arrived by co­ on Rottnest, where the botanist Alan Cunningham landed; he wrote a valuable incidence in pairs. In September 1791 Vancouver, on his way to the western description (1828). Lieut. King called at King George Sound in January 1818 coast of America, landed and explored in several places and named the area and December 1821 in the course o( his surveys of the Australian coast, en­ King George Sound. Vancouver actually took possession of the land for the abling Alan Cunningham to collect there; and Captain J. S. Dumont d'Urville crown of Britain, at Point Possession, but this was· never officially acknow­ passed through with another French party in 1826. It was widely rumoured (in­ ledged by the British Government. Vancouver named many others of the correctly) that he intended to take possession of the land for France; in any coastal features (data from Garden 1977). case the British had already decided to claim it, and a party of soldiers and Archibald Menzies, the naturalist aboard this expedition, wrote enthusiasti­ convicts under Major Lockyer in the brig Amity were landed on December 25, cally: 1826. Their settlement was at first called Frederickstown after Frederick Augustus, Duke of York and Albany, second son of George III, but the name If we may judge of the fertility of the country in general from the luxuriancy of vege­ was later changed to the shorter Albany using one of the Duke's titles. The tation in many places, we may pronounce the tract within our view capable with a little intention was to establish a penal settlement as an outpost of Sydney, but it labour of sustaining thousands of inhabitants with the necessaries as well as th.e com­ forts of life. [Menzies 1791] proved very difficult to maintain communications owing to the prevailing westerly winds along the south coast and the settlement was withdrawn in 1831 Menzies made the first botanical collections in southwestern Australia, here after Captain Stirling's colony on the Swan River had been established. The at this time, though the results were not published until much later by Robert first party overlanded from Fremantle in summer 1830-31: Captain Thomas Brown (1810). Bannister, George Smythe (a government surveyor) and two others. A small In December of the same year the French under Bruny d'Entrecasteaux garrison was brought round by sea from the Swan, and Albany was pro­ sighted but were blown past King George Sound, and landed later at Esper­ claimed part of the new Colony in March 1831. Thereafter free settlers gradu­ ance·. The next Franco-British pair arrived in 1801. A French scientific expedi­ ally-very gradually-occupied Albany and its hinterland (Garden 1977). tion under Nicholas Baudin in the ships Geographe and Natura/isle made a W. Baxter, travelling by sealing vessels in 1823-25, collected specimens and landfall at Cape Leeuwin and proceeded northwards, going ashore in Geo­ live plants for Henchman's nursery in England on the south coast. graphe Bay near the present site of Busselton, where the botanist Leschenault The next official investigation came in 1827 when Captain Stirling was de la Tour was able to make collections. The two ships then became separated, exploring the Swan and Canning Rivers to determine the suitability of the area

2 3 VEGETATION SURVEY SWAN as the site for a settlement. He was accompanied by Charles Fraser, Colonial to identify poisonous plants which were causing serious stock losses. Drum­ Botanist of who later wrote a full and enthusiastic account mond at first suspected the herb Jsotoma hypocrateriformis but Preiss identi- · of his observations (Fraser 1830). Fraser's journal was reprinted locally by· fied Gastrolobium calycinum (York road poison) as the cause of deaths, J. G. Hay (1906) with a commentary, and both were incorporated in G. Sed­ though at first he discounted poisonous properties and said it was only an irri­ don's book Sense of Place (1972, pp. 177-83), so that they are readily acces­ tant. Drummond later confirmed the poisonous nature of Gastrolobiuin by sible to modern readers. It is possible to form some general impressions of the experiment (Erickson 1969). vegetation alorig the Swan River as it was at that time, which are of help today In the summer of 1841 James Drummond and his son Johnston accom­ ·, in reconstructing a picture of the original natural vegetation. ! : panied two other Toodyay settlers, Captain J. Scully and S. P. Phillips, on a After the foundation of the Swan River Colony in 1829, botanical explora­ sortie northward to look for new land, and discovered the country which they tion was furthered by fames Drummond who had been Curator of the Botani­ called the , beginning at Badji Badji Spring not far to the north­ cal Gardens at Cork in Ireland and accepted an offer to accompany Captain east of New Norcia (Erickson 1969). Described as 'beautiful open grassy coun­ Stirling to the Swan River as honorary Government Naturalist, with the pros­ try', the Victoria Plains stretched northward from there in the basin of the pect of becoming Superintendent of a Government Garden, since Stirling and were covered with open stands of York gum with a grassy realized the necessity of setting up a nursery to propagate plants for the understory suitable for immediate introduction of stock. The word 'plain' was settlers' benefit. Unfortunately the Colonial Office refused to sanction this often used at that time to denote open country and does not necessarily mean appointment, so that Drummond went farming at Toodyay and added"to his that it was flat. The Drummonds drove stock up there the next winter and were income by collecting botanical specimens for sale to patrons in England. follo~ed by others, beginning the settlement of the district, e.g. by the Lefroys ·After the establishment of the Swan· River Colony the coastal plain south of at Walebing and the Clinchs at Berkshire Valley. During 1842 Drummond Perth was the first part of the country to· be explored, but the prevalence of made two collecting expeditions there, on the first reaching the site of Moora sand ridges and swamps was discouraging to settlers. In the year 1829 itself, and on the second the Wongan Hills. He wa,s accompanied by the English orni­ Captain M. J. Currie and James Drummond made a sortie to the south and thologist John Gilbert who was working for the famous John Gould but who east of Cockburn Sound, while Lieut. W. Preston and Dr A. Collie examined also collected botanically. the coast by boat betweenPerth and Busselton, discovering and exploring the ,! Drummond carried on correspondence with the recipients of his collections Inlet. In 1831 Lieut. Preston, following the coast, made the same journey overseas, and in one letter to Sir William Hooker, Director of Kew Gardens in by land. In 1837 the Governor Captain Stirling crossed the Darling Range England, there is a first accoupt of the sandplain country known to the natives from Williams to the Brunswick area and then travelled north along the foot as the Guangan: · of the through Pinjarra and Armadale, which showed him much better country. A settlement was established at Pinjarra at this time and, Guangan means sand, but I mean by it the open sandy desert which commences about eighty miles E.N .E. of Freman tie and is known to continue in the same direction for following his journey, Stirling himself took up 25 000 acres ·along the Harvey 200 miles ... Fresh water is scarce ... even in our rainy season. It is undulating coun­ River, but this estate was not developed until the 1850s, and the district still did try, the hills generally small and low, the soil on them is strong clay ... the valleys be­ not go ahead. Development remained very slow until the last decade of the tween these hills are generally extensive and sandy, covered thinly with small shrubs. century. [Quoted by Erickson 1969]. An Austrian visitor, Baron Karl Von Hugel, collected at the Swan River and at King George Sound in 1833. A large sandplain now cleared, for began in those days In view of the shortage of suitable land on the Swan Coastal Plain the 20kmN.E. of Toodyay, and as Drummond said extended intermittently far settlers probed inland. Ensign Dale reached the site of York in 1830, opening beyond into the Wongan Hills and Bencubbin districts (Beard 1979a, 1980a). up-for settlement the lands of the inner wheatbelt beyond the Darling Range. . 1 It was the starting point of many of Drummond's collecting expeditions . Drummond moved out there and from 1836 onwa@s was regularly collecting Beard (1976g) discussed the variously spelt appearances of this word Guangan plant specimens and seeds for consignment. He began to undertake collecting in the literature, and suggested that it be standardized under the spelling "' expeditions from his home at Toodyay, some of them in company with the Kwongan as a term for southwestern Australian sandplains and their ­ German botanist Ludwig Preiss who was in the colony from 1838 to 1842. land vegetation. It is believed that the same word is perpetuated in the name Preiss eventually left with a huge collection of botanical specimens which he Wongan Hills (Kenneally 1977), and it occurs as Kwangan Plains on the Ben­ distributed to continental herbaria in Europe. In 1838 Drummond went out to cubbin topographic sheet just to the west of Koorda (see vegetation map in the northeast from Toodyay. In September 1839 he and Preiss were together .Beard 1980a). on Rottnest Island, and in 1840 at Albany, where they collaborated in attempts Drummond made no less than four expeditions· during 1842, the other two ' '

4 5 VEGETATION SURVEY SWAN of them to the south. In the month of May, with a Dr Harris he rode south to botanists Ludwig Diels and Ernst Pritzel, supported by the Humboldt Founda­ then to Pinjarrah (as he spelt it) and on to Australind and Busselton tion, arrived in Wes tern Australia on 30 October 1900 and travelled widely where he stayed with the botanical enthusiast Georgiana Molloy. Drummond until their departure at the end of December 1901, covering virtually all of the went on south and returned home in June, suffering much from exposure to country that was accessible at that time through agricultural and settle­ the winter weather. In October, this time with John Gilbert, he again visited ments. Their observations were incorporated in Diels' book of 1906, the first Pinjarra and made a sortie into the Darling Range succeeding in reaching, and and still the only detailed acc~unt in one volume of the flora and vegetation of climbing Mt William, where Drummond was disappointed in not fil-iding the southern half of the state. alpine vegetation. On the way, however, Gilbert discovered the now famous Local study of the flora became possible once more after establishment cif a 'noisy scrub bird'. Drummond's later expeditions were to more remote parts post of Government Botanist. Dr A. Morrison _was appointed in 1903 and was of the colony. In 1846 he again went south, examining the Stirling Range succeeded in turn by Dr F. Stoward, Mr W. M. Carne and Mr C, A. Gardner. botanically for the first time, and crossing the Kalgan Plains to Cape Riche, Under Gardner a state herbarium was established, in which collections were thence to Albany. He passed through Albany again in 1848 on his way to built up by Gardner and his staff and· collaborators, notably the medical explore further east in the Barren Ranges. doctor W. E. Blackall, who originated the 'Blackall Key', the first practical In 1850 Drummond accompanied a party led by brothers William and key to the recognition of native plants which was published posthumously and Lockier Burges overlanding stock from the Swan to Champion Bay (Gerald­ completed by Prof. B. J. Grieve (Blackall & Grieve 1954-75). ton). The party travelled via Dandaragan where Drummond's son Jam'eS had All the names of the early botanical pioneers have been appropriately per­ already established the station 'Yere Yere', and Drummond senior spent petuated in plant names from to Eucalyptus dielsiana. several days collecting in the area. They subsequently travelled east of Mt Le A new complete census of the vascular plants of Western Australia has Sueur to the and so to the Irwin. recently been published by Green (1981). John Septimus Roe, first Surveyor-General of Wes tern Australia, made two important expeditions on which he collected plant specimens. In 1836 he led a Settlement party east from York to reach the present site of Merredin where they turned north to reach Lake Brown, returning on a westerly bearing to the vicinity of All this time the settlement of the southeast of the state was steadily pro­ New Norcia; sighting and naming the Wongan Hills on the way. In 1848-49 he ceeding, and we must take note of it, since in addition to the creation of a civil­ set out again from York for the southeast, traveJiing by a circuitous route ized there has been widespread land-clearing and the elimination through the Corrigin and Dumbleyung districts to the south coast at Cheyne of much of the original native flora and vegetation. Little settlement took Bay, thence inland to the Bremer Range and further east to the Russell Range, place at first on the Swan Coastal Plain owing to its largely sandy and swampy returning along the coast. In the Barren Ranges they came across James Drum­ nature.* Fruit-growing and dairying began about 1895, but neither flourished mond and his party. Mt Drummond was so named in consequence. greatly until agricultural problems of drainage and poor soils had been over­ Dr W. H. Harvey collected between Perth and Albany in 1854. The great come. Gradually swampy areas were drained, fertility problems became under­ botanist landed a( Albany on a visit from Melbourne in stood and irrigation (between Perth .and Bunbury) was made possible by 1867 and collected rather thoroughly -over the south coast, Porongurups and construction of dams in the Darling Range between 1933 and 1966. At the Stirlings, and the sandplains. He came again ten years later on an invitation present time the Swan Coastal Plain south of Perth has largely been settled, .. from the Government of Western Australia to report on the forest resources of with agricultural holdings on the Pinjarra Plain and Bassendean Dunes, and the colony, and the contacts made on these visits secured numerous correspon­ with industry and recreational areas on the Coastal Limestone. The large dents who collected for him and sent him specimens. Maxwell and Oldfield ( ± 11 000 ha) on the coast south of Mandurah pre­ were prominent as general collectors. Webb sent a collection from Mt Linde­ serves some of the natural vegetation of the latter. .. say, Hassell from the . All these collections were documented in In the vicinity of Perth and northward the poor leached sands of the Bassen­ von Mueller's Fragmenta (1858-82) and contributed to Bentham's Flora Aus­ dean Dunes have not attracted settlement, and remain under the original traliensis (1863-73). banksia woodland, with some local conversion to pine plantations. The Botanical exploration in Western Australia languished somewhat in the Coastal Limestone north of the metropolitan area is largely untouched. second half of the nineteenth century, but was revived at its end by overseas On the Dandaragan Plateau productive soils upon calcareous Mesozoic visitors. Spencer Moore from England set out in 1894 from Southern Cross, I rocks were taken up very early around the settlements of Gingin and Dandara­ gan, but remained mere pockets in a vast extent of inhospitable lateritic sand- making his way across country to Lake Goongarrie, thence through the gold­ I fields and Mt Margaret to Lake Darlot, returning via Coolgardie. The German 0 • For physiographic units mentioned in this section see Fig. 11. i 6 7 VEGETATION SURVEY SWAN plain until advances in farming techniques eventually permitted such land to lieved that stands of karri originated in a similar manner in the past after be profitably worked. Most of it was taken up in the land boom of the 1950s. periodic destructive wildfires: However approximately 30% of the karri-forest At Dinner Hill west of Watheroo there is a commemorative tablet at 'Lang's area has been set aside from the general logging programme in the interests of Lookout' recording the discovery of the agricultural potential of the Badgin­ conservation and aesthetics. garra Sandplain by Larig in 1948 and its settlement from 1953. Substantial Further east along the coast at Albany, the extension of the early settlement sections of the original vegetation have been preserved in the Badgingarra, at the port was frustrated for a very long time by the extreme igfertility of the Alexander Morrison and Watheroo national parks. The coastal belt is unoccu­ surrounding country. Charles Darwin, who landed there on the home voyage pied except for fishing settlements, and a large part of it is included in various of the. Beagle in March 1836, proved a more penetrating observer than the national parks and reserves including the Nambung National Park which con­ rosy-tinted Menzies (quoted at the beginning of this chapter): tains the scenic area of 'The Pinnacles'. The general bright green colour of the brushwood and other plants viewed from a At the southern extremity of the Perth Basin the Blackwood Plateau has distance, seemed to bespeak fertility. A single walk, however, will quite dispel such an been considered intractable for farming and remains covered with original illusion: and he who thinks with me will never wish to walk again in so uninviting a forest, mostly stunted and below commercial grade. It slopes down into the country. [Darwin 1839] Scott River swamps, which again are still largely untouched. A strip of land between this plateau and the Naturaliste Ridge, containing the settlements of For many years the port of Albany survived as an isolated settlement living and Augusta, has been cleared, and the ridge itself iS"'partly from the sea as a centre for sealing and whaling and as a port of call. A coaling cleared. station was established in 1852 when steamships were introduced, and the The laterite-crusted western margin of the Darling Plateau, known as the colony's mails were shipped in and out through Albany. Parties pushing in­ Darling Range, was considered intractable by the early settlers, but being land from Albany reported better land in the interior but the first settlements forested was a valuable source of timber: Following the opening of the South failed when sheep were killed by poisonous plants. For the same reason Western Railway in 1893, the jarrah forests became the basis of an important attempts to overland sheep between Albany and the Swan failed. Once this timber industry. In due course with the introduction of conservation and menace was recognized however, pastoral leases were gradually taken up forest management, the commercial forest area has been created State Forest beginning on the Hay River west of Mt Barker and at Kendenup, and were dedicated to timber production. As it has been policy to continue to regenerate followed by agricultural settlement. By 1870 some small areas around Albany native , the effect of forestry operations on the forests, from the itself and at Kendenup had been alienated, and by 1900 there had been a little point of view of native vegetation, was not great, until in recent years two further expansion: at Cran'pfook, Mt Barker, Albany and Denmark. The threats appeared. First, the pathogen cinnamomi causing jarrah opening of the Great Southern Railway connecting Perth and Albany in 1889 die back disease has begun to decimate stands usually on moister, relatively failed substantially to stimulate settlement, though timber cutting first for rail­ low-lying sites. The disease not only attacks the dominant jarrah trees but also way sleepers and then for the general market began at Torbay and later members of the understory, particularly Banksia spp., other , and Denmark, to which the railway was extended. The prosperity of Albany was Xanthorrhoea. Secondly, the laterite crust has been found to be a rich source improved by activities following the discovery of gold at Coolgardie in 1893. of bauxite and large-scale exploitation has been initiated with alumina re­ Between 1900 and 1930 set~lement of the country between Mt Barker and fineries at Kwinana and Pinjarra-and further extensions are planned. There Kojonup was completed, and of the coastal strip from Albany to Denmark. has rightly been soine public concern as to the effect of these operations on the Advances in farming techniques permitted the huge areas of infertil<:! soils on forests, but in fact exploitation is limited to picking out rich pockets, and the Kalgan Plains and between Albany and Narrikup to be taken up only as during the first 50 years it is expected to mine only 6% of the area leased to recently as since the Second World War, while the hinterland west of Narrikup Alcoa of Australia. The likely acceleration of the spread of dieback by the has remained substantially under its native forest until now, much of it having operations is a greater cause for concern. been proclaimed as State Forest. A considerable area of natural vegetation is The forests spread southwards into the high-rainfall area of the lower south­ preserved in the Stirling Range National Park and in the various smaller \ national parks and reserves. west where tall forests of karri (Eucalyptus diversicolor) are included. .,I Attempts were made to establish soldier-settlements after both world wars in ·/I The interior country on the Darling Plateau east of the forest belt of the the karri forests and both failed. Agricultural occupation is still minimal and / I Darling Range, which had proved so inviting to the early settlers, gradually the district remains devoted to forestry. The effect on native vegetation developed into the extensive wheatbelt of tt'.>day, but progress was at first appears so far to have been minimal, and is likely to remain so even under the extremely slow. A small agricultural settlement grew along the axis from present practice of regeneration by burning after clear felling, since it is be- I. ·Toodyay to Beverley, but beyond this development was essentially pastoral 9 8 /

. \ VEGETATION SURVEY SWAN with large areas under lease from the crown except for small freehold blocks tion which has qualities of structure as well as composition, and these can be around homesteads where crops and fruit were grown for subsistence. A related to environmental and evolutionary factors. change occurred in 1887 with new government regulations for 'conditional As early as 1839 it was possible for J. Lindley to write A sketch of the vege­ purchase' of land designed to encourage closer, freehold settlement. All condi­ tation of the Swan River Colony in London, even though this consisted mainly tional purchasers had to meet minimum requirements of fencing and improve­ in the description of new species. In 1867 F. von Mueller published effectively ment. At this time also railway construction began, and the settlement of the for the first time a general note on the vegetation of the southwest, drawing country went hand in hand with extension of the lines. The Great Southern attention to its special character. Railway was completed in 1889, the Eastern Goldfields Railway reached Diels' expedition of 1900-01 had as its objective the description and defini­ Southern Cross in 1894, and the Midland Railway reached Moora the same tion of vegetation types as well as taxonomic study of the flora, and both year. A network of branch lines was then put in, most of which were com­ aspects are amply covered in his subsequent book of 400 pages. Diels and pleted by 1919, though work continued until 1931. The depression at that time, Pritzel also visited the north, but the book is restricted to the southern half of followed by the war, called a temporary halt to land development, but it was the state, its full title being Die Pflanzenwelt von West-Australien sudlich des resumed actively in the post-war years, when in the 1950s and 1960s there was Wendekreises (The Plant World of Western Australia South of the Tropic). It a land boom of unprecedented proportions. In the northern part of the wheat­ is a magnificent work, covering almost every conceivable aspect of the subject, belt, development has reached the 300-mm isohyet and the boundary of the and is amply illustrated by photographs (taken by Pritzel) and line drawings, and even by a coloured vegetation map of Australia scale 1 :27000000. That South-West Botanical Province, which seems likely to be the ultimate limit of the work has never been published in English is almost incredible, and is a sad cultivation (Figs 4, 6). In the southern half, where the advance has been into commentary on the lack of interest of Australians in the natural history of the mallee region, it is Hkely that the limit has not yet been reached, but their country. An English translation of most of the volume was made bit by economic conditions have called another temporary halt to expansion. In the bit at the Botany Department of the University of Western Australia and earliest days of settlement no thought whatever was given to retention of assembled in 1950, but as there were only two copies they were kept closely natural areas. After 1887 surveyors, laying out farms for conditional pur­ guarded. chase, normally set aside uncultivable areas, rock outcrops, stands of timber Diels' book is organized into an introduction and five parts. The introduc­ and land surrounding springs and public waterholes if these were used by tion 'Foundations of the Plant World of Australia' gives a brief general travellers and for drovirig stock. A large number of reserves vested in the account of the vegetation of the under nine formation-types, deals crown were retained in this way, but most were very small. Even as late as the with altitudinal variation in Queensland and the southeast and discusses the post-war land boom very little attempt was made to retain conservation flora in terms of Hooker's (1~60) Antarctic, Palaeotropic and Autochthonous reserves, with few exceptions such as the large Reserve 25113 for the protection elements and its modern distribution in the Eastern, Eremaean and South­ of mallee fowl, adjacent to Lake Magenta, which covers 94 000 ha. It is good western Provinces. The five parts are devoted to Western Australia. Part I is to record that in the -past decade much has been done to improve upon this 1. historical: 'History and Literature of the Botanical Exploration of Extra­ situation by government departments responsible for conservation, who have tropical Western Australia'; Part II is a resume of the physical ; secured the reservation of many uncleared conditional purchase blocks sur­ Part III deals with the vegetation of the South-West Province, and Part IV rendered by farmers. with the vegetation of the Eremaean Province. The Eremaea is the Arid Zone, North and east of the wheatbelt the country is for the most part unoccupied, the term coming from the Greek for solitude or wilderness. Tate in 1890 had as the dense bush it carries makes it inoperable for pastoral use. There are used Eremia for the arid northern portion of , but whether some pastoral leases in the far northwest where, with decreasing rainfall, the Diels was following him is not known. In view of the different spelling, Diels country opens out. The natural vegetation in this outlying sector is thus largely may have proposed the term independently. Each of the parts on vegetation is intact. Some clearing took place in and around mining sites in the heyday of organized into: Chapter 1, General Nature; Chapter 2, Physiognomic the goldfields, and some felling for mining timber and firewood took place, character-plants; Chapter 3, Leading or characteristic plant families and their but natural regrowth has largely obliterated the traces of, such disturbance. life-forms; Chapter 4, Ecological character (morphology, epharmosis and 1- seasonal aspects); Chapter 5, Plant formations. Finally Part V of the book 1 Previous treatment of the vegetation . I deals with the flora. In Chapter 1 of this the area is divided into botanical pro­ vinces and districts, the South-West Botanical Province having six districts and Most of the botanical exploration cited in the previous section was con­ the Eremaean Province two (Fig. 2.). Chapter 2 discusses the affinities and cerned with , that is, the identification of elements of the flora. The distribution of the taxa of the flora, and endemism. Chapter 3 deals with rela- _plant cover can however be studied from the ecological point of view as vegeta- . tionships with other areas, and Chapter 4 the evolutionary history of the flora.

10 11 VEGETATION SURVEY SWAN (iii) W andoo forest AUSTIN t (iv) Transitions to the woodlands of the Eremaea I b. Mixed woodlands of the coastal plain

KALGOORLIE o 3. Shrubland formations a. Sclerophyll scrub oSOUTI-IERN CflOSS b. Sand heaths o MEflflEDtN 4. Swamp formations COOLGARDIE a. Alluvial formation b. Formation of granite rocks

• HVDE.N EREMAEAN PROVINCE 1. Littoral Jormations a. Mangrove and mudflat formations b. Formations of sandy beaches and dune scrub 2. Woodland formations a. Eucalypt woodlands of the Eremaea b. Savanna woodland 3. Shrubland formations a. Mulga formation of the north b. Bush formation on sand 4. Halophyte formations of the salt-pans. J; It will be seen that Diels did not follow a formal classification. The main headings are in general physiognontic and the subheadings floristic, but Fig. 2 Botanical provinces and districts in the South-West according to Diets (1906). Redrawn from Diels' map, p. 314. edaphic and geographical criteria are also used. Diels' vegetation map, being very small, did not show all the above forma­ tions. The forest country of the lower southwest was shown as sclerophyll The plant formations of Diels were arranged under the following headings forest. The inland beyond the boundary of the South-West Botanical Province (not, strictly speaking, a classification): was described as 'Brigalow scrub, mallee scrub or sand heath', and stretched east to the (which was mapped as 'savanna'), and north to the SOUTHWEST PROVINCE zone of 'mulga scrub' whose. boundary was correctly showri. Between the 1. Littoral formations forest and the mallee-sand heath belt a transitional zone was shown striped, as a. Mangrove partly savanna forest, partly mallee and sand heath. The map is curiously out b. Mudflat formation of accord with the treatment in the text of the book. c. Open formation of sandy beaches Vegetation mapping in greater detail began with the production by the d. Littoral woody formations Woods and Forests Department of a sketch map scale 1 inch to 20 miles (about (i) Northern zone 1: 1250000) to accompany the conservator's annual report for 1901 (Richard­ ', (ii) Tuart zone I son 1902). This showed with remarkable accuracy the extent of forests I. dominated by the principal species. (iii) Southern zone In 1914 J. T. Jutson produced a vegetation map of the state scale 2. Woodland formations 1 : 5 000 000 to accompany his classic work on physiography. The map was a. Eucalyptus forests published in colour and distinguished nine basic vegetation types, alluding to (i) J arrah forest .two more (fringing forests and mangrove woodlands) in the legend. There was (ii) only a very brief accompanying note on vegetation in the text. Acknowledge-

12 13 / I VEGETATION SURVEY SWAN ment of the data for the map was given to the Forests Department. In the southwest the map was obviously inspired by Diels but was slightly more detailed. The 'Sclerophyllous forest' had the karri areas indicated as 'Temper­ ate Eucalyptus rain forest', and both the Swan Coastal Plain and a belt along the south coast from Flinders Bay to Albany was taken out as 'Savannah KALGOORLIE Q forests and woodlands'. Diels' belt of 'Brigalow scrub, mallee scr_ub and sand o SOU"fHE.F!N CROSS heath' now became more accurately 'Low rainfall temperate forests and wood­ COOLGARDIE lands with belts of sand heaths and mallee', and the Nullarbor appeared also more accurately (but still not correctly) as 'saltbush plains'. The striped zone inland of the southwest forest belt was retained, coloured for savanna wood­ lands and low-rainfall temperate woodlands. This map was republished by the Forests Department at a larger scale, 1 inch to 50 miles (approx. 1 : 3 000 000) in 1928, identical except for the addition of some numerical data to indicate occurrence of species of Eucalyptus, and with the isohyets overprinted. It was reprinted again in 1967. In 1942 C. A. Gardner, then Government Botanist, presented a papei:;,.on the vegetation of the state. Data given for the north were new and original, par­ ticularly for the Kimberley, where Gardner had taken part in exploration. Remote parts of the south such as the Nullarbor Plain, of which Diels had no knowledge, were also described'. For the Southwest Gardner followed Diels closely and adopted his system of botanical provinces and districts, extending the system to the whole state in a map (with H. W. Bennetts) in 1956 (Fig. 3). The next treatment of a general nature came in a doctoral thesis by N. H. Speck in 1958, when he pr'esented an account of the vegetation of the Darling and Irwin Botanical Districts. This was expanded from an earlier thesis (1952) on the vegetation of the Swan Coastal Plain. Speck classified his vegetation ~1 Fig. 3 Botanical provinces and districts in the South-West according to units more formally than Diels into physiognomic formations containing Gardner and Bennetts (1956). Enlarged from portion of their map. floristic associations. He also originated the concept of the vegetation system-a sequence or pattern of plant associations linked to edaphic into a copious literature: Abbott 1977; Baird 1958; Bell, Loneragan and Dodd factors-which has been adopted by subsequent vegetation mappers (Beard 1979; Bridgewater and Zammit 1979; Fox, Downes and Maslin 1980; Mc­ 1969, 1972-80: F. G. Smith 1972-74). Arthur 1957; Marsh and Hodgkin 1962; Sauer 1965; G. G. Smith 1957, 1968, The overall mapping programme of the Vegetation Survey of Western Aus- · 1973, 1979; Storr 1962, 1963; Storr, Green and Churchill 1959. The Swan tralia began in 1964, the first two sheets on the I : 250 000 scale appearing in Coastal Plain was described by Speck in a student's thesis in 1952, and Seddon Beard 1969a. Other component sheets of the Swan area appeared subsequently (1972) summarized his account together with a vegetation map scale 1 : 500 000 as shown in Fig. 1. Details of concepts and classification were given in the 1969 which distinguishes 11 units. Two of these are 'complexes' or mosaic units, the paper and are repeated here on page 79. other physiognomic formations are classified according to Specht (1970). J. A. More detailed local studies of vegetation on small areas have begun to ap­ \ and A. J. McComb published an interesting paper on swamp vegetation at pear during the past half-century in steadily increasing numbers. Localities Yanchep (1967), and the original natural vegetation of King's Park was treated are heavily biased in favour of proximity to the metropolitan area. described by Beard in the same year. Havel (1968) made a detailed survey of The first of the modern local detailed studies was a paper by Williams in understory communities in the banksia low woodlands of the coastal plain, in 1932 in which he examined the nature and geological origin of soils controlling which mathematical ordination methods were used to detect and define group­ the occurrence of Eucalyptus marginata, E. calophylla and E. wandoo on the ings. These methods were later used in the northern jarrah forest on the Dar­ western slopes of the Dariing Range. Much later, in 1945, Williams published ling Range (Havel 1975), and have provided very detailed knowledge of the a supporting study on the same subject made on the eastern side of the range. vegetation of the forest area. This work was summarized and discussed by Publication on the west-coastal belt and islands began in 1957 and blossomed Beard when mapping the Perth 1 : 250 000 sheet (Beard 1979b).

14 15 VEGETATION SURVEY SWAN In 1978 the Department of Conservation and Environment of Western Aus­ E. calophylla were discussed by Churchill (1968). Eco-physiological studies of tralia made a detailed ecological study of an area known as 'System 6', com­ E. marginata were published by Doley ( 1967) and Kimber ( 197 4). On the south prising the Darling Range and Swan Coastal Plain from Bridgetown north to coast _Bald Island was described by Storr (1965), and some heath communities the Moore River. A series of maps scale 1 : 250 000 were prepared (Department - ,\ I in the by Enright (1978). Observations on coastal of Conservation & Environment 1978). One of these comprised maps of land­ vegetation were published by Schweinfurth (1978). In the wheatbelt in 1976 the forms and soils by Churchward and McArthur, and another of vegetation by I Western Australian Museum selected 30 reserves for a biological survey, the Heddle, Loneragan and Havel. A separate paper based on the latter describing results of which have begun to appear (Muir 1976-77-78). Subsequently the its rationale and providing in effect an explanatory text to the maps has been t Department of Fisheries and Wildlife undertook the examination of some 300 published by Heddle (1979), including a vegetation map reduced to a scale of other small reserves, the details of which are available in unpublished depart­ 1 : 400 000 and covering the central portion of 'System 6'. It extends on the mental rC:ports (Muir 1978-79). Other relevant wheatbelt studies comprise: coast from Mandurah to Yanchep and inland as far as Northam. The maritime Beard 1967; Bettenay and Hingston 1961; George and Hnatiuk 1978; Ken­ vegetation was described in a section of Heddie's paper by G. G. Smith. To neally 1977; Lange 1960; Main 1967; McKenzie, Burbidge and Marchant 1973; suit the requirements of the environmental survey it was desired to map the Monk, Hnatiuk and George 1979; Youngson and McKenzie 1977. Recent vegetation in as much detail as possible and it was therefore decided to discard general papers of interest have been Marchant 1973, George, Hopkins and the relatively simple physiognomic classification of Specht used by F. G. Marchant 1979; Hopper 1979. Smith as it would have 'oversimplified the pattern ... A large proport-iQn of the Darling Plateau would be classified as an open forest of jarrah-marri and a woodland of wandoo. Such a classification would have disregarded all known METHODS OF SURVEY variation in the floristic composition of the understory in these two forma­ tions' (Heddie 1979). This statement is not really true since it is frequently In the preparation of the Swan 1 : 1 000 000 sheet the basic methods of survey possible in mapping to subdivide any formation classified on its upper stratum were the same as for previous sheets (Beard 1974-78), but a different procedure into understory types and vice versa, and this has been done by Beard in the was adopted in compilation. All components (Fig. 1) had previously been pub­ vegetation survey where desirable. The real difficulty was that the bulk of lished at the 1 : 250 000 scale. A simplified copy omitting detail too fine to ap­ Havel's ground-layer assoc'iations, styled site-vegetation types, (Havel 1968, pear at 1: 1000000 was made of each of the sheets prepared by Beard 1975) do not give recognizable photo-patterns and cannot be mapped by (1969-80) and was reduced ph.9tographically for compilation. The three sheets photogrammetric methods. The solution was adopted of using the landform/ prepared by F. G. Smith do not show original natural vegetation. They show soil map of Churchward and McArthur, styling their units 'vegetation com­ I' extant natural vegetation, cleared areas being left blank. Copies showing plexes' and listing the components of the mosaic known to occur in each. original natural vegetation therefore had to be made showing an appropriate ' i This approach is analogous to Speck's mapping of vegetation systems, and degree of detail, and these were reduced for compilation. The compilation to the well-known practice of the CSIRO Land Research Division in mapping copies were assembled and redrawn into the completed 1: I 000000 sheet at the land systems (e.g. Mabbut et al. 1963). A vegetation system can be said to be Department of Geography, University of Western Australia, in 1979. The the vegetational component of a land system, and a vegetation complex can be topographic base used for the assembly had been furnished by the Mines said to be a smaller unit, a number of which go to make up a vegetation Department of Western Australia. system. A similar approach is commonly followed in soil surveys where a Mapping of the sheets used for compilation had been done in a similar number of soil series make up a soil association. Maps showing land systems, manner by both authors, from aerial photography controlled by ground vegetation sysiems or vegetation complexes can be interpreted for vegetation, traverses normally made by vehicle using available roads and tracks. Some but do not directly portray plant associations or formations. In order to help \ mountainous areas such as the Stirling Range and Barren Ranges were covered overcome this difficulty the colours of the map in Heddie (1979) were carefully on foot. Detailed notes of the plant cover, soils, topography and so on were chosen to relate to _the major plant formations. -The jarrah forest of the Dar­ made. Botanical specimens were collected as necessary for the accurate deter­ ling Plateau appears in green colours~-erging to blue where swamp and I_ mination of plant names. Mapping was subsequently carried out on photo­ riverain components become significant Marri-wandoo woodlands appear in mosaics mostly at the ·scale of 1 inch to 1 mile (I : 63 360) compiled by the orange, vegetation. on coastal limestone n shades of red. Department of Lands and. Surveys and loaned by the map library of the Outside the met~opolitan area, the structure and composition of the karri / Department of Geography, University of Western Australia. Recent mosaics forest around Pemberton was described by McArthur and Clifton (1975). ( at 1 : 50 000 published as photomaps were used for the Albany, Mount Barker Distribution and prehistory of Eucalyptus diversicolor, E. marginata and and Dumbleyung areas. Quality of the earlier photo-mosaics varies widely,

16 17 VEGETATION SURVEY SWAN some being. only uncontrolled photo-indices, neither very clear nor very recorded, and types of scrub, mallee and heath were distinguished. Anyone accurate. However, for a broad survey of this kind time did not permit map­ with the time and inclination, given access to the Lands Department records, ping on the basis of individual photographs. Mapping was greatly assisted in could accurately reconstruct a vegetation map of the wheatbelt, though it the forest area of the southwest by the use of unpublished Forests Department would only distinguish structural types, with dominant species for woodland, stock-maps scale 1: 63 360, which were made freely available to both authors, and give little or no information on associated flora. and of some printed forestry maps. On the eastern fringe of the wheatbelt it Floristic detail for the units mapped in the present vegetation survey was was possible to use some land classification plans (in effect, soil surveys) and developed in the first instance from the authors' traverse data, supplemented pastoral classification plans of the Department of Lands and Surveys. Refer­ where available by the detailed local studies cited in the previous section. ence was made to the soil survey of the Merredin area (Bettenay and Hingston Greatest detail is obtainable from the various studies of coastal islands (esp. 1961) and to the geological maps of Boorabbin, Kalgoorlie, Hill River, Perth McArthur 1967), the work of G. G. Smith on the coastal belt, of Speck (1952, and Pinjarra. 1958) for the Swan Coastal Plain and Darling Range, and the surveys of A large proportion of the country in the Swan area, particularly in the reserves remaining in the wheatbelt (Muir 1976-78, 1978-79). The writer is in­ wheatbelt, has been cleared for farming (Fig. 1). The map shows original debted to the W. Aust. Museum and the Department of Fisheries and Wildlife natural vegetation, i.e. that assumed to have existed before clearing or other for making available data from the results of these surveys which had not yet disturbance by civilized man. In farming areas the map is not evidence that the been published. · vegetation is there now except as roadside relics and uncleared paTches. Reserves, where the natural vegetation remains, were shown on the majority of 1 : 250 000 sheets. In uncleared country the photo-patterns of natural vegeta­ NATURAL REGIONS tion can still be readily traced, but in farming country they have been almost entirely eliminated. Sufficient of it almost always remains along the verges of Perhaps owing to the large size of the state there is a longstanding tradition in roads traversed to enable determination of the communities originally present, Western Australia of recognizing distinct natural areas, of which the most their composition and catenary relationships, but not of course for the extra­ obvious are the Kimberley or tropical north, the central desert and the fertile polation of boundaries across intervening country. It was discovered when southwest, each of which can be further subdivided. New South Wales is the mapping the Perenjori district, where this problem was first encountered only other state where such a concept has been applied (Cameron 1935, Ander­ (Beard 1976e), that the catena could be mapped from the colour of the soil son 1947). The subject was first raised in Western Australia by van Mueller seen in the photography. The wheatbelt catena is usually a simple one: kwon­ (1867, 1883), who drew attention to the special character of the southwestern gan on sandplain on the higher ground, woodland on red loam on lower flora and indicated (but with no map) a boundary running from Shark Bay to ground. Salt-flats, which in any case have very distinctive photo-patterns, Israelite Bay. Diels (1906) gave practical expression to this (Fig. 2) hy dividing occur along the drainage lines. Sandplain was distinguished by its light­ the southern half of the state into two botanical provinces, the South-West and coloured soil, and red loam by its darker colour. This method was carefully the Eremaean, the former divided into six botanical districts and the latter, as checked by plotting the plant-community boundaries recorded on all the road far as known to him at that time, into two. The boundary between the two pro­ traverses in the Perenjori district onto the photo-mosaics when a complete vinces, he said, coincided approximately with the 30-cm isohyet, separated the correlation with visible soil changes was found in all cases. The method was internal drainage area of the country from the portion draining to the sea, was therefore used later throughout this survey. of importance to human settlement in being the boundary of cereal cultivation Since almosJalnarmland in the southwest of Western Australia has been and had also at that time been picked up in zoogeography (Woodward 1900). cleared within the past century, natural vegetation on road verges, in uncleared It is interesting to comment today on these observations of Diels'. The short patches and in t~m of scattered trees left in paddocks, still exists quite period of rainfall records available in the colony up to his visit in 1900 evi­ abundantly, but this natural vegetation is in decline andwill not survive in­ dently covered a relatively dry cycle, for modern rainfall maps show the 30-cm definitely. It is fortunate that it has been possible to effect this vegetation isohyet further east (Fig. 6). Diels' observation on the drainage pattern is true survey while so much visible trace is still there. from the southward, though not further north, and his line co­ An alternative method for reconstructing a map of original natural vegeta­ incides with that chose~ by Jutson (1914) for the boundary between his South­ tion would be to use the Surveyor's records. From 1887 onwards surveyors West Physiographic Division and Central or Salt Lake Division, given the were instructed to record natural vegetation when marking out farms for con­ alternative names of Swanland and Salinaland in the 1934 edition. It is also the ditional purchase, and these large scale 'classification plans' remain in the Meckering Line of Mulcahy (1967). Cereal cultivation has moved out vastly archives of the Lands Department. In woodland areas the dominant trees were further east since Diels' time. The writer has been unable to trace Woodward's

18 19

/ VEGETATION SURVEY SWAN map of 1900 which may be no longer extant, and therefore cannot comment in this case. Each of the botanical districts was characterized by a range of rainfall, by SOUTH-WESTERN particular types of vegetation and by species distribution. Gardner (1942), in an account of the vegetation of the whole state, added the concept of a KAlGODALIE o INTERZONE Northern Botanical Province, and later (Gardner and Bennetts 1956) expanded Diels' botanical districts on a state-wide basis. He in general retained Diels' a MERREDIN treatment of the southwest, but moved the provincial boundary further east COOLGARDIE (Fig. 3; also figured in Marchant 1973) so that the districts were also affected. In the meantime a geologist, E. de C. Clarke (1926), had proposed a regional subdivision of the state on tht basis of a synthesis of all ecological factors to determine 'natural regions'. These were selected in the following way:

A. The state was primarily divided into major physical regions. r B. It was again divided into major geological regions, effecting a strbdivi- /, sion of the major physical regions. ' : C. Climatic considerations, chiefly the amount and season of rainfall, were found to necessitate further subdivision of A and B.

':By this stage', wrote Clarke, 'we should have arrived at a classification into natural regions and our result should be in harmony with the distribution of distinctive plant associations.' In this way Clarke arrived at 15 natural regions and one , shown 'in a sketch map which has been reproduced in suc­ cessive editions of the geology text-book of Clarke, Prider and Teichert (1948 et seq.). Clarke's treatment of the southwest will be discussed below. Fig. 4 Botanical provinces and districts in the South-West according to Gardner's approach to phytogeographic regionalization was also ecological. Beard (1980), with boundaries established by vegetation mapping. In explaining the map (Gardner & Bennetts 1956), from which Fig. 3 is drawn, he made it clear that the classification was based upon climate and vegetation, e.g. accordingly been done for the Swan map. A summary is shown in Fig. 4, where all the boundaries have been drawn from vegetation mapping and The South-West Province is that part of Western Australia which receives a winter follow the boundaries of ~egetation units. Modern mapping does not support rainfall of 10 inches or more. Apart from its area of sandplain and thicket growth on very well the reality of much of Diels' treatment, which has been revised with laterite, it consists of Eucalyptus woodland and mallee lands, and the jarrah of the the retention of his names as far as possible. southwest. In addition it ... is precisely the area to which the main elements of the The Darling District is the high-rainfall forest zone of the extreme south­ South-West Flora are limited, e.g. the heaths, Kangaroo paws etc. west, enjoying the moderate and dry mediterranean climatic regions (Fig. 8), with a rainfall exceeding 500mm per annum. The eastern boundary is defined In view of Gardner's ecological'approach it is not suurrising that outside the by the eastern limit of woodlands of marri and wandoo (E. calophylla­ southwest, wherehewas operating tinder the constraint of Diels' prior treat­ E. wandoo) and closely follows the 500-mm isohyet (Fig. 6). Owing to its rela­ ment, his botanical districts frequently agreed~rather closely with Clarke's tive complexity, the district is divided into four subdistricts. The Drummond natural regions. When the preparation of vegetation maps in the present Subdistrict lies on the ·Swan Coastal Plain of Jutson (1914, 1934) and Mc­ 1: 1 000 000 series began, Beard (1969b) observed that such regionalization Arthur and Beltenay (1960), and coincides with the Perth Region of Clarke could frequently be clearly seen in the maps themselves and that precise boun­ (1926). The Dale, Menzies and Warren Subdistricts comprise the Darling daries could be drawn for them. He proposed that botanical districts be con­ Plateau which is the remainder of Jutson's Swanland and the Jarrah Region of sidered also to be natural regions in the sense of Clarke. It became the practice Clarke. The Dale Subdistrict includes the northern jarrah forest with peri­ to mark their boundaries on the vegetation maps (Beard 1974-78), and this has pheral m~rri-wandoo woodlands, and the Menzies Subdistrict the southern

20 . I 21 VEGETATION SURVEY SWAN jarrah forest with ditto. The latter is more humid and there are botanical dif­ ferences, particularly in the understory. The Warren Subdistrict is the former Warren District of Diels and Gardner. Most humid of all, it has a moderate BOUNDARY

with less than four dry months in the year and precipi­ l

22 I 23 VEGETATION SURVEY SWAN CLIMATE Table I Summarized meteorological data recorded at Albany

The weather in southwestern Australia is controlled by a succession of high­ Total and low-pressure systems which move steadily eastward one behind the other. Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec or mean · During summer, high &tmospheric pressure with anticyclonic circulation is dominant, the most frequent situation being a slow-moving or more or less RAINFALL (mm) stationary anticyclone centred over the Bight. The anticlockwise direction of Mean 19 21 33 72 89 102 122 113 86 82 43 33 815 the associated atmospheric circulation brings the southwest under the influ- · Median 13 16 24 70 69 102 103 IOI 83 64 33 29 837 ence of northeasterly winds moving out of the interior which are both dry and Highest monthly 217 161 166 234 290 293 269 286 202 187 170 117 hot. Summer anticyclones tend to block the movement of low-pressure distur­ Lowest monthly I 0 3 5 44 40 52 50 20 14 5 2 bances or to deflect them southeastwards away from the continent. A common Av. no. rain days 9 8 11 16 17 20 23 22 19 14 10 10 179 cycle during summer is for a low-pressure trough to form off the west coast TEMPERATURE ( 0 C) into which there is a northwesterly and northeasterly influx of warm air, often Mean maximum 25.8 25.4 24,2 21.0 18.5 16.3 15.7 15.5 16.7 18.8 21.1 23.9 20.2 Mean minimum 13.3 13.9 12,9 11.6 9.5 8.1 7.4 6.8 7.4 9.0 10.4 12.4 10.2 humid and of tropical origin. Eventually the trough moves inland, displacing Highest 45.6 44.8 40.8 37.7 35.2 24.6 23.1 27.2 30.6 36.2 41.1 41.1 the anticyclone ahead of it, and winds move southwesterly and then soqtbeast, 1towest 5.7 5.0 3.7 4.2 1.7 1.7 0.1 1.3 1.1 2.3 4.8 5.1 becoming much cooler and creating the phenomenon known as a 'cool RELATIVE' HUMIDITY(%) change'.. After a few days a new anticyclone becomes established. Some in­ Average index 55 59 61 72 74 77 77 74 72 70 68 60 68 stability rainfall may occur in during the passage of the low­ pressure trough. Rarely, a tropical off the northwest coast reaches the Northwest Cape at a time when there is a west coastal low-pressure trough in Table II Summarized meteorological data recorded at Perth position, and may then enter the trough, moving southwards just off the coast­ line and eventually crossing the coast to move inland. Carnarvon is regularly Total devastated by such cyclciaes but it is very rare for them to be experienced Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec or further south. Summer rainfall may also be occasioned by periodic irruptions mean of middle-level cloud of tropical origin whose effect is normally limited to the interior, and by onshore winds during a 'cool change', whose effect is limited RAINFALL (mm) to the south coast. The summer is therefore essentially dry, relieved by Mean 8 11 20 46 125 187 174 139 82 55 21 15 883 thunderstorms in the interior and local rain along the south coast. Median 5 4 12 39 124 182 167 140 75 51 17 10 882 ,,. Highest monthly 55 166 145 149 308 476 425 318 199 200 · 71 81 During winter the anticyclones are weaker and the cyclonic low-pressure Lowest monthly 0 0 0 0 14 55 61 12 9 0 0 disturbances stronger, so that the southwest experiences t}te periodic arrival of Av. no. rain days 3 3 4 8 14 . 17 18 17 14 11 6 4 119 cold fronts which cause rain initially on the west coast, sdreading inland, and TEMPERATURE ( "C) later along the south coast, spreading inland as the front passes east. There are Mean maximum 30.3 30.3 28.1 23.9 21.2 18.6 17.6 18.0 19.4 21.9 24.8 28.2 23.5 thus two rainfall gradients in the southwest, the west coast and the south coast Mean minimum 18.6 18.6 11.0 14.1 11.9 10.7 9.2 9.1 IO.I 11.9 14.2 16.9 13.5 gradients. In the former case the principal rainbearing winds come from the Highest 44.7 44.6 41.3 37.6 32.4 28.1 26.3 27.8 32.7 37.3 40.3 42.3 southwest, so that rainfall increases at first from the coast as far as the Darling Lowest 9.2 8.7 7.7 4.1 1.3 1.6 1.2 1.9 2.6 4.2 5.6 8.6 Scarp, reaching a peak about 10 kn;t east of it and then declining progressively RELATIVE HUMIDITY ( %) in a northeasterly direction into th~ interior. The effect of this is felt irii the Average index 45 46 51 59 61 70 69 65 62 54 50 47 56 western portion shown as'western s~ctor' in Fig."8. In the eastern sector the gradient is from the coast northwards due to onshore winds. The high rainfalls attracted by the Darling Scarp are not found in the eastern sector, most of Fig. 6 gives a rainfall map from which the above trends will be apparent. It which receives under 500mm annually. However, although on is taken from a state map published by the Commonwealth Bureau of the whole is low,· it is spread over a longer rainy season than a comparable in 1962 and which is the latest available. This showed the isohyets rainfall in the western sector (Fig. 10). Along the south coast from Cape in inches, but approximate metric equivalents have been substituted in the Leeuwin to Denmark the two systems overlap, giving rise to the highest figure. Mean annual rainfall exceeds 1375 mm in the Pemberton-Northcliffe- precipitation in the whole state, spread over most months/he year. Walpole section of the south coast, and reaches this figure locally along the

24 . 25 I I VEGETATION SURVEY SWAN Table III Summarized meteorological data recorded at Kellerberrin

Total Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec or l<.ALGOORLU: o mean (~o RAINFALL (mm) Mean 11 14 23 21 43 60 55 42 27 19 II 13 339 Median 3 4 11 13 39 57 49 39 23 14 7 4 336 Highest monthly 87 127 152 110 119 163 123 100 76 77 68 67 Lowest monthly 0 0 0 0 0 15 11 3 2 0 0 0 Av. no. rain days 2 2 4 5 9 12 13 11 8 6 3 2 77

TEMPERATURE ( 0C) Mean maximum 33.9 33.1 30.0 24.9 20.8 17.3 16.1 17.2 20.1 24.8 28.9 32.1 24.9 Mean minimum 17.7 17.5 15.6 12.2 8.8 7.9 6.1 5.6 7.2 9.4 12.7 15.8 11.4 Highest 46.5 43.6 42.1 37.7 32.8 23.6 24.0 28.3 33.5 37.8 41.3 42.9 Lowest 7.2 6.1 4.8 I.I -2.2 -3.1 -3.3 -2.4 -I.I 0.3 1.7 So&

RELATIVE HUMIDITY (Ofo) Average index 33 38 43 52 60 73 70 66 56 42 24 31 50

Table IV Summarized meteorological data recorded at Coolgardie

Total Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec or mean Fig. 6 Rainfall map of rhe Swan area from Commonwealth Bureau of RAINFALL (mm) Meteorology 1962. The isohyets are for mean annual rainfa~l in millimetres. Mean 17 25 24 23 28 28 24 25 14 17 15 16 256 Median 7 15 13 13 24 27 22 17 11 9 8 10 Highest monthly163 236 133 105 115 119 76 90 92 78 77 89 0 inland stations, with absolute minimum down to - s;o • These are radiation Lowest monthly 0 0 0 0 0 0 1 0 0 0 0 frosts lasting only a few hours. Frost has never been recorded at Albany or Av. no. rain days ; Perth. Mean monthly minimum temperatures range from 6.8 ° at Albany to TEMPERATURE ( °Cl 5. 6 ° at Kellerberrin and 4. 8 °· at Kalgoorlie. Mean maxima range similarly from Mean maximum 33.2 33.0 29.3 24.9 20.5 17.0 16.2 IS.I 22.2 25.3 29.4 32.2 25.1 Mean minimum 17.0 17.0 15.3 11.8 8.5 6.4 5.3 5.8 8.0 10.3 13.5 15.8 11.1 25.8° to 33.9° and 33.6°. Absolute max~ma of about 45°C may be regularly Highest -- 46.1 45.8 43.3 39.4 33.2 26.3 27.2 29.9 34.4 39.4 42.8 46.1 experienced at coastal stations, and of 46 ° in the interior in the summer Lowest 7.8 8.2 5.0 2.2 0.7 - 1.0 -1.7 -0.5 -0.6 1.1 3.0 6.l months. An indication of the reliability of the winter rainfall is given by the

RELATIVE HUMIDITY (Ofo) figures showing lowest monthly rainfall ever recorded. 'Nil' has only been Average index not available recorded in one month of the year at Albany. Some rainfall has invariably been recorded in each of the six winter months at Perth, four at Kellerberrin '.\ . "- and only one at Coolgardie. Darling Scarp (Karnet 140~m, Dwellingup 1306mm). lt declines to 250mm Attempts have been made at various times to produce climatic indices em­ in the northeast at Kalgoorlie. bodying characteristics of climate which are the most important particularly The range of mean monthly temperature is lowest on the south coast, where for vegetation, i.e. not only total rainfall but its distribution throughout the Albany ranges from 12°C in June to 19°C in February. On the west coast at year and its effectiveness when temperature, humidity and evaporation are Perth it is 13 ° to 26 °. The mean temperature of the coldest month is always , considered. Such indices may be used for classification of climate. In the past, above 10°C; however, light frosts can be experienced7on winter nights at those which attracted most attention and still command much respect were the 26 · 27 1----+--\--+-,----+------+-----,-----+---+------+-----+----+--+//----11 00 100 ~"" A ... BANY Kl LLE RBE RRI N .. 80

30' f-----+--+-+-\-\--f----!---+--+---1-+-+/_+----l 60 30' 60 u u . \ I E . ~~- ..... ,,,_ I E E Ill...... E ~ \ I ::I /' V 20· f--+--+--+---\~,------4-----:-:Ji.-.-=-1..:~=--+--+--+---140 ~ ... 20' ~ r, 40 -ia E ~ .... Ill l/ -.l'i. C: ~ LX ..- I -...... , ~~ ·i Q. f ' \ a:~ E II) ...... ! T.2!llll!!~ _.- ",.... C:: a~ ""_v -..,...... _ I- ~~ .,r,-- I 1 o· 1---1---1---1-----11----i---i---+---+---+---+----1 20 10· "- 20 _L__ ---V ' "' 0) > u C: ., 0) > u C .!:J :,.. ll) ::, 0. 0 ., a. C: ~ ::, 0. u 0 ll) ., oi a C ., ::, Q) <( z Cl --,"' <( ::, <( 0 Ci --, u.. ~ <( "' ::, en --, --, en z "' ~ 7

I I ~ . 100 100

PERTH ,· . C00 .. GA ADIE 80 \. 80

30° \ / 60 30" 60 u . ' E ~ E II) - E II) '- ...... '- ...... E ::I __,.,,,.. / ... \ t, ' - ::I ,,. h .. - (Ii 20" 40 ia ... 20' 40 ia ... -- ...... ~ L/ .... II) C Q) C: Q. _1,e

w :,. 0) > u C .!:J :,. >-"" Ol > u C .!:J :,.. Q) u ::, 0. 0 Q) ., oi C ::, 0. ti ., oi C :i ., a "::, 0 ., a --, <( 0 z Cl --,"' u.. ~ <( "' :i <( ., 0 Cl --,"' IL <( ::, en ~ --, 7 en z ~ ~"' --,

Fig. 7 Ombrothermic diagrams for recording stations representa­ tive of the four major climatic zones: Albany, moderaJ6 inediter­ ranean; Perth, dry mediterranean; Kellerberrin, extra;dry mediter­ 29 ranean; Coolgardie, semi-desert mediterranean. VEGETATION SURVEY SWAN systems of Koppen (finalized 1936) and Thornthwaite (1931, 1948, of which the 1931 approach is the better). A Thornthwaite map for Australia appeared 0 DJl,LWAU..INU in Keast (1959). It was found however that these indices are not accu·rate SEMI-DESERT enough: for Australia they correctly show the arrangement of various inter­ I KA.lGOORLIE O grading climatic zones but do not properly delineate them (Leeper 1949). An J MEDITERRANEAN important improvement was effected by Bagnouls and Gaussen (1957) with I a SOUTHERN' CROSS their introduction of the ombrothermic diagram. This is a chart in which mean I monthly rainfall is plotted against temperature on double the scale so that o/MERREDIN r = 2t (r, rainfall; t, temperature). Examples are given in Fig. 7. Months in I which the rainfall line falls below the temperature line are assumed to be 'dry', I i.e. that precipitation is inadequate to sustain plant growth. The number of dry DRY/ MEDITERRANEAN months is read off from the diagram for each recording station. Classification / O M:YOEN is based on the type of rainfall distribution, whether with a summer maximum, I winter maximum, bimodal and so on, divided into types according to the j;-sector Boundary number of dry months, and further divided as required according to other I criteria. _,. I An elaborated form of the Bagnouls and Gaussen diagram known as the ecological climate diagram was used to compile the Klima-Diagramm Welt­ atlas of Walter and Lieth (1967), which contains over 8000 of such diagrams from stations all over the world. Their treatment of southwestern Australia, taken on a world scale, is too simplified for local use, while the UNESCO­ F AO map of 1963 is more complicated than required for our present purpose. A climatic map of the Swan area compiled by the writer according to the original Bagnouls and Gaussen system is given in Fig. 8. Four major climatic types are recognized, all known as 'mediterranean' because of their winter rainfall maximum. They are classified by the number of dry months in the year Fig. 8 Climatic zones according to the Bagnouls and Gaussen (1957) • as follows: classification, based on the average number of dry months per annul_ll. f Moderate mediterranean 3-4 dry months Moderate mediterranean zone: high-rainfall zone of the extreme southwest. Dry mediterranean 5-6 dry ~6nths Forests of karri, tingle and jarrah mingled with low forests on poor soils and Extra-dry mediterranean 7-8 dry;fuonths swamps. Forestry the chief activity, little agriculture. Semi-desert mediterranean 9-11 dry months Dry mediterranean zone: humid zone of the southwest. Forests of jarrah, J / woodlands on poorer soils and drier areas. Forestry, dairying, fruit-growing. The boundaries are drawn at 4.5, 6.5 and 8.5 dry months. In the extreme Extra-dry mediterranean zone: equates with the wheatbelt, the prime agri­ northeast of the Swan map, climate becomes desert: all months there are tech­ cultural region of the state. Original vegetation eucalypt woodlands, mallee, nically 'dry'. The mediterranean tendency is then lost however. Northwards in thickets and heath according to soil. The interior boundary of this zone co­ the Austin Botanical District rain w~~ it comes may be expected either in incides with that of the South-West Botanical Province (Figs 4 and 5). summer or winter, and in the Eucl~AJistrict in any month in the year indis­ Semi-desert mediterranean zone: semi-arid, largely unoccupied. Limited criminately. No part of the desert in Australia has precisely a winter rainfall. pastoral use. Woodlands and thicket. A typical diagram is given in Fig. 7 for each of the mediterranean climatic Desert zone: arid. Lc~rge pastoral stations. Mulga low woodland. types, and a summary of meteorological .data for the four stations is given in An alternative method of calculating the effectiveness of rainfall was Tables I-IV (taken from Bureau of Meteo}ology 197 5). · applied in a study by the Bureau of Meteorology (1965) using the formula of There is some practical value in the cl~ssification, as it expresses a natural Prescott (1952), which derives effective rainfall per month (r)Jrom the amount ecological division showing the effect of climate on vegetation and human . of evaporation (e) by the formula · activity. r = 0.54 x e0.7 30 31 VEGETATION. SURVEY SWAN are nine dry months or more, but is eucalypt woodland in the eastern sector at this degree of aridity. At the opposite extreme the karri forest zone straddles an intermediate curve, representing as it does the overlap between the west and south coast weather systems. Karri forest must have less than four dry months in the year, but its rainfall may be as low as 800 mm per annum. In the inter­ mediate range the eastern sector has a mallee vegetation where the western has woodland. For any given degree of aridity as measured by the number of dry months the mallee area has a lower wet-season rainfalJ, and thus presumably a lower moisture reserve to carry through the dry season. This is not the entire explanation for the predominance of mallee in the eastern sector. Soil has an important influence, and the matter will be further discussed later. Climatic history is important also for the interpretation of modern vegeta­ tion, as it is known that there have been quite profound changes in prevailing climate accompanying the oscillations of glacial and interstadial conditions. during the Quaternary period. Some of these have occurred remarkably recen'tly. Churchill (1959, 1961, 1968) was the first to investigate the subject in depth on Western Australian evidence. During the past decade great progress has been made in developing a sequence and chronology for Quaternary climatic changes, in particular through the work of Bowler (1971, 1977) and Dodson (1974 a & b) in the radio-carbon dating of lake levels in southeast Australia, and of Kershaw (1970-74) on pollen-dating in lakes in Queensland. Rogno'n and Williams (1977) have made a comparative study of the data for Australia and North , and proposed the following general time-tables:

Fig. 9 Period (in months) during which average rainfall exceeds effective 40000 to 20000BP: heavy rainfall, high lake levels, increased fluvial activity rainfall, calculated with the Prescott formula. From Bureau of Meteorology in southern Australia. 1965. ~ ·~. 17 000 to 12 000 BP: inter-tropical aridity and dune building, extending north of the present desert boundary. Desiccation in semi-arid New South Wales. If the actual mean rainfall is compared with the calculated effective rainfall, it gives for each station the number of months during which actual exceeds effec­ 11 000 to 5000 BP: very high lake levels and increased precipitation m tive rainfall, a period which is assumed to reprrsent the agricultural growing northern and southern Australia. season and is the converse of the dry months calculated for the Bagnouls and 5000 BP to present: recession of precipitation to present levels. Gaussen classification. The appropriate portion of the map published in the official Yearbook of Western Australia 1965, reproduced here as Fig. 9, shows Bowler (1977) disagreed slightly with the above chronology, placing maxi­ that there is reasonable agreement on the position of all the boundaries. mum aridity between 20 000 and 15 000 BP, but confirmed the general Fig. 8 shows the area divided into eas;.etn'and-western sectors as discussed sequence. He suggested that climate was cool and wet, favourable to vegeta­ earlier. The difference between the twosectors is expressed in Fig. 10 (where tion, during the. stage prior to 20 000, then became hot and dry. It was during I mean annual rainfall is plotted against number of dry months for stations in q this phase that the desert dunes of the interior were formed, spreading not only each sector), using black symbols for the western sector and open symbols for north of the present desert boundary, as noted above, but far to the south of the eastern. Symbols are also keyed for vegetation as shown in the diagram, it, since linear dunes and other aeolian landforms such as sand sheets and using zonal vegetation considered to represent prevailing climate. The stations lunettes can be detected far down into the southwest of Western Australia in each sector lie close to two distinct curves which cross one another on enter­ (Beard 1980g). Climate was evidently also very windy at this time. Widespread ing the semi-desert zone. Thus in the western sector, mostly further north than regression .of vegetation must have occurred. The arid phase was succeeded by the Swan area, the vegetation is acacia low woodland and scr4b where there a warm wet phase for about 5000 years, during which there were very favour-

32 33 1500

SWAN ... 1400 able conditions for the plant cover to re-establish itself. Since about 5000 BP • D • Katri Ta!I Forest there have been minor oscillations within an overall decline. Conditions today .6. A Jarrah Forest

0 • Woodland may be regarded as intermediate, neither extremely adverse nor ideally favour­

1300 Karri 'v · Mallee able. • Acacia Scrub Future research will no doubt throw further light on the effects of these • violent climatic fluctuations in the southwest, where it would appear that there 1200 • may have been some extensive extinctions and migrations of species during • • and after, the aridity. Lower sea-level made an additional land area available for refuge, but even so, on present evidence the probable area of humid

1100 climate remaining at the height of the aridity seems remarkably small, and a problem to resolve is what happened to the huge endemic flora of the south­ west. Did it find refuge, or are many modern taxa the result of a speciation

1000 explosion following amelioration of the climate?

GEOLOGY 900 • To the time of writing only a small part of the Swan area has been mapped

800 geologically in detail. The following maps have beert published (see Fig. 1 for location): '? E Boorabbin: Sofoulis 1963 700 Kalgoorlie: Kriewaldt 1967 ..."' Busselton and Augusta: Lowry 1967 ·;;C: Eas1ern Sector Curve er: Hill River (combined with Dongara): Lowry 1974 'io :l 600 Lake Johnston: Gower and Bunting 1976 C: C: Ravensthorpe: Thom, Lipple and Sanders 1977

400 Australia (Geo!. Survey W. Aust. 1975); it appeared as well in the general geo­ logical map of the whole state (Geol. Survey W. Aust. 1978). The information which follows has been mostly taken from the 1975 publication.

300 The greater part of the Swan area belongs to the Western Shield, an exten­ sive region underlain by Precambrian rocks which has remained essentially stable during Phanerozoic time, i.e. in the past 570 million years. A minor

200 portion of the Swan area belongs to the Perth Basin (Fig. 11), a trough bounded on the east by the Darling Fault, which runs north and south slightly west of the Darling Scarp. The basin became filled with sediments to a depth

100 - of nearly 15 000m (Rae· 1965). A portion of Precambrian crust has been preserved on the west side of the Perth Basin in the south and appears in the · Leeuwin-Naturaliste Ridge. In addition to the sediments of the Perth Basin there are some superficial deposits upon the Precambrian Shield, of which the 4 5 6 8 10 11 12 most important are the Plantagenet Group of siltstones, sandstones and lime­ Length of Dry Season (months) stones of late Eocene age ( ± 30 million years old) deposited along the south Fig. 10 Relation of average annual rainfall to length of dry season in eastern and western climatic sectors. 35 SWAN VEGETATlON SURVEY about 30% of the area, as against 5% in the Southwestern Province. The •~ " 1RCHISO \ greenstone. belts are of economic importance as they contain valuable aDALWALUNU ~'Ir'!!!,'' \ ,.., - - ~,~~-~• ' ,.11zo,:'"o minerals, principally gold and nickel sulphide which are exploited. An account \ I Bungalbin \ "'f""iz 1\ ~- / Ridges '" '?<, ~,, of the formation of the greenstone and granite belts in the Kalgoorlie area was l \ ~ KAL~OOFUIE a given by Kriewaldt (1967). The former originally consisted of layers of shale ''•, ~ ~,l ' \~~ and greywacke alternating with layers of volcanic lava. In the course of time \,fOUTHER N CROSS ..,. \ ' COOLGARDIE \ these were metamorphosed and strongly folded with a strike of NNW-SSE. 1 ~·\,.. , REGION • Truncation of the folds by later resulted in repetition of the outcrop, t .,. Boorabbi,, n Plateau so that the strata are repeatedly exposed in an east-west direction. Metamorph­ ,,,, ism has altered the shale and greywacke to slate, phyllite, schist, and in some B cases to banded ironstone. The volcanics have been altered mainly to am­ .,.-,¥.,,<.e \1 remer 0 HYDEN Y. \\'- 'X -

38 39 / SWAN VEGETATION SURVEY published information is still of a very general nature. A need exists to redress this uneven balance which will be attempted here by summarizing previous work for known areas and furnishing equivalent information for those less known parts. · In the course of the vegetation survey detailed observations were made in the field and by photo-interpretation which can be applied to landscapes as well as to vegetation. In the previous publications of the survey at the 1 : 250 000 scale, the vegetation was all treated through the medium of 'vegetation systems', a concept originated by Speck (1958). The 'vegetation system' is currently de­ fined (Beard 1959a et seq.) as a particular series of plant communities recur­ ring in a catenary sequence or mosaic pattern linked to topographic, pedologi­ -cal or geological fea,tures. The 'vegetation system' covers a defined area within which a single typical pattern of vegetation occurs. Owing to the inter-relations which exist, there will also normally be a single typical pattern of topography, landforms and soils, and the area covered by the 'vegetation system' can be treated as a landscape unit, becoming comparable with the 'land system' unit widely used by the CSIRO, e.g. Mabbutt et al. {1963). 'Vegetation systems' for the Swan area have been defined and mapped in the previous work, and are shown in Fig. 31. It has already been the practice to regard them as component units of 'botanical districts', and an intermediate grouping into physiographic units is also possible. An integrated system will be outlined here, a hierarchy built up from vegetation systems into physiographic units and these into 'natural regions'.

PHYSIOGRAPHY Fig. 12 Drainage. Contin.uous· lines show active streams and rivers, broken lines valleys which no longer carry co-ordinated drainage. In 1914 J. T. Jutson published his major work, a long-term classic, on the physio~r~~hy of Weste~n Australia. In the sout_hwest he distinguished a So~­ west D1V1s1on, alternatively named Swanland ma later edition (1934), and a regional landscapes (1938) and landform regions (1944). The Western Austra­ Central or Salt Lake Division, later Salinaland. Swanland is drained by active lian portion of his map was reproduced by GentilH (1979). It is of historical interest. Gentilli and Fairbridge (1952) produced a treatment slightly more '· streams and rivers which reach the sea, whereas in Salinaland Jutson thought drainage flowed into interior basins. The line separating the two divisions detailed than that of Jutson, The name Swan Coastal Plain was here, as is approximately coincides with the boundary of Diels' South-West Botanical proper, restricted to the plain of marine denudation on the Perth Basin, distin­ Province (Fig. 2) and was later named the Meckering Lifie by Mulcahy (1967). I. guishing it from the two residual plateaux, named the Dandaragan Plateau Better understanding of the drainage of the interio:t; and its history gained since and the Donnybrook Sunkland. The Western Shield area of the geologists was the days of Diels and Jutson showed that the Meckering Line does not repre­ divided into the Yilgarn Block, the Darling Hills (Darling Plateau of Jutson) sent a watershed. The valleys of existing rivers stretchf..a,r back into the interior and the Stirling-Mt Barren Block along the south coast. The Swan Coastal Plain was studied in depth by McArthur and Bettenay I (Fig. 12). The Meckering Line joii,:is the points where these valleys cease to carry active drainage in normal seasons. Further upstream they contain only (1960) who recognized a number of 'geomorphic elements'. These were chains of salt lakes and pans. Jutson divided Swanland into the Swan Coastal systematized as 'physiographic subdivisions' of those parts of the plain that have been geologically' mapped by Lowry (1967, 1974a & b) and Wilde and I' Plain a~d the Dar~ing _Plateau, separated by the 1arling Scarp, and with the Naturahste-Leeuwm Ridge as a further element in tlie southwest. Low (1978). No other part of the southwest has been treated in such detail. As noted in a previous section Clarke (1926) divided the state into 'natural Playford, Cockbain and Low (1976) published a map of 'physiographic regions', which are relevant here, since the forms one of regions' of the Perth Basin, in which the Dandaragan Plateau was subdivided, the criteria for classification. J.M. Holmes (1938, 1944) mapped Australia for ·distinguishing the Arrowsmith Region and the Yarra Yarra Region from the

40 41 / l______VEGETATION SURVEY SWAN plateau proper; the Donnybrook Sunkland was renamed the Blackwood Truslove Plateau Plateau and the N~furaliste-Leeuwin Ridge the Naturaliste Region. The pre­ Lake Hope Upland vious 'physiographic subdivisions' of the Swan Coastal Plain were confirmed and the Scott Coastal Plain subdivided into the Warren Dunes and the Coastal Eyre Region: Jerramungup Slopes Belt. Stirling Range Jennings and Mabbutt (1977), treating Western Australia in part of a conti­ Barren Ranges nental study, endeavoured to systematize the previously very confused hier­ Ravensthorpe Hills archy of physiographic terms on the basis of 'divisions', 'provinces' and 'sections'. They also followed more precise definitions of such terms as Coolgardie Region: Boorabbin Plateau plateau, range, hills and lowland. In their treatment the southwest of Western Bungalbin Ridges Australia forms part of the Division, divided into the Parker Hills Western Coastlands Province, and the Yilgarn Plateau Province, divided by Bremer Range the Darling Scarp. The 'provinces' were divided into five and seven 'sections' Coolgardie Plains and Hills respectively within the Swan area. This was the most detailed treatment so far, and made an admirable attempt to stabilize nomenclature even if it involved Murchison Region: Barlee Subregion upsetting long established names, e.g. changing Stirling Range into Stirling Hills. However, it was framed on an Australia-wide scale and is not detailed enough for the purpose of this chapter. SOILS McArthur and Bettenay (1979) published a map of Landform-soil Regions of Western Australia which was based on Clarke's Natural Regions with re­ Following the early general account of Western Australian soils given by visions. Teakle (1938), some detailed local studies were conducted by CSIRO, of which The treatment adopted here is shown in Fig. 11. The physiographic units are the most important were in the Margaret River-lower Blackwood valleys (R. built up from vegetation systems and consist either of a single system or a Smith 1951a), the Frankland Valley (R. Smith 1951b), the Swan Coastal Plain group of them. Their bountlaries are derived from the mapping of the systems (Bettenay, McArthur & Hingston 1960), the Merredin area (Bettenay & (Fig. 31). Descriptive details will be given later in conjunction with soils. The Hingston 1961) and the York-Quairading area (Mulcahy & Hingston 1961). I following is a summarized list: The data so gained were used _as a basis for a general soil map scalt 1 :2000000 in the Atlas of Australian Soils series (Northcote et al. 1967). I More recent local treatments of interest have been by Mulcahy, Churchward Greenough Region: Arrowsmith Slopes ~ .. and Dimmack (1972) for the Darling Plateau, and McArthur and Clifton Perth Region: Dandaragan Plateau (1975) for the karri forest area at Pemberton. Mulcahy (1973) gave a brief Swan Coastal Plain review of landforms and soils of the southwest with a generalized soil map Blackwood Plateau scale 1 : 4 000 000 distinguishing eight soil groups-this being essentially a Leeuwin-Naturaliste Ridge simplification of the larger map in the Atlas of Australian Soils. A similar Scott Coastal Plain ~ review and map, but with a different treatment of the soil groups,· was fur­ nished by Bettenay, Cooper and Pilgrim for the Atlas of Human Endeavour I Darling Region: Darling Plateau \ (ed. Jarvis 1979); and there is yet another in a Soil Map of Australia scale Scott Coastal Plaih" 1 : 5 000 000 (Northcote et al. 197 5). Bannister Uplands It has not been found practicable to reproduce a small generalized soil map ~ Albany Slopes of the Swan area here as it could not be printed in colour. However, the vegetation map itself is a good guide to the soils, once the correlations are Avon Region: Meckering Upla9cts understood. The soils underlying the more extensive of the vegetation types Yilgarn Plateau \ shown in the key to the map are listed below. The nomenclature is from Stace \ Roe Region: Hyden Plateau et al. 1968 and is that of the Great Soil Groups. Later in this section when Forrestania Tableland details of soils are being given by physiographic regions, simple descriptions of . Ongerup Plateau typical profiles will be given, taken from Northcote et al. (1967) .

42 43 VEGETATION SURVEY SWAN Karri tall forest. Red earths, red and yellow podzolic soils. need for trace elements came to be understood. It is now widely recognized Jarrahjorest. Siliceous sands and lateritic podzolic soils. (, that the highly-leached sandplain soils are generally deficient in copper and Marri and wandoo woodlands. Lateritic podzolic soils and soloths. zinc, and sometimes in manganese and molybdenum. Sulphur may locally be Mallet and powderbark woodlands. Ironstone gravels. deficient, but is usually provided as a constituent of superphosphate. Cattle Other woodlands. Tua.rt is an indicator of yellow earthy sands over coastal and sheep in some areas fail to thrive owing to deficiencies in , copper or limestone. York gum and wandoo-as for marri and wandoo above. selenium. It is only the determination of these deficiencies, and means to over­ Salmon gum and gimlet-solodized solonetz and solodic soils, and red­ come them, that has made possible since 1950 the development under crops brown earth, grading to solonized brown soils east of Southern Cross. and pastures of vast areas of 'light land', the sandplains of the northern Perth Banksia, jarrah and sheoak low woodlands. Siliceous sands. Basin, on the Yilgarn Plateau and on the Esperance Plains (all details from Thicket. The Acacia and Casuarina thickets, together with the scrub-heath Burvill 1979). formation, indicate the sandplains with their sandy yellow earths to Some soils on the other hand have presented problems not of deficiency but earthy sands. of toxic excess. The calcareous earths of the drier eastern interior first fell into Ma/lee. Sandy alkaline yellow-mottled duplex soils (soloths). disrepute because their powdery fluffy character caused inefficient absorption Mallee-heath. Soloths, also lateritic podzolic soils. of water under light rainfall conditions; later in many cases they were found to Succulent steppe. Saline loams and solonized brown soils. contain toxic amounts of salt. The whole landscape on the Yilgarn Plateau and . Greater detail will be given at the end of this section...... further inland contains a considerable store of sodium chloride which is It has long been recognized that most Western Australian soils are of low to accounted for by accession of ions in rainwater. Only a small proportion of extremely low natural fertility, which is to be expected considering the great this salt occurs on the surface in salt lakes. The bulk of it is held within the age of the landscape and the long period of weathering and leaching under pre­ pallid zone beneath the valley floors (Bettenay, Blackmore and Hingston vious more humid climates, and the low levels of P in parent rocks. The only 1965), and has only come to have an adverse effect on crops and vegetation soils possessing rea.sonable natural fertility are some of the young soils on after widespread land clearing, which by reduction of evapotranspiration in alluvia or fresh rock, particularly the York gum soils of the inner wheatbelt, catchments causes a rise in water-tables. the marri woodland soils of the Dandaragan Plateau, the alluvial terraces of Thus on the one hand the prolonged time-scale has removed almost all plant the Swan Coastal Plain, and some estuarine soils. These were rapidly identi­ nutrients from the widespread sands and gravels of Western Australia and on fied by the pioneers and settled, as they can be moderately productive without the other hand replaced them,. with soluble salts, mainly sodium chloride, the use of artificial fertilizers, unknown at. that date. The yellow-mottled blown in from the ocean and deposited with the rain. Lack of runoff and the woodland soils were the next to be taken up for settlement, but proved less fer­ high potential evaporation/precipitation ratio during the current climatic cycle tile. Reliance was placed on the use of locally-mined guano and fallowing until causes these to accumulate. the 1890s when the use of superphosphate was introducecl. Its popularity i" Nutritional aspects of soils have so far been investigated almost entirely with spread widely after 1900, and today it is regarded as the life-blood of Western regard to cultivated plants, and little work has been done on the nutritional Australian farming. Between. 1910 and 1977, 30 million tonnes of superphos­ requirements and responses of native plants, particularly in the west. Phos­ phate were manufactured in Western Australia, its use currently running at phate nutrition of native plants was investigated by Beadle (1954, 1966) in New over 1 million tonnes per annum (Burvill 1979). South Wales, who demonstrated a relationship between sclerophylly and phos­ Soils are widely considered 'fertile' if they require only superphosphate to phorus deficiency. Specht and Rayson (1957) worked on nutritional aspects of yield good crops and pastures, and this applies generally to the yellow-mottled heathland in South Australia as did Bradhurst (1954) in New South Wales for duplex soil formerly under eucalypt woodlands. Additional problems began to the Hawkesbury Sandstone flora. Halliday and Pate (1976) demonstrated be encountered as farmers began to experiment with 'light land', the sandy and ability to fix nitrogen by Macrozamid riedlei. There has been some interest in gravelly soils of the sandplains. Crops fail completely on these soils unless the curious organs known as proteoid roots produced in the family ­ superphosphate is applied, and it was reported to be effective on sandplain at ceae, particularly in Hakea-presented in a series of papers by B. Lamont. Meckering as early as 1902, but later in the eastern wheatbelt after clearing These organs have a possible role in overcoming low availabilities of nutrients. Acacia-Casuarina thickets known as 'wodjil' results were disappointing. A Lamont (1978b) included a range of references to other work. On the whole Wodjil Board (sic!) was actually appointed to investigate the problem and this is a field which has as yet been barely explored. Since native plants are suc­ demonstrated the advantage of adding nitrogen and potash. This did not cessful in environments which are critically limiting in nutrients, they must always work effectively, and the board concluded that there must be some h:i.ve developed tolerances for low levels, or mechanisms for efficient extrac­ toxic principle produced by the wodjil roots. Only much later, in the l 930s, the tion and utilization of nutrients.

44 45

I VEGETATION SURVEY SWAN

DESCRIPTION OF THE NATURAL REGIONS 45 m. _There ~re no permanent drainage channels, though a number of swamps form m low mter-dune areas during winter and a few lakes occur towards the 1 Greenough Region (Irwin Botanical District) eastern end of the island. Benches around the coastline and ·around the margins of the lakes at 0.5, 1.5 and 3.0m above mean sea-level are believed to 1.1 Arrowsmith Slopes (Playford, Cockbain & Low 1976) have resulted from higher sea-levels of Recent date. During the last glacial The small portion of the Greenough Region on the Swan sheet was distin­ period the islands were joined to the mainland and have only been cut off for guished by Lowry (1974) in the geological survey, as the 'dissected region' of about 5000 years (Churchill 1959). the Dandaragan Plateau, from the plateau proper, and further named the Soils are calcareous sands (Ucl .11). Arrowsmith Region by Playford, Cockbain and Low (1976). The country has 2.2.2 The Quindalup Dunes (McArthur & Bettenay 1960) are the youngest been eroded by the Hill River and its tributaries and is undulating, descending of the coastal dune systems, and in places are still mobile and receiving new in general to the west. Its topography is influenced inland of Jurien Bay by material from the sea, though most are fixed by vegetation. They override resistant Triassic Sandstone which forms the prominent mesas of Mt Peron older dunes. In general they form a disordered topography but north of Perth and Mt Le Sueur, about 300 m in height. It is also influenced by the presence there is a progressive tendency to form linear ridges with a ~orth-south trend in of laterite, which caps these mountains and most of the hills, creating a mesa­ response to strong southerly winds in summer. form topography. Surfaces are almost entirely covered by sand and laterite. · Soils are calcareous sands (Ucl .11). Chief soils are sandy acidic yellow mottled soils (Dy5.81)* containing-much ' ironstone gravel in the A horizons, or soils with an ironstone layer separating . 2_-~-3 Th~ Spearwood Dunes (McArthur & Bettenay 1960) consist of dunes the A and B horizons (Dy5.84), alternating with leached sands (Uc2.21). hthlf1ed to limestone and are without any recognizable trend patterns. The dunes are piled up to heights of 100-150m. There are some permanent lakes 2 Perth Region (Drummond Botanical Subdistrict) tending to occur in chains parallel to the coast, which may represent old lagoons cut off by foredunes from a prograding shoreline. Salinity of these is 2.1 Dandaragan Plateau (Gentilli & Fairbridge 1952) very variable. All the lakes north of Perth up to Loch McNess at Yanchep are permanent and fresh, Lakes Cooloongup and Walyungup are intermittent and The plateau is a sand~ •and laterite-covered area which overlies Mesozoic saline, Lake Preston and the chain o.f small lakes between it and Lake Clifton rocks. It rises from 130m above sea-level in the south to 250m in the north. are saline, but Lake Clifton is. fresh to slightly brackish. Lakes situated along The surface is a plain, little dissected, except where the Moore River cuts the boundary between the coastal belt and the Bassendean Dunes are all fresh. through it. Most of the precipitation is absorbed by surface sand. On the west Soil_s are slightly podzolized yellow sands (Uc4.2), almost entirely quartz, an abrupt boundary is formed by the Gingin Scarp trending northwest from but with some local areas abundant in heavy minerals. The yellow sands are Bulls brook to the Caren Caren Brook, then by the Dandaragan Scarp running always underlain by aeolianite rock which, however, extends beyond them far due north through Mt Misery (278 m) west of Dandaragan, to die out north of to the west, underlying the present-day dunes at the coast and on the offshore Dinner Hill. The eastern boundary is formed by the Darling Fault marking the islands, so that the system must have been at one time far more extensive; change to Precambrian rocks. The Swan and estuaries, the Peel Inlet (with the Harvey Soils on the plateau are in part as above on the Arrowsmith Slopes, where e~tu~ry) and the Leschenault Inlet are drowned valleys flooded by the same the vegetation is heath and scrub heath, but beneath marri woodlands are red 7 nse m sea-level following the last glacial period which cut off the islands. The earthy sands (Uc5.21) and beneath banksia low woodlands are yellow earthy Peel and Harvey Inlets with the Murray and Serpentine Rivers, covering sands (Uc5.22). 115 km2 , form the largest estuarine system in the southwest. They have a very 2.2 Swan Coastal Plain (Jutson 1914) small daily tidal range, a maximum of only 50Jo of the ocean tide; River flow is I relatively small and salinity seldom drops below lODJo for more than a brief This unit is divided into seven subunits equating with 'vegetation systems' perioq, and may become slightly hypersaline in summer (Hodgkin 1978). (Fig. 31) The above two _dune systems comprise the Coastal Belt of Lowry (1974), Playford, Cockbam and Low (1976), Wilde and Low (1978) 2.2.1 Rottnest Island (together with Carnac and Garden Islands) has a rolling, sand-dune topography and reaches a maximum elevation of about 2.2.4 The Bassendean Dunes (McArthur & Bettenay 1960) occur in a belt * The letters and figures in brackets refer to the Factual Key for the Recognition of Australian _15 km wide, and consist of low, vegetated hills of quartz sand with numerous I! Soils (Northcote 1971). interdunal swamps and lakes. There is no organized drainage, except where the

46 47 VEGETATION SURVEY SWAN various rivers cross the plain. The Bassendean Dunes are not continuous but capped with. laterite and sand. It has a maximum· elevation of 123 m in the isolated into distinct areas by projections of the Pinjarra Plain. They are the north at Chapman's Hill and slopes down gently to the South. It is traversed in oldest system furthest inland which has now lost its dune morphology, and is a meandering course by the Blackwood River. of low relief compared with the younger systems nearer to the coast. Its soils Chief soils are hard acidic yellow-mottled soils (Dy3.61) containing variable are extremely leached and podzolized white quartz sands with B horizons of amounts of ironstone gravel. iron and organic matter accumulation (Uc2.3). They are impor.tant intake areas for the coastal plain aquifers and are underlain by fresh groundwaters at 2.4 The Leeuwin-Naturaliste Ridge (Jutson 1914) shallow depths. This is a north-south trending horst of Precambrian granite and granulite 2.2.5 The Pinjarra Plain (McArthur & Bettenay 1960) is an alluvial tract forming hills rising to 200 m. Most of the outcrop is obscured by laterite and lying between the Bassendean Dunes and the Darling Scarp. It is from 1.5 to sand on the inland side, and by dune sand and calcarenite on the western, sea­ 25 km wide, irregular and discontinuous. The alluvial flats along the Moore ward side. The coast. has a rugged retrograding shoreline with small sandy bays River belong to this element. The plain proper begins with a broad expanse at between promontories of granite and limestone. the foot of the scarp north of Gingin, then narrows further south, extends for Soils are calcareous sands (Ucl.11) on the seaward slope; on the inland side 16 km downstream along the Swan River, extends westward in a lobe to meet the soils are acid grey earths (Gn2.94), sometimes containing ironstone the coastal belt inland of Rockingham, and again extends further so);!!.h to gravels, and some sandy yellow-mottled soils. meet the Peel Inlet. It continues to form an irregular boundary with the Bassendean Dunes to the far end of the Swan Coastal Plain south of Duns­ 2.5 The Scott Coastal Plain (Lowry 1967) borough. The older, and most widespread, alluvial deposits have been lateritized, but This lies between the Blackwood Plateau and Flinders Bay. It is low-lying also have been extensively stripped, so that the dominant soil is a meadow pod­ and swampy with remnants of dunes which form scattered hills and ridges and zolic (Dy5.81) consisting of a sandy surface over a poorly-structured subsoil a belt of both Iithified and active dunes along the coast. The swamps have clay of low permeability developed in the lateritic pallid zone. Younger resulted from blocking of the drainage by coastal dunes. deposits, in the form of the terraces 'incised in these older n;iaterials, or of Chief soils are leached sands (Uc2.2 and Uc2.3), with dunes of calcareous alluvial fans laid over them, carry a sequence of red and yellow podzolics sands (Uc 1.11) fronting the coast.. (Dr2.81 and Dy2.21) and of undifferentiated soils on the relatively fresh youngest deposits. 3 Darling Region 2.2.6 The Piedmont Zone, better known as the Ridge Hill Shelf (Mc­ 3.1 The Darling Plateau {Jutson 1914) Arthur & Bettenay 1960) is a narrow strip of country 1.5 to 3 km wide along the foot of the Gingin and Darling Scarps. It consists of coalescing alluvial The northern portion of the Darling Plateau, corresponding fo the Dale fans deposited by streams losing grade. at the bottom of the scarp and rem­ Botanical Subdistrict, comprises the area to the east of the Darling Scarp. It nants of marine terraces. overlies Archaean granite and metamorphic rocks and has an average eleva­ Soils are as above. tion of about 300m. The plateau is an ancient erosion surface capped by an extensive lateritic duricrust which bas been dissected by later drainage. The 2.2. 7 The Gingin and Darling Scarps rise steeply from the coastal plain to general level is broken here and there by granite hills, which probably repre­ the continental plateau and represent the eastern edge of a plain of marine sent ancient monadnocks. The principal summits are: Mt Gungin 410m, Mt denudation formed in Late Tertiary or Quaternary time. It will be observed William 482 m and Mt Curtis 415 m close to the scarp; Mt Saddleback 575 m that the Gingin Scarp is parallel to the present coast (Fig. 11). South of and Mt Wells' 547 m near the ; a chain of hills in the centre Bullsbrook the Darling Scarp is also the surface expression of the Darling including Mt Cooke 582 m and Mt Randall 525 m; and Mt Dale 548 m in the Fault. northeast. The plateau is dissected by streams rising locally, and by rivers Soils are acid red earths (Gn2.14) on the colluvial slope deposits with originating in the interior which cut across it from east to west. Valleys vary (Dr.2.21) and (Dy3.21) on upper slopes, (Uc4.ll) on spurs and ridges. from youthful to mature. The major rivers comprise the Swan-Avon system 2.3 The Blackwood Plateau with its tributaries the Helena, Brockman and Mortlock, and the Murray River . with its tributaries the Williams and Hotham. Drainage forms an intricate pat~ The Blackwood Plateau is gently undulating, underlain by Mesozoic rocks tern (see topographic and geological maps). Fragments of an ancient drainage

48 49 \ / VEGETATION SURVEY SWAN system are thought to be preserved on the major divides which carry broad, the coast there are extenshie swampy plains underlain by leached sands (Uc2.2 shallow, flat-floored, perched valleys. With distance downstream the inter­ and 2.3). fluves are reduced to ridges capped with massive ironstone, their flanking slopes mantled with detrital materials derived from it · and frequently re­ 3 .2 The Scott Coastal Plain cemented. For this reason the plateau was named the 'zone of detrital laterites' by Mulcahy (1967). The plain extends into this region along the south coast, becoming nar­ · In the east the plateau becomes more and more deeply dissected, anq the rowed. It does not finally pinch out before reaching Albany. Soils have been boundary is drawn where it loses its coherence to be broken up into isolated previously described. remnants. The dominant soils are the lateritic gravels (KS-Uc4.1 and KS-Uc4.2) con­ 3.3 _ The Bannister Upland sisting of up to 5 m or more of ironstone gravels in a yellow sandy matrix, and This unit forms part of the 'zone of younger laterites' of Mulcahy (1967) (to the related lateritic podzolics (Dy3.61) with ironstone gravels in a sandy sur­ which the Meckering Upland Unit also belongs), bounded on the east by the fa-ce overlying a mottled yellow-brown clay subsoil. These materials frequently Meckering Line. The landscape represents the first stage in the rejuvenation of overlie a pallid zone up to 30 m or more in thickness. Massive ironstone pave­ the drainage. Valleys were deepened following uplift of the continent, so that ments are common on ridgetops and occasionally on slopes. It is worth empha­ ancient drainage lines originating further east here become an active system of sizing that, apart from more extensive divides, there is some considerable"Felief seasonally flowing streams, which eventually unite and plunge into deep nar­ with slopes up to 8 °. In general th,e gravels tend to become finer downslope, row valleys cutting through the Darling Plateau. Remnants of massive lateritic sometimes grading into sandy yellow earths (Gn2.21) in the lowest positions. duricrust cap the higher ground and are usually bordered by abrupt break­ The mid-slope gravels are thos~ currently being mined as bauxite. The broader aways. Such remnants become more extensive and more elevated above the valleys of the more extensive divides carry grey sands over ironstone gravels valley floor, in a westerly direction. A feature of the country is the extensive (Uc2.3) or solonetzic profiles (Dg3.81), both overlying deep pallid zones. occurrence of lateritic profiles on the valley sides and floors, interpreted by Further downstream the sides of the more incised valleys have a range of soils Mulcahy (1967) as younger than the laterites of the plateau remnants. The including red and yellow podzolics (Dr2.21 and Dy3.21) and red and yellow . . . lower slopes along the major valleys are laterite-free. The topography in the earths (Gn2.14 and Gn2.21). area is thus varied and undulating,_ with an amplitude decreasing from west to South of Collie, in the Menzies Subdistrict, the plateau broadens and turns east from 140 to 70 m. to the east parallel to the south coast, where it no longer terminates in a scarp The Bannister Upland is the western half of the zone of younger laterites, but a gentle slope down to the coast. The plateau is dissected by the Collie, distinguished by deeper and narrower valleys and extensive mesaform plateau Preston, Blackwood, Donelly and Frankland Rivers, which cut across it from remnants. inland, but more and more towards the east it comes to form a broad level sur­ The dominant soils are a range of hard and sandy, neutral and acidic yellow face of poor drainage with one iarge permanent lake, Lake Muir, and in­ and yellow~mottled soils (Dy3.82, 3.81, 5.82, 5.81) containing variable numerable small freshwater lakes and swamps. At the same time the ironstone amounts of ironstone gravels, especialfy on the tops of ridges, where sand and gravels become steadily less in evidence, being buried beneath sands which ironstone may predominate. On the pediment slopes red earths (Dr2.31, 2.21, become paler and more leached. There is an area of neutral and acidic red soils 2.32, 2.22) are found. (Dr2.22 and Dr2.21) around Bridgetown in response to gneissic country rock, but otherwise acidic yellow-mottled soils (Dy3.61, 3.71, 3.81) containing 3 .4 Albany Slopes variable amounts of ironstone gravel are dominant. Towards the southeast the mosaic contains progressively larger areas of deep, leached sands overlying The Albany unit consists essentially of a plain ascending gradually from the ironstone gravels or clays (Uc2.2, 2.11, 2.21, 2.3). coast and levelling off further inland. Albany airport is 69 m above sea~level, The Warren Subdistrict is on the south slope of the plateau, and is dissected, Narrikup 134 m, Mt Barker 254 m. Beyond this point the plain undulates hilly, with steep valley side-slopes. Pedogenesis is influenced by an underlying gently with little significant change in level. Above the plain rise numerous metamorphic belt with gneissic rocks. Chief soils are hard, and also sandy, isolated granite bosses and the commanding peaks of the Stirling Range. neutral and also acidic, yellow and yellow-mottled soils (Dy3.62, 5.62, 2.82, Below the plain are the entrenched valleys of the numerous short rivers drain­ 3.21) with conspicuous but relatively smaller areas of red earths (Gn2.l5 and ing to the south coast. Sand dunes have been built up on the coastal margin of Gn2.14). The karri forest grows on the latter and on the better phases of the Jhe plain and have impounded numerous swamps and sea inlets on their land­ yellow-mottled soils. Ironstone gravels and leached sands occur, also. Towards ward side.

50 51 / VEGETATION SURVEY SWAN Taking these features in order, along the coast the granite bosses are rela­ 1:entrated in certain areas presumably representing the major granitic intrusive tively small but very numerous. They have been exposed by dissection of the belts. They vary from small tors or rock pavements to extensive masses such as country and rarely exceed 200m in height. Two of them, Mt Melville and Mt Billyacatting Hill, which covers 1369 ha (Muir, unpubl.). Clarence, dominate the town of Albany, rising to bare, smooth rounded The major valleys contain chains of salt lakes and pans caused by the low domes of rock. Most of the coastline is dominated by granite bosses forming gradient, local deposition of alluvial and aeolian material, and the lack of suf­ headlands with embayments in the lower country between them .. Further in­ ficient rainfall to maintain coherent channels. The system still occasionally land the outcrops become higher and more massive. Mt Lindesay attains flushes out in years of high rainfall, and did so in 1955 and 1963 {Mulcahy 456m, Mt Barrow 486m, the Porongurup Range 670m and Mt Manypeaks 1967). The lakes are associated with aeolian features such as lunettes and 562 m. The Porongurup is one of the largest granite massifs in the state, where transported sheets of sand and finer material called 'lake parna' by Bettenay granite domes crowd upon one another over a length of 12 km and a breadth and Hingston (1961). The salt-lake valley system is mapped in Fig. 12. of 3 km. Such granite outcrops are limited to a belt 40 km wide from the; coast, The nature of the landscape here is such that a broad-scale catenary beyond which the plains stretch to the foot of the Stirling Range. sequence of soils can be distinguished (see Fig. 30). On the sandplains there is a Neutral yellow-mottled soils (Dy3.82) containing ironstone gravels are mosaic of sandy yellow earths {Gn2.21 and 2.22) and yellow earthy sands found on the higher plateau level, becoming more acid on the slopes towards {Uc5.22), both containing or overlying ironstone gravels. An ironstone out­ the coast. On the lower slopes and swampy plains sandy neutral yellow­ crop or low breakaway normally marks the edgP. of the sandplain. On the mottled soils (Dy.5.42) predominate with leached sands (Uc2.2 and 2.3)Pln the extensive slopes below, alkaline red {Dr2.33) and yellow-mottled (Dy3.43) Porongurup Range and other granite bosses there are shallow loamy soils duplex soils are developed upon underlying pallid zone materials. Towards the (Um4. l), with red earths (Gn2.14) in pockets where karri is present. north and east the yellow-mottled soils tend to drop out, while red earths (Gn2.lf and 2.12) and calcareous earths (Gcl.22 and 1.12) appear. On the broad flat valley floors alkaline yellow soils (Dy2.43 and 2.33) are common, 4. Avon Region underlain by acid lateritic clays below depths of 60-120 cm. The salt-lake chan­ 4.1 The Meckering Upland nels are mostly devoid of true soils. Common soils in the fringing areas are gypseous and saline loams (Uml.1 and Uml.2) on riverine wash, and are This area forms the eastern portion of the 'zone of younger laterites' usually underlain by clayey or sandy strata at about 30 cm depth. Associated described above. It is distinguished by broad, shallow valleys, and plateau are various resalinized (Dy) soils such as (Dy4.83) on fringe areas, and dunes remnants reduced to small buttes and mesas, the so-called 'mallet ridges' from and lunette$ of various sandy· (Uc), silty (Um) and clayey (Uf} soils of slight the brown mallet tree (), which is characteristically profile development. found on massive ironstone. Soils are as described for the Bannister.Upland. The Yilgarn Plateau contains two enclaves, the W estonia and Holleton greenstone belts, which belong to the Parker Hills physiographic unit (q.v.). 4.2 The Yilgarn Plateau 5 Roe Region The Yilgarn Plateau is the 'zone of salt lakes and sandplains' of Mulcahy (1967), and corresponds to the southern part of Jutson's Salinaland.(1934). On 5 .1 The Hyden Plateau - this portion of the Western Shield drainage has not been rejuvenated since valleys were formed, i.e. since Early Tertiary time or earlier. There is a general The Hyden Plateau represents the extension to the southeast into the mallee gentle slope down from east to west; altitudes along the Eastern Goldfields region of the Yilgarn Plateau, so that the landscape is somewhat similar. The Railway rise from 150m at Northam to 353m at Southern Cross. Valleys are principal difference is that the valleys are narrower and the sandplains more shallow, wide and have little fall, so that drainage is sluggish. The trunk extensive; also the latter are less clearly demarcated. There are no breakaways valleys may be as much as 15 km across, while even the larger tributaries may and the sandplains merge indistinguishably downhill into the valley soils. The be up to 8 km · wide. They lie only about 60 m below the smooth, gently same soil units have been mapped by Northcote et al. ( 1967) as for, th·e Yilgarn rounded divides. Despite the width of the valleys, they are narrow in compari­ Plateau, but with different relative extent. son with the extent of the uplands between them which carry broad areas of sandy deposits (Mulcahy 1960) commonly known as sandplains. Thus the 5 .2 The Forrestania Tableland landscape is gently undulating and on the whole featureless, except for a The Forrestania Tableland straddles an ancient continental watershed number of large granite bosses found occasionally on the highest parts of the dividing the Swan-Avon Basin from palaeodrainage heading east towards the divides, or more commonly on the valley slopes. These bosses tend to be con- Tertiary sea (Fig. 12; Beard 1973) and lies about 410 m above sea-level. Out-

52 53 / VEGETATION SURVEY SWAN crop of banded ironstones has created four prominent hills distributed along 5.5 The Lake Hope Uplands the western margin of the Forrestania belt, Mt Holland (450m), North Iron­ This unit lies inland of the Truslove Plateau and slopes northward to em­ cap Hill, Middle lroncap and South Ironcap. The strike is due south from Mt ~race the Johnston Lakes system, of which Lake Hope is a part. The country Holland to Middle lroncap, thence southeast. Otherwise the Forrestania belt is hes 250 to 3501:1 above sea-level. Relief is subdued without granite outcrops, mostly a high plain co-extensive with adjacent granitic sandplains without exce~t for the isolated group of Fitzgerald Peaks, which are exceptionally change of level, though lacking the superficial sandy deposits except over massive. The tallest, Peak Charles, rises to 658 m and is the greatest granite patches of included granite. It forms a flat and featureless tract of country rock ~n the state. Sand soils with ironstone gravels (Uc4.11 or Uc2.12) occur on without defined drainage lines but with numerous small salt lakes and pans the highest ground, mallee soils on the slopes. These form a distinct group with (Lake Cronin, which is fresh, is a former mine dam). The only exception isin contrasting texture profiles, having loam or sand overlying clay, and are alka­ the southeastern lobe of the belt, the Hatter's Hill area, which is hilly. line with acid clays at depths of 1.5-1.8 m. They are classed as sandy alkaline Chief soils are brown and grey-brown calcareous earths {Gel .12 and 1.22). yellow and yellow-mottled soils (Dy4.43, 4.83, 5.43 and 5.83) or hard ditto Salinity problems were encountered here in attempted agricultural develop­ (Dy2.43, 2.83, 3.43, 3.83). Grey-brown calcareous earths (Gcl.12 and 1.22) ment. occur only locally. Beard (1973b) described the transition to woodland mov­ 5.3 The Ongerup Plateau ing inland away from the coast. Patches of woodland appear initi;lly on calcareous soil and as this soil type spreads they become .larger until they The Chidnup Vegetation System (Beard 1980d) typifies this unit which coalesce. represents an eastward extension of the Darling Plateau and forms a watershed between the rejuvenated streams of the south coast and the disorganized 6 The Eyre Region drainage of the interior. Unlike the Darling Plateau, no rivers originating-in the interior cut across, though as noted by Beard (1972a, 1973) there are This extends along the south coast from the to the Bight, and shallow air gaps linking the Gairdner River with Lake Grace, the Fitzgerald is analogous to the Perth Region, comprising a coastal plain, a scarp of the with Lake Magenta and the Phillips with Lake King which may be fragments Western Shield and blocks of older rocks. of a drainage system in existence prior to the separation of Australia from Ant.arctica. 6.1 The Esperance Plains The surface of the watershed lies between 300 and 365 m above sea-level and The Esperance Plains are contiguous to the southern coast, and the principal forms a very gently undulating or almost level plain which tends to become features have been developed in relation to this coastline. The edge of the con­ waterlogged in winter and is dotted with numerous circular depressions con­ tinental shelf is only 30 km offshore at Bremer Bay. The coastline itself shows taining intermittent lakes or swamps. On the south side it has been dissected to evidence of uplift during the Tertiary, as there is a coastal strip mantled with varying degrees by the south coast rivers, while on the north side it merges into Tertiary sediments and other indications. The modern coastline is controlled in the gently undulating topography of the Hyden Plateau. the south from Cape Riche to Point Hood by a chain of large granite bosses-· Sandy alkaline yellow and yellow-mottled soils (Dy2.43, 4.43 and 5.43) are Mt George, Mt Belches, Mt Groper, Tooleburrup Hill and the Doubtful dominant, with some narrow ironstone gravel ridges and grey clay subsoils in Islands-some of which rise to over 150m above sea-level. These are respon­ gilgai areas. Acidic clayey materials are common at depths of about 1 m. The sible for the numerous bays-Cheyne Bay, Dillon Bay, Bremer Bay-and sandy nature of the surface horizon shows an increase from west to east. headlands-Cape Riche, Groper Bluff, Cape Knob, Point Henry and Point Hood. Inland of these features is a flat and monotonous coastal plain which 5.4 The Truslove Plateau rises gently inland from sea-level at the coastline to about 100 m and is formed This unit continues the line of the Ongerup Plateau but is lower, about on the Tertiary sediments of the Plantagenet Group, which are sands and silt­ 180 m, and in the same way divides the south coast drainage from the interior. stones now generally referred to Upper Eocene age (Cockbain 1968). The sea­ It forms a flat to gently undulating plain, which is winter-wet and has a gilgai ward margin of the plain is much mantled with Quaternary drift sands, some surface. Lack of relief is attributed to marine transgression during the Eocene consolidated, some still in movement. The surface of the plain is marked by period (Morgan & Peers 1973). On the south side, rivers have dissected this numerous small, often circular depressions, which fill with water and become prior land surface since the mid-Tertiary, creating tracts of broken country swamps in winter. The rivers, the Pallinup and its tributary the Corackerup which expose granite or migmatite. Creek, the Bremer River and the Gairdner River, have cut deep and steep-sided Soils are essentially the same as for the Ongerup Plateau. . _ trenches into this plain.

54 55 VEGETATION SURVEY SWAN The plain continues to the east inland of the Barren Ranges at the same 90-m Albany to Borden, and Red Gum Pass between Donnelly Peak and Mon­ level as their platform (see 6.4 below), deeply entrenched by the Fitzgerald and durup. In the Stirling Range there are steep to precipitous slopes, bare rock Hamersley Rivers. Once the Barrens are passed, beyond the Phillips River, the walls of quartzites, and gentler hilly ridges; chief soils seem to be shallow plains slope gently up from the shore, where there is a narrow band of dunes, sandy soils (Uc4.11 ). lakes and inlets built upon a platform slightly above present sea-level and 6.4 The Barren Ranges probably of Recent age. Rivers descending from the Truslove Plateau have cut deep steep-sided valleys in the plain, a development considered by Morgan and Northeast of the Gairdner River mouth the structure of the coast is con­ Peers (1973) to have taken place during Quaternary low sea-levels. trolled by the outcrop of hard massive Proterozoic quartzites, which form a Chief soils are sandy neutral yellow-mottled soils (Dy5.82) containing vari­ platform up to 20 km in width from the coast with a general surface 90 m able amounts of ironstone gravel in the surface sand, alternating with leached above sea-level. The platform stretches from the Gairdner River to the Phillips sands (Uc2.21 and 2.22), which sometimes contain ironstone gravel, and are River: intermediate rivers are deeply entrenched into it, forming quite im­ underlain by a clay substrate at depths of 90-150cm. Valleys incised into the pressive canyons in places, e.g. Echo Glen on the Fitzgerald. From the plat­ Esperance Plains, with a mallee vegetation, have hard alkaline and neutral form rise small abrupt mountains formed by the harder and more resistant yellow-mottled soils (Dy3.43 and Dy3.82). members of the quartzites. Known in general as the Barren Ranges from the name aptly conferred by Flinders and referring to their bare appearance, these 6.2 The Jerramungup Slopes are in three groups: the West Mt Barren group between the Gairdner and the Fitzgerald comprises· West Mt Barren (371 m), Mt Bland (329 m) and the low This unit comprises the seaward slope falling from the Ongerup Plateau to stump of Mt Maxwell; the middle group between the Fitzgerald and the the Esperance Plains. It consists of a long gentle slope rising from the edge of Hamersley comprises Mid Mt Barren (457 m), the Thumb Peak range (about the coastal plain at about the 100-m contour, incised by the Phillips, West, 450m), the Whoogarup Range (about 410m) and the off-lying Mt Drummond Hamersley, Fitzgerald and Gairdner Rivers, and underlain by Precambrian (309 m). The eastern group between the Hamersley and the Phillips comprises rocks. It is analogous to the Darling Scarp, but has a much more gentle slope. the Eyre Range with Annie Peak (about 450 m), No Tree Hill and East Mt Bar­ As in the Darling Scarp the shallow skeletal soils are much influenced by litho­ ren (about 275 m). logical changes in the country rock which are reflected in the vegetation The 90-m high platform fronting onto the sea, with the mountains rising (Williams 1932, Beard 1967). behind, creates one of the most_ striking stretches of coastline in the south of As mapped by Northcote et al. (1967), chief soils are considered to be hard the state. ,- neutral yellow-mottled soils (Dy3.82) locally containing ironstone gravels. Soils are shallow, skeletal, and as described for the Stirling Range.

6.3 The Stirlin,g"Range 6.5 The Ravensthorpe Hills The range extends east to west for 60 km, and contains Bluff Knoll (1074 m), The Ravensthorpe unit is a greenstone belt. Topographically it consists of the highest eminence in the southern half of the state. In keeping with its image the Ravensthorpe Range stretching southeast from Mt Short to Mt Benson, Mt as a relict geological outcrop of immense age the range consists of a series of Desmond (which is lower), and adjacent plains and undulating -country on isolated high and precipitous peaks or groups of peaks rather than a continu­ Archaean diorite and Proterozoic metamorphic rocks which have been ous chain. The formation begins in the isolated Warriup Hill (400m) 15 km stripped of sand and_ laterite. No heights are given on the topographic west of Cranhrook, continues through Sukey Hill and Hamilla Hill to Don­ 1 : 250 000 sheet. From aneroid readings Ravensthorpe township appears to lie nelly Peak (650 m), where the. range proper begins, thence through Mondurup at about 260 m above sea-level, and the Ravensthorpe Range has been esti­ (817m) to Talyuberlup (784m) with its adjacent Gog (625m) and Magog mated (Thom, Lipple & Sanders 1977) to reach about 400m. The hills are of (857 m) and Toll Peak (735 m). Finally the eastern part of the Range is more no great relief and of subdued outline. Mt Desmond is an elongated whaleback continuous, and ·stretches from Yungermere (753 m) through Mt Success ridge. The Ravensthorpe Range has shallow calcareous loamy soils (Um5.11) (750m), Bluff Knoll (1074m) and Isongerup (994m) to terminate abruptly at on the greenstone hills, with cracking clays (Ug5.37 and Ug5.2) on the more Ellen Peak (1012m). The peaks become steadily higher towards the east and at moderate slopes and surrounding plains. the same time more jagged and angular, with exposed cliffs and rock faces replacing rounded outlines. 7. Coolgardie Region Deep gaps between the peaks have been used as passes such as Chester Pass between Toolbrunup and Yungermere, which carries the main road from This region has close silnilarities to the Avon Region, being developed on

56 57 ! / I i i SWAN VEGETATION SURVEY the granites and greenstones of the Western Shield, but lying further into the of Bullfinch, Southern Cross and Marvel Loch. Tracts of low rounded hills interior it has a higher topographic position and a much higher proportion of reaching about 400 m alternate with plains of heavy loam soil. The highest residual sandplains. Greenstone belts are more numerous and extensive, form­ elevation appears to be at South Mt Rankin, 463 m. The unit is devoid of sand­ ing four of the physiographic units. plains except for patches in the vicinity of the Parker Range; these patches may overlie included granite or quartzites. 7 .1 The Boorabbin Plateau The Westonia and Holleton belts consist of low hills, mostly with deep soils and an absence of laterite and sand. These are small outlying sections which The Boorabbin Plateau comprises the granite country of the region, and like form enclaves in the Yilgarn Plateau unit to the west. the Yilgarn Plateau is topographically monotonous, gently undulating with a In the more hilly parts there are calcareous loams overlying rock at shallow repetitive succession of salt flats, broad valleys and broad interfluves covered depth, and brown calcareous earths (Gcl.12 and 1.22) on the slopes and with laterite and sand. It is usual in this unit for the boundary between upland plains. Neutral red earths (Gn2.12) are found on some of the more deeply and valley to be marked by a distinct breakaway of massive laterite about weathered low plains. 1.5 m high. Additional topographic relief is contributed by granite bosses, which are common, but normally protrude little from the general surface. The 7.4 The Bremer Range general level is given by the heights of stations along the Eastern Goldfields Railway, which undulate, gradually rising from 353 m at Southern Cross to Another greenstone belt trending NNW-SSE, the Bremer Range, is a chain 424m at Coolgardie, with a maximum of 516m. Amplitude of the larrdscape of small rounded rocky hills with broad alluvial areas at their foot. Relative does not exceed 90 m, and slopes are gentle, rising about 4 m per km. Fig. 11 elevation in the Range does not exceed 90 m. The principal summits are Round shows that the unit straddles a principal watershed dividing the Swan-Avon Top Hill, Maggie Hays Hill, Mt Gordon and Mt Glasse, but no heights are Basin from country draining towards the east. In the northern part of the given on maps. The Johnston Lakes, extensive playas, lie on either side of the Boorabbin unit sandplains are very extensive and the valleys relatively narrow, range, and it is evident that drainage at one time passed through from south­ but in the southeast the country is more dissected and sandplains are reduced. west to northeast by one or more gaps. There are some large playa lakes in this section. Soils are essentially the same as in the Parker Hills. The landscape has a well-marked catenary pattern which is physiographi­ cally similar to that on the Yilgarn Plateau (Fig. 30), but the soils are different 7 ,5 The Coolgardie Plains and Hills due to the lower rainfall. On the sandplains the yellow earthy sands (Uc5.22) The very extensive greenstone belt which is the heart of the Eastern Gold­ predominate over sandy yellow earths (Gn2.21 and 2.22). Ironstone gravels fields forms this unit. It is a:n area of low hills and broad valleys leading to salt (KS-Uc4.ll) tend to be exposed by erosion at the edges of the sandplain. lakes. The highest elevation is probably at Mt Burges north of Coolgardie, Valley soils are typically brown and grey-brown calcareous earths (Gcl.12 and which is 552 m. There are other occasional hills and elongate ridges. The coun­ 1.22), associated with crusty loamy soils (Drl.43, 1.33 and 1.83) on the flatter try drains 10 a northeasterly direction, and is dissected by numerous flood ground, and there are saline soils in and around the playa lakes. channels which terminate in extensive salt flats containing playa lakes. There is an expressive physiographic map iri Kriewaldt 1967. The unit is devoid of 7 .2 The Bungalbin Ridges \ sandplains, except for small patches on included granites. This unit consists of a number of abrupt hills and elongated ridges occa­ The most typical soils of this unit are neutral red earths (Gn2.13) which sioned by the outcrop of banded ironstones, which stand out about 200 m occupy the plains. Calcareous loams (U m5 .11) and brown calcareous earths above the surrounding country, and are visible as landmarks for a long (Gcl.12 and 1.22) are found in the more hilly portions, and saline soils in and · distance in the prevailing flatness. They include the Koolyanobbing Range around playa lakes. (max. 510m), the Mt Jackson-Bungalbin ridges (607-680m), the Hunt Range, the Die Hardy Range (heights not known) and Mt Dimer (538 m). 8. Murchison Region Chief soils are said to be shallow loams (Um5.51). A small portion at the northeast extremity of the Swan sheet belongs to · 7 .3 The Parker Hills the extensive Murchison Region, developed further north, a wide pastoral An elongated greenstone belt forms this unit, running SSE from the Woon­ region with a vegetation of mulga typically on red-brown hardpan soils. garing Hills overlooking the Hamersley Lakes, through the Highclere Hills The portion here consists of low hills on both granite and greenstone and a and the Yilgarn Hills to the Parker Range. It includes~the mining settlements playa lake, Lake Goongarrie.

58 59

i I VEGETATION SURVEY SWAN FORMATION OF THE LANDSCAPE sions with certain amendments. Beard found that the Western Shield possessed The earliest event which can perhaps be identified as influencing the formation a self-contained drainage pattern, such as it could be expected to develop as a of the present landscape was the glaciation of the Early Permian period (250 peninsula of Antarctica in pre-Eocene time: a north-south central watershed million years ago), which gouged out the Collie coal basins and has left traces from which rivers flowed either east or west. The Canning and Officer Basins of glacial deposits in many parts of the state. If the Western Shield was possessed independent drainage of their own, such as could be expected to covered by a continental ice sheet at that time, it is likely that it left the country develop following their uplift from the sea at the close of the Cretaceous. The in the condition that we see today in Finland and Labrador, both recently inference was that drainage patterns on the Western Shield became established glaciated areas of Precambrian rocks. Relief is very subdued, a mass of bosses during Mesozoic time, a conclusion voiced simultaneously by Johnstone, and hollows with a pattern imposed by the direction of ice movement, so that Lowry and Quilty (1973) on stratigraphic evidence. Van der Graaf et al (1977) there may be strings of long narrow lakes. It is possible that Permian glaci­ concurred; adding that none of these patterns changed much after the late ation imposed the predominantly north-south trend of the uppermost valleys Eocene (40m.y. BP). of rivers and palaeorivers on the Western Shield (Fig. 12, and map in Beard The impression of the immense age of the Western Australian landscape in 1973c). It is a curious fact that this trend is apparent, when the middle and the interior, the 'ageless and undateable oldland' of Hills (1961), is thus sus­ lower courses head east and west. The suggestion that it follows the strike of tained. As Mulcahy (1967) wrote: the rocksis not sustainable, since the strike is NNW-SSE and palaeodrainage Here, east of the Meckering Line, is a landscape which is undoubtedly ancient and for example in the ParkerHills physiographic unit can be seen to trans~t the extenstvely preserved, in the sense that it has been tectonically stable for a long period, strike. Other cases of drainage coincident with Permian glacial valleys were its river systems have not been rejuvenated, and it has not been affected by the Pleisto­ cited by Van der Graaf et al. (1977). .cene glaciations. During the long Mesozoic period, 225 to 64 m.y. BP, the Western Shield was above the sea and subject to erosion, whereas the sedimentary basins flanking Fig. 12 (p. 41) shows the reconstructed drainage pattern of the Swan area. it, the Perth and Carnarvon Basins on the west and the Canning and Officer At one time the Swan River was a mighty stream with a basin larger .than that Basins on the east were at least intermittently submerged and received sedi­ of the Murchison, its tributaries reaching back to the main watershed. Head­ ments. The to the southeast began to subside in the Early Creta­ water trends are north-south but main channels head west. East of the main ceous. In the Perth Basin enormous thicknesses of fluvial and estuarine sedi­ watershed, headwater trends are northeast towards the Mesozoic sea in the ments were accumulated, locally up to 6000 m for the Jurassic and Early Officer Basin. Rivers to the south coast are all short. This is because Australia Cretaceous, and a further 200 m for the Middle Cretaceous (Quilty 197 5). It is was joined to Antarctica alopg the south coast until a final rupture in mid­ inferred therefore that the climate was humid and that rivers were active upon Eocene time, ± 45 m.y. BP (Griffiths 1971). The separation appears to have the continental surface .. been accompanied by a downwarping of the coastline and a marine trans­ On the western coast of the state at the present day there are active rivers, f.') gression, during which Upper Eocene sediments were deposited (Morgan & the Ashburton, the and the Murchison in the subtropical zone, Peers 1973). Today's south coast rivers can only have developed after with­ where summer storms cause flash flood run-off of considerable erosive power. drawal of the Eocene sea or possibly a later Miocene transgression. The onset The upper courses of these rivers reach back about half way across the of aridity then reduced their erosive potential. Western Shield. South of the Murchison River, as the zone of light winter rains Events along the west coast went differently, as there were already substan­ is entered, the rivers become short, draining only a relatively narrow belt, and tial rivers flowing into the Perth Basin. At the close of the Cretaceous period this is also the situation along the south coast. The whole of the rest of the the shoreline apparently lay close to the line of the Darling Fault, the Perth state outside the Kimberley and the has no rivers, only ill-defined Basin under water, and the continental platform lying with its edge close to ephemeral channels emptying into salt lakes. It was gradually realized that sea-level, sloping up gently into the interior. Its topography would have these lay along interconnected valleys, and-in 1909 Gibson first suggested that resembled that prevailing today east of the Meckering Line (Mulcahy & Bet­ former complete river systems could be traced. Although this was not accepted tenay 1971). Then during the Tertiary the whole landmass, except at first for by many for a long time, as mapping techniques and facilities improved, at­ the Eucla Basin, was progressively uplifted to its present height. Uplift was tempts were made to reconstruct the courses of former rivers which flowed and probably episodic, and did not involve differential movement ·along the Dar­ shaped the landscape in earlier more humid times and ceased to flow regularly ling Fault, which had become inactive. Morgan and Peers (1973) identified at when the Australian climate changed from humid to arid (Ivlulcahy & Bettenay least five benches on the monadnock bedrock hills of the Esperance area at 1972). The first complete reconstruction for Western Australia was that of ·. elevations between sea-level and 240 m interpreted as the result of sea-level Beard (1973c). Later van der Graaf et al. (1977) confirmed his general conclu- changes. One of them corresponds to the 90-m platform of the Barren Ranges. // 60 61

.I 1, i"· VEGETATION SURVEY I SWAN !· The Cretaceous and Jurassic sediments of the Perth Basin were simultane­ i slowed due to reduction of grade and the formation of a dense vegetative ' ously uplifted at this time, and in the north formed a plain continuous with f cover. Climate was warm, warmer than today, and the rainfall high even far that of the .interior. In the south a plain now represented by the Blackwood into the interior (Kemp 1978). It is also likely that the climate was essentially Plateau formed at a lower level. McArthur and Bettenay (1960) pointed out non-seasonal as suggested by Carey (1976). For a picture of the landscape as it that the southern end of the Dandaragan Plateau, the Ridge Hill Shelf and the was then we should look at the of today, a Blackwood Plateau are parts of a continuous surface sloping down gently region of generally low relief drained by broad sluggish meandering rivers and southward relative to the surface of the Darling Plateau, which is thought due covered by dense tropical jungle. Under these conditions a process of deep to incomplete filling of the Perth Basin by sediments before uplift (E. Bet­ weathering of the surface rocks set in, from which only the hardest and most tenay, pers. comm.). Whatever the explanation, the rivers draining the Darling resistant were immune. The effects of this deep weathering are still to be seen Plateau had to find new outlets to the sea further west. A river which had an all over the state, on igneous and sedimentary rocks alike, and may extend to extensive basin at that time stretching from Mt Magnet to Carnamah, where it depths of 60m. On granite and gneiss the weathering gives rise to a white, entered the sea, took a new course following the line of the Darling Fault to the kaolinitic 'pallid zone' (Walther 1915), which has lost iron, aluminium, com­ south for 110 km to Moora, where it joined the ancestral Moore River. The bined silica and bases. The pallid zone may be capped by a lateritic duricrust. combined stream then continued south for a further 40 km to Mogumber, We know that deep weathering took place at least as early as the beginning of where it finally escaped to the west. The Hill River is a young river formed in the Tertiary, because Upper Eocene sediments have been found deposited the Perth Basin since uplift which has not cut back sufficiently to capture the upon 'a previously decomposed and highly weathered bedrock' (Morgan & older drainage, and is hence analogous to the young rivers of the south coast. Peers 1973). Further south, the Swan, Murray and Blackwood Rivers found new courses­ Whether the lateritic duricrusts were also formed at this time is a moot as we see the Blackwood today traversing the Blackwood Plateau-and were point. They are of exceptional abundance in southwestern Australia (Prescott rejuvenated, beginning to deepen their beds down to the new level. New inter­ & Pendleton 1952, Mulcahy 1967) and a striking component of landscapes on mediate streams, the Helena, Canning, Serpentine, Collie and othF.r rivers and the Western Shield, where they normally cap any of the higher ground. A great brooks came into being along the scarp and began to cut backward. Possibly many papers have been written on the subject and a variety of ages throughout the Murray River should be in this younger group, as it does not ~xtend the Tertiary and Quaternary attributed for their formation. Johnstone, Lowry beyond the Meckering Lirle. Progressive uplift and the lowering of the level in and Quilty ( 1973) in a brief review cited stratigraphic evidence that in eastern the Perth Basin by marine erosion contributed to make this rejuvenation of the arid areas the laterite is Oligocene to Miocene in age. This represented in their rivers an on-going process until the present day, when its effect has progressed view the major period of general lateritization. Since the middle Miocene it has as far as the Meckering Line. No doubt there were adjustments and diversions occurred (presumably intermittently) only in coastal areas of the southwest by river capture. It is believed that shallow flat-floored valleys at the highest that have a moderate and strongly seasonal rainfall. This chronology is in levels on the Darling Plateau may represent remnants of the old drainage keeping with that worked out in Southern Africa (King 1972). system now preserved only in the interior, and it has been suggested that the These conclusions are in keeping with the latest evidence on climatic change ancestral Avon flowed through the valley containing the Darkin Swamp to during the Tertiary (Kemp 1978). A general cooling during the Eocene was descend along the present course of the Helena (Mulcahy, Church ward & Dim­ followed by a dramatic drop in early Oligocene, a levelling off until mid­ mock 1972). Miocene, and then a steady fall until the present day. These temperature move­ The owes its development to exploitation of the more easily ments were probably paralleled by the trend to greater seasonality in which erodible Chittering Metamorphic Belt (Wilde & Low 1978). The diversion of case the Eocene would largely have been uniformly humid, the Oligocene to the Avon to its present course is similarly attributable to exploitation of the mid-Miocene humid but seasonal, and the post-Miocene dry and seasonal. JimperdingMetamorphic Belt. Since seasonal alternation of wet and dry periods is usually postulated for It is curious that the Darling Plateau, while dissected by a close intricate lateritization, the Oligocene and Early Miocene would have been favourable to drainage system, has retained greater elevation and greater relief than country the process which would thus have been subsequent to the principal period of immediately to the east. King (1962) suggested that there might have been a deep weathering. marginal upwarping of the western edge of the shield along the Darling Fault. Fig. 13 reproduces a diagram from Bettenay and Hingston 1964, showing a The fact that the heights of the monadnocks on the range are not equalled by typical landscape section on the Yilgarn Plateau. Pallid zone underlies both any others within 400 km to the eastward, may support this,suggestion. the valley floors and the uplands. Laterites and laterite-derived materials occur On the interior plateau it was climate 1;ich played a dominant role in the chiefly on the uplands, while the valleys contain alluvial and colluvial detritus shaping of the landscape. At some stage \uring the later Mesozoic, erosion overlying the pallid zone, as well as aeolian deposits in lunettes, sand sheets

62 63 VEGETATION SURVEY SWAN

Old plateau lnterfluve Pediment ! Pedi- Aeolian Valley Floor Deposits

Beginning of new plateau ELEVATION DIFFERENCE BETWEEN PLAYA LAKE AND INTERFLUVE APPROX. 300 FT I Present-day Land Surface - Eroded Tertiary Land Surface--- Old I plateau

~ ~ 1..-...1 ~ ~ ~ ['.;,Y:/fj Yellow Durie rust Deep Tertiary Colluvlal.. Riverine Aeolian Sands Weathering Rock Sediments Sediments Deposits ll:2Slllt~~t..,.i_I_.4,..,J""7'.r'r,I'7/f"'T"T7f'T;znl'7'[7';1l'7'7":I;'r7f7"tr,r>7,~ Fig. 13 Diagrammatic cross-section of landscape on the Yilgarn Plateau, showing principal features and modifications (after Bettenay & Hingston 1964). --·

and parna. Since the landscape entered its dry, seasonal phase (after the mid­ Miocene ), the process has been one of relevelling by decay. Since the rivers ceased to flow, products of erosion could no longer be transported out of the area and were distributed instead on the valley floors and lower slopes. Where a thick laterite capping existed on the uplands, it formed a breakaway often with a steep pediment below it. These are in gradual retreat, yielding material for transport downslope, while the sandplains above are little subject to erosion, only to reworking. The presence of deep weathering beneath both valleys and uplands shows that it is correct to say that the landscape has been substantially unmodified ------since the Eocene. It effectively contradicts Jutson's (1914, 1934) theory of the

Old and New Plateaux, which commanded support for so long, and which still Old plateau entirely removed today is often quoted. Scientific opinion has gradually shifted its standpoint on the issue (Mulcahy 1967, Mulcahy & Bettenay 1971), but no one has said in sci many words that the Old and New Plateaux are a myth, though the latter authors can be said to have implied it. New plateau Jutson's theory is illustrated by his own diagram, reproduced in Fig. 14. A Fig. 14 Diagrammatic cross-sections illustrating Jutson's theory of the peneplain surface is envisaged as having been formed at some remote date, Old and New Plateaux. From Jutson 1934, p. 97. conceived essentially as being flat, and capped by laterite. The stippled areas in the diagram presumably represent pallid zone. Later the laterite is breached, material eroded to expose the New Plateau level, extensive as it is, have been breakaways recede with erosion of the pallid zone beneath, and a new level removed from the Western Shield? It is not in accord with known climatic eventually takes shape. If this view were correct ,the New Plateau would be history to suppose that this could have happened. Also some form of inte­ covered by young soils developed on bedrock, as is actually the case on the grated drainage is necessary to develop the chemically depleted lateritic pallid Mitchell Plateau in the north Kimberley, where the very,process illustrated by zones. Jutson can be seen in operation (Beard 1976h); but it d<'.l'es not apply here It must be evident that a gently undulating landscape of low relief was where the ~ys are underlain by pallid zone. There are other objections. If . originally shaped by rivers, it became deeply weathered and lateritic duricrusts the Old Plateau had been continuous, how and when could the vast mass of were formed. Latterly it became subject to levelling by arid erosion with trans- 64 65 VEGETATION SURVEY SWAN port of material from upland to valley. Part of this process is the formation was the series of glacial periods or ice ages during the Quaternary, the last of and retreat of breakaways, creating a misleading impression of the progressive which ended about 12000 years ago. While Western Australia was not actually removal of one section of the landscape. The 'New Plateau' was always there glaciated during these periods, there were phases of severe aridity when the in the valleys, the 'Old Plateau' in the uplands, and there was a gentle slope climate was apparently much drier and more windy than now, giving rise to between them. Latter-day processes have inserted a scarp and pediment in the numerous aeolian features-discussed by Bettenay (1962) and Beard (1980g). former gentle slope, that is all. The most important of these include: The sandplains consist of deep, generally yellowish sandy materials, origi­ nally thought to be fossil soils in situ (Prescott 1931) which had suffered the Linear sand ridges, · It is seldom possible to recognize dune formations on minimum of denudation, but now considered to be deposits originating from the upland interior sandplains, but there are substantial occurrences on the the weathering of Iaterite and subsequent colluvial transport downslope Esperance 'Plains east of Esperance itself (Beard 1980g; mapped by Morgan (Brewer & Bettenay 1973). They may overlie unweathered rock, pallid rock or and Pears 1973). Lineation of Recent coastal dunes north of Perth is north­ ironstone gravels. Mulcahy (1967) believed that the Tertiary laterite on the south in accord with present strong wind directions, but at variance from that divides had been largely destroyed and that there has been a general lowering inferred for the last arid phase .. of the surface with the subsequent reworking of the sands. Sand sheets. Sheets of yellow sand frequently occur in valley bottoms, and Laterites west of the Meckering Line and in the Darling Range have been appear to have been redistributed by wind from an adjacent source such as a discussed already under Physiography. Yet another different situation plevails river-bed or lake (R. Smith 1951, Northcote et al. 1967). Some of the largest on the Dandaragan and Blackwood Plateaux, and on the Esperance Plains. show dune patterns, and were mapped and reported by Beard (1979d, 1980d) The former are stable peneplain surfaces which were formed in Eocene time along the Beaufort, Gordon and Pallinup Rivers. The largest such deposit of and appear to carry lateritic profiles in situ. The Esperance Plains are younger, all believed by Beard (1979a) to be an aeolian sand sheet mantles the country in probably post mid-Miocene (Morgan & Peers 1973). The soils show strong the Moora district from Marchagee and Gunyidi almost to Dalwallinu. The pedological development but formation of ironstone gravel is relatively weak. sheet is 60 km long and up to 20 km wide. The sand source is in a depression The Swan Coastal Plain is Pleistocene to Recent in age-it has been largely south of the Yarra Yarra Lakes. All of the principal sand sheets show a direc­ described in previous sectioqs. The Pinjarra Plain is the oldest unit, and ranges tion of movement to the ESE. up to 160m above sea-level. It is believed to be early Pleistocene or late Ter­ tiary in age. The Bassendean Dunes, which are probably early to middle Lunettes. Lunettes (Hills l940j are crescent-shaped dunes bordering small Pleistocene, were deposited upon the Pinjarra Plain. The present shape of the lakes and swamps. Stephens and Crocker (1946) found that they occur dunes may be largely inherited from that of the original coastal dunes, but the throughout the southern half of Australia on the east to southeast side of relief has been much diminished as a result of leaching. The Spearwood Dunes lakes, and may be formed of a wide range of materials. They are considered to (late Pleistocene) are still younger and only superficially leached, the body of be relics of the last arid, windy climatic phase. Bettenay (1962) studied them on the dunes being lithified so that relief has been preserved. The contact between the Yilgarn Plateau and found that in addition to such lunettes, now stabil­ overlying sand and unleached limestone is irregular, with rounded pinnacles of ized, there tended to be more recent ltinettes of gypseous material adjacent to limestone extending upwards into the sand. In some places where vegetation salt lakes still in process of accumulation. Sheets of this material called lake has been removed, the sand has been blown away, exposing the pinnacles and parna could also cover valley floors beyond the principal lunette. Bettenay smaller calcified root channels. This can result in a spectacular landscape such indicated that lunettes only occurred above the Meckering Line, although an as at the Pinnacles and the Tombstone Rocks near Cervantes, for which a occurrence at Lake Muir had been mentioned by Stephens and Crocker. Beard national park has been created. The idea that the Pinnacles are the petrified (1979d, 1980g) showed that lunettes are normally associated with all the stumps of tuart trees, while widely believed, is a fairy tale put about by tourist numerous small lakes and swamps in the Mt Barker district, where annual companies. In fact the cylindrical columns of limestone represent strongly rainfall today reaches 900 mm. · lithified fillings of solution pipes which formed in the aeolianite during an These aeolian evidences of aridity bring the effects of the last severe arid earlier erosion cycle. The surrounding softer aeoliariite was decalcified leaving phase well down into the lower southwest. Only the extreme southwestern tip a residue of sand. In recent times, a younger mobile dune1f the Recent cycle of the continent, enlarged perhaps 50 km offshore by falling sea-level, seems to moved nort~rds across the area, destroying the vegetat~n, and when it have escaped the rigours of desert conditions. Southwestern Australia, passed, all the sanp cover departed with it, exposing the underlying pinnacles through time, has undergone many vicissitudes: from being Labrador in the (Lowry 1974, Playford, Cockbain & Low 1976). Permian it became the Amazon in the Cretaceous and then the Sahara in the The latest series of events to leave a substantial imprint upo-\1 the landscape sub-Recent I

66 67 - VEGETATION SURVEY SWAN HUMAN INFLUENCES cally in sections, usually in middle to late summer, and while it had the PRE-SETTLEMENT (1829) primary objective of serving to hunt game, it also served to bring on fresh young herbaceous growth in the ensuing rains, which attracted more game Aboriginal man was present in southwestern A . t from outside and encouraged it to proliferate, after which it could be again (Merrilees et al. 1973) During that 1. h US raha for at least 25 000 years . ime e made regular use ff t h . hunted by fire-drives; and the process repeated. The burning naturally took and other purposes, and it is only likel th . . . o ire or unting tion were induced. Y at mod1f1cat1ons to natural vegeta- place principally in localities which responded best to this treatment and which then came to support relatively high Aboriginal populations. The constant A careful study of the burning of the I ds . . - corning of Europeans was made b M Sa~ cape by Abongmes prior to the burning would have the effect of thinning out the tree covet by reducing observations of early residents of lib rs · · ~allam (1975), who quoted the regeneration. Areas likely to be most favourable would be relatively fertile medical officer to . the initial settl any• particu_Iarly o_f Scott Nind, who was young alluvial and bedrock soils with a minimum of sclerophyll understory. showed that b · ~ment eS!abhshed m 1827. Nind (1831) The woodland on the alluvial terraces of the Swan River appears from early . urnmg was not an accidental or incid t I . . accounts to have been thinned out in this way and to have had a soft grassy _ gmes but was closely meshed into th . _en a actiVIty of the Abori­ tions demonstrate. e1r pattern of life, as the following quota- and herbaceous ground layer. The York gum woodlands in t~e Avon valley, further inland were described by the pioneers as thickly populated, grassy and open. Evidently the Victoria Plains were also of this character when At King George's Sound they live upon the production . -- seasons and in different districts Th I . . s of nature, varymg at different discovered, and it would appear that the Aborigines' burning had reduced the · · • e popu ation 1s far f A s t h e country does not abound i'n f d h . . . rom numerous. tree cover. It seems probable that York gum and yate woodlands in the inner • • 00 , t ey are seldom stati • mg to the time of year to those part h" h d . onary, removmg accord- wheatbelt may have constituted the prime habitat for Aborigines in the south­ be in season ... During the winter a~d:a1~ pr~ uce the articles of provision that may west. Occurring as they do on lower slopes and river flats, they would be near summer advances they assembl . r y sprmg they are very much scattered· but as em greater numbers ' water, and the soils would best respond. to burning for the production of About Christmas they commence firing the countr. . herbage. Such woodlands would have been in a particularly open condition at procure the greatest abundance of game b ! fo~ game ... At this season they the time of settlement, and it would appear that they remained in this condi­ which, being dry, is rapidly ·11urnt \~e~ng fire to the underwood and grass W'~h tion at the time of Diels' visit in 1901 as he classed country of the grass tree they set fire to the sid. . f ~h a m of torch made of the dry of Eucalyptus loxo­ The hunters concealed stand in the es oth e cover by which the game is enclosed ... phleba and E. occidentalis as 'Savannen-Wald' (savanna forest). Gardner facility spear them as they pass b Opa tbs most fre~uented by the animals and with (1942) continued this description.fa the· form savanna woodland, and it has d t d . - y. n ese occasions vast n mb f • survived down to the present time, appearing on the frontispiece map in es roye . The violence of the f"Ire 1s• f requent1 y very t d u ers o ammals are of country; but this is generally guarded . b gr~ -an extends over many miles Hallam (1975). It is interesting that very few uncleared stands of E. loxophleba tions. [Nind 1831] agamSl Y thelf burning it in consecutive por- (York gum) still survive in the wheatbelt, apart from scattered trees left in pad­ docks, but where they do, they would not now be described as savanna wood­ This. account of 'controlled burning-off' was confirmed . land. Trees are more closely spaced and the ground layer is fairly sparse. Have Stokes m describing a sally northwards f Alb . by Lieut. J. L. such stands reverted to woodland since cessation of burning? a visit by H.M.S. Beagle. rom any m November 1940 during On the flats along the Swan River very little of the original vegetation now remains, but its character may be reconstructed from relict trees and early On ~ur way we met a party of natives enga ed in b . . accounts such as that of Charles Fraser (1830). If we interpret Fraser's obser­ sectmns every year. The dexterity with h" : h urmng the bush, :,vh1ch they do in vations in terms of current nomenclature, he found the lower flats of brown agent as fire is indeed astonishing. Thos: t: w~oey m~nage s? prove~b1ally a dangerous loam 'thinly studded with gigantic blue gums' (), and the who guide or stop the running fl - m_ this duty is especially entrusted, and 't . ame, are armed with large green b hs . higher ground which had a red soil 'covered with magnificent Angophoras I moves m a wrong direction th b t ·t - . oug • with which if conflagrations seems to be the' d eyt eat_. I ouf t. Their only object in these periodical [E. calophy/la], Zamias [Macrozamia] and Xanthorrhoea'. We are also able to k es rue mn o the various ,_ r angaroos, called wallaby which with shouts and II snan:es, izards, a~d small recognize samphire marsh, bordered by Casuarina obesa, paperbark swamps to be despatched by the spears or th . . ye s they thus force fl:pm their cover and teatree thickets. 'Stringybark' (Eucalyptus marginata) was only found in 1846, II:228]; rowmg sticks of the hunting divis~ns. [Stoke; 'stripes of good forest land' extending out from the Darling Scarp, in which we may recognize the more sandy alluvial fans at the foot of the range. Early Accounts of early settlers at the S . . settlers at the Swan constantly referred to the open, parklike appearance of the that the same burning pra t -~ wan are Jes~ exphc1t, but leave no doubt country with scattered trees and the grassy ground layer (cited by Hallam c ices were used. Burmng was often done systemati- 1975). Fraser referred to this as 'The Brome, or Kangaroo-grass of New South 68 . 69 / VEGETATION SURVEY SWAN Wales in great luxuriance', but the identity of this is now a mystery, as there in the interior for want of early accounts. The explorers Landor and Lefroy, seems to be no indigenous grass in Western Australia fitting the description. It on the discovery of Lake Dumbleyung on January 17, 1843 recorded that 'On is an equal botanical mystery to try to identify the plants growing in the 'beau­ the northern and eastern shores, there is good grazing country down to the tiful open grassy country' so often alluded to by pioneers. There are very few lake, ending in precipitous banks, and extending over the hills two or three native grasses in the southwest, and it seems unlikely that they actually formed miles distant from the lake.' However this is still York gum country of the grasslands. It is more probable that the settlers used the term 'grassy' in a loose inner wheatbelt. Woodlands of the outer wheatbelt have sparse understory and sense to mean young green herbage which could consist of annuals of all kinds, ground layers and are not subject to burning in normal circumstances. On the new shoots of perennials, sedges and Restionaceae as well as grasses. Diels other hand the shrublands of sandplains, and mallee, are highly inflammable (1906) in describing Eucalyptus loxophleba woodlands, which in his day were and their component taxa show so much adaptation to fire (Gardner 1957) that still plentiful, gave what is clearly a selective list of component taxa, many they must have been subject to burning since a remote period. mentioned only as to , with the indication that several species were repre­ Fires can be set by lightning which is common in the interior in summer, sented. With these limitations, we have a list comprising (number of taxa): though comparatively rare on the coast. They are not necessarily extinguished by rain, and once kindled in large expanses of inflammable vegetation may Trees 1; Small trees 3; Shrubs 9; Graminoids-grasses 1; Juncaceae 2; spread for long distances. Beard (1967b: Fig. 1 and Plate 1) showed burn Other monocots 7; Dicots-herbaceous perennials 8; Composites 16; patterns in aerial photography of a study area in the Ravensthorpe mallee, Other annuals 3: Mosses 2. -- whic4_ could only be attributed to lightning strikes. Unfortunately it is impos­ The list is obviously selective as there are no Cyperaceae or Restionaceae, sible to distinguish between the effects of natural fires and those lit by Abori­ both of which should be represented according to present-day observation. It gines. is significant however that there is only one grass listed. The. best evidence for the long-term effects of fire on vegetation is obtained On the other hand it seems that the jarrah forests in Aboriginal times were from the_ offshore islands: Rottnest and Garden Islands offFremantle, (Mc­ relatively empty of both animal and human populations, burnt only in odd Arthur 1957, Storr, Green and Churchill 1959, Storr 1963, Baird 1958), Bald patches, certainly not frequently. This made the forests difficult to traverse. In Island near Albany (Storr 1965) and the Recherche Archipelago near Esper­ 1839 Sir George Grey crossed the Darling Range working westerly from ance (Willis 1953), which have received detailed study by the authors cited. Williams, and left this description (Grey 1841, quoted by Hallam 1975): Aborigines in the southwest did not have the use of canoes and had therefore had no access to these islands,,since they became separated from the mainland an elevated tableland of ironstone and granite [with] little or no herbage; the lower by rising sea.;.level about 5000 years ago (Churchill 1959). At the time of settle­ vegetation a short prickly scrub, in some places destroyed by native fires, but the whole ment no fire had occurred for a long but indeterminate period, judging from country was thickly clothed with mahogany [jarrah] trees, so that in many parts it the maturity of the vegetation. might be called a dense forest. These mahogany trees ascended, without a bend or Rottnest and Garden Islands are formed by the same coastal dune systems as throwing off a branch ... forty or fifty feet ... and the ground was so encumbered by occur on the- mainland. The principal vegetation is believed to have been low the fallen trunks of these forest trees that it was sometimes difficult to pick a passage forest of Callitris preissii on the dunes, and of Melaleuca lanceolata on low­ between them ... I have never seen so great a want of animal life ... we had in vain looked for natives. lying flats. At the time of its discovery by Vlamingh, Rottnest was reported to be well It is likely that the banksia woodlands of the Swan Coastal Plain were a wooded, with an unmistakable reference to the cypress pines (Callitris.) These similar inhospitable environment, not much occupied, and thus unmodified by also impressed the botanist Alan Cunningham in 1822, who reported Callitris Aborigines; but the tuart woodlands of the coastal limestone were most prob­ as generally dominant, and only occasionally replaced by Melaleuca and Pitto­ ably populated, especially owing the occurrence of numerous freshwater lakes. sporum; these three 'constituted the timber of the island' [Cunningham 1828]. The vegetation of the Recent Quindalup dune sands does not regenerate Callitris preissii has since disappeared in the wild on Rottnest, but still covers a rapidly after fire and there is evidence that most commµnities on the mainland large part of Garden Island. It is tender to fire, and only survives in a few represent seral stages. isolated patches on the dunes of the mainland. The principal substitution com­ Hallam (1975) believed, on relatively smaller evidence, thatth~ karri forests ·I munity, thicket, is one originally confined to small areas of were little frequented by Aborigines and thus not systematically'burnt. This adverse habitats (shallow soil, exposure) on the islands. may be so, but there can be little doubt that they were swept by fire at frequent I Bald Island is an isolated granite boss, cut off from the mainland by a chan­ intervals. I nel less than 2km wide and 32m deep. The island rises to 310m above sea­ ! It is much more difficult to determine the effects of Abori~;inal occupation level, but is largely capped by sand and calcarenite. Six communities were dis-

70 71 / VEGETATION SURVEY SWAN tinguished by Storr (1965) which are zoned according to altitude and soil, and islands is not strictly ecologically comparable with the sandplains of the main­ exposure to the prevailing southwest winds. All were apparently unaffected by land. An equivalent was studied in detail on coastal sands south of Albany by man and fire. They were listed as: Enright (1978), and was found to be different in composition from that on Bald Island and richer in species. Heaths described by Willis on Mondrain and 1. Succulent mat: confined to a narrow zone above high watermark. Sandy Hook Islands in the Recherche were floristically rich and suggestive of 2. Tussock-land: of Paa caespitosa and Scirpus nodosus, above the succu­ the heaths of the mainland, though the flora was significantly different. While lent mat, all round the island, but mainly on the exposed southwest side, numerous genera typical of the mainland heaths are represented, the Protea­ where it rises to the 120-m contour. ceae, dwarf and Amaryllidaceae, which dominate the latter and 3. Heath: a wind-pruned shrubbery along the exposed side. impress them with so much of their physiognomic character, are lacking or 4. Peppermint scrub: of Agonis flexuosa on sand over granite, on the almost so (Willis 1953). More information is required before conclusions can higher part of the island. be drawn in the matter of these heaths. 5. Bushy yate forest: low forest of on leeward slopes. The low forests of the islands are not represented on the mainland except by Callitris preissii occurs with it or forms pure stands on its own. Presum­ relict patches in the case of fire-tender species. The eucalypts, being fire-hardy, , ably the amount of calcarenite present determines this distribution but are present on the mainland in mallee form, so that mallee of Eucalyptus the point was not rnade by Storr. lehmannii and E. cornuta is commonly found on the granite bosses of Mt 6. Teatree forest: low forest of Melaleuca lanceolata on steep, calcl'f!'eous Manypeaks, opposite Bald Island (Beard 1979d), and those which dominate leeward slopes. the Esperance Plains (Beard 1973b). This prompts the suggestion that all mallee on the mainland may be a fire-climax and that the true climax would be The Recherche Islands have a similar structure, and are thus comparable low forest of the same species. A recent paper by Hopkins and Robinson (in with Bald Island, but with a wider range of habitats and thus of communities. press) on the effects of fire in mallee supports the same conclusion, Species of Eucalypt low forest of E. lehmannii and E. cornuta was considered the climax Eucalyptus forming part of the mosaic in the mallee region which occur on the by Willis (1953), changing to Melaleuca lanceolata and M. globifera on the less heavier clay soils (E. platypus, E. i:mnulata, E. spathulata, E. diptera, leached sands. Heath and thicket communities occur on steep exposed slopes E. forrestiana) regenerate from seed, not from the root stock, and form low or poor sandy plateaux. Variants of the smxulent mat are represented, but forest under present conditions (Beard 1967 b, 1973d). Further than this it is there are only very small patches of grassland. impossible to go at present. Almost ·au mainland communities are subject to When one goes ashore on these islands, there is an immediate impression of fires and most of them are periodically destroyed and regenerate after fires, or lushness, with relatively luxuriant vegetation growing in age-old accumula­ alternatively seedling regrowth only effectively appears from fires. In all these tions of humus, whereas on the mainland there is the usual impression of cases they must be in some way fire-modified. Since fire appears to be an ever­ barrenness and sterility. With time and freedom from fire for a long period, present ecological factor, it is perhaps pointless to enquire what the true climax island communities have built up to some degree to their potential climax. Un- . in the absence of fire would be. A fire-free situation may be unattainable in fortunately comparisons with the mainland are of limited value since the nature under the present climate and perhaps fire-tender climax species are not islands represent only a restricted range of mainland habitats, i.e. those of available in the area. In eastern Australia 'wet sclerophyll' forests physiog­ granite bosses and coastal dunes and limestone. Also precipitation may differ, nomically similar to the karri forests of the southwest have resulted from burn­ exposure to wind very likely does, and there is a factor of exposure to salt ing, and are subject to colonization by rainforest tree species. Western Aus­ spray to consider. Certain comparisons can however be made. tralia has none of these. The last relative, Podocarpus drouynianus, is a small The succulent mat is observable on mainland coasts, though less noticeably. undershrub. All the rest have been forced off the tip of the continent by The tussock land of Bald Island is apparently unique and attributable to the Pleistocene aridity. One of the determinants of vegetation is available source exposure factor. Agonisflexuosa dominates a range of structural communities material. on the mainland from Mandurah round to Bremer Bay on Recent coastal dune sands. Fire keeps most of these communities back to a st~ge of scrub-heath, in POST-SETTLEMENT which the Agonis occur~ as scattered large s~rubs in heath of,~xed species. Where freedom from fire and/ or better soll enable the Agoms to supress A history of the spread of European settlement has been given in the initial undergrowth and reduce fire risk it may form low woodland or low forest, a chapter, and the current situation of land occupation is shown in Fig. 15. In false climax replacing the true climaxes of Callitris preissii or Melaleuca .the north, alienation for agricultural purposes has proceeded to its likely limit. lanceolata, which are only seen on the mainland as relict patches. Heath on the South of Southern Cross it has not yet done so, and a substantial area of

~ 72 73 VEGETATION SURVEY SWAN Swan Coastal Plain originally contained only banksia low woodland and were •',:;:a<·1 secured to be converted into pine plantations. Vacant crown land adjoins the state forests along the south coast and at the southeastern end of the Darling .,, Plateau. It consists of swamps, coastal dunes and stunted timber which have '.,~:~t;~ ~. ", no value for farming or forestry. The first national parks had a similar history \~~-. to the state forests. The Stirling and Porongurup Ranges are uncultivable and were reserved for their aesthetic values after land development flowed around them. The Barren Ranges are also uncultivable but when the latest wave of • Northam land development spread in that direction a considerable area of adjoining PER~-~ Rottnest 1,.., country was placed with them in the Fitzgerald National Park in response to Fremantllt pressure from conservationists. The mallee fowl reserve and the Frank Hann Garden I. National Park are both modern reserves established with conservation as the motive. In agricultural areas human activities have been mainly directed to whole­ sale clearing of native vegetation and its replacement by introduced crop plants, weeds and ornamentals. Native vegetation was normally left intact on roadsldes, as public rqads run along strips of land retained in public ownership • Katannlng which may be 1, 2 or more chains wide (1 chain= 20.12m). Where trees were originally present they mostly survive to this day, but as there is seldom any regeneration, their life will be limited. Sandplains usually fare badly. Heaths and scrubheaths are sensitive to drift of fertilizer and weedicides applied to Cape Leeuwln adjacent croplands, which weaken the native vegetation and promote its colo­ Point D'Entrecasteaux nization by introduced grasses such as wild oats (Avena barbata). Sandplain thickets of Acacia and Casuarina are more resistant, and being in many cases ~ . ~ Pastoral no longer burnt, grow immensely tall and dense. These too will die out as the existing plants come to the_ end of their natural life. Problems exist in the iZlil.1]zrm:w. Vacant Crown Land ~ National Park or Reserve ... State Forest management of national parks and reserves which contain vegetation for which fire is an ecological factor, since variations to the previous burning pattern may upset quite delicate balances and initiate deleterious changes. Fig. 15 Land occupation in the southwest at 1977 based on a map in Beard (1967a) described the collapse of the original ecosystem in King's Park, Jarvis (1979). ' Perth, over a period of a century and attributed this to a change in the fire pattern since settlement. Research is being conducted today by government vacant crown land still exists east of the wheatbelt. There is some crown land departments ori the effects of fire in reserves, so that management .may be under pastoral lease in the far northeast. The state forests on the Darling placed on a secure basis. _ Plateau owe their existence in the first instance to the heavy laterites which the It has been a mEtter of official policy in recent years to retain native vegeta­ early settlers found intractable. Forest reservation did not come until after tion on road reserves and even to widen the reserves to as much as 10 chains 1918 when the value of timber production had been recognized. As it is, the (200 m) in newly-surveyed areas where the flora was particularly rich, as on map shows that the forest area is fragmented by development on the better sandplains. On the other hand the terms of conditional purchase of land have soils, especially around Collie. Attempts were made after both World Wars to continued to require that all land be cleared. Farms are normally surveyed in establish agricultural settlements for returned soldiers in'ihe karri forest. Both rectangles with due NS and EW boundaries, imposing what has been called failed owing to fertility ~roblems, but if it had been otherwi~ there would 'square farming in round country'. No official provision has been made for have been much less karn forest left today. Conversely the crowrt·land on the rational farm planning which would include such items as the retention of Blackwood Plateau was accepted into the forest estate after its agricultural shelterbelts, woodlots or belts of natural vegetation along drainage lines. One potential had been assessed and found wanting, although the economic value . of the consequences of this policy has been the widespread salinization of of its natural forest was almost equally minimal. The forest reserves on the bottom lands. - 74 75 / VEGETATION SURVEY As has been seen in a previous chapter, there is a considerable accumulation of salt held in the pallid zone beneath the valleys. Land clearing decreases evapotranspiration on catchments leading to a rise in watertables, so that salt is brought to the surface on low ground. Salinized patches become scalds on PART II which no crops or pasture will grow, and if native vegetation had been re­ tained, it is killed. There is now evidence that samphires (Arthrocnemum spp.) are spreading onto such areas and are establishing a new plant/soil equi­ DESCRIPTION OF THE VEGETATION librium. Man's activities have been instrumental in introducing a large range of weed species as well as economic and ornamental plants. There are now about 600 alien plant species naturalized in Western Australia, almost 10% of the total INTRODUCTION flora (Aplin 1979). Most of these are weeds of crop and pasture land, but some have become established in the wild, notably Ehrharta calycina (veld grass) In previous explanatory notes to maps of this series it has been the practice to (now a significant component of the flora of the Swan Coastal Plain), Wat­ include all available information on the vegetation of the area. In the present sonia and Zantedeschia (Arum lilies) spp. which have become dominant there case, however, due partly to the much greater complexity of vegetation pat­ in moist places, and Rubus fruticosus (blackberry) which has spread°"along terns,, partly to the greater amount of detailed work that has been done, the creeks and rivers ih parts of the forested southwest. Grasses such as Avena volume of information would be too great to include in a single book c;f fatua (wild oats) and Eragrostis curvula colonize roadsides to the exclusion of reasonable size. It has already been put together in the explanatory notes to native flora in farming areas. The majority of alien species require disturbance sheets of the 1: 250000 series (Beard 1969-80; F. G. Smith 1972-4), which com­ of the soil and nutrient levels in excess of those normally required by the in­ prise in total some 400 pages of descriptive data on plant communities. As the digenous flora (Aplin 1979). In a large number of small reserves in the wheat­ material is already available from that source, the treatment here will be belt examined recently the native vegetation was found to be still intact to a limited to aspects of a more general natt;re, classification, a summarized large degree, and there was seldom evidence of invasion by alien species (Muir account of the vegetation units mapped and shown in the key, physiognomy 1978-79). On the other hand in King's Park, Perth, with a higher rainfall and and vegetation systems.· Details of flo~istic composition will be omitted beyond greater exposure to disturbance over a longer period, Ehrharta calycina is now mention of dominant or diagnostic species, but there will be some discussion. generally dominant in the understory and there has been substantial invasion of problems of species and community distribution. by garden escapes such as Gladiolus caryophyllaceus, Watsonia and Freesia spp. CLASSIFICATION

A physiognomic classification of the vegetation units distinguished on the map has been adopted following the usual practice of the Vegetation Survey as set out in Table V which is from Beard (1979h). The classification is based upon the physiognomy (structure and life-form) of the ecologically dominant stratum to determine plant formations. Floristic dominance (or character species if no clear dominance is apparent) is used for secondary classification, dividing plant formations into plant associations. Initial classification is based on the following life-form/height classes denoted by the capital letters. 1. Physiognomy of dominant stratum (capital letters) T Tall trees > 30 m tall M Medium trees 10-30m tall L Low trees < 10 m tall S Shrubs > 1 m tall

------76 77 ..

Table V. Nomenclature of vegetation units as used in the Vegetation Survey of Western Australia

1. COMMUNITIES WITH A SINGLE SIGNIFICANT LAYER

CANOPY COVER

LIFE FORM/HEIGHT CLASS Dense d Mid-dense C Incomplete Sparse r Very sparse b 70-100% 30-70% 10-30% <10% Negligible

T Tall trees_ >30m Dense tall forest Tall forest Tall woodland Open tall woodland M Medium trees l0-30m Dense forest Forest Woodland Open woodland L Low trees Im Dense thicket Thicket Scrub Open scrub Sparse scrub z Dwarf shrubs

------· -..... ------,----~----

2. COMMUNITIES WITH MORE THAN ONE SIGNIFICANT LAYER

COVER OF TREE/SHRUB LAYER

DESCRIPTION Incomplete Sparse r Very sparse b Absent 10-30% <10% Negligible

Wooded bunch grassland Savanna woodland Tree savanna Sparse tree savanna Grass savanna Shrub savanna Sparse shrub savanna Wooded hummock grassland Steppe woodland Tree steppe Sparse tree steppe Grass steppe Shrub steppe Sparse shrub steppe Wooded succulent steppe Thickly wooded Lightly wooded Sparsely wooded Succulent steppe succulent steppe succulent steppe succulent steppe Heath with trees Tree-heath Heath with shrubs , Scrub-heath Heath with mallee Mallee-heath

* When mapping the Kimberley (Beard 1979e) four different types of bunch grassland were distinguished, and this class may also include other graminoids, e.g. sedgeland as on the Swan map. VEGETATION SURVEY SWAN Z Dwarf shrubs < 1 m tall and Webb (1974), where its evolution from earlier work of Kuchler (1949) and G Bunch grasses Dansereau (1951) was described. It has been used throughout the Vegetation H Hummock grass (spin ifex) Survey of Western Australia since the first publication, Beard (1969a). Specht F Forbs r (1970) put forward a somewhat similar system of classification but based on X Lichens and mosses the tallest stratum of the vegetation, not the dominant one; the present writer regards this as contrary to ecological principles. Specht also does not distin­ C Succulents I I guish between sclerophyll and succulent/semi-succulent shrubs except at the \ The physiognomic classification is completed by adding density of the ·, species level. ecologically-dominant stratum expressed as projective foliage-cover per cent as defined by Specht (1970), and coded by a small letter: PLANT FORMATIONS AND ASSOCIATIONS

2. Density (small letters) of canopy cover The Swan map distingmsnes 18 plant formations, each mapped with a differ­ d Dense canopy. Projective foliage cover > 70% ent hue. Many are subdivided florisiically, and are distinguished by a different c Mid-dense canopy. P .f.c. 30-70% shade or other means, so that a total of 44 plant associations is shown. In i Incomplete canopy-open, not touching. P.f.c. 10-30% addition, there are eight mosaic units, which are mapped when an area is occu­ r Rare but conspicuous. P .f.c. < lOOJo pied ~y more than one community whose importance justifies distinction in b Barren, vegetation largely absent. P .f.c. negligible mapping, but which cannot be separately shown on the given scale. Beard­ Webb formulae for each component are given, separated by a stroke. Areas p Scattered groups. No definite foliage cover more than 50% bare of vegetation are likewise shown, and comprise playa Finally, floristic dominants or character species are determined and also lakes, fr~shwater lakes and the sea, rock outcrops and drift sand. coded by a small letter for genus as shown below, giving those genera which A large proportion of the area has been cleared for farming or for residen­ appear in the Swan area. Species are distinguished by adding a subscript tial and industrial purposes. The map shows original natural vegetation as 'Iii existing prior to European settlement. In occupied areas the map is not number e.g. a32, e8 according to the list given in Table VII. ' evidence that the vegetation is there now except as ro~dside · relics and 3. Floristic (small letters). Dominant genus uncleared patches. State 'for~sts, - national parks and reserves, where the a Acacia, Agonis natural vegetation remains, have been marked on the larger scale 1: 250000 b Banksia maps to assist location of surviving examples of it. c Casuarina ·· The mapped units shown in the Key in the right-hand margin of the map are asfofuM: . d Dryandra e Eucalyptus 1. Tall Forest (Plate 8) h Hakea Closed but mid-dense canopy of tall trees exceeding 30m. Eucalyptus j Jacksonia diversicolor (karri) is the principal species occurring either pure or in mixture k Halophytes (A triplex, Maireana, etc.) with E. calophylla (marri) and E. marginata (jarrah). m Melaleuca 2. Tall Woodland (Plate 9) p Triodia Open formation of tall trees > 30m. There is only a single mapped example, x Heterogeneous (mixed or other) of E. gomphocephala (tuart) between Bunbury and Busselton. The resulting three letters, two small letters and a capit.aJ, are combined into 3. Forest(Plates 10, 11) a triplet formula writing the floristic first, then life-form/height class, finally Closed, medium height formation of trees 10-30m tall, normally density: example e8Mi meaning Eucalyptus salm(!nophlQla woodland, • I E. marginata in mixture with E. calophylla, locally also E. wandoo (wandoo). medium-height trees with incomplete canopy. The classification-'is. tied to the i .- nomenclature as shown in Table V. The triplet is used as a mapping notation, 4. Woodland 1 i.e. it appears on the map where ordinary names for mapped units would . Open medium-tree formation. Three types of woodland are separately occupy too much space. It is known as the Beard-Webb formula from Beard mapped:

------' 80 81 VEGETATION .SURVEY SWAN (a) E. calophylla and/or E. wandoo (Plate 13) (b) Casuarina species, normally C. campestris or C. acutivalvis (b) E. astringens (brown mallet) and E. accedens (powderbark wandoo) (c) Acacia and Casuarina with mallee eucalypts (c) Other associations. These are formed principally by E. loxophleba (d) Melaleuca spp. (teatree) (Plate 21) (York gum), E. salmonophloia (salmon gum), E. salubris and E. wan­ (e) Eucalyptus-Dryandra, in the Barren Ranges doo which may occur in mixtures in varying proportions in the Avon (f) Casuarina-Dryandra, in the Wongan Hills district. E. gomophocephala and E. marginata associate on the Swan (g) Mixed thicket in the Stirling Range (Plate 24) Coastal Plain and various other species in the Coolgardie District (Plates 11. Scrub (Plate 25) 14, 15). Open shrubland over 1 m, cover Less than 30%. Four associations are recog,­ 5. Open Woodland nized, characterized by Acacia spp., Eucalyptus and Acacia, Melaleuca spp. Scattered medium-height trees of the above species. and Agonis flexuosa. 6. Low Forest (Plate 12) 12. Mallee (Plate 26) Closed formation of low trees under 10 m. Three associations are mapped, A special type of shrubland with Eucalyptus spp. dominant. The eucalypts which are more or less single-dominant, the character-species being E. margi­ adopt a multi-stemmed form by resprouting after fire from a substantial root­ nata, E. platypus (moort) and Callitris preissii (Rottnest pine). stock. A dense understory typically of Melaleuca spp. is characteristic. Further research would be required before the mallee could be mapped into associ­ 7. Low Woodland (Plates 16-19) ations. Six different species combinations have been shown on the map. Open low-tree formation under 10 m. Nine associations are distinguished: (a) Acacia aneura (mulga) 13. Ma/lee-heath (Plates 27, 28) (b) A. aneura with Casuarina cristata (sheoak) and Eucalyptus spp. Low shrubland less than I m tall with scattered taller mallee frequently of (c) , B. menziesii and spp. gnarled form. Two associations are mapped with Eucalyptus tetragona and (d) Eucalyptus marginata with ditto E. marginata as character-species respectively. (e) E. marginata alone · , 14. Scrub-heath (Plates 29-33) (f) E. marginata with Casuarinafraserana Shrubland with two layers,)he lower closed and under 1 m tall, the upper (g) Melaleuca rhaphiophylla and/or M. spp. (paperbark and teatree) taller and open. Composition is normally heterogeneous without clear species­ (h) Casuarina huegeliana-Eucalyptus loxophleba dominance. Myrtaceae tend to be the most numerous element in the lower (i) Agonis flexuosa layer, Proteaceae in the upper. There has not been sufficient information in 8. Low Woodland with Scattered Trees most cases to recognize floristic associations on a formal basis, but a number Open low-tree formation with scattered medium height trees as emergents. of broad groupings associated with geographical areas have been recognized in It occurs in the form of Banksia low woodland with emergent Eucalyptus mapping, with a notation on the map as shown below. Some of these carry out marginata. a prior treatment on sheet 6 of the survey. hSZc/dZc Mosaic of scrub-heath and heath, Le Sueur vegetation system, 9. Thicket with Scattered Trees Irwin District with as character-species (Plates Closed or dense shrubland with emergent medium-height trees. Two associ­ 33, 34) ations are mapped: x2SZc Scrub-heaths in the Coolgardie District (Plates 29-30) (a) Casuarina campestris thicket with scattered Eucalyptus wandoo x3SZc Ditto in the Roe District (Plate 31) (b) thicket with scattered Eucalyptus loxophleba 14SZc Tathra vegetation system, Irwin District x5SZc Fanny's Cove vegetation system, Eyre District 10. Thicket (Plates 20-24) xtiSZc Jurien System, Darling District Shrubland over 1 m tall, either closed (30-70% canopy) or de11~e (70-100%). x7SZc As x8, with sand ridges present Seven types are recognized, the first three characteristic of sandplains of the xsSZc Banksia- alliance on deep yellow sands, Irwin and Avon and Coolgardie Districts, the last three of hills and ranges, while Mela­ Avon Districts leuca thicket is a swamp formation: x9SZc Acacia-Ecdeiocolea association in part of the Marchagee (a) Acacia species dominant (Plates 20, 22) vegetation system, Irwin District

------82 83 VEGETATION SURVEY SWAN x10SZc Mosaic of scrub-heath and Casuarina thicket, Corrigin vege­ Table VI. Mapping notation and Jormulae tation system, Avon District Dansereau For vegetation systems see Fig. 31. Beard-Webb Kaehler formula formula formula 15. Heath and Low Scrub (Plates 34, 35) Btc . Tteaxc By definition, heath is constituted by a closed layer of low shrubs under I m Tall Forest eTc Bti Tteaxi Tall Woodland eTi tall, and low scrub by an open layer. Other authors have used the terms 'closed Bmc Tmeaxc Forest eMc heath' and 'open heath', which has not been followed by the writer because Bmli.szt Tmeaxi. Fmleaxb Woodland eMi some low-scrub communities in Western Australia are not at all heath-like, i.e. Bmr Tmeaxr Open Woodland eMr sclerophyllous with small, leptophyll or deeply-divided pungent leaves. Specht BlcorElc Tleaxc Low Forest eLc Tleaxi (1970) placed the height limit for 'low' shrubs at 2 m instead of I m, but this d eLi Bli or Eli LowWoodlan . Tmeaxp. Tleaxi does not fit Western Australian communities satisfactorily as there seems to be Low Woodland+ Scattered Trees eMr.bL1 Bmr.li Tmeaxp.Fteaxi a natural dividing line at the lower level. Thicket with Scattered Trees eMr.mSc Bmr.si Bsc Fmeaxc Heaths, as distinct from scrub-heaths, occupy relatively small areas in Thicket xSc Bsi prEsi Fteaxi or Ftemci Western Australia and many of them are not mappable at the I: I 000000 Scrub xSi Bsz.i Fteaxi.Fmeaxc scale, though they have been described in previous larger-scale work. Bridge­ Mallee ' eSi Bszc Fteaxi.Fmeaxc water and Zammit (1979) made an initial attempt at some floristic classifica­ Mallee-heath eSZc Bszc Fteaxi.Fmeaxc tion in terms ofBraun-Blanquet phytosociology. The following associations or Scrub-heath xSZc Bzc Fmeanxc informal floristic groupings can at present be recognized: Heath dZc Gmx Hmegxc Sedgeland xGc Gmiq.Bszi Fteaxb.Hmenxi (a) Coastal, wind-pruned Shrub Steppe eSi.tHi BzikorOik Fljaki (i) Acacia lasiocarpa-Melaleuca acerosa community, Guilderton Succulent Steppe kCi System (Beard 1976d, 1979a, b) (ii) Dryandra sessilis-Acacia cuneata association, Rockingham System (Dryandro-Acacietum of Bridgewater and Zammit 1979) 16. Sedge/and (Plates 36, 37) . ,· . - . W S bdistrict. They are (iii) ferruginea association, Boranup System (Pime/etum f . d cur m swamps m the arren u Communities o ree s oc . t' rincipally of Cyperaceae and Res- ferrugineae of Bridgewater and Zammit) . . 1 l yered up to 1 m cons1s mg P (iv) Jacksonia horrida-Acacia decipiens community, Boranup System dense, smg e- a ' h n' h bs up to 2 m may be present. tionaceae. Scattered sclerop y s ru (F. G. Smith 1972-3) (v) Coastal heaths of the Torndirrup System (Enright 1978) and Bald 17 Shrub Steppe (Plate 38) Island (Storr 1965) ~ummock grassland with scattered shrubs present. (vi) Low scrub on granite bosses of the Bremer System {Beard 1972, Schweinfurth 1978) (Plate 35) 18. Succulent Steppe (Plates 39, 40) lent and semi-succulent species of (b) On coas-tal limestone Communities, often hal~phytes, of sue;~ shrubs annuals and grasses. ! Chenopodiaceae with varymg numbers o rees, , I j (i) Dryandra sessilis-Calothamnus quadrifidus association, Spear­ ! : Three types have been mappe~: f ltbush (Atriplex vesicaria), bluebush wood System. (Dryandro-Calothamnetum of Bridgewater and f Zammit 1979). (a) Unwooded: commumties h? s(~ throcnemum spp.) without trees or (Maireana spp.) or samp ire r I (c) Inland, on laterite shrubs (Plate 40) . h r ht cover of shrubs, usually Acacia or (i) Xanthorrhoea-Dryandra community, Le Sueur System (Plate 34) (b) Lightly wooded: as (a) wit ig (ii) Dryandra spp. communities, mainly along the ~estern boundary Melaleuca . . cal ts scattered· or in groves (Plate 39). of the Avon District. Good examples were detailed in--the· Dongo­ (c) Thickly wooded: as(?) wit~ e;1 Y~. 10 to 15 if they occur on sand- locking Reserve by Muir (1978). Many of the shiubla~ds listed 1~ orma ions ) (iii) Other occasional communities of limited occurrence in the Avon . · vegetation (Beard 1976g • I . p}ains constitute kw?~gru:1 1 e for the Swan map are given in Table VI. District, mainly with and Melaleuca dominant The relevant classification formu a on the vegetation map. They are con- {Beard 1979a, l 980a~ Those in the Beard-Webb column appear I

84 85 VEGETATION SURVEY SWAN

Table VII. Species designated in mapping ei, E. redunca Schau. Black marlock ~2 E. f orrestiana Diels Forrest's marlock Code Common name ~3 E. platypus Hook. Moort ~4 E. salubrisF. Muell. Gimlet an Acacia spp,, various ~5 E. corrugata Luehm. a1 A. aneura F. Muell. ex Benth. Mulga ~7 E. cornuta Labill. Bushyyate 119 A. ramulosa W. V. Fitzg. Bowgada ~8 E. lehmannii (Schau.) Benth. Bald Island marlock a,4 A. quadrimarginea F. Muell. ~9 E. sheathiana Maiden a,9 A. acuminata Benth. Jam ~ E. erythrocorys F. Muell. Illyarrie a23 A. rostellifera Benth. e.is E. accedens W. V. Fitzg. Powderbark wandoo a26 A. lasiocarpa Benth. ~ . E. astringens Maiden Brown mallet a31 A. decipiens R. Br. C(;5 E. staeri Maiden Albany blackbutt a32 A. cyclops A. Cunn. ex D. Don ~8 E. jacksonii Maiden Red Tingle ag Agonisflexuosa (Spreng.) Schau. Peppermint ~9 E. gardneri Maiden Blue mallet b1 Banksia attenuata R. Br. h Hakea obliqua R. Br. bi B. menziesii R. Br. j Jacksonia horrida DC. ' b3 B. prionotes Lindl. k, Atriplex spp. Salt bush C Casuarina, unspecified Sheoaks k3 Arthrocnemum and other samphires Ci C. cristata Miq. m Mela/euca, general Teatrees & paperbarks C3 C. campestris Diels mi M. acerosa Schau. C4 C. acutivalvis F. Muell. ms M. thyoides Turcz. Cs C. huege/iana Miq. p Cal/itris preissii Miq. Rottnest pine G; C. obesa Miq. t. Triodia scariosa N. T. Burbidge Spinifex d Dryandra spp. X Heterogeneous e Eucalyptus, numerous .e, E. diversicolorF. Muell. Karri ei E. marginata Sm. Jarrah trasted in the adjacent columns with the parallel world system of Kuchler (1949) and Dansereau (1951). ~ E. calophylla R. Br. Marri e4 E. gomphocephala DC. Tuart es E. wandoo Blakely Wandoo THE FLORA ~ E. loxophleba Benth. York gum e, E. occidentalis Endl. Yate The flora provides the building blocks from which vegetation is constructed, fjl E. safmonophloia F. Muell. Salmon gum and the nature of this source material obviously influences its physiognomy. eg E. longicornisF. Muell. Morrell As early as 1860 Hooker commented on the special, highly endemic character e10 E. transcontinentalis Maiden of the flora of the southwest as dicl von Mueller in 1867. Many unfounded ell E. flocktoniae Maiden Mirret statements about it continue to appear in popular literature, a widespread im­ e,2 E. torquata Luehm. Coral gum pression being that the flora is extremely rich. Measured in numbers of species e13 E. le souefii Maiden (foldfields blackbutt relative to the area this is not the case, mainly because the evenness and lack of e14 E. dundasii Maiden Dundas blackbutt topographic diversity in Western Australia reduce the range of ecological e,s E. eremophila (Diels) Maiden Horned m}l(ee habitats available. Just how many species are to be numbered in the state can­ e1s E. rudis Endl. Rivergutn not be said with exactitude, since both botanical exploration and classification ei2 E. oleosa F. Muell. Redwood are far from complete. New species are constantly being found, while taxo­ ei6 E. tetragona (R. Br.) ~I. Tallerack nomic study both reduces and increases the numbers of valid species repre- . sented in herbaria. Calculations based on the first edition of Beard's Cata­ (Table Vil cont. ove,..,._) logue (1965) gave a state-wide total of 5802 species of flowering plants (Beard

86 87 VEGETATION SURVEY SWAN

Table VIII. Distribution of species within Western Australia based on the 5312 species of flowering plants listed in the 1965 edition of Beard's Catalogue, using the distributions given for each in terms of the Provinces Species botanical provinces and districts of Gardner and Bennetts (1956). The Cata­ logue did not include Gramineae or Cyperaceae, and data were added from Northern Province only 1117 Gardner (1930 and 1952), to give a total of 5802 species. The range of most Northern and Eremaean 263 species was still imperfectly known, but on the basis of existing knowledge the Northern and Southwestern 22 All provinces 43 figures were believed to give interesting indicatiqns. Table VIII gives the species distribution within Wes tern Australia itself: Total Northern 1445 On the above basis 79% of the southwestern flora of 3611 species is restricted to that province, and in that sense can be said to be endemic. How­ Eremaean Province only 811 ever,. many species listed as southwestern on the ground that they" do not enter Northern and Eremaean 263 the Eremaea do occur in southeastern Australia, so that a further assessment Southwestern and Eremaean 705 was made resulting in Table IX (p. 90), where Endemic means confined to All provinces 43 Western Australia, ElAust means occurring in eastern Australia as well, A/ means extending to New Guinea, New Caledonia and New Zealand, Total Eremaean 1822 and Cosmo (cosmopolitan) means extending further than . -- From Table IX the following percentages of endemism were calculated Southwestern Province only 2841 (Beard 1969d): Southwestern and Eremaean 705 Northern and Southwestern 22 % All provinces 43 Northern Province: whole northern flora 30 Total Southwestern 3611 plants solely northern 32 Eremaean Province: Total all species 5802 whole eremaean flora 62 plants solely eremaean 66 1969d); the second edition of the catalogue (1970) listed 6087 species; the Southwestern Province: number is now believed to be closer to 6500 (Aplin 1979) and may very well whole southwest flora 83 reach 8000 with closer exploration. By contrast , with broadly plants solely southwestern 87 similar climates has about double this species number on half the area, a A misprint occurred in the last figure but one, which read 86% instead of reflection of the mountainous nature of that country and the varied habitats 83%. Marchant (1973) wrote that these figures were 'not clearly comprehen­ that it provides. Since the flora of the whole world is considered to number sible', and that the percentage of species restricted to the South-West Province about 300 000 species, Western Australia can claim 2% of the total. should read 68%. It all depends what is meant by endemic. Table VIII, as The feature which does single out the special character of the southwestern noted above, shows that of the southwestern flora of 3611 species 79% are not flora is the abnormally high proportion of endemic species, i.e. which are con­ found elsewhere in the state and in that sense are endemic. If allowance is fined to the province and found nowhere else in the world. The figure is so made for the southwestern species which while not occurring elsewhere in the high as to be comparable with oceanic islands such as Mauritius and the state, do have a wider range in the east and beyond, the figure drops to 680/o as Hawaiian group, whose floras have evolved in isolation and from limited correctly stated by Marchant. On the other hand it is found that of the 3611 source material. It is abnormal to find this behaviour on a part of a continental southwestern species 3002 are restricted to Western Australia, 2472 being landmass, and suggests ~at the southwest has functioned as an island for a exclusively southwestern, another 519 extending from the southwest into the considerable period, isol . ted from the humid east of Australili by the desert. Eremaea and 11 extending through to the north. So, 3002 is 83% of 3611 and it To endeavour to furnish actual figures, Burbidge (1960) in a detailed analysis could be held legitimately that this is the true figure for endemism. The boun­ of Australian genera listed 462 genera in 96 families in the southwest province. dary of the South-West Province is only a human concept, and very few south­ Of this total 111 genera (24%) and five families (5%) are endemic or confined western plants terminate their ranges exactly at that line. Those that extend to the province. Beard (1969b) made a tentative analysis at the species level some distance beyond it may also be considered southwestern plants if their

88 89 :

/ VEGETATION SURVEY SWAN Table IX. Wider distribution of Western Australian plant species about 300 species of Acacia, 170 of Eucalyptus, 160 of Melaleuca, 120 of and 80 of Hakea. The writer knows of no comparable situation in Provincial Distribution Endemic ElAust A/Asia Cosmo Total any other continent. It means that the flora has evolved from a small range of source material. The explanation probably is that since Australia was already Northern only 355 610 72 80 1117 isolated as a continent when increasing aridity and seasonality began to make Northern and Eremaean 64 167 12 20 263 themselves felt, the evolution of new forms tolerant of these conditions had to Northern and Southern II 34 10 10 65 take place from suitable forms already present within the continent, of which there was only a small number adapted to locally adverse habitats. The Total Northern P. 430 811 94 110 1445 climatic and topographic uniformity of Early Tertiary Australia probably im­ plies a relatively small range of habitats, and the evolutionary requirements Eremaean only 532 259 11 9 811 were complicated by the previous deep-weathering, leaching and impoverish­ Northern and Eremaean 64 167 12 20 263 ment of the soils, so that the new flora of the Late Tertiary had to adapt not Southwestern and Eremaean 519 177 5 4 705 All Provinces 7 25 5 6 43 only to aridity but to nutrient deficiencies as well. It is again in accordance with expectation that only a small number of genera possessed the necessary Total Eremaean P. 1122 628 33 39 1822 evolutionary potential. Repeated climatic fluctuations during the Late Tertiary . and Quaternary most probably promoted active speciation in these genera, pri­ Southwestern omy 2472 280 61 28 2841 marily in the intermediate zone between humid and arid, where the effects Southwestern and Eremaean 519 177 5 4 705 were most.pronounced. As Hopper (1979) expressed this: 'evolutionary studies Northern and Southern 11 34 10 10 65 of southwestern angiosperms provide support for the emerging concept that semi-arid transitional climatic zones are particularly favourable sites for speci­ Total Southwestern P. 3002 491 76 42 3611 ation, while permanently humid and permanently arid zones favour evolu­ tionary stability.' There has been a general impression that shrublands in the southwest are principal range is within the province. If we are framing the question 'what richer in species than woodlands and forests. George, Hopkins and Marchant proportion of the flora of southwestern Australia is found nowhere else in the (1979), in a very valuable paper, endeavoured to provide precise comparative warld?' , the answer (on Beard's 1969 figures) is 83 OJo. figures by enumeration of quadrats of a standard size of 500 m2 at 25 sample . By whatever standard we take, the proportion is large. In 1912, when only sites in a study of 'heathlands' (equivalent to 'scrub-heath' of the· Vegetation 2239 species were known from the southwest division, 2013 (90%) were be­ Survey). Number of species per plot varied from 37 to 95, with a mean of 59.5. lieved endemic (East 1912). Gardner (1959) made an estimate of 75%. Mar­ Other data available to them when brought to the same basis of 500 m2 gave chant (1973) made an interesting general review of the question and listed these comparative figures: many other facts, such as relative richness and endemism in different botanical Acacia rostellifera scrub (on coastal dunes) 9 spp. families. Tht; pos~'ble reasons for this phenomenon have been touched upon Eastern Australian heathlands 30-56 spp. by numerous aut ors and there has recently been a deeper discussion by -E. wandoo woodland 28 spp. Hopper (1979). E. wandoo woodland 35 spp. A high rate of endemism in the southwest is only to be expected when it is E. marginata-E. calophylla forest 43 spp realized that climate, geological structure, geomorphology and soils are all Eastern Australian forests and woodlands 26-95 spp. very different from those in the southeast of the continent. The whole environ­ (with heathy understory) mean40 ment is different. It would be in accord with expectatic\rt that the floras of the southeast and the southwest should have diverged from the date that the The 25 Western Australian heathlands sampled in this study appeared to be post~lated ~arly Ter_tiary universal h~mid non-seasonal condji'ons began to generally richer in species than other Australian heathlands and shrublands, detenorate, 1rrespect1ve of any separation into disjunct areas l5y the extension and most are richer than forests and woodlands of the southwest. The authors of the Arid Zone. · pointed out that most of the floristic richness of the latter is accounted for by Looking at the problem more closely, tne second most important peculiarity the heathy understory. In other words there is a general tendency for a sclero­ of the Australian flora in general, and the southwestern in particular, is the phyll shrub vegetation to develop, but where conditions also favour trees, their relatively large number of species in each genus. Western Australia possesses competition can be expected to reduce the understory species to some extent.

90 91 VEGETATION SURVEY SWAN This generalization is not wholly true, since heathlands occur exclusively on would occur in a graded sequence and not the mixed groups which are actually found. sands and laterites, as do the three types of Western Australian woodland and There has so far been no experimental verification of this hypothesis of positive benefit forest for which figures are given above. Other woodlands occur on less or 'mutual aid' between different Eucalyptus species in mixed stands, but in view of the nutrient-deficient soils, and frequently have rather little heathy understory (see fact that low nutrient supply is characteristic of the soils of the Australian environment ... it seems likely that such a pattern could have a nutritional basis. p. 70 for data on Eucalyptus loxophleba woodland, and Plate 14), with a con­ sesequent reduction in species richness. It is a pity that the data of Muir If this principle applies to Eucalyptus associations there seems no reason (1976-78) were not based on sampling sites of standard area, since these why it should not be extended to the more complex shrublands, arguing that covered a wider range of vegetation: as it is, his 'locations' cannot be used for the more deficient the soil, the greater the biological benefit in mixture of a species/area comparisons. His figures given for the Bendering Reserve for large number of taxa, all differing in their nutrient strategies and exploiting the number of species per hectare which purport to show that woodland has the limited environment in different ways, some competitive, some non­ highest number and heath the lowest are meaningless, since they were obtained competitive, some mutually beneficial. Legumes and Casuarina, as nitrogen by dividing the total number of species recorded for each formation in the fixers, are beneficial associates and are always well represented in our shrub­ reserve by the area occupied. Thus woodland shows the highest species rich­ lands. Some taxa have mycorrhiza, some have proteoid roots (whose function ness because it has a very small area in the reserve, and vice versa for heath. is still not fully understood), some are parasites or saprophytes. There is an In the same way it is unfortunate that the species lists given by Beard (1969a, unusually large population of Drosera in Western Australia (43 spp. in Beard 1972-80) were not taken from enumerated quadrats and cannot be US@a for 1965 2nd edn) which augment their supply of nutrients by trapping insects species/area comparisons. However, this vegetation survey would never have (Pate 'and Dixon 1978). All orchids (148 spp.) in the southwest are terrestrial been completed if time had been taken over quantitative work. The lists give and saprophytic. The number of reputedly parasitic shrubs is considerable indications of relative richness, and bear out the conclusion of George et al.· with 26 spp. in 6 genera in Santalaceae and 2 spp. in Olacaceae. The most suc­ (1979) that the greatest species richness in heathlands occurs on sandy soils cessful parasite is the tree Nuytsia floribunda in Loranthaceae. In the Esper­ associated with ironstone gravel, while the least richness is found on deep ance sandplains it is generally the tallest plant (Plate 30), and in the heaths near sands-and also (from Beard lac. cit.) at the other extreme on block laterite. Duke of Orleans Bay it is the only tall plant. Specimens can be seen to have It is clear that the areas of greatest species richness m Western Australia are :)J extensive underground stems 5 cm thick, grafting to other Nuytsia plants and associated with some of the poorest sand and gravel soils, an apparent paradox emitting roots with parasitic haustoriogena. Too little is known about the which remains unexplained. As in Australia generally, the more deficient the nutrient strategies of heath pla9ts, buf it is clear that they are very diverse. The soil, the richer the flora appears to be, which is in contradiction to the usual mutual benefit hypothesis is suggested pending experimental verification. It principle in that the more adverse the habitat the fewer the has been further discussed with reference to eucalypts in a recent paper by species found in the corresponding plant communities. Thus the number of Rogers and Westman (1979). species appears to decline from the tropics to the poles, from lowlands into Yet another prominent characteristic of the sclerophyll shrub flora is its high mountains, from dry land into swamps and from humid areas into brilliant display in spring flowering (Plates 23, 29). This constitutes yet . In the tropics, rainforest is notorious for its number of species whereas another apparent paradox, for flowering and fruiting are demanding of a mangrove swamp has few. Biogeographers who have examined species rich­ nutrients, a commodity in short supply. Reproductive strategies like nutrient ness in Western Australia (Churchill 1968, Hopper 1979) have invoked con­ strategies vary widely, but most species presumably depend upon outcrossing ventional dogma on isolating mechanisms to explain speciation, and'obviously to maintain evolutionary vigour and potential. If in the harsh environment of these processes have been in operation; but they do not explain the difference the sandplain few or inefficient pollinators are available (or were before the in species richness betWeen the poorer and the more fertile soils. The reasons introduction of the honey ), a brilliant floral display may be required to for this must be due to evolutionary pressures contained within the . ensure a minimum rate of . In general, the display takes the form of Pryor's (1959, 1976) hypothesis of mutual benefit seems very credible though great numbers of small showy in the mass, rather than of fewer large it has not yet been applied to mixed-dominance shrub communities. When showy individual flowers. They may be arranged in capitula e.g. Banksia, or in examining stable ecualypt associations in Eastern Australia, P.7 ryor observed corymbose heads, e.g. Verticordia, but the majority of the flowers may never that where two or more dominant species are sympatric / produce fruit. It will be clear that it would actually be physically impossible for it follows that they can grow together in a mixed stand only if there is some positive all flowers in a Banksia cone to result in a fertilized follicle. Each flower in biological benefit in such growing together, and it is postulated that the mixed stands Verticordia produces a single-celled indehiscent fruit. In most species in the of the virgin Eucalyptus populations are in combinations in which there is such bio­ genus these are notorious among wildflower enthusiasts for their low fertility logical benefit. If they were not, it must be presumed that pure stands of each species rate. Examination at the King's Park Botanic Garden showed about 4% fer-

92 93 VEGETATION SURVEY SWAN Table X. Life-/orm classes for five types of vegetation equivalent region of South Africa found that there appeared to have been co­ on the Swan Coastal Plain adaptive evolution of plants and animals along different evolutionary path­ ways in the two continents. Thus large nuts and large granivores are found only in Australia; nectar-producing flowers and nectarivores are more com­ mon in Australia and some types are confined to Australia. On the other hand, berries on trees or tall shrubs are confined to South Africa, as are most types of avian frugivores. The present writer suggests that the basis of this difference Community taxa "' ,c, "' ,c, "' ,c, "' lies in the general Australian adoption of dry fruits even in genera which have succulent fruits in other continents as pointed out by Burbidge (1960). This Littoral vegetation 74 000310625 0 0 8 15 23 6 0 4 0 may be related to the prevailing lack of nutrients in Australian soils, in the Stable dunes 65 0 0 0 3 21 1 28 0 0 9 9 3 16 2 6 0 same way as sclerophylly which Beadle (1954, 1966) has related to deficiency E. gomphocepha/a woodland 84 5 5 5 2 10 5 18 I 7 19 2 15 0 5 0 of phosphate. Beard (1976() suggested that the predominance of sclerophylls in Banksia low woodland 69 0 I 7 5 9 7 26 1 7 23 I 10 l 1 0 Freshwater swamps 64 2030508 2 0 3 52 3 11 3 2 6 the Australian desert could be ascribed to the leached soils, succulent forms being confined to alkaline and saline soils richer in soluble salts including phosphate. tility in most Verticordia species. Closer examination showed that up tO"?0o/o PHYSIOGNOMY of fruits had been fertilized but that most had aborted (L. Bousfield, unpubl.). In this.field also, too little work has been done for verification, but it is sug­ Details of height, stratification, crown cover and so on will be given for the 18 gested as a general hypothesis that the brilliant floral display serves to attract formations distinguished on the Swan map, illustrated as far as practicable by · pollination, and that there may be mechanisms in many taxa for partial shed­ diagrams of measured profiles. Lists of associated plant species will not be ding of the load if pollination has in fact been heavy, as an adjustment to suit given as they are available in previous work. · availability of nutrients or seasonal conditions. Certain general features may be mentioned at the outset. All dominant trees Very little work has been done on plant forms in Western Australia. The i! in forests and woodlands are eucalypts. Only in low woodlands do species of descriptions which follow ln the next section under Physiognomy will give Acacia, Agonis, Banksia an,d Casuarina become important, and like Eucalyp­ some data for dominant species. George et al. (1979) presented a table showing tus they are evergreen and sclerophylfous. Eucalypt leaves are falcate and pen­ the Raunkiaer life-form spectrum for three of their sampled heathland sites; dant, so that much light is admitted through the crown, and the formations are· they used Raunkiaer's (1934) original classes which are not very relevant for frequently known as 'open forests' (Specht 1970). In the eastern states it is such vegetation in Western Australia, since the overwhelming proportion of usual to distinguish eucalypts by their bark, but this is not the practice in species fall into one class: nanophanerophytes. Beard (in press) worked out Western Australia, where they have non-descriptive names. It may be helpful spectra for five types of vegetation on the Swan Coastal Plain, for which he to note that on bark types, karri is an ash, jarrah a stringybark, marri a blood­ used the expanded Raunkiaer classification of Ellenberg and Mueller-Dombois wood, tuart a box; wandoo, powderbark wandoo, the mallets, salmon gum (1967), and these appear in Table X. and gimlet are gums, while many trees of the eastern goldfields are typical An analysis of proportions of species falling into Raunkiaer's -size blackbutts (for botanical· names see Table VII). However these terms are classes for a heathland area near Eneabba was given by Lamont (1976a). Over descriptive only, as in Western Australia the bark types do not accord with 500/o of the species were leptophylls, the remainder nanophylls and micro­ botanical groupings within the genus as they mostly do in the east (Hall, phylls. The leptophyU-scharacterize the common form frequently referred to Johnston & Chippendale 1970). Eucalypts carry no vascular epiphytes and no by Diels (1906) and Beard (1972-80) as the 'ericoid shrub', mainly found in climbers: the few creepers in the flora are confined to the understory. members of the Myrtaceae. Proteaceae on the other hand tend often to have Diels (1906) did not distinguish between forests and woodlands, since the long but extremely deeply-divided leaves with pungent points, ~hose area is German word Wald covers both concepts. Forests and woodlands of south­ difficult to assess and which do not readily conform to Raunkjaer classes. A western Australia were classed as Sklerophyllen-Wald with a few exceptions, study of plant forms particularly in shrub lands would be ,fascinating and including the Eucalyptus loxophleba and E. occidentalis woodlands which rewarding, and should take shape and mode of growth into consideration were considered to be Savannen-Wald. These terms have been translated as rather than applying concepts introduced from the -e.g. Sclerophyll Forest and Woodland, Savanna Forest and Woodland, and euca­ see Beard 1969c. lypt formations came to be known generally as sclerophyll forests with two Milewski (in prep.) in a comparison of southwestern Australia with the types distingmshed, wet sclerophyll and dry sclerophyll (Beadle & Costin

94 95 VEGETATION SURVEY SWAN

1952). Specht (1970) pointed out that a misunderstanding had occurred. 80m 'Sclerophyll' in Diels referred to the understory not to the tree layer. Sklero­ phyllen-Wald has an understory of sclerophyll shrubs, Savannen- Wald an understory of grasses. Most forests and woodlands of southwestern Australia are correctly termed Sklerophyllen-Walder on this basis. The karri forest is wet 60' sclerophyll and the jarrah forest dry sclerophyll. The distinction is useful and descriptive, but the use of the latter terms is now discouraged in scientific literature as it has become fashionable to employ more precisely descriptive physiognomic terminology. 40 In addition to forests and woodlands in southwestern Australia, mallee is also an important formation which is dominant in terms of area in the Roe District and-as mallee-heath-in the Eyre District. These two districts consti­ tute a mallee region in Western Australia coincident with the eastern climatic 20 sector of Fig. 8. Woodlands and forests are characteristic of the ~estern sector. While this fact is, obviously, something of which people are in general aware, it lacks expression in the literature. Diels (1906) who had little oppor­ tunity to travel in the mallee said almost nothing•aboi.lt it, and Gardner (1942) said even less. It is curious that while a great deal has been written about Fig. 16 Profile of Eucalyptus diversico/or (karri) tall forest from a measured strip mallee, mallee-lands and mallee-soils in South Australia, the subject remains 100 x 2m in the Pemberton area. Reproduced from McArthur and Clifton 1975. virtually a closed book in the West. We do know that the physiognomy and [Key to symbols in Table XI] environment of mallee in the two states appear to differ significantly. This I subject will be discussed further in a later section. mixed with E. calophylla (marri) and E. marginata (jarrah), or the latter two

Shrublands of several types other than mallee occur widely throughout the {l may associate without karri. southwest and are largely associated with poor siliceous soils under low rain­ ; Valuable descriptions were given by McArthur and Clifton (1975) who also fall conditions, or occur in some cases on shallow skeletal soils of rocky ranges presented profile diagrams· from which Fig. 16 has been reproduced. Fig. 16 or on the massive laterite of ironstone ridges, but predominantly on the exten­ gives a profile of pure karri tall forest from a measured strip 100 m long but sive sandplains. Such shrublands are of a number of different types, as listed only 2m wide (W. M. McArthur, pers. comm.). Owing to the narrow width of in a previous section and shown in the key to the vegetation map; they will be the profile the forest appears more open than it really is and canopy-cover less. described in more detail below. Diels (1906) used the general term Sand-Heide Pure stands of karri or mixed karri-marri have four distinct stories. The euca,. for them, translated by Gardner (1942) as sand-heath. It is a useful general lypts form a discontinuous canopy at about 70 m, below this at about 10 m is a term. Analogous shrublands in other mediterranean regions have distinctive scattered layer of Agonis flexuosa, Casuarina decussata and Banksia, and at local names-maquis or macchia in the Mediterranean, in Cali­ 3 m there is a continuous stratum of predominantly soft-leaved shrubs such as fornia, Jynbos in South Africa. Beard (1976g) discussed _the meaning and Trymalium spathulatum, Chorilaena quercifolia, Hovea elliptica and Acacia application of an Aboriginal word spelt in various different forms in early pentadenia. While numerous sclerophyll species occur, e.g. Bossiaea aqui­ literature such as guangan, gongan, quangen and quonken. In a modern work f olium which may be locally frequent, the softening of this characteristic is (Douglas 1968) it appears as kwonkan (to be pronounced 'gwong-gan'), with typical of 'wet sclerophyll' forest. The ground layer consists of many low the English equivalent 'plains country'. Beard suggested that it should be stan­ shrubs and creepers-Clematis pubescens, , Ken­ dardized under the spelling kwongan as a term for Western Australian sand­ nedia coccinea-a very light cover of the grass Tetrarrhena laevis together with plains and their vegetation. This vegetation is varied and comprises several some mosses, liverworts and occasional epiphytic ferns. different physiognomic and floristic types which must retain t~it own names, Stands of E. marginata and E. calophylla, which occupy the poorer soils in but it is useful to have a general overall term of local origin. the same area, attain heights not normally exceeding 40in. They have a sclero­ phyll understory, and are a taller version of the medium-height j arrah forests. 1 Tall Forest (Plate 8) 2 Tall Woodland (Plate 9) Structure of the tall forest varies somewhat with the three species present. Typically Eucalyptus diversicolor (karri), forms the tree layer, but it may be Only a single example of this formation is known in the state: on the coastal

96 97 VEGETATION SURVEY I SWAN limestone between Busselton and Bunbury, where Eucalyptus gomphocephala greater number of younger stems which have arisen from lignotuberous sap­ (tuart) at the southern limit of its range forms open stands with heights of l lings on the floor of the original forest. Whereas the virgin forest originally 30-40m. These are single~dominant stands with a well-developed lower tree I contained mainly large mature and overmature trees, most stands now contain layer of Agonis flexuosa and a few at about 15 m. The area smaller immature trees. In addition many stands have been thinned by dieback has been dealt with by F. G. Smith (1974). There is no information on the disease caused by . ground vegetation. Fig. 17 is a reproduction of a profile measured in jarrah-marri forest by Speck (1958). The location of the sample is no longer known, nor the width of 3 Forest (Plates 10, 11) the strip. The forest has a discontinuous lower layer of small trees of 10-15 m, As distinct from Tall Forest, which exceeds 30 m, Forest consists of trees 10 chiefly Banksia grandis, Casuarina fraserana and longifolia, and a to 30m in height. Nearly all the forest formation in Western Australia consists ground layer of sclerophyll shrubs 1-2m tall and averaging 185 individuals to of a mixture of E. marginata (jarrah) and E. calophylla (marri), the propor­ the hectare (Hav_el 1975). Grass trees (Xanthorrhoea, Kingia) and trunkless tion of the latter varying from 50% downwards. It is known generally as the cycads (Macrozamia) are included. Ground plants include a range of Cypera­ jarrah forest, and is a typical 'dry sclerophyll' forest with a dense sclerophyl­ ceae and Restionaceae, terrestrial orchids and other herbaceous monocotyle­ lous understory. As jarrah is a stringybark, the physiognomic resemblance to dons, Drosera and Pteridium esculentum. The same creepers as in the karri the E. obliqua forests of Victoria is very close. E. patens (blackbutt) occurs as forest colonize gaps in the forest or become temporarily rampant after fire. a codominant on valley loams and associates with E. megacarpa and Agonis Floristics of the understory have been exhaustively studied on an ecological basis tiy Havel (1975). · linearifolia in swampy bottomlands. Eucalyptus rudis (flooded gum) lines the banks of major creeks and rivers, occasionally growing on slopes on young 4 Woodland (Plates 13, 14, 15) soils on bedrock. E. wandoo (wandoo) and E. accedens (powderbark) associ­ ate \1/ith E. inarginata on some sites at the drier end of its range. Like the forest, the woodlands are eucalypt-dominated with one to four species present at any one site. There is a large number of different associ­ ations, which vary in structure according to rainfall, soil and the morphology of the dominant species. Eucalyptus gomphocephala (tuart) forms open stands on the coastal lime­ stone from Bunbury northwards, with stout spreading trees 20-2,5 m tall, rarely 30m, and 60-90cm in diameter, rarely· 150cm. The trees branch or. fork low 20 down, usually between 1.5 to 4.5 m above ground, and the branahes spread widely (Fig. 18). Density in a sample in King's Park, Perth (Beard 1967a) was 48 eucalypts per ha, half being dominants aild half smaller trees, with a crown cover of 280Jo. A scattered stratum of small trees under 10m and a well­ developed layer of sclerophyll shrubs from 1 to 3 m are present, containing the 10 grass tree Xanthorrhoea preissii and the cycad , the latter always trunkless. There is a small number of creepers and herbaceous ground plants. (Speck 1952, Beard 1967a, 1979b.) · Eucalyptus calophyla (marri) and E. wandoo (wandoo) which form wood­ lands on pallid zone soils in the Darling District were studied on two sites by 50m Williams (1932, 1945), who found similar height but greater density, given as 100 stems per ha. Two shrub layers were distinguished, at 1.3 to 1.5 m and Fig. 17 Profile of Eucalyptus marginata-E. ca/ophylla forest (jarrah-marri). Repro- 45-60 cm in height. Xanthorrhoea and Macrozamia were included, the former duced from Speck 1958. [Key to symbols in TableXI] / very common with 600 to 1000 plants per ha. Eucalyptus accedens (powderbark) and E. astringens (brown mallet) form The jarrah forest averages 25-30 min height in the western part of its range, woodland on surfaces of massive laterite on the eastern fringes of the Darling about 4m less in the eastern (Havel 1975). Williams (1945) recorded a density Plateau, where rainfall is too low for forest of E. marginata. Intermediate of 125 to 150 stems per hectare. Today nearly all stands have been logged so associations of E. marginata, E. wandoo and E. accedens occur. Height is that many or most of the largest trees have gone and have been replaced by a ,;r r~duced to 15-20 m, but density may increase. The understory consists of 98 I 99 i i VEGETATION SURVEY SWAN

25m 25m

20 20

15 15

10 -p 10 j 5 5

60m Fig. 18 Reconstructed profile of original Eucalyptus gomphocephala (tuart) wood­ land in King's Park, Perth. After Beard 1967a. [Key to symbols in Table XI] Fig. 20 Profile diagram of woodland from a measured strip 200 X 20 feet, 42km south of Hyden on the Hyden-Newdegate road. From Beard 1~69a. [Key to symbols in Table XI] sparse sc1erophyl1 shrubs, especially sparse to absent under E. astringens. The grass tree X anthorrhoea reflexa is occasional. E. loxophleba (York gum) which is an important woodland component in Table XI. Key to symbols in Figures 16-29 the Avon District, particularly in the western part, has an unusual form, fork­ ing repeatedly from low down to resemble an overgrown mallee (Fig. 19). It is f A Acacia sp. Es E. salmonophloia Eo E. oleosa normally not as tall as other woodland species; it reaches aQOut 15 min height '[.~ Ap A. pentadenia Et (Fig. 21) E. transcontinentalis M Me/aleuca sp. \ (Fig. 28) £. tetragona in the west and declines gradually in an easterly direction to 12 m, 8 m and B Banksia sp. Ma M. acumin«ta 1 Ba B. attenuata G Grevillea hooker«na Mc M. cordata finally to a mallee form. Crown cover is in the range 10-30%. Scattered small Ge 1. !~ Bg B. grandis G. excelsior Mp M. pauperiflora trees of 3-5 mare present, typically Acacia acuminata and Casuarina huegeli­ r H Hake« sp.'· ·:• Bi B. ificifolia Ms M. striata ana. Shrubs are sparse, but herbaceous species form a ground layer which may \ Bm B. media He H. corymbosa P sp. constitute a sward during the winter months. A spectrum of the flora recorded -~ C Casuarina sp. Ht H. trifurcata ~~} by Diels in 1901, when these woodlands were still plentiful and less disturbed Ca C. acutivalvis Ib lsopogon bquxifolius Cc C. corniculata Ed E. diversicolor s Santa/um acuminatum than today, was discussed at p. 70. L•i \{ Cd C. decussata Ef (Fig. 21) E. flocktoniae T Thryptomene . I Woodlands of Eucalyptus wandoo, where they occur in the Avon District, Cs C. campestris (Fig. 28) E. falcata . Ts Trymalium spathulatum have a structure similar to that described above for the E. ca/ophylla-E. wan­ Ct C. fraserana Eg E. gomphocephala V Verticordia doo mixture. D Dryandra sp. El E. loxophleba X Xanthorrhoea preissii _f;. salmonophloia (salmon gum) and E. salubris (gimlet) are important E Eucalyptus sp. Em E. marginala species.in both the Avon and Coolgardie Districts, occurring singly of'in mix- - ture. ~- E. salmonophloia is a vigorous tree, normally over 20m tall when mature, 15m El with a maximum of about 28 m. There is a very strong trunk, smooth-barked, up to 1 m in diameter and extending to half the height of the tree. Stands are 10 very irregular, so t~at it is difficult to estimate density or crown cover: trees may be as much as 60 m apart. E. salubris is commonly a smaller tree up to 5 15 m, but may locally reach equivalent sizes to E. salmonophloia. There are two highly sparse layers of shrubs, the one 2-4 m tall and mainly of 'broom­ bush' habit (Beard 1969a), the other of low shrubs under 60cm. Sporadically, Fig. 19 Example of height and form of Eucalyptus /oxophleba (York gum) wood­ and probably on patches of winter-wet soil, there may be a small tree layer land from portion of a figure by Speck (1958). [Key to symbols in Table XI] 4-6 m of boree () which has a dense, compact crown of 1' 100 101 VEGETATION SURVEY SWAN 25m assessed as dominant a classification of shrubland with scattered trees is pre­ ferred. 20 6 Low Forest (Plate 12) Low forest, a closed formation of low trees under 10 m, with a crown cover Et of 70-100%, is not a common formation in Western Australia, and only four 10 examples have been mapped, with the dominant species being Callitris preissii, Et Eucalyptus marginata-Casuarina fraserana, Eucalyptus platypus and E. lehmannii-E. cornuta. Other communities of low forest too small in area to be 5 mapped are formed by Melaleuca lanceolata, Eucalyptus annulata, E. spathu­ lata and E. diptera. Small single-stemmed eucalypts forming low forest are called 'marlocks', distinguishing them from the multi-stemmed mallees. 60m '! Surviving examples of Callitris low forest on Garden Island in 1957 (Mc­ Fig. 21 Profile diagram of Eucalyptus transcontinent~lis woodland from a Arthur 1957) consisted of dense slender trees 5-6 m tall, occasionally up to measured strip 200 x 20 feet. Beard 1969a. [Key to symbols m Table XI] _.. 10m, 5-8 cm in diameter. There was virtually no undergrowth, only the shrub Phyllanthus calycinus being at all common. A tiny annual Trachymene pilosa flourished in season. a dark colour. A few species of herbaceous perennials and grasses occur in a Eucalyptus marginata forms low forest on extremely poor (shallow, ill­ ground layer. In the vicinity of salt lakes in the Avon District a ground layer of drained, highly leached) siliceous soils in the lower southwest. Trees up to 15 m assorted succulent plants is frequently present, or of saltbush (Atriplex vesi­ tall are noticeably crooked. With increasing tendency of the soil to deep, caria). The latter becomes more common on the calcareous soils in the Cool­ bleached sand, tree height is reduced and Casuarina fraserana comes in, gardie District. eventually forming a pure stand. There is a sclerophyll shrub understory under woodlands become more diverse in -the Coolgardie District and are in Eucalyptus marginata, but many of the denser Casuarina stands may lack this general not as tall as E. salmonophloia. In the measured sample of E. trans­ (Beard 1979d). continentalis (Fig. 21) one outstanding tree reaches 22 m but most of the Eucalyptus platypus, E. annulata. E. spathulata and E. diptera form dense dominants attain between 12 and 18 m. There is an understory of eucalypts in stands on heavy clay soils in the mallee region. Trees are 5-7 m tall. There is mallee form in the sample, and low shrub and herb layers were virtually virtually no understory, and bare soil is normal beneath the trees (Beard absent. Elsewhere in such woodlands however, understories similar to those of 1967b). E. salmonophloia can be observed. Diameters of the dominants are 20-30 cm. Eucalyptus lehmannii forms low forest with Callitris preissii on Bald Island, The trunk forks into a number of ascending branches at about a third pf tree and with on tlie Re(;:herche Islands. Trees are 3-6 m tall, or height. The profile illustrates the irregularity of the woodland and the open­ twice as much locally on favourable sites. There is little understory (Willis ness of the canopy. There are wide gaps between groups of dominants which 1953, Storr 1965). tend to occur in clusters, the result no doubt of group regeneration. On soils derived from granite, the trees in these woodlands are smooth-barked, but 7 Low Woodland (Plates 15-19) where they are derived from greenstones, the majority.. .of the species have per­ sistent rough bark on the lower tru:g_lvor on the trunk at'ld lower limbs-:The sig­ Low woodlands are more open, in the crown cover class 30-70%. Nine nificance of this-if there is any significance-is not understood. Trees of associations have been mapped which fall into six groups as follows: saline soils in Western Australia are also blackbutts (E. kondininensis, E. gracilis, E. melanoxylon), as also on gypsum (E. striaticalyx). 5 Open Woodland Structure of open woodlands is essentially similar to that of the woodlands except for the wider spacing of the trees which fall into the 2-10% crown cover class. Understories are correspondingly more vigorous. However, in open Fig. 22 Profile diagram of Eucalyptus platypus low forest from a measured strip 50 woodland the tree layer is still assessed as dominant. Where t~e understory is x 10 feet near the Phillips River southwest of Ravensthorpe: Beard 1972a. ·

102 103 VEGETATION SURVEY SWAN Mulga (Acacia aneura) may be mixed with Casuarina cristata and Eucalyp­ 15m tus spp. at the southern limit of its range. Mulga is characteristic of the Austin and Ashburton Districts further north (Beard 1975b, 1976/). Structure con­ sists of an open low-tree or tall-shrub layer 3-6 m tall, a sparse low-shrub layer 10 of 1-2m and a ground layer of ephemeral herbs which may be dense and con­ tinuous in a favourable season, to absent at the opposite extreme. There are a few perennial grasses, ·which are confined to sandy areas. Most of the ground layer consists of forbs, mainly composites, with a few annual grasses. The 5 shrub layer contains some sclerophyll species but is predominantly malaco­ phyllous. In the Swan area mulga is confined to the small portion of the Eremaean Province and a few outliers. Banksia spp. dominate low woodlands on deep· leached siliceous sands, Fig. 24 Profile of Eucalyptus marginata low woodland from a measured chiefly on the Swan Coastal Plain. Small trees of about 6-8 m comprise strip 60 x 2m in the Pemberton area. From McArthur and Clifton 1975. [Key to symbols in Table XI] Banksia attenuata, B. menziesii, more rarely B. ilicifolia, and Nuytsia Jloribunda. Casuarina fraserana is present in the southern part. Leaves of the are 10-15 cm Jong, rough, chartaceous, serrate; ttrough M. c11ticularis, form communities in swamps varying in height and density large, they are relatively few, so that the crown is thin, and branching of the according to the conditions. Height rarely exceeds 6 m, but the trees may be as tree is somewhat open. Bark is very thick, dark, scaly. The formation stout as i m in diameter. Bark is thick, peeling off in thin papery layers. resembles the cork oak (Quercus suber) woodlands of the Mediterranean Leaves are short, needle-like, densely crowded. Undergrowth consists of reeds, region, and the trees resemble Curate/la americana of savannas in tropical both Cyperaceae and Restionaceae, varying from dense to absent according to America (Beard 1953), which significantly is named chaparro, Spanish for tree density. may form similar groves in swamps. cork oak. Some convergence of evolution is perhaps impressed by the poor Casuarina huege/iana and Eucalyptus loxophleba may form low wood­ siliceous sands. There is a well developed sclerophyll shrub understory in this land on granite outcrops in the Avon District. The association varies from formation, for which Speck (1952) listed 28 species of tall shrubs, 130 of low pure E. loxophleba on loaµi to pure Casuarina on coarse sand. Stands vary shrubs and 182 ground-layer plants including many Restionaceae, Cyperaceae, from very open to very dens,e, anl from 5-10 m in height. The understory and other herbaceous monocotyledons (Fig. 23). varies from open to absent according to tree density, generally containing a few sclerophyll shrubs, tussocks of restionaceous reeds, annual grasses and forbs. Agonisflexuosa is dominant in a range of structural types from scrub to low forest on recent sands of the southwestern coasts. Structure is influenced by 5 fire, soil quality, and exposure to wind. The understory contains a range of large and small shrubs, reeds and herbaceous perennials.

8 Low Woodland with Scattered Trees On the Bassendean Sand from Perth southward, Banksia low woodland Fig. 23 Profile of Banksia low woodland from a measuied strip 70 X--2·fu in the Pemberton area. From.McArthur and Clifton 1975. [Key to symbols in Table XI] contains scattered taller trees of Eucalyptus marginata as emergents reaching 12-15 m in height. On the Dandaragan Plateau south of the Moore River there is a complex Eucalyptus marginata may form low woodland in mixture with mosaic of Banks/a low woodland with patches of Eucalyptus marginata­ where rainfall is higher, or as a sole species, or in mixture with Casuarina E. calophylla forest merging one into the other, with an intermediate stage of Jraserana. These low woodlands are essentially attenuated forms of the low low woodland with scattered trees of the two species. forests previously described. Eucalyptus marginata is replaced by the related species E. staeri on bleached sands over laterite on poorly-drained sites along 9 Thicket with Scattered Trees the south coast (Fig. 24). Melaleuca spp., in particular the paperbark trees M. rhaphiophylfa. and Two examples of this formation have been mapped in the Avon District.

104 105 VEGETATION SURVEY SWAN being possible. Where undershrubs occur, they naturally will flourish mainly in the early stages, becoming suppressed later. The dominant components of 2 the thicket are virtually confined to different species of Casuarina, Acacia and Melaleuca, all of which have the same habit of growth: the stem divides repeatedly into a large number of thin, largely-erect branchlets terminating at the same height and giving a dense, gently-domed crown to the bush. This may be referred to as the 'broombush' habit. In Casuarina leaves are reduced to 3m scales, and their function is taken over by the thin, terete, green twigs. The 2 fruits are held on the bush until it dies, or is killed by fire, when seed is liberated. The Acacia species have phyllodes, narrow, linear and about 5 cm 1 long. The seed is shed but is protected by a hard seed coat; takes place copiously after burning. Melaleucas have small ericoid leaves,· and their ·fruits behave like those of Casuarina. 15m Two profiles have been measured to illustrate the structure of this formation Fig. 25 Profile diagrams of Acacia-Casuarina thicket (broombush thicket). Top: and appear in Fig. 25, being an 'early' and 'late' stage after fire. early stage after fire; bottom: later stage. Measured strips 50 x 1O feet, Hyden­ There is no essential difference except that the virtually closed canopy Norseman Road. From Beard 1969a. [Key to symbols in Table XI] formed already at about 1.2 m in the 'early' stage has advanced to 2.5 m in the 'late' stage. Heath components such as Banksia, Hakea, and Isopogon have grown rather less in height, and are becoming suppressed by the broom­ Casuarina campestris thickets may contain scattered emergent trees of Euca­ bushes. Restionaceous reeds, especially Ecdeiocolea monostachya, generally lyptus wandoo of about 15 m on shallow stony gravelly uplands. form a ground layer, or else the tussock plant Borya nitida. Melaleuca uncinata thickets may have scattered Eucalyptus /oxophleba of Other thickets do not develop the broom-bush habit to the same degree. 8-15 min sandy, winter-wet bottomlands. dominates thickets on sandy soil receiving run-off Structure of the thickets i~ described below. from granite outcrops. A Casuafina-Dryandra association covers lateritic 10 Thicket (Plates 20-24) duricrust in the Wongan Hills, a-Eucalyptus-Dryandra association on steep slopes iri the Barren Ranges .and Mt Desmond, and a mixed association with­ Thickets are very widespread on sandplains in the Irwin, Avon and Cool­ out definite dominants at the higher levels on the peaks of the Stirling Range .. gardie Districts, and may originally have occupied nearly half the landscape in Dryandraformosa, lsopogon latifolius and Oxylobium atropurpureum are the the last two of these districts. ln the Roe and Eyre Districts the equivalent for­ most conspicuous species in the latter at the flowering stage. Typically for m~tion is mallee. A few special types of thicket occur on hills and ranges, but these hill thickets, in the Barrens the stand is always very dense and an impres­ are of minor extent compared with those of the sandplains. In the latter, sion of impenetrability is heightened. by the prickly nature of many ]_eaves. species of Acacia, Casuarina and Melaleuca are variously dominant, so that About half the stand is form~d of mallee with stiff, entire leaves. Many ·or the these thickets could be grouped as belonging to an Acacia-Casuarina­ other associated shrubs, especially Dryandra quercifolia which is very com­ Melaleuca alliance. Numerous component associations have been distin­ mon, have lobed or deeply-divided leaves well armed with pungent points. g~ished and m~pped in earlier ~fn general, Casuarina is dominarl\under On greenstone hills, e.g. in the Parker and Bremer Ranges, Acacia­ ramfall exceedmg about 325 mm per annum, Acacia \vhere rainfall is \)elow Casuarina thickets persist, though with different composition. Calothamnus that figure. Melaleuca comes into prominence on clayey, winter-wet or asper may be a significant component. Acacia quadrimarginea is dominant on swampy soils. ridges of banded ironstones. In jts purest form the thicket is a dense, closed (70-1000/o cover), single­ layered community of relatively simple floristic composition. It grades how­ 11 Scrub (Plate 25) ever very gradually into scrub-heath where the two adjoin, so that there are By definition, scrub is an open community of tall shrubs exceeding 1 m in intermediate structures such as the addition of a ground layer of small ericoid height at maturity, without a significant lower layer. Few examples occur .in shrubs. Like the scrub-heath the thicket is subject to frequent fires by which it the southwest. ·- is destroyed, regenerating from seed. Height of the vegetation therefore The coastal Eucalyptus-Acacia association found east of Albany is com­ depends largely on the time that has elapsed. since the last fire, up to 3 or 5 m posed partly of mallee-type eucalypts and Agonis flexuosa which also adopts a

106 107 VEGETATION SURVEY SWAN mallee form when burnt, and partly of species of Acacia, all these forming 4m large spreading shrubs 2.5-3 min height. Their leaves are sclerophyllous, and ,-r mesophyll in size. The spaces between the large shrubs are filled irregularly 1 3 with smaller plants not forming a genuine closed understory as in heath, and including diverse elements such as both broad-leaved and ericoid shrubs, 2 grasses and annuals. The teatree scrub of swamps is an irregular open formation of large shrubs 1 of Melaleuca spp. 2.5 to 3.5 m tall which have very dense dark-coloured ~' crowns, and thick deeply-fissured bark, adopting the broombush habit with very numerous steeply ascending branches given off near the base and no main 15m stem. Leaves are very small, tiny and needle-like in most species, broad in M. laterijlora. The ground is often devoid of other species beneath. Fig. 26 Profile diagram of low mallee from measured strip 50 x 10 feet, Hyden­ Norseman road: Beard 1969a. [Key to symbols in Table XI] In the Coolgardie District an Acacia scrub may occur on young soils over granite. It is an open formation of spreading shrubs about 2.5 m in height, with occasional small trees of Casuarina cristata, Brachychiton gregorii, Callitris columellaris, or Acacia aneura. is the pri»eipal dominant shrub. _A few low shrubs occur also and a ground layer of ephemerals. 12 Mallee (Plate 26) Mallee is a shrub-eucalypt formation. Each plant has an underground root­ stock about 0.03 ml in size, from which arise numerous slender stems giving a bushy crown similar to the 'broombush' habit. Mallee is subject to frequent fires which destroy the top growth, regeneration taking place from coppice. It is not clear to what extent the mallee habit is genetically controlled or due to fire, Certainly any small Eucalyptus of a species having the power to coppice would automatically assume a mallee habit if frequently burnt, and very many mallee species can also be found in tree form, either moderately-sized or in the Fig. 27 Profile diagram of tall mallee from measured strip 50 x 10 feet, Hyden­ small but single-stemmed tree form known as 'marlock' in Western Au,stralia Norseman road: Beard 1969a. [Key to symbols in Table XI] (Plate 19). The structure of mallee is extremely variable, its height varying with age from the last fire, and its density and associates varying also. The most 13 Mallee-heath (Plates 27, 28) typical form of mallee is a closed community of mallee habit rising from 3-4.5 m in height, with an un~rstory of small ericoid shrubs of the genus This formation differs from the pure mallee formation in that the upper Melaleuca. The understory may els·ewhere consist of mixed shrubs belonging eucalypt layer is very open. In mallee proper the eucalypt layer is dominant, to the scrub-heath wnere there is a transition to the latter formation, ot· salt­ but in mallee-heath the heath layer is dominant. The most characteristic bush under alkaline soil conditions, or of hummock-gtass on red sand. t~ the species of the Eyre District, Eucalyptus· tetragona, is of extremely straggly Swan area the last two types occupy only small patches. The same species of growth; the stems are twisted and rambling and form very open clumps, rarely mallee eucalypts may occur over different understories and vice-versa, and the attaining 3.5 m in height. E. tetragona is noted for its extreme glaucousness; . stature of the· eucalypts may vary without change of species from true mallee the twigs, leaves and fruit are of a bluish colour and thickly covered with a to marlocks and small trees. Profile diagrams measured in mallee are pre­ silvery bloom. The leaves are simple, entire, elliptic and mesophyll in size. sented in Figs 26 and 27, the former a low form and the latter a tall. It is be­ E. tetraptera, an associated species, shares the rambling habit but not the lieved_ that these represent early and late growth stages. In both cases the glaucousness. Other species have the ordinary upright mallee habit, including mallee forms an almost closed canopy layer, at 2 m and 6 m respectively, with a E. marginata which characterizes one of the associations. The two profiles of discontinuous lower layer of Melaleuca broombushes. Occasional small this formation have been drawn in Fig. 28. The understory is as described clumps of grass were the only ground vegetation in both cases. below under scrub-heath. E. tetragona mallee-heath is characteristic of the

108 109 VEGETATION SURVEY SWAN 6m with simple (though in many cases deeply-divided) leaves. There is scope for considerable further investigation into the life form of scrub-heath plants, their regeneration after fire and other aspects. Et Et D Et Et 3 Et Thirty-one sample areas in heath a_nd scrub-heath were described by George, Hopkins and Marchant (1979), but details of physiognomy and floristic composition are extremely brief; there is no indication as to whether each was considered a mature example, nor are they related to previous vegetation map­ ping. The photographs reproduced are very helpful. Well-organized data are available from Muir (1976-78, 1978-79). Based on this information and the general mapping for the 1 : 250 000 series, the Swan map distinguishes ten associations or other informal floristic groups as noted on p. 83, between which physiognomy varies somewhat. The diagrams of Fig. 29 are from Beard 1969a: and illustrate the scrub- heaths of the Coolgardie District, mapped as x2SZc.

Fig. 28 Profile diagrams of two examples of mallee-heath 30 x 3 m measured 4m between the Phillips and Hamersley Rivers on the access track. Beard 1972a [Key to symbols in Table XI] 3

2 sandplains of the Eyre District, except where rainfall is higher on the Kalgan - Plains northeast of Albany, where E. marginata replaces it. The latter is also ·the character-species on the slopes of the Stirling Range. There are other mallee-heaths: with E. burracoppinensis in the Muntadgin System of the Avon District, and with E. drummondii along the boundary between the Darling and Avon Districts. 5m : i 14 Scrub-heath (Plates 29-33) 4 It is difficult to describe a characteristic structure for this formation, since 3 the vegetation is burnt so frequently that a mature structure has little chance to develop. On regeneration after fire by coppice and seedling growth, a layer of 2 low shrubs appears, at first open and then more or less closed. With further growth, the naturally taller species begin to outstrip the smaller, and stratifica­ 1 tion begins to develop into a-l-0-wer-tayer of small ericoid shrubs with emergent taller species with large_r leaves. In_ time ~he upper,, layer, while remaining irregular due to the varyn1g mature sizes of its compdnents, may tend fi? close up and partially suppress the lower layer. The latter grows from 30-75 cm in 15m height, its components typically belonging to the Myrtaceae, with leaves lepto­ Fig. 29 Profile diagrams of scrub-heath, type ~SZc, strips 50 x 10 feet, Hyden­ phyll in Raunkiaer size. Some of these have a corymbose habit of growth, Norseman road. Top: early stage after fire; bottom: late stage. Beard 1969a. [Key to others are erect, thin and straggly. The components of the upper layer may symbols in Table XI] reach 4.5 m in height; they belong typically to the Proteaceae and have very deeply-divided, harsh, prickly leaves which are difficult to assess for leaf area, They are drawn from actual measured strips 50 ft (I 5 m) long, 10ft (3 m) wide, but would be mainly microphyll in Raunkiaer size. There may be some admix­ and represent what appear to be early and later stages of development. In the ture of Casuarina from adjacent thicket formations, and low mallees tend to 'early' stage the tall, pyramidal shrubs have reached 3-4.5 m occur where there is some clay in the subsoil. All components are evergreen, in height, and a lower layer of 60-90cm high·shrubs has become established,

110 111

j. VEGETATION SURVEY SWAN interspersed with small clumps of sedge, small caespitose aphyllous plants, and heath types, in reasonably mature examples. In ari area near Winchester, prostrate woody plants such as Balaustion pulcherrimum and Borya nitida. In examined by Beard (1976d}, which had not been burnt for over 25 years, struc­ the 'later' stage many of the Grevillea are much taller, and all of them are ture was very irregular. Occasional specimens of the taller species had grown beginning to show signs of senility. One in the left centre of the profile is to as much as 6 m in height, but many small plants in patches did not exceed recorded as stagheaded. Broombush and melaleucas have grown up to 1 m. Structure remained basically the same as in less mature stands, all plants 2 m in height, and there appears to be invasion in progress by Callitris preissii, being taller but relatively comparable. Thus, in other areas all stages up to this Santa/um acuminatum and a Hakea sp. In the vicinity of this profile, but not can be seen, depending on time since the last burn. Actinostrobus is coloniate, recorded in it, other such invaders were observed to include Hakea multi­ tending to occur in groves of small pyramidal trees of a typical cypress habit. lineata, Calothamnus quadrifidus and Casuarina corniculata. The supposed The banksias form small dense trees, while Xylomelum is diffuse with con­ invaders are all relatively young plants of species which are known to become spicuous persistent pear-shaped fruits. Communities of this alliance are among much larger. It seems probable that Grevillea excelsior is a pioneer species in the most colourful of all scrub-heaths when in flower in the spring due to the scrub-heath following fire, and that a succession can be recognized. The abundance of species of Verticordia and (further north) of Pileanthus. ground layer of the 'later' stage differs in that there are large and well­ Type x9SZc is related to the above, occupying sand-choked valleys in the established sedge clumps, with numerous small ericoid shrubs of 30-45 cm. extensive aeolian sandplain of the Marchagee System. Most of it has been Grevillea excelsior, with G. pterosperma which behaves similarly, strongly cleared. An example in a small reserve has scattered Actinostrobus 3 ni, open affects the physiognomy of this group of scrub-heaths. Elsewhere, where-they Acacia spp. 2 m, and a ground layer of Ecdeiocolea monostachyalooking like are not present, other species take over the character role. In the Badgingarra a gras;iand and concealing numerous small ericoid shrubs. · · sandplain (hSZc), Hakea /iqua is common, an erect straggling plant of · Type x10SZc is found in the Pikaring and Corrigin Systems, and is essen­ pecttliar appearance. It is part of an open stratum of tall shrubs about 2 m tall, tially a mosaic of Casuarina thickets with several different types of heath· and principally Proteaceae, over a dense, rich assemblage of low shrubs, mostly scrub-heath, so that there is no typical physiognomy to describe. very··sclerophyllous and pungent, under 1 m tall, with scattered small herba­ ceous plants as a ground layer, many of them Cyperaceae and Restionaceae. 15 Heath and Low Scrub (Plates 34-35) In the Roe District, whic)l is in the mallee region where mallee in some form The low stature of this vegetation gives little scope for variation between dif­ is almost universal, the scrub-heaths (x3SZc) consist typically of heath with ferent types apart from the degree of_density which distinguishes heath from scattered small mallees (Eucalyptus albida, E. incrassata) as emergents. Other low 'scrub. The particular physiognomy of dominant specie_s impresses certain tall shrubs are present, Grevillea hookerana and Casuarina pinaster being differences. In general, in heath there .is a single closed layer of.low shrubs characteristic. ; under 1 m, principally sclerophylls with small (leptophyllous) or deeply­ I In· the Tathra vegetation system the type x.iSZc is very heterogeneous with­ divided pungent leaves. In the Dongolocking Reserve, Muir (1978a) was able out special features. The normal two-layered structure is present. Type xsSZc to distinguish two strata of shrubs about 0.5 and 1.0 m tall respectively in most on the Esperance coast has .and inermis as samples, with rare scattered trees or mallees, and a scattered herbaceous r; character species. These are large bushy shrubs. Type xt;SZc is found on sand ground layer including numerous Restionaceae and Cyperaceae, a few grasses over coastal limestone in the Jurien System. The upper tall-shrub layer com­ and forbs. Wind-pruned coastal communities may often be particularly low, prises Banksia attenuata, B. menziesii, B. prionotes, Nuytsia floribunda and 30-60 cm tall, and matted; in some the succulent-leaved Scaevola crassifolia the grass tree Xanthorrhoea P¥eissii. The shrubs are bushy, and given suffi­ and S. nitida are conspicuous. The majority of heaths in inland and drier cient time-lapse after burning, the community mi~pt _c~ose up to.~become coastal areas are dominated by Dryandra or have Dryandra spp. as conspicu­ Banksia low woodland. In the understory Dryandra sessihs and Calothamnus ous elements, and appear to belong to a Dryandra-Acacia alliance as suggested quadrifidus are conspicuous and the community evidently represents a north­ by Bridgewater and Zammit (1979). These communities tend to form impene­ ward extension of the Dryandro-Calothamrietum of Bridgewater and Zamrnit trable low thickets of prickles due to the rigid, pungent-pointed leaves of (1979). Dryandra. ;\ Types x7SZc and x8SZc belong to the 'Banksia-Xylomelum alliance' of Quite a different physiognomy is presented by the low scrub on rocky head­ Beard (1979a) which occupies a chain of sandplains with deep yellow earthy lands of the south coast, which are exposed to gales and have little depth of sands, which stretch from north of the Murchison River south as far as Kulin, soil. The component shrubs, standing in open formation and less than 1 m tall, in the 350-400 mm rainfall band. The alliance is characterized by the presence adopt a dense rounded or tussock-like habit. Sometimes the spaces are filled of Actinostrobus arenarius, Banksia spp. (varying locally) and Xylomelum with a dense heath layer 20-30 cm high. There seems to be no characteristic angustifolium. This is the most distinctive and easy to recognize of all scrub- type of leaf, or of any other growth property except the domed habit. Many of

112 113

I, VEGETATION SURVEY SWAN the species present occur in other, inland vegetation and adopt quite different any magnitude up to 70% cover. The denser the shrub layer, the more attenu­ forms (Beard 1972a, Schweinfurth 1978). ated the understory which may contain a few low shrubs, some of them succu­ lent (Rhagodia, Enchylaena, Lycium), and a ground layer of scattered low or 16 Sedgeland (Plates 36, 37) creeping succulents (Arthrocnemum, Carpobrotus, Disphyma, Maireana). On heavier soils eur.:aiypts appear also, constituting 'thickly wooded' cate­ This formation is confined to the subcoastal areas in deep swamps fringing gory. They may be generally scattered or in groups, at heights from 10 to 20 m. lakes and estuaries, or in the Warren subdistrict on very poorly-drained sandy The species present, which may associate variously, conform in general to a plains. The term sedgeland is to be taken in a broad sense, s.ince reed-like 'ff. sequence with increasing clay fraction in the soil, e.g. Eucalyptus loxophleba­ plants of other families than Cyperaceae, ·especially Typhaceae, Juncaceae and E. gracilis-E. salmonophloia-E. salubris. E. longicornis is found on highly Restionaceae may be present or even exclusive. Juncus marsh frequently calcereous material, the 'lake parna' of Bettenay and Hingston 1961. Distribu­ borders open water in tidal estuaries, sedges and bulrushes do so in the lakes of tion of E. kondininensis is irregular: it is suspected that it occurs on gypseous the Swan Coastal Plain, while Restionaceae may be dominant or co-dominant deposits. The shrub and ground layers are essentially as described above. iri the south coastal area. In all cases transitions to dry land take the form of In the lower-rainfall areas a variation occurs where unwooded communities appearance of trees and shrubs, with the sedgeland forming an understory. In of Atriplex (saltbush) border lakes, usually on the leeward side subject to the south coastal swamps scattered sclerophyll shrubs such as Beaufortia deposit of salt by deflation. Away from the lake scattered eucalypts appear, sparsa may be generally present in the sedgeland. In general, the sed~!J-nd which become more dense until the normal woodland is entered. In the Cool­ consists of a single story, very dense, and 0.5 to I.Om in height. (See McComb gardie District a Frankenia zone may occur in a lake-shore band between the &McComb 1967, Hodgkin 1978, Beard 1979d.) samphire and the saltbush. Frankenia are small ericoid shrubs. Saltbush com­ 17 Shrub Steppe (Plate 38) munities consist of mixed Atriplex vesicaria, Frankenia interioris and the grasses Danthonia setacea and Stipa elegantissima. This is essentially an Eremaean formation and is limited (in the Swan area) to some small patches in the Coolgardie Distrct on red sandy duplex soils. The ground layer consists mainly of the hummock grass Triodia scariosa, which VEGETATION SERIES probably gives a cover of abbut 30% (Winkworth 1967), interspersed with low shrubs mostly of an ericoid form (Olearia,. Thryptomene, Wehlia). There are It is unsatisfactory to define u.nits o(vt;getation and to map them without also scattered taller shrubs up to 2m, which are larger-leaved sclerophylls (Acacia, clarifying the ecological factors of climate, physiography and soil which con­ Grev ii/ea, Hakea) and a layer of scattered mallee up to 4 m. trol them. The ecological relationships of the different units one to another can then also be explained. In soil mapping it has become fashionable to 18 Succulent Steppe (Plates 39, 40) 1. I classify soils purely on their profile characteristics and to discard the earlier Succulent steppe is a technical description for the communities which are regional approach which sought to interpret the effects of climate, parent found on saline and gypseous soils in and around playa lakes. They are divided material and the plant cover on soil formation. In the case of vegetation it is physiognomically into three classes for mapping purposes, described as Un­ also possible to classify it purely on its profile characteristics (Specht 1970) and wooded, Lightly Wooded and Thickly Wooded. this has been the practice throughout the Vegetation Survey of Western Aus­ Most of the unwooded com:mumt1es consist of samphires, low shrubs with tralia (Beard 1969a, Beard & Webb 1974), but it is unsatisfactory to stop short succulent, jointed stems. The lowest portions of salt lakes which are_sea:sonally at the factual classification; otherwise this results in the loss of the ecological flooded, in summer dry and surfaced with salt crystals, ate devoid of vegeta­ content of the classification, and we are left with a mass of unrelated indi­ tion. The samphires border these areas or cover extensive flats of saline mud vidual units. less subject to prolonged or deep inundation. The shrubs, 30 to 60cm tall, are There are two ways in which vegetation units may be meaningfully related to scattered to give an estimated 30-700Jo cover and comprise several species of one another; the first is through the medium of 'vegetation series' and the Arthrocnemum. Few or no other species occur, and may be other low succu­ second through 'vegetation systems'. The first illustrates the vegetation lents (Bassia, Disphyma, Maireana) or ~phemerals such as Senecio lautus. changes induced· by ·varying climate upon similar substrates, and the second Sandy flats adjoining the lakes but at a higher level, which are also saline due those induced by changes of substrate within areas of similar climate. The con­ to groundwater or deflation of salt from the lake beds, frequently ciµ-ry scrub cept of 'vegetation series' was found useful by Beard (1944, 1955) in classify­ or thicket of Melale1,1ca, Acacia, Hakea and/or other species, constituting the ing the vegetation of tropical America. A single climatic optimum formation I 'lightly wooded' category. The shrubs attain 2 to 5 min height and densities of )f was postulated-the tropical rainforest-from which five series of formations

114 I 115 VEGETATION SURVEY SWAN Table XII. Major vegetation communities on acid and basic rocks in the rainfall and substrate, so that for example the deep sands become less and less three climatic zones of the Kimberley leached as rainfall decreases, and the pallid zone soils change from yellow to red and from neutral to alkaline. Average heights of the vegetation are inserted Basic rocks in each case on the bottom line. Mean annual Acid rocks and Soils other than It is obvious that there is no simple climatic zonation of vegetation or soils in Cracking clays rainfall /aterite cracking clays southwestern Australia. Substrate has a very substantial effect, and explains the apparent paradox in zonation seen on crossing the Darling Plateau east­ >700mm Stringy bark- Northern t,ox- Blue-grass grassland ward from Perth. As rainfall decreases in an easterly direction, the jarrah­ bloodwood savanna bloodwood savanna marri forest changes to marri-wandoo woodland, and this to York gum wood­ woodland woodland land, with height and density decreasing in accordance with the rainfall. If this 400-700mm Snappy gum Blood wood- Barley-Mitchell-grass were a simple response to rainfall, the first wandoo and later the first York tree savanna southern box low-tree grassland and Mitchell gum would appear on the driest sites, namely on the ridges, but they do not; savanna woodland and other grass grass­ they first appear in the valley bottoms together with their appropriate soil land type. <400mm Tree and shrub steppe Jarrah-marri forest has a wide range, occurring on most soils in the higher rainfall bands. Other communities are more restricted. Casuarina campestris has two habitats, on ironstone duricrust and bedrock soils, in separate rainfall were conceived to radiate from optimum to pessimum, each series showing bands. In 'four out of five series there is a sudden cut-off point where wood- progressive reduction of structure with increasing adversity of the habitat. , land gives way to kwongan (shrubland), and this is presumably determined by Each series comprised a single 'essential habitat'. One series was on well­ the moisture-retaining capacity of the soil. No cut-off to kwongan occurs at all drained deep soils, a second on well-drained shallow soils, both mainly reflect­ on the heavier pallid zone soils, whereas deep sands cannot support anything ing increasing dryness of climate. Two other series were on ill-drained soils, taller than low woodland below 900-mm rainfall, and the transition from this the one permanently wet, the other seasonally waterlogged: these tended to be to scrub-heath-the most open formation of any shrublands-occurs early at a less dependent upon climate: rather upon depth of inundation. The fifth series point of 625 mm of rainfall. The cut-off point of young bedrock soils occurs at was montane and controlled by the effects of increasing altitude. Such series the low rainfall of 300 mm, on durkrust at 450 mm and on sands with iron­ cannot so usefully be applied in Western Australia with its entirely different stone gravel at 625 mm, the s;me as on deep sands. It is interesting that the climate, topography and soils. However, ·Perry (1970), in describing the vege­ apparently inhospitable duricrust should carry woodland so far out, evidently tation of the West Kimberley, showed that there were three different suites of due to the ability of tree roots to penetrate the duricrust into the pallid zone plant communities varying with the underling rocks and soils through three beneath (Ooley 1967, Kimber 1974). Shrublands on sands with ironstone climatic zones, as expressed in Table XI above. gravel have the richest floras throughout the series: this confirms George et al. These in a simple form are 'vegetation series'. In the southwest the series (1979). Shrublands on deep sands while poorer in species are taller. Those on differ in the two climatic sectors of Fig. 8, the western sector being the wood­ duricrust are the least tall. land region and the eastern sector the mallee region. In the western sector five While no measurements have been made, it would appear to the eye that major substrate types can most usefully be illustrated. There are others such as biomass is at its lowest in the formation which first succeeds woodland in each coastal limestone whose occurrence is more limited, but the major ty.pei(are: series: thereafter as rainfall decreases further, biomass appears to increase again. In the first three series in the table thickets found under less than 300- massive ironstone duricrust (Ks-Uc4)* soils mm rainfall certainly appear to have greater biomasses than the Dryandra sands containing or overlying ironstone gravel (Uc2.12) (Uc4.11)* heath, Casuarina thickets and Banksia-Xylomelum scrub-heath found with deep sands (Uc2.2) .(Uc2.3) (Gn2.21) (Uc5.22)* higher rainfall. The reason for this probably lies in the increasing tendency of pallid zone soils (Dy3) (Dr2) (Gn2.12)* precipitation in the interior to fall in heavy thunderstorms which more effec­ young soils on bedrock (various). tively promote groundwater recharge. Also sands in drier areas have uniform profiles and may b~.less leached of clay particles. Height of the trees, but not The vegetation upon each of these under varying rainfall is illustrated in necessarily biomass, increases again in woodlands on pallid zone soils in the Table XIII, p. 126. It has to be expected that there is some interaction between lower rainfall bands. * Northcote soil classification One ofthe most interesting conclusions from Table XIII and perhaps sur-

116 117 , VEGETATION SURVEY SWAN prising in the light of views expressed (Gardner 1944, George et al. 1979) is that It must be borne in mind that nearly all Western Australian plant communi­ moisture relations rather than nutrient availability have the paramount effect ties are established upon nutritionally-deficient soils and thus have many on gross physiognomy in Western Australian vegetation. It is likely that morphological characteristics in common. It was shown in a previous section nutrient availability may have some effect on selection of species whose par­ during a discussion of species richness that the sclerophyll, 'heath' flora ticular growth form then influences physiognomy to some degree, but the extends as an understory into forests and woodlands on sandy and lateritic gross variations between forest, woodland, heath and thicket within each soils. This flora must thus be viewed as a continuum within vegetation types series are brought about by differences in moisture relations, not fertility. The which vary in height and density according to rainfall, so that shrublands are concept of moisture relations embraces moisture-holding capacity which will only one segment of a complete peinobiome, employing Walter's (1979) useful be more important in drier areas, and permeability, drainage and aeration term. (A peinobiome is an environment dominated by nutritionally deficient chiefly in the higher-rainfall areas. These properties are determined by the soils). This was seen clearly by Specht and Rayson (1957) in their classic study physical characteristics of the soil. Owing to the ancient deep-weathering of of heathland in South Australia, which was undertaken to investigate the the soil mantle under prior climates, the inherent capability of the substrate to ecological relationships of 'the sclerophyllous understory in Australia' (sic, supply nutrients can be assumed to remain approximately constant within each authors' summary). Forests and woodlands with such understories may be vegetation series, except for the young soils on bedrock, where parent material regarded, in a broad sense, also as heathlands. It is well established by now (17 will be important. Differences in efficiency of recycling may occur between references cited by Specht and Rayson 1957: also especially Beadle 1954, 1966) vegetation types but that is a secondary consideration. It does not seem logical that the scleromorphy is associated with nutrient deficiency, especially in phos­ to suppose that at the cut-off point from woodland to kwongan there is sud­ phate; and is a form of peinomorphosis (Walter 1979). denly a dramatic drop in availability of nutrients, whereas it is quite conceiv­ Sclerophyll understories are present in all the forest and woodland forma- able that a limiting moisture threshold is reached. This point is of importance . tions shown in Table XIII, with the exception of the karri tall forest, York in that the sandy and lateritic soils are known to be highly nutrient-deficient gum woodland, Acacia acuminata low woodland, and some stands of salmon for agricultural purposes, so that it might be assumed that kwongan vegetation gum and gimlet woodland. Karri soils are frequently developed on less defi­ growing on them is stunted for that reason. This is seen to be a false assump­ cient parent materials, and while low in phosphate, are less critically so than tion when it is realized that equivalent soils carry woodland and forest under many other soils. The understory is woody but not sclerophyllous. York gum higher rainfall. • and jam (A. acuminata) soils were among the few found cultivable by the early This general conclusion is supported by the opinion, commonly held, that settlers without fertilizer. The 1Jndersfory is predominantly herbaceous orsoft­ after agricultural development the crops and pastures consume less moisture leaved. Salmon gum and gimlet woodlands may have either a sclerophyll · than the natural vegetation they replaced, so that water tables rise and salt is ('broombush') understory or a non-sclerophyll ('saltbush', 'bluebush' or

brought to the surface. If this is so, it follows that the natural vegetation, 'greybush') understory (Beard 1975a). The latter occurs on the more cal 0 whether woodland or heath, was highly moisture-efficient. This it could not be careous soils, so that as usual nutrients and sclerophylly are linked. With this if biomass had been reduced by nutrient starvation. exception all woodlands on pallid zone soils. have sclerophyll understories and Nutrition may be responsible for some of the differences between 'vegeta­ belong to the peinobiome. tion series', although the physic~tructure of the soil which determines its As in tropical America all the 'vegetation series' in Table XIII could be con­ moisture capacity is still likely to be paramount in controlling vege~ion ceived to radiate from a single optimum formation. In southern Australia the height and density. Eucalyptus diversicolor (karri) the principal specie~-0f tall optimum generally appears to be rainforest with eucalypt tall forest ('wet forest has been shown to require red earth soils, which in the Pemberton area sclerophyll forest') as a substitution community resulting from fire. In the (McArthur & Clifton 1975) develop upon basic and intermediate gneiss, i.e. southwest, rainforest is apparently feasible, at least on karri red earths, but the parent materials of higher inherent fertility. The red earths also have very flora is absent, perhaps due to Pleistocene aridity. Eucalypt tall forest may favourable physical properties but are deficient for agricultural purposes in therefore be considered the optimum formation within the peinobiome. phosphate and zinc. Outside the metamorphic belt at Pemberton they develop. It is difficult to construct a similar table for the eastern sector, for a variety around bosses of granite. Karri is also found on brown sands derived from of reasons, although it has been done in Table XIV, p. 128. The maximum coastal limestone. Tall forest is formed by E. marginata and E. calophylla rainfall in the eastern sector is 1000mm, and very little of the area receives also, given adequate rainfall, on red and yellow podzolic soils of less favour­ more than 600 mm, confined to small portions in the vicinity of Albany and able physical characteristics than the red earths. These two species replace Esperance. Certain substrate types predominate over wide areas, while others E. diversicolor on red earths under lower rainfall. Even in this case therefore may occur only in local pockets or not at all. The 'massive ironstone duricrust' nutrition plays a subordinate role to moisture relations. group is so rare that it may be disregarded. Instead, the widespread soil type

118 119 VEGETATION SURVEY SWAN 'soloth' (Stace et al. I 968), characteristic of the mallee region, has been intro­ The question to be resolved is whether mallee reflects the rainfall regime of duced into the table, i.e. sandy duplex soils with clay subsoils (Dy4, Dy5) this sector, or whether it is an artifact of the solodic Dy5 soils. MaUee and its which appear as a variation to the pallid zone soils. In the western sector, depauperate form mallee-heath are closely tied to the Dy5 soils, which occur to pallid zone soils of the more humid climates typically have hard-setting loamy only a minor extent in the western sector. However, mallee is also to be found topsoils (Dy2, Dy3), whereas in the eastern sector they typically have sandy on the deep sand of lunettes near the Stirling Range, on granite bosses and on topsoils (Dy4, Dy5) overlying clay. This much more pronounced textural dif­ dissected country on Plantagenet Beds; it occurs on Dy3 and Dr2 soils, mixed ferentiation may be expec.:ted to have adverse effects on moisture relations. with patches of woodland, and as scattered plants in the scrub-heath of the Perched water-tables tend to occur in the rainy season; drainage is poor, as x2SZc type. Mallee is absent from the low-rainfall vegetation in the interior, in slopes have a low gradient, and aeration is diminished. Beard (1953) found in the Coolgardie District, and from the higher-rainfall range of its own duplex tropical America that where soils with similar profiles appeared, savanna soils, where these have at the same time deeper top-soils. An important clue is replaced forest. Predominance of Dy5 soils in the Roe and Eyre Districts may given by the existence of eucalypt low forest on granite bosses forming perhaps be an effect of the different rainfall regime discussed earlier in connec­ isolated, fire-protected off-shore islands, whereas such bosses on the mainland tion with Fig. 10. have mallee of the same species, The first inference is that fire has degraded Comparing Table XIV with Table XIII, it is to be expected that owing to the the low-forest to mallee on these sites; the second inference that all mallee may difference in the relationship between rainfall and length of dry season illus­ be a fire disclimax. Because of its sandy top-soil the mallee formation has a trated in Fig. 10, all formations and their cut-off points will exhibit a shift to dense inflammable sclerophyll understory, and it is suggested that the mallee the right in Table XIV, which seems to be the case. The ironstone duricrust habit'is a product of frequent burning. The climax is likely to qe low forest or series is absent from Table XIV and sands with ironstone gravel are also absent low woodiand. The mallee-heaths might have some form of tall shrubland as a in the high rainfall range, since they become Dy5 soils in this sector. At low climax. The rainfall regime, however, is not one which would support taller range they are similar to Table XIII, with a right-hand shift. The scrub-heath trees than the 'low' category on such soils, so that climate is to that extent has scattered small mallee. In the deep-sands series, the nature of the vegeta­ responsible for the character of the mallee region. The real control is by a com­ tion is doubtful in the high-rainfall range due to paucity of examples. The plex of factors, climate, soil and fire interacting, Banksia-Lambertia association is the analogue of the Banksia-Xylome!um As in the western sector, soil must be taken into account in interpreting alliance, but is found on feached sands. Two other scrub-heath associations distribution of vegetation. In terms of climate alone, an apparent paradox is occur on yellow sands, x1SZc the Boorabbin type and x2SZc the Hyden type: again encountered, in fact th~.Great.Paradox of the traverse from Esperance character species are Grevillea excelsior and Grevillea hookerana respectively. to Kalgoorlie. At Esperance; rainfall 674 mm, the mallee-heath vegetation is Finally there is the Acacia resinomarginea thicket, as in Table XIII, with a 1-2m tall. Inland, at Scaddan the mallee is 3-6m tall and the rainfall has right-handed shift. Loamy pallid-zone soils are absent at high-rainfall range, dropped to 400 mm. At Salmon Gums (342 mm) woodland 20 m tall is entered, except in the Mt Barker area which is marginal to the sector. Yellow and red continuing through to Kalgoorlie (238 mm). The explanation lies in a complex duplex soils and calcareous earths are present at low range, with a right­ of differing rainfall regimes and differing soils. In the eastern sector there is handed shift. The sandy duplex soils of pallid zone B,. being so characteristic again no evidence that nutrient status is at all effective a determinant of of the Roe and Eyre District~sh~:" a complete range from 1000 mm to as 275 mm, where they stop abruptl~he series begins with jarrah-marri forest,/ vegetation height and density within the overall context of the peinobiome, moves to jarrah-Casuarina low forest and to jarrah mallee (illustrating ,the although it may affect other features. extraordinary plasticity of Eucalyptus marginata on siliceous soils), then to Since much woodland and forest in the western sector also has an inflam­ E. tetragona mallee-heath and finally to mallee. All soils above 400-mm rain­ mable sclerophyll understory it may be asked why this also is not burnt out and fall may (but not necessarily do) contain ironstone gravel. As remarked in reduced to mallee. Most probably heavier rainfall and more favourable soils other series in Table XIII, biomass rises again at the dry end of the series. enable the trees to outgrow the dangerous stage more rapdily. The scattered Young soils on bedrock are very heterogeneous. Karri tall forest occurs on its patches of woodland in the mallee area are on heavy Dr soils which do not red earths around granite bosses down to 800 mm of rainfall, a very marked have inflammable understories. right-handed shift. Under lower rainfall granite bosses carry eucalypt low It is interesting that some soils in the Badgingarra-Eneabba sandplains have forest on fire-protected islands, otherwise mallee. Thickets and mallee-heath been mapped as Dy5.8, and it seems probable that this is the reason for the occur on quartzites of the Stirling and Barren Ranges, yate and York gum appearance of such species as Eucalyptus tetragona and (E. occidentalis-E, loxophleba) woodland in the Pallinup River basin, but there. It has long been recognized that there is a relationship between the floras mallee on similar stream-dissected slopes further east, and under lowest rain­ of the Esperance and Badgingarra-Eneabba sandplains, which could be attri­ fall Casuarina thickets on greenstone or granite. butable to the development of similar soils upon sedimentary rocks.

120 121 , ~ "O ·53 :S! cu t C: = C: Ill n:I Ill 0- rJ) j 0. N Q VEGETATION SURVEY

..c:: VEGETATION SYSTEMS 1u ill ..c:: .6 The concept of the 'vegetation system' was originated by Speck (1958) and has - ::, 0 been applied by the later vegetation mappers of the southwest (Beard 1969a, (/) "O 1972-80, F. G. Smith 1972-74), It is currently defined as a particular series of q) plant communities recurring in a catenary sequence or mosaic pattern linked to u:: II) , ..."' ,.i::::II) climatic range. 0 ... i:i:l,.i:::: On undulating landscapes, communities are usually determined by their -~~.~ ..c:: topographic position, and are arranged in catenary sequences. On flatter '0 ii:: ground other factors may be dominant, and communities are usually arranged .E\li::a"' ill 0 , "' lined in the Appendix at the end of this book, arranged by 'botanical pro- "' i:: vinces' and 'districts'. Greater detail may be obtained by reference to the work =o•~ 0- ",::j t published at the 1 : 250 000 scale (Fig. 1). "' 0 'v 0. Fig. 30 has been assembled from Figs 20, 21, 25, 27 and 29 to demonstrate a ofJ- II)"';,- ::s catena, that of the Boorabbin System of the Coolgardie District. It should be = 8' compared with the landscape diagram in Fig. 13. This particular catena is illus- :E ofJ ~ .s trated as the profiles were available, but it is interesting in that it has a fair .... >, "O 0 0. number of components and an extreme range of structural types from 2 to C: 0 ::s 'i:i"' Ill 8 25 min height. This range is entirely controlled by substrate within an area of 0 II) 0 / 0 -.i::: "' :!: ... "' virtually uniform climate. The upland soils ar~ sandy, leached, underlain by '+. II) "O 0 u ironstone duricrust; partly weathered rock or clay. Down-slope the mallee has Q) X "'E =-~II) i:: a sandy wash derived from decay and recession of the breakaway creating a i ... II) Dy5 duplex soil. The woodland soils have loamy surface layers and are earths "'(.) =;,- ~ II) 0 (On, Ge) or Dy3 soils. At the lowest level they accumulate calcium carbonate ..c::...... (.) ..... o in the form of concretions. All valley soils are underlain by pallid zone clays. O""" i:: The valley soils have higher inherent fertility tan the upland soils, demon- § ;!::" strated by their agricultural viability with the ad ition only of superphosphate, ·~e~ 0 whereas sandplains require application of all rriajor and minor nutrients for "O t; ~ C: .2 ro successful crop and pasture production. However, valley soils have also more al 'c = ~ favourable physical characteristics, particularly as to water absorption and 0 0 0 0 ·.o water-holding capacity. Within the context of the catena of each vegetation :;:: .,., ro I: oJ).a ,._ system it might legitimately be inferred that the marked structural reduction of ::, OJ ·-f..,o.,.0 upland vegetation is caused by the lower fertility of the upland soils rather C: 0 than or as well as by their poorer physical qualities. The study made through I: '

KARROUN DIE HARDY ~ JIBBERDING BU~

JACKSON

BOORABBIN

CAVE HILL

Fig. 31 Vegetation systems in botanical districts and subdistricts of the Swan area.

125 ~le XIII. Vegetation series related to soils and rainfall: western sector

ANNUAL RAINFALL (mm)

SUBSTRATE 1200 1000 800 700 600 500 400 300

I I I I I I I I

1. Massive Jarrah- marri forest Jari ~h, marri, i Vandoo & powder- · Mallet Dryan ra Casuarina Acacia ironstone 1 andoo bark woodland wood- heat campestris neurophylla duricrust (KS-Uc• .II, 4.2) wpodland land thicket thicket (KS-On, .24) (K B-Uc4.2) "(KS-Uc4.2) (Ks-Uc4.ll) (KS-Uc4.ll) (KS-Uc~ .12) ,Sm 20m 15-20m 15m Im 2m 2m

' I I I I

2. Sands with Jarrah-1 narri forest Ba: ksialow Scrut heath Casuarina Acacia ironstone w odland Hetero ~eneous 1 dominant dominant gravel Also(Dy5.8 in this range Acacia - Casi arina thickets (UC2.l 2), (Uc4.11) thro1 ghout, containing ir pnstone gravels :sm r,-8m 1-~m 2m 2m \ \ .- --·--·---·----··-·--.------.... -··--. ·--..------· -~------·------..-,,--,------

r I ~ 1 l I I 3. Deep Karri tall Jarrah- sands forest and marri flanksia low ~ oodland Scrub-heath, Bai ksia-Xylo)tlelum Acacia marri forest wood- allii nee -esinomarginea on brown land Leached! ~nds thickets sands (Uc2.2, Sandyyel ow earths Y11llow earthy sands (Uc4.l) 2.3) (Uc2.3P) (On .21) ; (Uc5.22) 30-70m 20m 6-811 1- m 3m

I I I I 4. Pallid Zone Jarrah-marri J arrah-marri orest Marri-wando pwoodland Wandoo-Yo; ·k g1 m Salmong m-gimlet soils tall woodlavd woo ~land forest Neutral and'a ~die yellow Alkaline red an Alkalin red soils podzoli soils yellow pod :oli, and alkalii ~red earths Acidic n d & yellow podzc ic (Dy3. 82) soils (Dr2.33) (On2.13) soilswi h ironstone grav, I (Dy3.43) tDr2) (D 3)

Dr3.21, 2.21 (Dy3.8I) C 40m 25m 2011 15-20m 20- ·------Sm

I -' l l 5. Young soils Karri tall Jarrah-ma ri Marri - wando ~woodland York gum Low woodland Casuarina on bedrock forest forest (Dr2.32) Dr3.41) woodland A. acuminata campestris (On2.14) (On2.15) (Dr2.22) c_ huegeliana thicket E. loxophleba (Uc4.1) (Urn4) 70m 25m 201p 15m 6-8m 2m

.... -rN

~·::.:·- :~-----=----.,__;---=------·""·'--.---··-- -· .,.-.-..... -.-._..,. ·- Table XIV. Vegetation series related to soils and rainfall: eastern sector ------ANNUAL RAINFALL (mm}

SUBSTRATE 1000 900 800 700 600 500 400 300

- I. Sands with Absent in thi range Scrub-heath & A cacia-Casuarina ironstone gravel Replaced by D f5 soils rnallee thickets x2SZc (Uc2.12), (Uc4.1 l) (Gn 2) & (Uc5) with gravel with gravel 1-3m 2m

I I I I I I 2. Deep sands ? E. decipiens Mallee Scrub-heat~ Scrub-heat Acacia [(wwoodland (E. angulosa - Banksia-Lamb ~rtia x2SZc x1SZc resino- ?(UC2) (E. decipiens) leached san ~ marginea or Banksia (Uc2.il) (Uc .22) thickets low Woodland Yellow ear hy sands {Uc5.22) (Uc2.21) (Uc2.22) 8-!0rn 6m t-3m 1-3m 3 rn

\ - -- --..,..:.------~ ------,r-; -

I I , 3. Pallid Zone soils A Red&yellow York gum and Salmon gum, gimlet podzolic soils Ja rah-mar i ? f\bsent in this range salmon gum with and other species Dy2, Dy3 forest patches of Brown calc earths to red earth (Dr) Dy3.8) rnallee (Gcl.12) (Gcl.22) and solonized (Dy3.43) (Dr2.33) brown soils (Ge) 25m 15-20m 20-25m

l I f I I I 4. Pallid Zone Ja, rah-mar i Jarra h-Casuarina J arrah mallee- E. tetragona Mallee soils B forest low forest. heath. mallee-heath. Soloths sand 1>ver hare pan San j over clay Acid, leached -- Neutral sand Absent ~ Sandy duplex or aterite at Sand over clay over clay Alkaline sand > soils Dy4, Dy5 depth over clay z --- wiih acid Uc2.33) (Uc2 ~) (Uc2.3) May contain iror stone gravel. clay subsoils (Dy5) (Dy5) (Dy4) (Dy5) 20m !Orn 1-3m 1-3m 3-6m

5. Young soils Thickets and on bedrock Kar i tall Mallee on granite bosses mallee-heath Casuarina- Calotl am nus thickets fore st on ? (Um4.ll on quartzite. on greenstone (Um5 11) or Casuarina

gr3 lnite Lo IV forest on offsh< re islands Shallow 1(Uc4.1 l) campestris on gr nite (Uc4.ll) n2) (G 1 - Yate& York gu111 Al l:Icia quadrimarginea (Dr 2) (D 3) 1 n ironstone ridges I _f 4( m 11', allee on Plantagenet Beds (Dy3 .43) (Dy .82) I VEGETATION SURVEY SWAN SOME PROBLEMS IN SOUTHWESTERN VEGETATION Within the area surveyed, karri forest is mainly restricted to red earths I THE DISTRIBUTION OF KARRI -~ (Gn2._14, Gn2.15) of the lower slopes in areas where rainfall exceeds about (Eucalyptus diversicolor) 1100 mm. In drier localities, these soils carry good quality jarrah forest. I Within the high-rainfall area karri grows on the alluvial soils (Um5.2) of the The occurrence of this species in tall forests of the lower southwest has for floodplains of the main streams adjacent to its lower slope habitat. In middle long been felt to present an ecological problem, since its distribution does not and upper slope positions the soil changes to red podzolic (Dr2) or more com­ exhibit any simple relationship to rainfall or to rainfall and soils. Broadly, it is I monly to yellow podzolic (Dy3); karri persists on the deeper and more lo~my 1 known that the species principally occurs where rainfall exceeds 1000mm per ! of these soils but in mixture with marri. Marri is dominant on the paler and annum and then on red soils which are commonly known as 'karri loams' shallower phases of these soils. (McArthur & Clifton 1975). The problem arises from the absence of karri While the survey area has not yet been geologically mapped in detail, the from suitable soils under rainfall exceeding 1000 mm on the Darling Plateau general data (Geological Survey 1975, 1978) show it to be underlain by a meta­ generally north of Manjimup, and its presence, if only in small patches on suit­ morphic belt of predominantly gneissic rocks. McArthur and Clifton showed able soils, to the east of its principal zone of occurrence under rainfall as low that podzolic soils develop on acid and intermediate gneiss, red earths on basic as 750mm. gneiss. The formation of suitable karri soils is therefore primarily determined A small distribution map for the species was given by Churchill (1968). Its by lithology, secondarily by topographic position. The red earths have a principal occurrences are shown on the Swan 1 : 1 000 000 sheet, and mmt of reddish-brown loam or sandy loam surface changing gradually to red clay at the smaller patchy occurrences can be picked out on the Busselton-Augusta, about' 50cm. There is usually some ferruginous gravel in the surface horizons. Pemberton and Albany-Mt Barker 1 :250000 vegetation maps (F. G. Smith These soils are extremely permeable when moist and have a fairly high water­ 1973, 1972, Beard 1979d respectively). These are easier to distinguish on ,holding capacity. The range of available water extends from ± 1OIIJ'o at wilting Smith's maps as they are in colour, and the Pemberton sheet in particular point to ± 350/o at field capacity for the surface 10 cm. There is a very high sur­ serves to emphasize the highly-mosaic character of karri distribution even in its face area in relation to the clay contentas measured by standard methods for zone of principal occurrence, the Nornalup Vegetation System. The latter is particle size analysis. The red earths have a high organic matter content and a situated on the dissected south slope of the Darling Pla~eau, bounded by the very high carbon/nitrogen ratio. The organic matter penetrates quite deeply line of the Darling Fault on the west and by an approximate line drawn into the profile and this is attributed partly, at least, to the high level of bio­ through Manjimup and Mt Roe on the northeast, and from Mt Roe to Irwin logical activity within the UPP,~r 30-40 cm. Reaction is about neutral or only Inlet. Karri is absent from the Blackwood Plateau, except for small patches slightly acid; this is attributed to the high turnover of organic matter which· near its margin with the Leeuwin-Naturaliste Ridge, and reappears on the would maintain calcium and magnesium at high levels. The exchange complex latter in numerous patches of varying size. Karri has a small patchy occurrence is usually dominated by calcium, though one profile sampled had very high on the coastal dune systems. The zone of principal occurrence reaches its magnesium in the surface layer. For agricultural production in the area an northern limit at Willow Springs 35 km northwest of Manjimup. There are annual dressing of superphospbate is required. Phosphorus content of surface three more northerly outlying patches, all small and within the next 8 km. soil (0-lOcm) from 50 forested red ·earth sites ranged from 74ppmP. to East of Irwin Inlet in the Denmark Vegetation System, which tapers east­ 310 ppm P, with almost half the samples occurring in the 100-150 ppm P class. ward towards the coast to pinch out at Princess Royal Harbour, karri bas a Glasshouse experiments with clover showed large responses to phosphorus and patchy but consistent distr,bution in a soil/landform relationship different zinc. (Data from McArthur & Clifton 1975.) from that in the Nornalup ~ystem. This area appears on the Swan map as Thus, while these red earths owe their genesis initially to relatively basic jarrah-marri forest with patches of karri tall forest. Outliers to the north and rocks, their inherent fertility as soils is low, and their ability to support tall east consist of small patches on valley alluvium near Rocky Gully and along forest reaching heights of 80 m must be attributed to their favourable physical the Denmark and Hay Rivers, a substantial occurrence in the Porongurup properties, which lead in turn to other favourable factors such as the high rate Range, and two small adjacent patches on a plain at the northwesterh foot of of biological activity, high carbon nitrogen ratio and high turnover of organic Mt Manypeaks. ,! matter. The alluvial soils in the area also share these properties. This distribution was outlined by Churchill (1968) and an attempt was made I Outside the Pemberton survey area, karri occurs over different parent to determine its ecological basis. McArthur and Clifton (1957) investigated the materials, and these cases also need to be examined. Karri is absent from the occurrence of karri as part of a detailed survey of vegetation and soils in· coun­ Blackwood Plateau because of the poor physical qualities and poor internal try surrounding Pemberton-broadly, the western two-thirds of the Nornalup drainage of the soils thereon. Even jarrah-forest there is mostly stunted. Karri System. Their findings will be discussed first. recurs on or near to the Leeuwin-Naturaliste Ridge. Comparison of the vegeta-

130 131 . i. r . I!· VEGETATION SURVEY SWAN tion (F. G.- Smith 1973) and geological (Lowry 1967) I :250000 sheets shows further to the northeast. It consists of a very large batholith of porphyritic that the three largest occurrences of karri overlie calcarenite wholly or mainly. granite with bare summits rising to 670m above sea-level: the whole mass is Of the small outliers, one is on calcarenite, one on alluvium near the lower 12 km long and 3 km wide. Karri occupies middle and lower slop~s on acid red Blackwood River, and the remainder {at least nine patches are shown) are on earths (Gn2.14), with some Dr4.22 and Db3.22 (red and brown loamy duplex young soils created by the down-cutting of small creeks. These would probably soils) according to mapping· unit LK21 of Northcote et al. 1967. The small be classified as red or yellow podzolic (Dr2.21 or Dy3.21). On calcarenite the karri outlier near Manypeaks was reported by Beard (1979d) to be situated on soils are old and deeply weathered and constitute a different mapping unit · a red earth soil. (JKlO) from the younger calcarenite and dune sands in the soil map of North­ . l-1 The association of karri with soils of certain favourable physical properties cote et al. 1967. In the legend it is said that chief soils are brown sands (Uc4.2). is thus demonstrated but the problem of climatic control remains. The meta­ Small patches of karri occur on these brown sands developed from morphic belt of Pemberton extends north to beyond Donnybrook a_,nd con­ weathered dunes all along the coast from Augusta to Albany. Stands of marri tinues to bear the same soils upon it (soil mapping unit Qb31). Rruhfall is or of yate (Eucalyptus cornuta) also occur, and yate commonly borders karri 1000mm per annum but karri is absent. Yet karri will inhabit such soils further patches. Evidently there are soil gradations within the brown sands, with karri east under lower rainfall, down to 750mm. occupying the most favourable phase. Churchill (1968) presented a diagram (his Fig. 3) designed to show marginal The gneissic metamorphic belt of the Pemberton area extends only about as rainfall requirements of karri, in which the mean rainfall of the wettest month as the survey area of McArthur and Clifton, i.e. to the Deeside--road was plotted against mean rainfall of the driest. Rainfall stations within the (S. A. Wilde, pers. comm.). East of this line karri is at once more patchy and \ prind.pal area of occurrence of karri (Nornalup and Denmark Systems) were becomes more so to the end of its main range at Princess Royal Harbour. Here found to cluster neatly within the upper right section of the diagram, while it occurs either upon granite, apparently in association with bosses of in­ stations north of Manjimup in the high-rainfall area of the Darling Plateau, truded, mainly porphyritic granite, still on red earths but in a different topo­ where there is no karri, clustered neatly at upper left. However, the stations graphic position; or on river alluvium. McArthur and Clifton (1975) dealt with for the two principal outliers of katri, Rocky Gully and Porongurup, fell well a karri occurrence of this nature at Mt Chudalup, where they described the outside this arrangement in the lower right of the diagram among a cluster of outcrop as gneiss, whereas actually it is a fine-grained .~ranite (S. A. Wilde, other stations, all of which are east of Denmark and include Manypeaks and pers. comm.). In the Denma'rk Vegetation System Beard (1979d) recorded that Albany, both close to other- karri outliers. These stations have a low wettest the granite batholiths might or might not be exposed as bare rock at the sum­ month figure but a high driest _montti figure, and this is because they fall in the mit. Karri is found on red earth around such exposures or on the hills and eastern climatic sector of Fig~ 8 of this work, where the relationship between ridges which they underlie. It is also present on the alluvial soils along the total rainfall and severity of the dry season differs from that in the western streams, but middle and lower slopes are usually occupied by jarrah or jarrah­ sector. ChurchiH endeavoured to explain the anomaly on the ground that addi­ Casuarina on sand and/or laterite. It was suggested that the latter soil material tional moisture was available to karri in the outlying patches, and it is true that had been deposited in this position in the catena in the course of formation of in the Porongurups, for example, there must be much run-off into the forest the landscape, having originated as laterite on the peneplain before dissection from the granite domes above. However, this does not apply at Manypeaks, of the country. where the karri patches are on a plain. It must be concluded that Churchill's In and to the west of Denmark there is a belt of high ground culminating in Fig. 3 does not employ the appropriate parameters to explain the climatic Mt Shadforth, where this tatena is present, but most of the karri has been requirements of karri. cleared for agriculture. Nor~cote et al. 1967, in mapping unit TalO confirmed McArthur and Clifton {1975) were evidently puzzled by the situation, say­ the presence of red earths (Gn2. l 4 and Gn2.15) as well as red and yellow pod­ ing: 'In looking for an explanation for the distribution of karri it is difficult to zolic soils (Dr2.21, Dy3 .21, 3 .22). Between the Wilson Inlet and Princess decide on any one factor.' As they were not considering karri in its total range, Royal Harbour the country is much lower, and while the same catena still the relatively minor climatic effects which they listed are not of general appli­ exists on rising ground, with karri on the hilltops, wide belts of swampland cation. occupy flat valley bottoms. The massif of Torbay Hill replicates the Denmark In the present writer's opinion the climatic zonation shown in Fig. 8, and the area. West of Denmark from William Bay to the Bow River the country is plotting of karri rainfall stations in Fig. 10 _are sufficient evidence to solve this mainly also low with swampy flats and gently undulating hills , with karri only problem. All karri occurrences fall within the Moderate Mediterranean on isolated hilltops and along streams (as at the ), most of the coun­ climatic zone of Fig. 8, and all are shown in Fig. 10 to have less than four dry try being sandy and originally under jarrah and Casuarina. _months in the year. The calculation of the 'dry months' for both figures was The Porongurup Range cradles the largest outlier of karri forest 100 km made from standard climate diagrams {Bagnouls and Gaussen 1957, Walter

132 133 VEGETATION SURVEY SWAN & Lieth 1967), which are now widely accepted as reliable for ecological inter­ between the present range and the existing outlying stands' must be treated pretations of this nature. The number of dry months precisely separates the with caution. Under such circumstances karri would probably extend its range karri area of Pemberton from the non-karri area further north which has as on coastal brown sands and on red and yellow podzolic soils (Dr2, Dy3), but high a total rainfall; and it includes all the outliers at Albany, Porongurup and ill-drained Dy5 soils, which are very prevalent in the Albany-Mt Barker area, Manypeaks which have low total rainfalls. The karri stations plotted in Fig. 10 would become less receptive to the species. On the whole however, there seems were as follows: no reason to challenge Churchill's general conclusions on climatic changes during the past 8000 years. The period is relatively short, and it would be Western Sector Ann. rainfall No. dry unlikely that it covered any great change in the climatic regime as regards mm months seasonality, weather patterns and temperature, so that inferences based on Glen Warren 994 3.4 current species would be valid. Karridale 1182 3.8 Kent River 1186 2.0 SOME OTHER EUCAL YPT DISTRIBUTIONS Manjimup 1055 3.7 Margaret River 1192 3.7 Problems of distribution are known to occur in a great many native south~ Nornalup 1262 2.1 western taxa, but are complicated by incomplete knowledge of distributions Northcliffe 1451 2.8 ,.,.... and habitats and by the sheer numbers of taxa involved. It may be helpful at Pemberton 1255 2.8 this stage to examine the occurrence of some tree species of Eucalyptus in the Walpole _ 1392 2.2 southwest which, being conspicuous elements, are comparatively well known, Eastern Sector in the hope of establishing some general conclusions and principles. Albany Town 940 3.1 There is a small number of dominant species which have comparatively wide Denmark 1012 2.7 ranges and defined habitats: E. ·calophylla, E. diversicolor, E. loxophleba, Grasmere 1032 2.8 E. marginata, E. wandoo (Group 1). There is an equally small number which occupy much smaller areas due to the restricted occurrence of their well­ Young's Siding • 957 3.0 Porongurup (north side of Range) 848 2.6 defined habitats: E. accedens, E. astringens, E. gomphocephala, E. occiden­ Yellanup (south side of Range) 788 2.6 talis, E. -rudis (Group 2). The,above ·species appear to be in equilibrium with Manypeaks 737 3.2 present climate and soils and-to present no particular problems except perhaps in E. marginata, which accepts a fairly wide range of lateritic and sandy sub­ It may be suggested as an ecological principle that a species will occur within strates in a corresponding range of rainfall bands, adapting itself structurally a certain climatic range wherever it finds a certain range of soils. For karri, from tall forest to mallee. It occupies niches where one would normally expect both the appropriate climate and soils can now be said to have been deter­ four or five distinct species. E. calophyl/a is almost as adaptable, and E. mined. gomphocephala, while always clinging to the same substrate (sand over coastal Churchill's paper was designed primarily to determine the marginal rainfall limestone), ranges between 900mm and 600mm of annual rainfall and from requirements of karri as a basis for assessment of palaeoclimates from pollen tall to low woodland. profiles. Greater or lesser abundance of karri pollen at certain levels was then By contrast, there is a larger number of species of restricted occurrence used to infer higher ~wer rainfall. Unfortunately it is now shown that the whose habitat preferences are frequently difficult to define and which may relationship of karri distribution to rainfall isnot a simple one, and this unfor­ appear to be relict species (Group 3). These include the tingle trees, E. guil­ tunately too makes the interpretation of pollen profiles more difficult. Karri · foylei, E. jacksonii and E. brevistylis, which have a patchy local distribution in could have been_ far more -widespread in the past under considerably lower tall forests of the Walpole district. E. brevistylis is the rarest of all, so rare that annual rainfall than now, if the rainfall/temperature regime were .different it was only described in 1974, occurring in a single creek catchment east of Mt and if rainfall were better distributed throughout the year or made more effec­ Frankland. The author of the species (Brooker 1974) remarked that it appears tive by lower summer temperatures. Also, Churchill assumed karri to occur on to be taxonomically somewhat isolated and a possible relict species. The same a wider range of soils and parent materials than is actually the case, so that part of the world harbours E. Jicifolia, a low tree found in a few places on increases in rainfall might not be so effective in causing the species to extend its leached sands of weathered coastal dunes and some inland valleys. E. haema­ range, His statement 'it follows that a mean increase of 10 in [250mm] would toxylon is restricted to sandy lateritic gravels on the slopes of the Whicher be the minimal extra precipitation needed to establish widespread ·continuity S~p. where it forms low woodland or associates with E. marginata (F. G.

134 135 VEGETATION SURVEY SWAN Smith 1974). E. cornuta is a small to medium-sized tree, with a curiously Churchill (1968) mapped isolated occurrences of E. calophylla and erratic distribution within or very close to the Warren Subdistrict, occurring in E. marginata to the north and east of the present main range of the species, the small stands from the Stirling Range to Cape Naturaliste. It frequently fringes nature of which is to suggest retreat of the species rather than an advance in patches of karri forest, e.g. in the Porongurup Range where it grows between progress. the karri forest and the bare granite outcrops, and on coastal dunes. It is com­ In view of the new well-documented climatic fluctuations of the Quaternary mon on and around any granite bosses, and reaches its maximum extent as (p. 33 of this work), it is likely that all species of Eucalyptus have been subject woodland at the foot of the Naturaliste Downs near Dunsborough (F. G. to stresses and have had to adjust their ranges of occurrence. Churchill (1956, Smith 1973) on acid grey earth, a rare soil type (Northcote et al. 1967). 1961), who attempted to reconstruct climatic history from pollen profiles in E. megacarpa often occurs with E. cornuta on granites, but is tolerant of poor bogs, found that the oldest peats dated back to 15 000 BP at Herdsman's Lake drainage, and extends into the Dale Subdistrict, forming stands along swampy near Perth, and to 12000 BP at Boggy Lake near Walpole. These dates are con­ bottomlands. E. megacornuta occurs only on a few hillsides in the Ravens­ sistent with commencement of peat formation after the end of the last major thorpe Range, with a slightly different form found on the . arid period, when conditions returned to humid. Unfortunately no recogniz­ The eight species of this group give the impression of being fringe dwellers able pollen was found in Herdsman's Lake peat. At Boggy Lake Eucalyptus unable to extend onto a full range of suitable soils because of the competition cornuta and E. marginata were already present in the area at the outset of peat of the more successful major species. formation. Gradually E. Jicifolia, E. megacarpa, E. ca!ophylla and later Further north, E. /aeliae is a local species on granite outcrops in the· Dale E. diversicolor became abundant with a decline in E. cornuta and E. margi­ Subdistrict; it so closely resembles E. wandoo that it was only recently recog­ nata. This was interpreted as indicating a more humid climate. About the nized as distinct. E. lane-poolei occurs as an occasional tree on the Pinjarra middle of'the peat section there was a return to the initial pollen dominance Plain, and again as a very rare mallee in the Badgingarra sandplain (Le Sueur followed by a slight recovery of E. Jicifolia and E. calophy!la, and finally a Vegetation System), where the rare mallees E. johnsoniana and E. pendens trend to current conditions with E. marginata dominant. These indications are also occur. The latter is taxonomically related to E. exilis, a rare species known in agreement with the general trends of climatic oscillation suggested by from three localities in and to the east of the Darling Range, and to E. sepul­ Bowler (1977) and Rognon and Williams (1977) for the relatively short period cralis of the Barren Ranges. Relict behaviour is suggest"'d here also. covered. It is now clear that no peats formed during the period 20 000 to 15 000 E. decipiens has a most curious distribution in two disjunct areas, figured by BP are likely to be found in this state due to prevailing aridity. The chronology Churchill (1968), representing two entirely different habitats. The one is on in southeastern Australia has been based on radio-carbon dating of lake levels. coastal limestone of the west coast between Cervantes and Mandurah, where it Evidence of aridity in southw'~stern Australia is to be seen in aeolian land­ occurs occasionally as a small tree on shallow limestone soils, and the other forms, which are treated as contemporaneous with similar features in the east more extensive distribution is in the eastern end of the Menzies Subdistrict, on a basis of common morphology. Changes in species distribution here ranging into the Eyre District in and south of the Stirling Range to reach the during the past 40 000 years should be referable with a reasonable degree of coast of Bremer Bay. Here it is a small tree or mallee, and occurs on deep sand confidence to the chronology otherwise established. in lunettes or in valleys and outwash from the Stirling Range, as well as in ' It is likely therefore that from about 40 000 to 20 000 BP there was a period sandy-swampy depressions of that area. Churchill (1968) found fossil evidence of stability when climate was cooler than today and conditions were more of its occurrence further south on the Swan Coastal Plain, indicating preva­ humid. Moist eucalypt woodlands and forests were probably more widespread lence prior to 5000 yrs BP. than now, but receded markedly with the onset of aridity. Gentilli (1951) On the consolidat~astal limestone of the west coast where yellow sands showed that vegetation in Western Australia would be more sensitive to overlie calcarenite, E. gomphocephala forms tall woodland in the south, climatic changes acting in the direction of aridity than vice versa. It is impor­ declining in height northwards. At Yanchep distribution becomes patchy, but tant to try to envisage exactly what does happen when there is a climatic the species continues to occur as far as Jurien Bay as stunted trees in depres­ change. Some plant geographers, especially Burbidge (1960), argued as if sions. From here northward E. erythrocorys appears, and in the same way is at climate were the sole factor in species distribution, so that if, say, a certain first abundant, thinning out to patchy occurrence north of Dongara but con­ climatic zone moved in a certain direction all the species and plant communi­ tinuing to Shark Bay. In this northern section rare occurrences of E. oraria are ties found there would also move wholesale. This, however, they could only do found, the principal on Tamala Station just south of Shark Bay, where there if substrates were the same in the new area, for plants are governed by soil and are patches of stunted trees. The behaviour of these species suggests that they site as much as by climate. Gentilli (1951) imagined the effect of 'a decrease of have been both more luxuriant and more widespread in the past under more ·. qnly 5 inches [125 mm] in the annual rainfall if suitably spread throughout the favourable climatic conditions. wetter part of the year ... The semi-arid woodland of mallee and salmon gum

136 137 VEGETATION SURVEY SWAN would become an expanse of mulga. The various species of mallee and salmon which replaces it on ill-drained south-coastal sites may be regarded as an gum with its associated species would be confined to a narrow belt, less than ecotype which has become taxonomically distinct. Group 2 contains species 100 miles [160 km] wide, where the wandoo grows at present.' This statement associated with relatively specialized substrates which may have altered their is not intended to be taken too literally, for in fact there is no way that salmon range but have not otherwise needed to adapt. The situation on the coastal gum could replace wandoo, as their soils are too different. However, there limestone is interpreted as indicating a southward retreat from more favour­ could be pockets of soil within the wandoo zone where salmon gum could able humid conditions by the three species, E. gomphocephala, E. erythro­ establish itself. corys and E. oraria, which appear formerly to have been dominant in respec­ Pryor (1959, 1976) showed that in stable, mature eucalypt populations in the tive sectors of the coastal belt. eastern states each species has a 'closely circumscribed microhabitat' to which It is suggested here that change in the mallee region has principally been it has become adapted by evolution. He argued that under stable climatic con­ structural, a reduction from low forest or woodland to mallee by frequent ditions only individuals of a particular ecotype survive. Other forms, and burning, and that there has been relatively little species change. This is sug­ hybrids, are eliminated by natural selection. There seems to be no reason why gested by the greater number of common mallee species compared with tree this principle should not apply in other Australian genera also. During climatic species, and their regular occurrence in associations of two to four species per stability it may be supposed that there is a natural selection pressure continu­ site. Tree associations very rarely exceed two species and may indicate im­ ally at work to evolve ecotypes closely adapted to each microhabitat. If there is maturity of southwestern tree eucalypt communities. a change or marked fluctuation of climate, a fluid situation is introdtteed in which hybrids or new ecotypes have the opportunity to establish themselves. If THE MALLEE REGION the original type of climate is still available not too far away with similar sub­ strates, the original ecotype of the species may be able to extend its range Until quite recently there was little indication in the literature that a mallee thereto. In the original locality it may become extinct, be reduced to a relict, or region existed in Western Australia. Beard (1979/, 1980/) proposed a new Roe give rise to a new ecotype adapted to the changed habitat. Such a new ecotype Botanical District formed out of the southeastern portion of the Avon District may or may not be taxonomically distinct from the former one. If not, and if 'to include the mallee ... Its boundaries coincide with the limits of the con­ the former survives in a part of its original range or has shifted, we may have tinuous mallee formation on all sides' [Beard 1979/]. The previously delimited the phenomenon of disjunct occurrences of the same taxonomic species in dif­ Eyre District is characterized by a 11].allee-heath formation, with some areas of ferent habitats as in E. decipiens. Relict species may be regarded as taxa which mallee, and these two districts together constitute the Mallee Region. have effectively been deprived of their habitat by climatic change. Diels (1906) had originally named and defined the Eyre District, but the area It has been shown that E. Jicifolia today is confined to a few isolated locali­ now proposed as the Roe District was part of his Coolgardie District and ties near Wal pole. It appeared at Boggy Lake 10 km from any present site belonged to the Eremaean Province (Fig. 2). On the small, coloured vegetation during two periods interpreted as more humid i:han today. Watson (1963) map in Diels' book the Coolgardie District was all shown as 'Brigalow Scrub, reported occurrences of the red-flowered variety rosea of Eucalyptus calo­ Mallee Scrub or Sand Heath', and Diels (p. 20) furnished a general description phylla in forests between Donnybrook and the Donnelly River. The trees were as part of his introductory review of Australian vegetation in general: apparently taxonomically identical with E. calophylla var. ca/ophylla except for the flower colour, but their progeny show typical hybrid segregation of On the southern edge of the plateau there is a more or less dense Eucalyptus shrubland characters between E. calophylla and E. Jicifolia. It is a likely inference that which covers the country. In general it appears as a mixture of various different species E. Jicifo/ia once extended its range into that area and that introgression of Eucalyptus with the addition of many other genera, but in the form of branchy occurred. shrubs with olive-green foliage and a general sterility all the way from the Stirling The relict species of Group 3 are interpreted here as taxa which have lost Range in the West to the Murray River on the eastern side of the continent. This is the 'mallee-scrub' of the Australians, country of appalling dryness, often stretching for their habitat and become fringe-dwellers. They are the little orphans of the hundreds of miles without surface water, broken at the most by bare salt pans. This it storm, victims of Quaternary climatic oscillations. The contemporary success­ is, which the literature and the maps often show as desert, but it is a desert of unique ful species of the southwest (Group I) are interpreted as taxa which possessed character. The mallee-scrub of South Australia has often been the subject of descrip­ greater inherent variability and were able to ride out the storm by development tion: the portrayals of it, for which we have to thank Schomburgk and Behr, are gener­ of new ecotypes. E. marginata is outstanding in this regard, and appears in a ally known. Even for Western Australia their observations apply largely without quali­ multiplicity of intergrading ecotypes, whose stature varies from mallee to tall fication. tree, and which tolerate ferruginous and bauxitic duricrusts, deep sand, shallow sand, and from free to impeded drainage. The closely similar E. staeri Curiously enough after this, mallee did not appear among the plant forma-

138 139 VEGETATION SURVEY SWAN tions listed by Diels in either the South-West or the Eremaean Province, nor aggregations. It consists of calcium and magnesium carbonates which show a was it included in other shrublands. There is no mention of mallee communi­ t concentration in the subsoil. ties under the shrublands of either province. Even when describing the traverse Such soils are widespread in Western Australia in the Coolgardie Botanical northwards from Esperance to Coolgardie (p. 334) there is no mention of District, and only to a minor extent in the Roe District. They invariably carry mallee other than of Eucalyptus tetragona in the sandplains. woodland, not mallee. Typical mallee soils in Western Australia are not cal­ Jutson's vegetation map of 1914 showed essentially the same treatment of careous. They may be alkaline at the surface but the B-horizon is of acid day the southwest as Diels' map, except that the zone of 'brigalow scrub, mallee (Northcote et al. 1967). Burvill and Teakle (1938) described typical soil profiles scrub or sand heath, was now labelled 'low rainfall temperate forests and of the Western Australian mallee, which they referred to the solonetz type. A woodlands with belts of sand-heaths and mallee'. The mallee concept had thus solonetz, however, by definition has a strongly alkaline subsoil, and a more receded further. proper description would appear to be soloth, where the profile is structurally The general account of the vegetatiun of the state by Gardner (1942) did not similar, but is acid at depth-(Stace et al. 1968). Soloths are found throughout mention the existence of a mallee formation. In the southwest Eucalyptus the humid and sub-humid regions of Australia. They have very low inherent species of a mallee form were recorded as occurring scattered in sand-heaths, fertility and poor moisture relationships. and a mallee community was described forming a transitional band between Some further notes on mallee outside the Roe and Eyre Dsitricts may be of woodland and kwongan, as it occurs in the Moorine Rock and Boorabbin interest. Beyond the northern boundary of the Roe District mallee gradually vegetation systems. retires upslope, with a corresponding expansion of woodland from below, There was therefore essentially no literature on mallee in Western Australia until the mallee finally occupies a narrow band immediately below the break­ until 1967, when Beard (1967b) published a small paper on some aspects. The away. A Dy5 soil is created here by sandy wash from above. In the Coolgardie mallee occurring on the Nullarbor 1: 1 000 000 map-sheet was mapped and District this transition is rapid, in the Avon District it is more gradual, so that described by Beard (1975a). Mallee communities in the Bendering and West in the Moorine Rock and Muntadgin Systems there are mappable expanses of Bendering Reserves were described in detail by Muir (1977a & b), and there has mallee on upper slopes and in the heads of valleys. In the remainder of the been a vegetation survey of the Frank Hann National Park, in which mallee is Avon Region (Fig. 11) as far as the Meckering Line small patches of mallee !' a substantial component (Monk, Hnatiuk & George 1979). continue to occur scattered in woodland, or sometimes in sandplains, some­ Occurrences of mallee litrge enough to be mapped at the 1 : 1 000 000 scale times still at the transition from kwongan to woodland. It has been very rare are now shown on the Swan vegetation map. These are largely restricted to the for rnallee to be mappable as such even at the 1 : 250 000 scale. This pattern Roe Botanical District, where they constitute the predominant formation. continues into the Irwin Botanical District, but mallee is to all intents and pur­ More isolated patches occur in the Eyre District, and in the Muntadgin, poses absent from the Darling District. In the Eremaea it reappears as a scat­ Moorine Rock and Skeleton Rock Systems (Fig. 31) of the Avon District. tered element on sandplains with a hummock-grass ground layer. These latter systems have many features in common with the Roe District. The following is a list of mallee species recorded: The physiognomy of the mallee formation as well as the characteristics of its Darling Botanical District soils and rainfall regime have already been described in previous sections of the present work. There is need for a thorough review in the form of a com­ Eucalyptus calcicola on coastal limestone near Boranup, E. f oecunda on parative study with mallee in the eastern states, as it is already evident that coastal limestone north of Fremantle (Churchill 1968 as E. leptophylla), there are important differences. E. exilis in the Darling Range in the catchment, at Boyagin Rock The lack of information_on mallee and its environment in Western Australia and near Wickepin (Brooker 1974), E. drummondii in mallee-heaths at the has led to the unwarranted assumption that generalizations formulated in the eastern margin of the district. east are applicable also to the west. The introduction to Forest Trees of Aus­ Irwin Botanical District tralia (Hall, Johnston & Chippendale 1970) states: 'mallees occur on alkaline soils, often salty at depth, and receive less than 18 in [450 mm] of rain per Coastal Limestone: year'. This generalization seems to have started with Prescott (1931). Such In Acacia thicket: , E. oleosa soils became known as mallee soils, as they are so characteristic of the mallee In Acacia-Banksia scrub: Eucalyptus dongarraensis region in South Australia and Victoria, and later the term 'mallisol' was In Acacia-Casuarina-Melaleuca thicket (Cliff Head System) E. dongarraen­ coined for them. They are included in 'solonized brown soils' by Stace et al. sis may be locally dominant. (1968), and are said to be characterized by large amounts of calcareous Sandplains: material in the profile, both in the fine earth fraction and as soft and hard In Tree Heath formation: , E. dongarraensis,

140 141 : VEGETATION SURVEY SWAN E. eudesmioide~, E. foecunda, E. mannensis, E. roycei. E. grossa is found peripheral to granite outcrops. In scrub-heath, Kalbarri System: E. oldfieldii; E. loxophleba, E. eudes­ The mallee formation comprises E. calycogona, E. celastroides, E. cerasi­ mioides, E. dongarraensis, in included patches of mallee. f ormis, E. cylindriflora, E. deflexa, E. eremophila, E. f oecunda, E. georgei, In Banksia-Xylomelum alliance, Eucalyptus pyriformis, E. ebbanoensis, E. incrassata, E. leptophylla, E. longicornis, E. loxophleba, E. micranthera, E. eudesmioides, E. Jucunda, E. leptopoda, E. oldfieldii, E. gittinsii. E. oleosa, E. ovularis, E. pi/eata, E. redunca, E. sheathiana, E. transcontinen­ In Acacia-Casuarina-Melaleuca thickets, Eucalyptus eudesmioides, E. old­ talis, E. uncinata. fieldii, E. oleosa. Marlocks (small single-stemmed trees which regenerate from seed not cop­ In scrub-heath, Tathra System: E. dongarraensis, E. eudesmioides, E. tetra- pice) include E. fa lea ta and E. gardneri found on ironstone ridges, E. erythro­ gona, . nema ·and E. flocktoniae on mallee soil'. E. annulata and E. diptera on red In scrub-heath, Le Sueur System: E. johnsoniana, E. lane-poo/ei, clay, E. platypus and E. spathulata on winter-wet grey clay, and E. forrestiana E.pendens. on gilgai country of the Truslove Plateau. Woodland: Eyre Botanical District Mullingarra System: E. eudesmioides. Gairdner System: E. marginata, E. johnsoniana, E. drummondii, E. eudes- On the slopes of the Stirling Range mallee-heath contains E. margi11ata, E. calophylla, E. doratoxylon, E. preissiana. On the footplains of the range mioides. E. te.,.tragona is conspicuous, with E. ·angu!osa, E. buprestium, E. decipiens, Avon Botanical District E. decurva, E. flocktoniae, E. marginata, E. pachyloma, E. preissiana, In the far north (Perenjori and Jibberding Systems) E. eudesmioides, E. redunca, E. uncinata. These species drop out towards the east, till east of E. dongarraensis, E, leptopoda and E. oldfieldii are still present on sandplains Ravensthorpe only E. tetragona is still consistent, joined by E. tetraptera and but disappear further south. E. incrassata; E. angulosa occurs on coastal dune sands. There is an extraordinary concentration of mallee species in the W ongan In the Barren Ranges and Ravensthorpe Range E. preissiana and E. leh­ Hills. On the summit plateau E. drummondii, E. ebbanoensis, E. eudes­ mannii form thickets on quartzites together with the local endemics E. acies, mioides, E. flocktoniae, E. redunca, E. transcontinenta!is are found, and on E. burdettiana, E. coronata and E. sepulcralis. E. desmondensis is found pediments E. dongarraensis, E. drummondii, E. ebbanoensis, E. erythro­ around the Ravensthorpe_ Range. On greenstoiies the principal species are nema, E. eudesmioides, E. f oecunda, E. ovularis, E. plenissima, E. redunca, E. nutans and E. gardneri with E. c·onglobata, E. flocktoniae, E. loxophleba E. sheathiana, E. transcontinentalis. and E. uncinata. On footplains of the Ravensthorpe Range the marlocks In the Dryandra heaths of the inner wheatbelt one finds Eucalyptus drum- E. annulata, E. platypus, E. spathulata and E. stoatei are found. mondii, E. macrocarpa and E. redunca. Mallee on young soils on granite consists of E. eremophila, E. oleosa, In sandplains of the Banksia-Xylomelum alliance: Eucalyptus flocktoniae, E. cylindriflora, E. pileata. In valleys incised into the coastal plain mallee is E. foecunda, E, incrassata, E. oleosa, E. pyriformis. composed of E. redunca and E. uncinata with E. astringens, E. conglobata, In the outer wheatbelt in kwongan there are E. burracoppinensis, E. drum­ E. flocktoniae, E. incrassata. mondii, E. foecunda, E. oldfieldii, E. redunca. The small patches of mallee formation usually have E. redunca as the dominant species, but E. loxophleba, Coolgardie Botanical District E. ovularis and E. transcontinentalis may also be important, with E. foe­ Mallee is much less common in this district. Patches of mallee below break­ cunda, E. oleosa, E--:sne«-thiana and the small tree E. erythronema. South of aways, or in woodland, contain E. eremophila, E. foecunda, E. incrassata. the main railway line (Northam-Southern Cross) E. albida, E. annulata, E. burracoppinensis, E. f oecunda, E. incrassata, E. leptopoda, E. platy­ E. cylindriflora, E. incrassata and E. pileata appear, and. south of Corrigin corys occur in scrub-heath on sandplains. E. eremophila. A curious feature is the occurrence of some localized species on granite out­ crops, here and there in an apparently random manner. These are E. caesia, Roe Botanical District · E. cruels, E. kruseana, E. orbifolia and E. websterana. They all share the Occasional specimens of mallee iri scrub-heath comprise E. burracoppinen­ peculiarity of a particular type of peeling bark. sis in the north, E. tetragona in the south, sometimes E. leptopoda. These are sandplain mallees with a gnarled habit and broad, somewhat fleshy leaves. General. Some of the mallee species listed above may occur as trees under Other sandplain malees with an upright habit and pendent, falcate leaves are more favourable circumstances. E. albida and E. incrassata, more rarely E. foecunda and E. redunca. Mallee species of eucalypt in the Southwest greatly outnumber tree species.

142 143 I VEGETATION SURVEY SWAN per annum, and are principally developed upon the Phanerozoic rocks of the KWONGAN north coastal and south coastal areas with more scattered patches between. Early writers did not have access to all the facts, so that misconceptions have Beard (1976g) defined kwongan as 'an indigenous term for the Western Aus­ arisen. Diets (1906) whose vision was limited by the lack of access to so much tralian sandplain and its vegetation', being the basic meaning of the Aborigi­ of the country in his day, divided the 'shrub formations' of the South-West nal word-spelt in various different forms in early literature such as guangan, Province into 'sclerophyll scrub' and 'sand-heaths'. Th1;: former included the gongan and quonken, and in a modern work (Douglas 1968) as kwonkan. The Melaleuca-Hakea thickets of the Moresby Range near (Beard vegetation was said to consist of at least two plant formations, described as 1976c), all Dryandra heaths, and the thickets of the Stirling and Barren scrub-heath and broombush thicket. In this sense kwongan would not include Ranges. The sand-heaths included all the scrub-heath and mallee-heath. The coastal wind-pruned heaths, nor the hill thickets of the Stirling, Darren, existence of Banksia-Xylomelum communities was mentioned, and the sand­ Ravensthorpe, and Parker Ranges. In a broad sense it could be held to include plain mallees (.Eucalyptus pyriformis, E. oldfieldii, E. macrocarpa, E. tetra­ mallee but for many purposes it might seem preferable to preserve a distinction gona) were identified. Diels mentioned having seen Casuarina tbrokets in the between these two. Mallee-heath, however, is definitely kwongan. On the Irwin and catchments but had no other knowledge of other hand it would be of more practical value to extend the term kwongan to Acacia-Casuarina thickets on sandplains. The importance of this formation cover all types of sclerophyll shrubland, as these are physiognomically similar, was thus overlooked. and this could legitimately be done. The Swan vegetation map shows the"eXtent Gardner (1942) unfortunately introduced a second misconception: that such of kwongan formations of which the principal are mapped as _Acacia­ thickets occur typically on dense laterite; whereas in fact they occur equally Casuarina thickets, mallee-Casuarina thickets, mallee-heath, scrub-heath and freely on sand. He added a third misconception by conveying the impression heath. The kwongan formations are concentrated in the Irwin and Eyre that heath and sand are associated irrespective of rainfall, e.g.: 'Wherever the Botanical Districts, in the inland parts of the Avon and Roe Districts and the ___soil is of a sandy nature,. whether a loose detritus or the more compacted Coolgardie District. Kwongan is virtually absent from the Darling District due yellow or red sand of the interior-, heath-like formations predominate.' to its higher rainfall, except along the coast, although suitable sandy substrates Unfortunately also the latest authoritative paper, entitled 'The Heathlands occur there. Tables XIII _and XIV have been used in a previous section to of Western Australia', by George, Hopkins and Marchant (1979), in the book demonstrate that kwongan replaces woodland on deep sands and sandy gravels Heath/ands and Related fihrublands of the World, tends to perpetuate these at about 625 mm of annual rainfall, and at 450 mm on lateritic duricrust. earlier misconceptions. In thc;ir introduction these authors gave a definition of Kwongan does not occur at all on pallid zone soils. Heath and scrub-heath 'heathland' which would appear to include Acacia-Casuarina thickets and occur under higher rainfall than thickets. They change to thicket below 400- mallee, and linked the occurrence with sandplains. The paper however essenti­ mm annual rainfall on sandy gravels, below·375 mm on duricrust and below ally deals with heaths in the strict sense, which includes scrub-heath and_ 325 mm on deep sands . rilallee-heath but excludes thickets and mallee. Because this is not made clear, .The presence of kwongan is thus determined by the occurrence of sandy, the impression is conveyed that these constitute the only sandplain vegetation, gravelly and ferruginous substrates at rainfalls below 450-625 mm per annum. and sandplains are restricted to areas of heathland, e.g.: In the Irwin Botanical District the necessary substrates are favoured by the The two major regions of these·sandplains lie (a) in the north, between the Moore River underlying arenaceous Phanerozoic rocks. Further south on the same geo­ and Shark Bay, including the Mt Le Sueur-Eneabba area, and (b) in the south; between logical formations rainfall is higher and vegetation changes to Banksia low the Stirling Range and Israelite Bay. Small discontinuous areas of sandplairr are also woodland and jarralMnarri forest. In the Eyre District also Phanerozoic scattered over the central part of the southwest on the Western sediments underlie extensive sandplains. In the interior, however, the sand­ plains mantle the higher ground in the landscape and occupy a larger propor­ If 'heathland' were substituted for 'sandplain', this statement would be tion of it the further one moves up valley towards the sources of the ancient entirely correct, but it is confusing as it stands. rivers. In the inner wheatbelt (Northa~ to Katanning) there is relatively little The vegetation map now shows the full extent of sandplains and their vege­ sandplain. In the Merredin area Bettenay and Hingston (1960) estimated that it - tation of various types of kwongan and mallee. Their physiognomy has been covered 350Jo of the country. In the Boorabbin area it may well exceed 600Jo. described in a previous section, and some suggestions for tentative floristic Reference to the vegetation map shows this graphically. groupings have been made. The map shows also that Acacia-Casuarina thickets are the most widespread It may be of interest to compare Western Australian vegetation with the kwongan formation, followed by mallee. The heaths, including scrub-heath . Dark Island heath described in a classic study by Specht and Rayson (1957) in and mallee-heath, occur on a middle rainfall band between 325 and 625 mm South Australia. Annual rainfall in that case was given as 457 mm per annum.

144 ;' 145 VEGETATION SURVEY SWAN If an ombrothermic diagram is constructed from the figures, the number of ever, that under a more pluvial climate the heath would exist not as such but as dry months is found to be 5 .0. Relationship of this figure to annual rainfall is an understory to forest or woodland. Specht and Rayson were aware of this in accord with that for the eastern climatic sector of Western Australia, i.e. the and did not differentiate in principle between open heaths and forest under­ mallee region. The temperature curve is in accord with that for south c.oastal stories. stations in Western Australia, and the diagram accords closely with that for Scaddan, which is on the Truslove Plateau 50 km inland from Esperance, at ACKNOWLEDGEMENTS the boundary between mallee and mallee-heath country. The Dark Island heath is on a gently undulating sandplain reworked by wind J In the preparation of the present work the writer is particularly indebted to Mr in the past. The sand exceeds 1.5 m in depth, is. bleached at the surface, becom­ E. Bettenay, Dr R. J. Hnatiuk and Mr A. Milewski for critically reading ing yellow, and overlies acid clay. The surface sand is acid and deficient in sections of the manuscript, and to Professor·M. J. Webb, Dr J. Gentilli and nutrients. The deeper sandy phases of soils on the Esperance Plains in Western Dr M. J. Mulcahy for helpful discussions. Thanks are due to the Department Australia are therefore virtually identical except that they are neutral to alka­ of Geography of the University of Western Australia, where most of the carto­ line at the surface. In Wes tern Australia under these conditions Banksia graphy was performed, especially to Mr G. N. Ward. Mrs V. L_. Foley under­ speciosa and Lambt;rtia inermis would be dominant in a mixed flora of many took all the drafting and cartographic work for the map, and made the line Proteaceae, Myrtaceae and , also Casuarina and Xanthorrhoea. This drawings in this book. appears -to be substantially the same at Dark Island heath, where Brtnksia Field work in the area extended over 15 years, and was supported in the ornata and B. marginata are present, but there is no Lambertia, and Xanthor­ early stages by the King's Park Board, later by the Australian Biological rhoea appears to be rather more common than in Western Australia. Mallee Resources Study. The writer gratefully acknowledges the assistance of the staff eucalypts would be more numerous in species and common in Western Aus­ botanists at the Western Australian Herbarium and the National Herbarium, tralia, but usually in those parts of the sandplain where the clay is closer to the - ---·-s-ydney, who identified plant specimens. Nµmerous other people assisted in surface. various ways and have been acknowledgea in earlier publications of the Summarized characteristics given by Specht and Rayson can be repeated for 1 :250000 map series. Western Australia with very little alteration, e.g.: • The vegetation is dominated by a number of nanophanerophytes, not more than 6ft. REFERENCES [1.8m] in height, with an understory of chamaephytes, hemicryptophytes and geo­ phytes. The majority of the species possess dull green, small, sclerophyllous leaves Abbott, I. 1977. Species .richness, turnover and equilibrium in insular floras near (leptophylls). Growth occurs predominantly dur.ing the summer, from January to Perth, Western Australia. Aust. J. Bot. 25: 193-208. March, while many of the species flower during spring. Most of the dominant species, Anderson, R. M. 1947. The Trees of New South Wales. Govt Printer, Sydney. however, flower during late summer to midwinter. Leaf-fall is greatest towards the end Aplin, T. E. H. 1979. The Flora. In Environment and Science, ed. B. J. O'Brien. of the dry summer period, while litter decomposition, which is only completed after University ofW. Aust. Press, Nedlands. 1 ½-2½ years, reaches its maximum in the spring. Bagnouls, F. & Gaussen, H. 1957. Les climats ecologiques et leur classification; Annis Geogr. 66: 193-220. · Growth and flowering periods may differ somewhat in Western Australia. Beadle, N. C. W. 1954. Soil phosphate and the delimitation of plant communities in There seem to be no published observations. Trees of Eucalyptus and Banksia eastern Australia. Ecology 25: 370-4. in King's Park, Perth-:-ma-ke growth during summer (author, unpubl.), but --_- 1966. Soil phosphate and its role in moulding segments of the-Australian flora shrubs in kwongan appear to do so mainly in early summer, becoming and vegetation with special reference to xeromorphy and sclerophylly. Ecology 47: dormant when moisture is exhausted (R. J. Hnatiuk, pers. comm.). Foliar 991-1007. twig-s of Casuarina campestris frequently become dry and brown at the end of Beadle, N. C. W. & Costin, A. B. 1952. Ecological classification and nomenclature. Proc. Linn. Soc. N.S. W. 77: 61-82. summer. Most kwongan species flower during spring, but some dominants, Beard, J. S. 1944. Climax vegetation in tropical America. Ecology 25: 127-58. e.g. Banksia, flower in autumn, and the Epacridaceae are winter-flowering. --- 1953. The savanna vegetation of northern tropical America. Ee. Mon. 23: Specht and Rayson summarized the outstanding features of the southern 149-215. Australian heath as (1) a summer growth rhythm, (2) consistent occurrence on -- 1955. The classification of tropical American vegetation types. Ecology 36: soils of low fertility. Both features were considered to be inherited from an 89-99. evolutionary adaptation to impoverished soils during an earlier period of more -.-- 1965. Descriptive Catalogue of West Australian Plants. Society for Growing pluvial climate. This seems most likely to be correct. It may be observed how- _, t Aust. Plants, Sydney. 2nd edn 1970.

146 147 VEGETATION SURVEY SWAN -- 1967a. Natural woodland in King's Park, Perth. W. Aust. Natur. 10: 77-83. --- 1980g. Quaternary climatic changes and their effect on species evolution. --- 1967b. A study of patterns in some West Australian heath and mallee com- Proc. Arid Zone Symposium, Adelaide. munities. Aust. J. Bot. 15: 131-9. ---- (in press). South-Western'Australia. In Dry Coastal Ecosystems of the World, --- 1969a. The vegetation of the Boorabbin and Lake Johnston areas, W.A. Proc. ed. E. van der Maarel. W. Junk, The Hague. Linn. Soc. N.S. W. 93: 239-69. Beard, J. S. & Webb, M. J. 1974. The Vegetation Survey of Western Australia, its --- 1969b. The natural regions of deserts in Western Australia. J. Ecol. 57: L aims, objects and methods. Part I of , Explanatory Notes to I 677-712. . Sheet 2, Veg. Surv. W.A.1: l 000000 Series. Univ. ofW. Aust. Press, Nedlands. --- 1969c. Casuarina pinaster, the Western Australian Compass Bush. W. Aust. Bell, D. T., Loneragan, W. A. & Dodd, J. 1979. Preliminary vegetation survey of Star Natur. 11: 73-5. Swamp and vicinity, Western Australia, Res. Notes, W. Aust. Herbarium 2: 1-21. --- 1969d. Endemism in the Western Australian flora at the species level. J. Roy. Bentham, G. 1963-78. Flora Australiensis. 7 vols. London. Soc. West. Aust. 52: 18-20. Bettenay, E. 1962.' The salt lake systems and their associated aeolian features in the -- 1972-80. Vegetation Survey of Western Australia 1 :250000 Series. Vegmap semi-arid regions of Western Australia. J. Soil Sci. 13: 10-17. Publications,·6 Fraser Road, Applecross, W. Aust. Bettenay, E., Bll:lckmore, A. V. & Hingston, F. J. 1964. Aspects of the hydrologic 1972a Newdegate & Bremer Bay; 1972b Hyden; 1972c Southern Cross; 1972d cycle and related salinity in the Belka valley, Western Australia. Aust. J. Soil Res. 2: Jackson; 1972c Kalgoorlie. 187-210. 1973a Ravensthorpe; 1973b Esperance & Malcolm. Bettenay, E. & Hingston, F. J. 1961. The soils and land use of the Merredin area, 1976a Shark Bay & Edel; 1976b Ajana; 1976c Geraldton; 1976d Dongara; 1976e Western Australia. CSIRO Aust. Div. Soils, Soils and Land Use Series No. 41. Perenjori. · ,_. Bettenay, E. & Hingston, F. J. 1964. Development and distribution of soils in the 1979a Moora & Hill River; 1979b Perth; 1979c Pinjarra; 1979d Albany & Mt Merredin area, Western Australia. Aust. J. Soil Res. 2: 173-86. Barker. · Bettenay, E., McArthur, W. M. & Hingston, F. J. 1960. The soil associations of part 1980a Bencubbin; 1980b Kellerberrin; 1980c Corrigin; 1980d Dum bleyung. of the Swan Coastal Plain, Western Australia. CSIRO Aust. Div. Soils, Soils and --- 1973c. The elucidation of palaeodrainage patterns in Western Australia •·· -- __ Land Use Series No. 35. through vegetation mapping. Vegetation Survey of W.A. 0cc. Paper 1, Vegmap Biackall, W. E. & Grieve, B. J. 1954~75. How to Know Western Australian Wild­ Publications, Applecross. flowers, Parts I, II, III, IV. Univ. ofW. Aust. Press, Nedlands. -- 1973d. The ecology and distribution of Eucalyptus forrestiana Diels. J. Roy. Bowler, J. M. 1971. Pleistocene salinities and climatic change. In Aboriginal Man & Soc. West. Aust. 54: 76-7., Environment in Australia, eds D. J; Mulvaney & J. Golson. A.N.U. Press, Can­ -- 1974-80. Vegetation Survey of Western Australia, 1: 1000000 Series. Univ. of berra. W. Aust. Press, Nedlands. --- 1977. Recent developments in reconstructing late Quaternary environments in 1974a Sheet 2, Great Sandy Desert Australia. In The Origin of the Australians, eds R. L. Kirk & A. G. Thorne. Aust. 1974b Sheet 3, Inst. Abor. Studies, Canberra. 1975a Sheet 4, Nullarbor Bradhurst, P. J. 1954. The nutrient deficiencies of the Hawkes bury sandstone soils: the 1975b Sheet 5, Pilbara !' adaptation of the native plant to nitrogen, with special reference to Hakea pugioni­ 1976f Sheet 6, Murchison ,,,. ( f or mis. MSc thesis, Univ. of Sydney. 1979e Sheet 1, Kimberley I' Brewer, R. & Bettenay, E. 1973. Further evidence concerning the origin of the Western I 980e Sheet 7, Swan I I­ Australian sandplains. J. Geo/; Soc. Aust. 19: 533-4. --- 1976h. The monsoon forests of the Admiralty Gulf, Western Australia. Vege­ t Bridgewater, P. B. & Zammit, C. A. 1979. Phytosociology of S-W. Australian lime­ tatio 31: 177-92 .. stone heaths. Phytocoenologia 6: 327-43. --- 1976g. An indigen~erm for the Western Australian sandplain and its vege­ Brocket, M. I. H. 1974. Six new species of Eucalyptus from Western Australia~ Nuyt­ tation: J. Roy. Soc. West._Aust. 59: 55-7. sia 1 (4): 297-310. ---· 19761. The evolution of Australian desert plants. In Evolution ofDesert Biota, Brown, R. 1810. Prodromus Florae Novae Hol/andiae et lnsulae Vandiemen. Vol. I. ed. D. W. Goodall. Univ. Texas Press, Austin & London. London. -- 1979f. Phytogeographic regions. In Western Landscapes, ed.-J. Gentilli. Burbidge, N. T. 1960. The phytogeography of the Australian region. Aust. J. Bot. 8: Univ. ofW. Aust. Press. · 75-211. ✓-- 1979g. Vegetation map of the Stirling Range National Park, 1:50000. Burvill, G. H. 1979 (author). Chapters 1-7 in Agriculture in Western Australia National Parks Authority, W. Aust. (unpubl.). 1829-1879, ed. G. H. Burvill. Univ. of W. Aust. Press, Nedlands. --- 1979h. Vegetation Mapping in Western Australia. J. Roy. Soc. West. Aust. Burvill, G. H. & Teakle, L. J. H. 1938. The occurrence of solonetz (structural alkali) 62: 75-82. soils in Western Australia. J. Dept Agric. (West. Aust.) 15: 97-109. --- 1980f. A new phytogeographic map of Western Australia. Res. Notes W. Cameron, L. M. 1935. The regional distribution of vegetation in New South Wales. Aust. Herbarium 3: 37-58. Aust. Geogr. 2·(5): 18-32. \_ f 148 r 149 , I· \

11 h 1] VEGETATION SURVEY SWAN

Carey, S. W. 1976. The Expanding Earth. Developments in Geotectonics 10. Elsevier Enright, N. J. 1978. The interrelationship between plant species distribution and Scientific PubL Co., Amsterdam. properties of soils undergoing podzolisation in a coastal area in S.W. Australia. Churchill, D. M. 1956. An investigation of some pollen-bearing sediments from S.W. Aust. J. Ecol. 3: 389-401. Australia. BSc (Hons) thesis, Univ. of Western Australia. Erickson, R. 1969. The Drummonds of Hawthornden. Lamb Paterson Ltd, Perth. --- 1969. Late Quaternary eustatic changes in the Swan River District. J. Roy. Fox, J. E. D., Downes, S., & Maslin, B. R. 1980. The vascular plants of Yalgorup Soc. West. Aust. 42: 53-6. National Park. Res. Notes, W. Aust. Herb. 3: 1• 18. · --- 1961. The Tertiary and Quaternary Vegetation and climate in relation to the Fraser, C. 1830. Remarks on the Botany of the Banks of Swan River, Isle of Buache, living flora in South Western Australia. PhD thesis, Univ. of Western Australia. Baie Geographe and Cape Naturaliste. Hooker's Botan. Miscell. 1: 221-36. --- 1968. The distribution and prehistory of Eucalyptus diversicolor, F. Muell., E. Garden, D. S. 1977. Albany-A Panorama of the Sound from 1827. Thos. Nelson marginata, Donn ex Sm. and E. calophylla R. Br. in relation to rainfall. Aust. J. (Aust.) Ltd, Melbourne. Bot. 16: 125-51. Gardner, C. A. 1930. Enumeratio Plantarum Australiae Occidentalis. Govt Printer, Clarke, E. de C. 1926. Natural Regions in Western Australia. J. Proc. R. Soc. West. Perth. Aust. 12: 117-132. --- 1941. The vegetation of Western Australia with special reference to the climate Clarke, E. de C., Prider, R. T. & Teichert, C. 1948. Elements of Geology for Western and soils. J. Roy. Soc. West. Aust. 28: 11-87. Australian students. Univ. of W. Aust. Press, Perth. --- 1952. Flora of Western Australia, vol. I, part I: Gramineae. Govt Printer, Cockbain, A. E. I 968. The stratigraphy of the Plantagenet Group, Western Australia. Perth. Geo[. Surv. W. Aust. Ann. Rept 1967: 62. --- 1957. The fire factor in relation to the vegetation of Western Australia. W. Commonweatlh Bureau of Meteorology, 1962. Average annual rainfall map of Aust~Natur. 5: 116-73. · Western Australia. Govt Printer, Perth. --- 1959. The vegetation of Western Australia. In Biogeography and Ecology in --- 1965. The climate and meteorology of Western Australia. Official Yearbook Australia, eds A. Keast, R. L. Crocker & C. S. Christian. W. Junk, The Hague. of Western Australia, No. 5 (new series): 44-57. Gardner, C. A. & Bennetts, H. W. The toxic plants of Western Australia. West Aus­ --- 1975. Climatic averages, Western Australia (metric edn). Aust. Govt Publ. - . tralia Newspapers Ltd, Perth (p. 206). Service, Canberra. Gentilli, J. 195L Bioclimatic changes in Western Australia. W. Aust. Natur. 2: 175-84. Cunningham, A. 1828. A few general remarks on the vegetation of certain coasts of --- 1958. Is the Western Australian Wheatbelt a Natural Region? W. Aust. Natur. Terra Australis, and more _especially of its northwestern shores. Appendix to King, 6(7): 157-62. P. P. (1827), Narrative of d survey of the intertropical and western coasts of A us­ --- 1979. Regions and Landscapes. In Western Landscapes, ed. J. Gentilli. Univ. tralia, 1818-22. 2 vols. John Murray, London. ofW. Aust. Press, Nedlands: Dansereau, P. 1951. Description and recording of vegetation upon a structural basis. Gentilli, J. & Fairbridge, R. W. 1952. The physiographic regions of Australia (booklet Ecology 32: 172-299. to accompany a geomorphological map of Australia by J. Gentilli). The authors, Darwin, C. 1839. Narrative of the Surveying Voyqges of HMS Adventure and Beagle University of W. Aust. between 1826 and 1836. London. Geological Survey of Western Australia, 1975. Geology of Western Australia. W. Department of Conservation & Environment, 1980. Atlas of Natural Resources: Dar­ Aust. Geo!. Surv. Mem. 2. ling System, Western Australia. Univ. of W. Aust. Press, Nedlands. --- 1978. Geological Map of Western Australia. I :2 500000. Govt Printer, Perth. Diets, L. 1906. Die Pflanzenwelt von West-Australien sudlich des Wendekreises. Vegn. George, A. S. & Hnatiuk, R. J. 1978. A vegetation and flora reconnaissance of Avon Erde 7, Leipzig. Location. Res. Notes, W. Aust.Herb. 1: 19-27. Dodson, J. R. 1974a. Vegetation history and water fluctuations at Lake Leake, South­ George, A. S. Hopkins, A. J.M. & Marchant, N. G. 1979. The heathlands of Western eastern South Australia~. J. Bot. 22: 719-41. Australia. In Heathlands and Related Shrublands of the World, A. Descriptive --- 1974b. Vegetation and climatic history near Lake Keilambete, Western Vic­ Studies, ed. R. L. Specht. Elsevier, Amsterdam. toria. Aust. J. Bot. 22: 709-17. Gibson, C. G. 1909. The geologicalfeatures of the country lying along the route of the Deley, D. 1967. Water relations of Eucalyptus marginata Sm. under natural condi­ proposed Transcontinental Railway in W. Aust. Geol. Surv. West. Aust. Bull. 37. tions. J. Ecol. 55: 597-614. Gower, C. F. & Bunting, J. A. 1976. Explanatory notes on the Lake Johnston Douglas, W. H. 1968. The Aboriginal Languages of the South-West of Australia. 1 :250000 geological sheet. Aust. Govt Pub!. Serv. Canberra. Aust. Abor. Stud. 14. Aust. Inst. Aboriginal Studies, Canberra. Graaff, W. J.E. van der, Crowe, R. W. A., Buntin, J. A. & Jackson, M. J. 1977. East, J. J. 1912. The flora of Western Australia. In Cyclopedia of Western Australia. Relict Early Cainozoic drainages in arid Western Australia Z. Geomorph. N.F. 21 Hussey & Gillingham, Adelaide. (4): 379-400. Ellenberg, H. & Mueller-Dombois, D. 1967. A Key to Raunkiaer plant life forms with Grey, G. 1841. Journals of two expeditions of discovery in North-west and Western revised subdivisions. Ber. geobot. Inst. ETH, Stiftung Rubel, Zurich 37: 56-73. Australia during the years 1837, 38 and 39. 2 vols. T. & W. Boone, London. Embleton, B. J.J. 1973. The palaeolatitude of Australia through Phanerozoic time. J. Griffiths, J. R. 1971. Reconstruction of the southwest Pacific margin of Gondwana­ Geo/. Soc. Aust. 19: 475-82. land. Nature 234: 203-7.

150 151 !I

VEGETATION SURVEY SWAN Hall, N., Johnston, R. D. & Chippendale, G. M. 1970. Forest Trees of Australia. 1971. A pollen diagram from Quincan Crater, North-east Queensland, Aus­ Aust. Govt Publ. Serv., Canberra. tralia. New Phytol. 70: 669-81. Hallam, S. J. 1975. Fire and Hearth. Aust. Inst. Abor. Stud. 58, Canbrrra. -.-- 1974. A long continuous pollen sequence from North-eastern Australia. Halliday, J. & Pate, J. S. 1976. Symbiotic nitrogen fixation by coralloid roots of the Nature 251 (5472): 222-3. cycad Macrozamia riedlei: Physiological characteristics and ecological significance. Kimber, P. 1974. The root system of jarrah (Eucalyptus marginata). Bull. For. Dept Aust. J. Plant. Physiol. 3: 349-58. West. Aust. 10. Havel, J. J. 1968. The potential of the northern Swan Coastal Plain for Pin us pinaster King, L. C. 1962. The Morphology of the Earth. Oliver & Boyd, Edinburgh. Ait. plantations. Bull. For. Dept West. Aust. 76. --- 1972. The Natal Monocline. Univ. of Natal, Durban. --- 1975. Site-vegetation mapping in the northern jarrah forest (Darling Range): K5ppen, W. 1936. Das geographische System der Klimate. Handbuch der I, Definition of site-vegetation types. II, Location and mapping of site-vegetation Klimatologie, vol. l part C. Berlin. types. Bull. For. Dept West. Aust. 86, 87. Kriewaldt, M. 1969. Explanatory Notes on the Kalgoorlie 1 :250000 Geological Sheet, Hay, J. G. (ed.) 1906. The visit of Charles Fraser [The colonial botanist of New South Western Australia. Bureau Min. Resources, Canberra. Wales] to the Swan River in 1827 . .. together with copious notes by J. G. Hay, to Kuchler, A. W. ·1949. A physiognomic classification of vegetation. Annals Ass. Am. which is added the Journal of H.M.S. Success [Captain James Stirling, RN] on the Geogr. 39: 201-10. above occasion. J. G. Hay, Perth. Lamont, B. 1976a. Report of a Biological Survey and Recommendations for Rehabili­ Heddle, E. M. 1979. Mapping the vegetation of the Perth Region. In Western Land- tating a Portion of Reserve 31030 to be mined for heavy Minerals during 1975-81. scapes, ed. I. Gentilli. Univ. ofW. Aust. Press. __.. WAIT-AID Ltd, Perth . Hills, E. S. 1940. The Junette: a new land form of aeolian origin. Aust. Geogr. 3. ..- 1967b. The effects of seasonality and waterlogging on the root systems of a --- 1961. Morphotectonics and the geomorphological sciences with special refer­ number of Hakea species. Aust. J. Bot. 24: 691-702. ence to Australia. J. geol. Soc. Land. 117: 77-89. Lange, R. T. 1960. Rainfall and soil control of tree species distribution around Narro­ Hodgkin, E. P. 1978. An environmental study of the Blackwood River Estuary, W.A. gin, Western Australia. J. Roy. Soc. West. Aust. 43: 104-10. Report No. 1, Dept of Conservation & Environment, Perth. ·. Leeper, G. W. 1949. Climates of Australia. The Australian Environment. CSIRO, Holmes, J. M.1938. Themeaningofsoilerosion. Univ. of Sydney Pub. in Geogr.1. Melbourne. --- 1944. The geographical basis of government. Angus & Robertson, Sydney. Lindley, J. 1839. Sketch ofthe Vegetation of Swan River Colony. Appendix to the first Hooker, J. D. 1860. The Botany of the Antarctic Voyage of H.M. Discovery Ships 23 volumes of Edwards' Botanical Register, London. 'Erebus' and 'Terror', in tli.eyears 1839-43. Flora Tasmaniae, vol. 3, 1855-60. Lovell Lowry, D. C. 1965. Geology of the southern Perth Basin. W. Aust. Geo/. Survey Rec. Reeve, London. 17 (1965). Hopkins, A. J.M., & Robinson, C. J. (in press). Fire-induced structural change in a --- 1967. Explanatory Notes on the Busse/ton-Augusta geological sheet. Bureau of Western Australian woodland. Aust. J. Ecol. Mineral Resources, Canberra. Hopper, S. D. 1979. Biogeographical aspects of speciation in the southwest Australian ---, 1974. Explanatory Notes on the Donagra-Hill River Geological Sheet. Aust. Flora. Ann. Rev. Ecol. Syst. 10: 399-422. Govt Printing Service, Canberra. Jarvis, N. T. (ed.) 1979. Western Australia 1829-1979, an Atlas of Human Endeavour. Mabbutt, J. A. et al. 1963. General report on lands of the Wiluna-Meekatharra area, Govt Printer, Perth. Western Australia 1958. Land Res. Ser. No. 8. CSIRO Aust. Jennings, J. N. & Mabbutt, J. A\ 1977. Physiographic Outlines and Regions. In Aus­ McArthur, W. M. 1957. Plant ecology of the coastal islands near Fremantle, W. A. tralia, a Geography, ed. D. N. Je~ns. Sydney Univ. Press, Sydney. J. Proc. R. Soc. West. Aust. 40: 46-64. Johnstone, M. H., Lowry, D. C. & Quilty, P. G. 1973. 1.-The geology of south­ McArthur, W. M. & Bettenay, E. 1960. The development and distribution of soils on western Australia-a review. J. Roy. Soc. West. Aust. 56: 5-15. the Swan Coastal Plain, Western Australia. CSIRO Aust. Soil. Publ. No. 16. Jutson, J. T. 1914. An outline of the physiographical geology of Western Australia. --.- 1979. The Land. In Environment and Science, ed. B. J. O'Brien. Univ. of Geo!. Surv. W. Aust. 61. Reissued as Bull. 95 in 1934 as 'The physiography (geo- W. Aust. Press, Nedlands. morphology) of W .A.' ,,_ McArthur, W. M. & Clifton, A. L. 197 5. Forestry and agriculture in relation to soils in Keast, A. 1959. The Australian Environment. In Biogeography and Ecology in Aus­ the Pemberton area of Western Australia. CSIRO Aust. Div. Soils, Soils and Land tralia, ed. A. Keast, R. L. Crocker & C. J. Christian. W. Junk, The Hague. Use Series No. 54. Kemp, Elizabeth M. 1978. Tertiary climatic evolution & vegetation history in the McComb, J. A. & A. J. 1967. A preliminary account of the vegetation of Loch southeast region. , Palaeoclimatology, Palaeoe­ McNess, a swamp and fen formation in W. Aust. J. Roy. Soc. W. Aust. 50: 105-12. cology 24: 169-208. McKenzie, N. L.; Burbidge, A. A., & Marchant, N. G. 1973. Results of a biological Kenneally, K. F, (co-ordinator) 1977. The Natural History of the Wongan Hills. Hand­ survey of a proposed wildlife sanctuary at Dragon Rocks near Hyden, Western Aus­ book No. 11, W. Aust. Naturalists' Club, Perth. tralia. DeptFish. Wildt. W. Aust. Rep. 12. Kershaw, A. P. 1970. A pollen diagram from Lake Eura.moo, North-east Queensland, Main, B. Y. 1967. Between Wodjil and Tor. Jacaranda Press, Brisbane, and Landfall Australia. New Phytol. 69: 785-805. Press, Perth.

152 153 VEGETATION SURVEY SWAN Marchant, N. G. 1973. Species diversity in the southwestern flora. J. Roy. Soc. West. Mulcahy, M. J. Churchward, H. M. & Dimmock, G. M. 1972. Landforms and soils on Aust. 56: 23-30. an uplifted peneplain in the Darling Range, W.A. Aust. J. Soil Res. 10: 1-14. Marsh, L. M. & Hodgkin, E. P. 1962. A survey of the fauna and flora of the rocky Mulcahy, M. J. & Hingston, F. J. 1961. The development and distribution of the soils shores ofCarnac Island. W. Aust. Natur. 8: 62-72. of the York-Quairading area, W.A., in relation to landscape evolution. CSIRO Menzies, A. 1791. Journal, folio 32-74. Mitchell Library, Sydney, Manuscript collec- Aust. Div. Soils, Soils and Land Use Ser. No.17. tion No. B1135. . Nind, S. 1831. Description of the natives of King George's Sound (Swan River Colony) Merrilees, D., Dix, W. C., Hallam, S. J., Douglas, W. H. & Berndt, R. M. 1973. Abo­ and adjoining country. J. Roy. Geogr. Soc. 1: 21-51. riginal man in southwestern Australia. J. Roy. Soc. West. Aust. 56: 44-55. Northcote, K. H. 1971. A Factual Key for the Recognition of Australian Soils. Rellim Milewski, A. V. (in prep.). A theory of co-adaptation with frugivores and nectarivores Tech. Publ., Adelaide. to explain differences in the vegetation of Mediterranean Australia and South Northcote, K. H. Bettenay, E., McArthur, W. M. & Churchward, H. M. 1967. Domi­ Africa. · nant soils of the Perth-Albany-Esperance area. Atlas of Australian Soils Sheet 5. Monk, D., Hnatiuk, R. J. & George, A. S. 1979. Vegetation Survey of Frank Hann CSIRO, Melbourne. National Park. Res. Notes, W. Aust. Herb. 2: 23-49. Northcote, K. H., Hubble, C. D., Isbell, R. F., Thompson, C. H. and Bettenay, E. Morgan, K. H. & Peers 1973. Explanatory notes on the Esperance-Mondrain Island 1975. A Description ofAustralian Soils. Wilkie & Co., Clayton, Vic. Geological Sheet. Aust. Govt Pub!. Service, Canberra. Pate, J. S. & Dixon, K. W. 1978. Mineral Nutrition of Drosera erythrorhiza Lindi. Mueller, F. von 1867. Australian Vegetation. lntercolonial Exhibition Essays 1866-7, with spepial reference to its tuberous habit. Aust. J. Bot. 26: 455-64. No. 5. Blundell &Co., Melbourne. Perry, R. A. 1970. Vegetation. In Stewart et al., Lands of the Ord-Victoria area, --- 1858-82. FragmentaphytographiaeAustraliae. 12 vols. Melbourne. Western Australia and . CSIRO Aust. Land Res. Ser. No. 28. -- 1883. The Plants indigenous around Sharks Bay and its vicinity. Parliamentary Playford, P. E., Cockbain, A. E. & Low, G. H. 1976. Geology of the Perth Basin paper no. 26, Govt Printer, Perth. Western Australia. Geo!. Surv. W.A. Bull. 124. Muir, B. G. 1976. Vegetation: Tarin Rock and North Tarin Rock Reserves. In Part 1 Prescott, J. A. 1931. The ve_getation of Australia. CSIRO Bull. 52 (1st ed.). of Biol. Survey of W. Aust. Wheatbelt by D. J. Kitchener, A. Chapman, J. Dell, -- 1952. The soils of Australia in Relation to Vegetation and Climate. CSIRO R. E. Johnstone, B. G. Muir& L.A. Smith. Rec. W. Aust. Mus. Suppl. no. 2. Aust. Bull. No. 52 (1st publ. 1931). · --- 1977a. Vegetation and habitat of Bendering Reserve. Part 2 of Biol. Survey of Prescott, J. A. and Pendleton, R. L. (1952). Laterite and Lateritic soils. Common­ W. Aust. Wheatbelt. Rec. West. Aust. Mus., Suppl. no. 3. wealth Bur. Soil Sci. Tech. Comm. No. 47. -- 1977b. Vegetation orWest Bendering Nature Reserve. Part 4 of Biol. Survey Prider, R. T., 1948. The geology of the Darling Scarp at Ridge Hill. J. Roy. Soc. of W. Aust. Wheatbelt. Rec. W. Aust. Mus. Suppl. No. 5. W. Aust. 32: 105-29. -- 1978a. Vegetation of Dongolocking Nature Reserve. In Part 5 of Biol. Survey Pryor, L. D. 1959. Species distribution and association in Eucalyptus. In Bio­ of W Aust. Wheatbeltby A. Chapman, J. Dell, D. J. Kitchener&B. G. Muir. Rec. geography and Ecology in Australia, ed. A. Keast, R. L. Crocker & C. S. Christian. W. Aust. Mus. Suppl. No. 6. . -- 1976. The Biology of the Eucalypts. Studies in Biology 61, Arnold, London. -- 1978b. Vegetation of Durokoppin & Kodj Kodjin Nature Reserves. In Part 6 Quilty, P. G. 1975. Late Jurassic to Recent geology of the western margin of Australia. of Biol. Survey of W. Aust. Wheatbelt by. G. Muir, A. Chapman, J. Dell & D. J. ln Deep Sea Drilling in Australasian Waters, ed. J. J. Veevers. Challenger Sympo­ Kitchener. Rec. W. Aust. Mus. Suppl. No. 7. sium, Sydney. --- 1981. Vegetation of Ba~jaling Nature Reserve, South Badjaling Nature Rae, J. R. 1965. Perth Basin digital reflection seismic survey, Bullsbrook seismic pro­ Reserve, Yoting Town Reserve ~\d Yoting Water Reserve. In Part 12 of Biol. Survey ject. West. Aust. Pty. Ltd, Petroleum Search Subsidy Acts Rept. of W. Aust. Wheatbelt by B. G. Muir, A. Chapman, J. Dell and D. J. Kitchener. 65/ 11048 (unpubl.). Rec. W. Aust. Mus. Suppl. No. 12. Raunkiaer, C. 1934. The Life Forms of Plants and Statistical Plant Geography. -- (in press). Vegetation of Billyacatting Hill Nature Reserve. In Part 13 of Biol. Clarendon, Oxford (623 pp.). Survey of W. Aust. Wheatbelt by A. Chapman, J. Dell, D. J. Kitchener & B. G. Richardson, G. E. 1902. Annual Report Woods & Forests Dept for 1901. Govt Printer, Muir. Rec. W. Aust. Mus. Suppl. Perth. -- 1978-79. Some Nature Reserves of the Western Australian Wheatbelt, Parts Rogers, R. W. & Westman, W. E. 1979. Niche differentiation and maintenance of 1-28. Unpubl. reports, Dept Fisheries & Wildlife, Perth. genetic identity in cohabiting Eucalyptus species. Aust. J. Ecol. 4: 429-39. Mulcahy, M. J. 1967. Landscapes: laterites and soils in southwestern Australia~ In Rognon, P. & Williams, M. A. J. 1977. Late Quaternary climatic changes in Australia Landform Studies in Australia and New Guinea, eds J. N. Jennings & J. A. Mab­ and North Africa: a preliminary interpretation. Pafaeogeogr. Palaeoclimatol. butt. A.N.U. Press, Canberra. Palaeoecol. 21: 285-327. --.1973. Landforms and soils of S.W. Australia. J. Roy. Soc. West. Aust. 56. Sauer, J. 1965. Geographic reconnaissance of Western Australian seashore vegetation. Mulcahy, M. J. &Bettenay, E. 1971. The nature of old landscapes. Search 2: 433-4. Aust. J. Bot. 13: 39-69. -- 1972. Soil and landscape studies in Western Australia: I, The major drainage . Schweinfurth, U. 1978 .. Beobachtungen an exponierten Standorten der stidwest­ divisions. J. geol. Soc. Aust. 18: 349-57. australischen Ktiste. Bot. Jahrb. Syst. 99: 168-87. '- i 154 155 VEGETATION SURVEY SWAN Seddon, G.1972. Sense of Place. Univ. ofW. Aust. Press, Nedlands. 1948. An approach towards a rational classification of climate. Geogr. Rev. Serventy, D. L. & Whittell, H. M. 1948. Handbook of the Birds of Western Australia. 38: 55-94. Perth. UNESCO-FAO 1963. A bioclimatic map of the Mediterranean Zone and its Smith, F. G. 1972-74. Vegetation Survey of Western Australia, 1 :250000 Series. 1972, homologues. UNESCO Arid Zone Research 21: 2-58. Pemberton & Irwin Inlet. 1973, Busse/ton & Augusta. 1974, Collie. W. Aust. Dept Veevers, J. J. 1971. Phanerozoic history of Western Australia related to continental of Agriculture, Perth. ' drift. J. geol. Soc. Aust. 18: 87-96. Smith, G. G. 1957. A guide to sand dune plants of South Western Australia. W. Aust. Walter, H. 1979. Vegetation of the Earth (2nd English edn). Springer-Verlag, New Natur. 6: 1-18. York. -- 1968. Plants of the seashore. Wildlife in Aust. 5: 66-8. Walter, H. & Lieth, H. 1967. Klimadiagramm Weltatlas. Gustav Fischer Verlag, Jena. --- 1973. A Guide to the Coastal Flora of South-Western Australia W. Aust. Walther, J. 1915. Laterit in West-Australien. Zeitg, Deutsch. Geolog. Gesel/schaft Naturalists' Club. Handbook 10, Perth. 67B: 113-40. --- 1979. Maritime vegetation. In Mapping the vegetation of the Perth Region by Watson, J.E. 1~63. Eucalyptus ca/ophyl/a var. rosea. Aust. Plants 2 (14): 61-2. E. M. Heddie (see ref. above). Wilde, .S. A. & Low, G. H. 1978. Explanatory notes on the Perth geological sheet. Smith, R. 1951 a. Soils of the Margaret River-Lower Blackwood River Districts, Geo!. Surv. W. Aust., Perth. · Western Australia. CSIRO Aust. Bull. No. 262. Williams, R. F. 1932. An ecological analysis of the plant communities of the jarrah --- 1951b. Pedogenesis in the Frankland River Valley, Western Australia. CSIRO region on a small area near Darlington. J. Roy. Soc. West. Aust. 31: 19-31. Aust. Bull. No. 265. --- 1945. An ecological study near Beraking forest station. J. Roy. Soc. West. Sofoulis, J. 1963. Explanatory notes on the Boorabbin geological sheet. Bureau Min. Aust. 31: 19-31. Resources, Melbourne. Willis, J. H. 1953. The Archipelago of the Recherche, Part 3a, Land Flora. Aust. Specht, R. L. 1970. Vegetation. In The Australian Environment, ed. G. W. Leeper. Geogr. Soc. Report 1, Melbourne. CSIRO/MUP, Melbourne, pp. 44-67. Winkworth, R. E. 1967. The composition of several arid spinifex grasslands of Central Specht, R. L. & Rayson, P. 1957. Dark Island heath (Ninety Mile Plain, South Aus­ Australia in relation to rainfall, soil and water. Aust. J. Bot. 15: 107-30. tralia): I, Definition of the ecosystem. Aust. J. Bot. 5: 52-85. Woodward, B. H. 1900. Guide to the contents of the Western Australian Museum Speck, N. H. 1952. Plant ecology of the metropolitan sector of the Swan Coastal ,. (with zoogeographical provisional sketch map of W. Aust.) Perth. Plain. MSc thesis, Univ. of W. Aust. Summary and main map in Seddon G. (1972), ',. Woolnough, W. G. 1920. A geological reconnaissance of the Stirling Ranges of Sense of Place, pp. 155-72. • W. Aust. J. Proc. Roy. Soc. N.S. W. 54: 79•112. --- 1958. The vegetation of the Darling-Irwin botanical districts. PhD thesis, Youngson, W. K. & McKenzie, N, L·. 1977. The wildlife of the proposed Karroun Hill Univ. of W. Aust. Nature Reserve, Western Australia. Dept Fisheries & Wildlife Report 30, Perth. Stace, H. C. T. et al. 1968. A Handbook of Australian Soils. Rellim Technical Publica­ tions, Glenside, S. Aust. Stephens, C. G. & Crocker, R. L. 1946. Composition and genesis of lunettes. Trans. Roy. Soc. S. Aust. 70: 302-12. Stokes, J. L. 1846. Discoveries i~ustra/ia 1837-43. 2 vols. T. & W. Boone: London. Storr, G. ~· 1962. Annotated fl ra of Rottnest Island, Western Australia. W. Aust. Natur. 8. 109-24. --- 1963. Some factors inducing change in the vegetation of Rottnest Island. W. Aust. Natur. 9: 15-22. --- 1965. Notes on Bald Island and the adjacent mainland. W. Aust. Natur. 9. Storr, G. M., Green, J. W. & Churchill, D. M. 1959. The vegetation of Rottnest Island. J. Roy. Soc. West. Aust. 42: 65-95. Tate, R. 1890. A Handbook of the Flora ofExtratropical South Australia. Adelaide. Taylor, G. 1918. The Australian Environment. Memoir 1, Advisory Council of Science & Industry, Melbourne. " Teakle, L. J. H. 1938. Regional classification of the soils of Western Australia. J. Roy. Soc. West. Aust. 24: 123-95. Thom, R., Lipple, S. L., & Sanders, C. C. 1977. Explanatory Notes on the Ravens­ thorpe Geological Sheet. Aust. Govt Pub!. Service, Canberra. Thornthwaite, C. W. 1931. The climate of according to a new classifi­ cation. Geogr. Rev. 21: 633. ''" 156 157 SWAN

Plate I Landscape in the inner wheatbelt (Meckering Upland). Dissected peneplain on granite, with tors. Relics of the original plant cover on fence lines, on rough ground, or as scattered trees in paddocks.

/

Plate 2 Wheatbelt scene. Relict trees of Eucalyptus loxophleba showing typical form; in rear·. Acacia acuminata and Casuarina huegeliana on granite outcrop. Wheat crop in foreground.

159 VEGETATION SURVEY SWAN

Plate 3 · Granite rock outcrop 'The Humps', Hyden: mainly bare rock, Plate 5 Breakaway marking the boundary between sandplain and valley, with some Casuarina huegeliana. Southern Cross district, with Eucalyptus wandoo at the foot of the break­ away.

Plate 6 Coastline in the .Barren Ranges, looking east from Point Ann, Plate 4 Profile beneath woodland and mallee in the Hyden district, show- with mallee-heath in the foreground. The hills are Mid Mt Barren and the ing indurated upper horizon underlain by pallid zone. · Whoogarup Range.

160 161 Plate 7 Effects of salinizatic;>n: dead salmon gum trees Plate 8 Karri tall forest (Eucalyptus diversicolor). Near in a bottom land. Moora district. the Gloucester tree, Pemberton.

Plate 9 Tuart tall woodland (Eucalyptus gompho­ Plate 10 Unlogged prime jarrah forest (Eucalyptus cephala). Ludlow. marginata). Pemberton area. Small trees are Banksia grandis. VEGETATION SURVEY SWAN

Plate 13 Woodland of wandoo· ·(Eucalyptus wandoo) in state forest west of Beverley.

f

Plate 14 Woodland of York gum (Eucalyptus loxophleba): an apparently undisturbed example near New Norcia. This species is less tall than other woodland trees, has a mallee-Iike habit and a largely herbaceous understory.

164 165 ;

. ~; VEGETATION SURVEY SWAN

Plate 15 Woodland of salmon gum (Eucalyptus salmonophloia) north of Plate 17 Banksia low woodland near Reagan's Ford, Swan Coastal Plain, Bonnie Rock. with Verticordia nitens in flower in the understory, and conspicuous Res­ tionaceae.

~,;;. . ',.;,.,~··

Plate 16 Low woodland, Callitris columellaris and Acacia spp., Karroun Plate 18 Low woodland of Agonis flexuosa on coastal dune sand, Bremer System, along the vermin-proof fence. Bay. Understory of Acacia and Stipa

166 167 VEGETATION SURVEY SWAN

Plate 19 Low forest of jarrah (Eucalyptus marginata). Denbarker area. Plate 21 Thicket of Melaleuca uncinata on sandy lateritic soil. North of Beacon .

.. ..._

Plate 20 Thicket with Acacia neurophylla dominant, on dense laterite. North of Beacon. Plate 22 Mature thicket of Acacia resinomarginea, 5 m tall, with heath understory, on deep sand. North of Bonnie Rock, on the vermin-proof fence. 168 169 VEGETATION SURVEY SWAN

Plate 23 Mt Toolbrunup in the Stirling Range. Jarrah low woodland in Plate 25 Acacia scrub on shallow granite soil. Along the vermin-proof foreground, grading to jarrah mallee-heath on slopes and mixed thicket on fence, 100 km east of Bonnie Rock. the summits.

Plate 24 Thicket on the heights of the Stirling Range, in flower in Octo­ Plate 26 Mallee, typical form, with Mela/euca understory. Ravensthorpe­ ber. Jsopogon /atijolius, Dryandra f ormosa, and Spheno­ Norseman track southwest of Peak Charles. , toma aff. dracophy/loides can be seen in the foreground. On Blu,ff Knoll. E. o/eosa.

170 171 VEGETATION SURVEY SWAN

Plate 29 Scrub-heath in early stage after fire: general cover re-established, Plate 27 Mallee-heath, with Eucalyptus marr;inata and E. calophylla shrubs of taller species beginning to rise above the general level. Hyden­ dominant. Stirling Range at the foot of Mondurup. Norseman road. )i

l•l

Plate 30 Scrub-heath in advanced pioneer stage. Grevillea excelsior and Plate 28 Mallee-heath with Eucalyptus tetragona on plain adjacent to the G. pterosperma rising above smaller heath plants. , Barren Ranges. Koorarawalyee.

172 173 VEGETATION SURVEY SWAN

Plate 31 Scrub-heath in spring, near Newdegate: Grevil/ea hookerana at Plate 33 Scrub-heath comporient of the Le Sueur vegetation system, on right, and V. roei. sand. The tall straggly plants are Hakea obliqua. Jurien Bay road.

Plate 32 Scrub-heath in the Barren Ranges. The large shrub in foreground Plate 34 Heath component of the Le Sueur vegetation system, on iron­ is Hakea victoriae, the whipstick mallee is Eucalyptus sepulcralis, trees in stone gravel. Blackboys Xanthorrhoea reflexa conspicuous in low heath of rear are the parasitic Nuytsia floribunda. extreme sclerophylly. Badgingarra. ·

174 175 VEGETATION SURVEY SWAN

i/ Plate 35 Low scrub on granite boss, Point Gordon, Bremer Bay. Scattered I cushion plants in sward of reeds and sedges. Plate 37 Sedgeland: reed swamp of Cyperaceae and Restionaceae with scattered Xanthorrhoea and shrubs. Near Mt Chudalup. ·•

Plate 36 Sedge swamps in foreground bordered by paperbarks Melaleuca Plate 38 Spinifex steppe: hummock grass of Triodia scariosa beneath rhaphiophylla, merging into jarrah low forest. Denmark-Mt Bar~er ro~d. mallee of Eucalyptus sheathiana, on red sand. Jackson area near the Die Hardy Range,

176 177 VEGETATION SURVEY

APPENDIX

DESCRIPTION OF THE VEGETATION SYSTEMS

/J'HE SOUTH-WEST BOTANICAL PROVINCE

Southwestern extremity of the state. Heath, thicket, mallee, woodland and forest. Winter rainfall 300-1500 mm.

1, Irwin Botanical District Scrub-heath on sandplains near the coast; Acacia-Casuarina thickets further inland; Acacia scrub with scattered trees of Eucalyptus loxophleba on the hard-setting loams. Climate: Extra-dry 'mediterranean'; winter precipitation 300-500 mm, with Plate 39 Wooded succulent steppe: saltbush Atrip/ex vesicaria with scat­ 7-8 dry months per year. tered Eucalyptusflocktoniae, adjacent to Lake Hope. Geology: mainly sedimentary basins exposing Permian to Cretaceous sedi­ ments; horsts of Proterozoic rocks. Physiographic unit: Arrowsmith Slopes.

1.1. The Le Sueur System The country is hilly, undulating, with numerous mesas and benches con­ trolled by laterite cappings. The catena comprises heath in which blackboys (Xanthorrhoea reflexa) and Dryandra spp. are a conspicuous element on laterite, usually on summits and upper slopes, scrub-heath with Hakea obliqua as conspicuous character-species on sandy middle-slope soils containing iron­ stone gravel, Banksia low woodland on deep sand in valley bottoms, and eucalypt woodland along major drainage. Eucalyptus calophylla, K wandoo, E. loxophleba, E. accedens and E. rudis may all be present, singly or in mix­ ture.

1.2 The Tathra System The Tathra System is similar to the above and continues it to the north. The boundary between the two is indistinct and has been represented by an arbi­ trary line. Blackboys are no longer a conspicuous element in heaths, nor Hakea obliqua in scrub-heaths, though both are still present. There is no obvi­ ous dominance or conspicuous elements. O{herwise the catena is the same;

Plate 40 Succulent steppe, unwooded. A triplex zone at left, samphire zone 1.3 The Gairdner System at right, playa lake in rear. Eastern margin of Lake Moore, looking south. Two areas of hilly country in the Gairdner and Herschel Ranges constitute

178 179 VEGETATION SURVEY SWAN this sytem. They consist of a number of prominent mesas, on the flanks of Climate: Dry 'mediterranean'; winter precipitation 600-lO00mm, with 5-6 which erosion has removed the sand and ironstone cappings in a patchy dry months per year. manner. Here heavier and richer soils capable of supporting woodland have Geology: Mesozoic to Recent sediments of the Perth Basin. developed, but uneroded country still carries heath and scrub-heath. Mt Le Physiographic units: Dandaragan Plateau (Systems 1-4), Swan Coastal Sueur has long been recognized to be an area of special character (Gardner Plain (Systems 5-11). On the Swan Coastal Plain systems relate to the geo­ 1942, Speck 1958) with some unique species such as Banksia tricuspis in the morphic units of McArthur and Bettenay 1960. scrub-heath. An outlier of Euca!yp(us marginata (jarrah) occurs on the slopes in mallee form. Vegetation in the Gairdner Range otherwise includes heath 2.1 The Dandaragan System and scrub-heath, as in the Le Sueur System, while woodlands are formed of A portion of the Dandaragan Plateau where the surface is little dissected, E. calophylla, E. wandoo or E. accedens. The Herschel Range is mainly the soil formed upon deeply-weathered calcareous rocks, consisting of red covered by E. wandoo mixed with some E. loxophleba and an understory of earthy sand. Typical vegetation is Eucalyptus calophylla woodland with small Acacia and Casuarina. A thicket of mallee E. eudesmioides and E. drum­ patches of Banksia low woodland on yellow sand and E. rudis on drainage. mondii with Dryandra spp. occurs peripheral to the woodland. 2.2 The Warro System 1.4 The Jllyarrie System Gently undulating plateau surfaced with deep yellow earthy sand. Principal A very small portion of this system is represented-on the coastal limestone. vegetation is Banksia low woodland mingling floristic elements of the Banksia­ The vegetation consists of scrub-heath with scattered groves of Eucalyptus Xylomelum alliance with those of the more southerly Banksia woodlands. On erythrocorys (illyarrie) in rocky places. the west side on gravelly sand, Hakea obliqua scrub-heath and Xanthorrhoea­ Dryandra heath appear. Locally in depressions there are patches of Eucalyptus 1.5 The Cliff Head System loxoph/eba woodland, and in the. lakes country of the eastern border wood­ land of Casuarina obesa and Eucalyptus loxophleba or Melaleuca thickets and This has also a very restricted occurrence extending further north onto the samphire. adjoining sheet. The country consists of a limestone platform with Recent sand ridges trending north-south and some shallow salt lakes. The sand ridges 2.3 . The Koojan System carry thickets of Acacia, Casuarina and Melaleuca spp., but if burnt revert Undulating plateau surfaced with sands containing large amounts of iron­ temporarily to a heath of Acacia lasiocarpa and Melaleuca acerosa, which stone gravel. Vegetation is heath improving to scrub-heath, or rarely to otherwise occupies the flats. Salt lakes are bordered by samphire and Banksia low woodland, in the valleys. In the heath D,yandra spp. are domi­ Melaleuca thickets. nant, Xanthorrhoea plants are present but small, trunkless, inconspicuous. In the valleys Hakea obliqua is dominant in patches, or Banksia burdettii merg­ 1.6 The Marchagee System ing into tall B. attenuata and B. menziesii. The Marchagee System covers a very extensive sandplain of yellow earthy sand which is believed to be of aeolian origin. The principal cover is scrub- . 2.4 The Gingin System heath of the Banksia-Xylomelum alliance, but there are limited areas of A fairly even plateau surface covered by laterite and sand, except where Casuarina compestris thicket on ridges of Proterozoic rocks, and of Eucalyp­ locally dissected by small streams which have created younger soils. tus loxophleba and E. sa!monophloia woodland on exposed loam soils. Sand­ I; Beginning in the extreme south at Bullsbrook where the Cretaceous rocks filled valleys contain a community of Actinostrobus, Acacia and Ecdeiocolea, r ! pinch out against the Precambrian, the original cover was woodland of Euca­ and small lakes in depressions may be bordered by if lyptus calophy/la and E. wandoo with patches of E. marginata forest. After fresh, and by Casuarina obesa if salt. i,. crossing the the expanse of the plateau becomes very sandy and is covered by Banksia low woodland with scattered taller trees of E. calophylla and E. marginata, thickening locally in patches to forest of these 2 Drummond Subdistrict two species. The banksias are Banksia attenilata, B. ilicifolia and B. menziesii, Mainly Banksia low woodland on leached sands with Melaleuca swamps associating with Eucalyptus todtiana and Nuytsia Jloribunda as elsewhere. where ill-drained; woodland of tuart (Eucalyptus gomphocephala), jarrah and B. ilicijolia are common on minor drainage, Eucalyptus (E. marginata) and marri (E. ca/ophylla) on less leached soils. rudis and on larger creeks. On the dissected country

180 181 VEGETATION SURVEY SWAN around Gingin and extending out onto the Pinjarra Plain there is woodland of woodland. The Banksia low woodland also diminishes towards the north, . Eucalyptus calophylla, which seems always to have been the sole canopy tree, becoming restricted to valleys, or with the trees small and scattered in the as is the case further north on these Cretaceous rocks. Dryandra-Calothamnus heath.

2.5 The Guilderton System 2.8 The Spearwood. System The Quindalup Dune System of McArthur and Bettenay (1960) is divided The Spearwood System consists of ridges of calcarenite disposed more or for vegetation purposes, owing to differences in the plant cover, into the less parallel to the coastline and mantled with yellow sand which becomes GuHderton System, north of the Swan River mouth, and the Rockingham more bleached .at the surface and less calcareous from west to east. The prin­ System south of it. Both are situated upon stabilized dunes of Recent cal­ cipal component of the vegetation is eucalypt woodland, but numerous lakes careous sand. In the Guilderton System the vegetation has been much modi­ occur in chains parallel to the coast in depressions between the limestone fied by fire. The climax, represented today only by small patches, may have ridges. The lakes north of Mandurah are fresh, and are partly or entirely over­ been Callitris preissii low forest. A sub-climax of Acacia thicket with A. rostel­ grown by vegetation, and both sedge swamp and sedge fen formations can be lifera and A. cycwps has also been much reduced by fire, commonly to a heath recognized. These formations are bordered by woody communities of Mela­ of an Acacia lasiocarpa-Melaleuca acerosa assocation. Other minor com­ leuca or Banksia. South of Mandurah the lakes are salt, except for Lake Clif­ munities occur on the less stable dunes and foredunes exposed to the action of ton, and are bordered by samphires. North of Wanneroo, as the eucalypt the sea. ,,,.... woodland begins to run out, there are increasing patches of Banksia low wood­ land (see Jurien System) which gradually isolate smaller and more open stands 2.6 The Rockingham System of eucalyp(s,. Rottnest and Garden Islands belong to this system, consisting of dune sands The eucalypt woodland is mapped as two communities, the Eucalyptus and coastal limestone. In the vicinity of Rockingham the coastal belt has been gomphocepha/a (tuart) association and the E. go,mphocephala-E. marginata built up by accretion of beach ridges rather than by dunes (see Seddon 1972 ! association, the former occurring to the west of the latter where limestone is pp. 63-5). The climax Callitris preissii low forest still exists on much of Garden closer to the surface. Although separately mapped, the two intermingle to Island, and formerly did so on Rottnest. Human activity in interaction with some extent, with E. gomphocephala favouring ridges and E. marginata quokkas (Setonix brachyurus) has reduced the plant cover of Rottnest to a depressions. In the extreme south; between ·Bunbury and Busselton, the steppe of species unpalatable to the animals. On the mainland, behind minor E. gomphocephala woodland'increases in height to the status of 'tall'. Minor strand communities there is a heath in which , Olearia axil­ communities include the Dryandra-Calothamnus heath which continues to laris and Scaevola crassifolia are conspicuous, merging into Acacia roste/lifera occur on limestone ridges, Agonis f/exuosa low woodland and low forest along thickets where these have not been burnt; Fite has much altered the structure the western margin of the tuart woodland, and low w-oodland of -Mela/euca of these ~ommunities. On the beach ridge country near Rockingham, present preissiana, M. rhaphiophylla or Banksia littoralis in swampy places. vegetation consists of thickets and scnib of Acacia saligna and Jacksonia furcellata with very numerous large Xanthorrhoea preissii. It is not known to 2.9 The Bassendean System what extent this repr,esents original natural vegetation. Corresponding to the Bassendean Dune System of older leached sands, this system stretches discontinuously for the whole length of the Swan Coastal 2. 7 The Jurien System Plain. Over this length there are naturally some variations. The overall cover is The Spearwood Dune System of McArthur and Bettenay (1960) has likewise Banksia low woodland dominated by Banksia attenuata. B. menziesii, B. ilici­ to be divided into a northern portion, the Jurien System, and a southern f olia, Eucalyptus todtiana and Nuytsiafloribunda, with a dense understory of portion, the Spearwood System, the division lying near Yanchep at the north­ sclerophyll shrubs, in which Havel (1968) recognized five floristic groupings, ward extremity of Eucalyptus gomphocephala woodlands as a continuous for­ differing from those in the Jurien System. Lows in the topography· are mation. In the Jurien System soils are similar to those further south, yellow swampy. North of the Moore River such patches are underlain by a calcareous earthy sands of varying depth over limestone, but rainfall is lower. There is a hardpan and are vegetated by heath communities; elsewhere there are deep catena comprising Dryandra-Calothamnus heath on shallow soil or ridges, swamps with low woodland and forest of Melaleuca preissiana, M. rhaphio­ Banksia low woodland of B. attenuata, B. menziesii, B. ilicifolia, Eucalyptus phylla or Banksia littoralis, or taller Casuarina obesa or Eucalyptus. rudis, or todtiana and Nuytsia fforibunda on slopes, and occasional patches diminish­ merely sedges. ing and becoming more stunted towards the north of E. · gomphocephala Casuarina fraserana joins the tree layer south of Gingin. South of Lake

182 183 I VEGETATION SURVEY SWAN Gnangara Eucalyptus todtiana begins to disappear, being replaced by scat­ streams which support a fringing woodland of Eucalyptus rudis and Melaleuca tered E. marginata as larger trees emergent from the low woodland. South of preissiana. Pinjarra a catena develops, with Banksia low woodland confined to higher and drier sites, Eucalyptus marginata-E. calophylla woodland with a Banksia and 3 Dale Subdistrict Casuarina understory on moister but still well-drained sites, and the various swamp communities in the wettest sections. Jarrah (E. marginata) forest on ironstone gravels, marri-wandoo (E. calo­ phylla-E. wandoo) woodlands on loamy soils, sclerophyll understories. Climate: Dry 'mediterranean', winter precipitation 600-1200 mm, with 5-6 2.10 The Barramber System dry months per-year. The Barramber System occupies the alluvial flats along the Moore River Geology: Archaean granite of the Yilgarn Block and included metamorphic which broaden below Reagan's Ford, have an offshoot to the two freshwater belts. Karakin Lakes, and then turning southward broaden out into a stretch up to Physiographic units: Darling Plateau, Bannister Uplands. 3 km wide of braided channels. The alluvial flats extend also for,,12km up the Gingin Brook, while along the main river below the confluence they are once 3.1 The Darling System more narrowed. The Darling System comprises the northern jarrah forest, which occupies From early accounts the tree cover seems always to have been ver)½Open, the most humid portion of the Darling Plateau. The major catena in the with s_cattered Eucalyptus calophylla and E. rudis, and {downstream) system comprises: E. gomphocephala. E. rudis lines the stream channels. There are scattered (a) The open vegetation of granite rock outcrops which protrude through Melaleuca, Banksia and Jacksonia shrubs. · the laterite mantle; (b) jarrah forest on the laterite plateau and screes descending from its 2.11 The Pinjarra Plain System edges. (c) marri-wandoo woodland on the younger red soils of the scarp and the The plain occupies a more or less continuous band along the foot of the slopes of the deeply-excavated Avon, Helena and Chittering Valleys; Darling scarp, varying in width from 1 to 25 km. As it contains the best soils (d) river gums and paperbarks along the watercourses in these. on the coastal plain for agricultural development, there is very little original There are also minor catenas on the plateau itself in the undulations of its sur­ vegetation left. The northern strip from Bullsbrook to Gingin was intact until face, running from the highest ground into the shallow valleys, and these are quite recently, and was a sandy-swampy section with the same catena as in the separated into those of a higher-rainfall western sector· and a drier eastern southern part of the Bassendean System. The river terraces along the Swan sector. appear from early accounts to have been very similar to the Barramber It is an apparent anomaly that the jarrah forest is the tallest and densest for­ System. In the mfl,in part of the plain it is believed that on the better-drained mation in the catena, yet grows on the inhospitable laterite duricrust of the soils the original cover was Eucalyptus calophylla woodland with some plateau. However, Ooley (1967) and Kimber {1974) showed that the root E. wandoo, some E. marginata on higher ground, and E. rudis in the wetter system of jarrah penetrates the duricrust into the deep-weathered zone beneath parts, especially as a riverain fringe. E. calophylla may have closed up to forest as deep as 16m, tapping reserves of moisture during summer and allowing in the more southerly areas. Ground subject to frequent flooding such as at growth to continue throughout the year. Soils of the scarp and valleys; where Benger Swamp supports low woodland or forest of Melaleuca rhaphiophylla, the deep-weathered zone has been stripped off, actually provide much less thickets of Melaleuca preissiana or sedgeland. water storage than the plateau. The minor catenas occur within the jarrah forest and were worked out by 2.12 The Ridge Hill Shelf System Havel (1975), applying the methods of his study of the Swan Coastal Plain Although it covers a small area in a narrow band along the foot of the Dar­ {1968) to determine 'site-vegetation types'. In the wetter western sector the ling Scarp from Bullsbrook southwards too small to appear in Fig. 31, it seems gross variation in the tree layer is from Eucalyptus marginata-E. calophylla preferable to recognize this geomorphic element {McArthur & Bettenay 1960) forest on uplands, downslope to mixture with E. patens on valley loams, and in a vegetation system. The principal element is forest of Eucalyptus marginata to E. patens with E. megacrapa and Agonis linearifolia in swampy bottom­ lands. In the drier eastern sector the gross variation in the tree layer is from and E. calophylla mixed with E. wandoo on the heavier gravelly soils and with i,- Casuarina.fraserana on the more sandy soils. Understory species are in general Eucalyptus marginata-E. calophy/la forest on uplands continuing all the way similar to those on the Darling Plateau. The Shelf is dissect~d· by a series of downslope on sands, finally changing to Melaleuta and Banksia on sand flats,

184 185 VEGETATION SURVEY SWAN or merging into Eucalyptus wandoo and E. patens on loam slopes, pure powderbark woodland on the plateau and laterite residuals, marri-wandoo E. wandoo on valley floors. woodland on the slopes below the plateau. The plateau woodland consists of shorter, more scattered and branchy trees 3 .2 The Chittering System than in the jarrah forest, the principal components being E. marginata, The Chittering System lies immediately to the north of the Darling System. E. wandoo and E. accedens. The woodland of the slopes can be very tall and It is bounded on the west by the Darling Fault, a geological boundary marking dense in some valleys in the range, but in general is still lower and more open. a change of country; on the north by the northern limit of Eucalyptus margi­ Relative proportions of marri and wandoo vary widely as was shown by nata, which drops out just south of the Calingiri turn-off on the Great Williams (1~45). Northern Highway, and on the east by a line determined by rainfall just short of the eastern edge of the plateau. 3.5 The Dryandra System The elements of the landscape here are basically the same as in the Darling This lies to the east of the Bannister System in part, from the Dale Road System, the laterite-crusted plateau and the deeply-cut valleys, but the plateau south to the Albany Highway. The country is well-dissected, but is underlain is considerably m~re dissected, and the decline of the rainfall ih a northerly by the same granite batholith as the Darling Range, and originally carried a direction leads to a replacement of the jarrah forest of the plateau with a more similar massive lateritic duricrust which is preserved in numerous mesaform open community, a woodland, in which jarrah and marri are joined by remnants. Rainfall is lower than in the Bannister System, and is principally wandoo (E. wandoo) and powderbark wandoo (E. accedens), while Yoff gum resppnsible for the change in the vegetation. The basic catena comprises'(a) the (E. loxophleba) appears in the valleys. The full catena therefore· comprises communities of granite outcrops, (b) woodland of powderbark wandoo jarrah-marri-wandoo-powderbark woodland on the plateau, marri-wandoo (£; accedens) and brown mallet (E. astringens) on laterite plateaux, (c) wood­ woodland on the upper valley slopes and York gum woodland on the lower land of wandoo and powderbark on upper slopes with a gravel wash below the slopes, with river gum (E. rudis) and paperbark (Melaleuca rhaphiophy!la) on breakaways, (d) marri and wandoo on middle slopes, (e) York gum on the drainage. lowest slopes close to major drainage channels, (f) river gum lining creeks and at times scattered on slopes. 3.3 The Mogumber Systrm The Mogumber System adjoins the Chittering System on the north and 3. 6 The Williams System occupies the remainder of the dissected laterite plateau extending northward. This system occupies undulating country in the Bannister Uplands from As jarrah has dropped out except for isolated individuals in the extreme south which most of the laterite sheet has been eroded. On laterite remnants there is both plateau and upper slopes are occupied by marri-wandoo woodland, with jarrah-marri-wandoo woodland, with powderbark and mallet becoming domi­ York gum still on lower slopes. On lateritic ridges and breakaways, however, nant along breakaways. These two also cover any of the smaller laterite­ the woodland tends to open out with· development of a dense sclerophyllous capped ridges. Marri-wandoo woodland covers the greater part of the land­ urtderstory. On such sites Eucalyptus accedens is the principal tree with some scape, giving way to York gum on the lowest ground. The catena is basically E. wandoo, and occasionally E. drummondii as a smaller tree. Dryandra spp. the same as in the Dryandra System, but the proportions occupied by the vari­ dominate the understory. On the normal gravel soils of the plateau Eucalyptus ous elements are different. calophylla and E. wandoo are dominant, and the understory appears to be much the same as in the Chittering System. 4 The Menzies Subdistrict

f 3.4 The Bannister System Forest and woodlands as in the Dale Subdistrict, but understories differ in The Bannister System occupies the easternmost portion of the Dale Sub­ composition, becoming more similar to those of the Warren Subdistrict district. It corresponds in part to the Bannister Uplands and extends in a long (below). Climate, geology, topography and soils are essentially as for the Dale strip from Bolgart southwards for over 200 km. It includes the eastern edge of Subdistrict, though conditions are slightly more humid. the laterite plateau, where woodland replaces the jarrah forest due to declining rainfall, and the slopes descending eastward from the plateau. Its eastern 4.1 The Bridgetown System J boundary is determined by the eastern limit of E. calophylla, and is drawn The Darling System of F. G. Smith (1972, 1974) which covered the whole along the mapped boundary between marri-wandoo woodland and York gum Darling Plateau has been subdivided between the Dale and Menzies Sub­ woodland. The typical catena therefore has two components: jarrah-wandoo- districts, and the southern portion renamed the Bridgetown System. It is essen-

186 187 VEGETATION SURVEY SWAN tially similar to the Darling System, with jarrah-marri forest as the major river, but for the most part the flats seem to have been covered element of the catena. Since the system does not include any portion of the by an open woodland of E. occidentalis and E. wandoo having a dense teatree Darling Scarp this element is missing, but marri-wandoo woodlands occur in understory, classified for mapping as 'thicket with scattered trees'. valleys towards the eastern boundary of the system. In the western portion blackbutt (Eucalyptus patens) appears singly or in mixture with jarrah and 4.4 The Jingalup System marri on valley flats, while bullich (E. megacarpa) occupies semi-swampy Rainfall is higher than in the Beaufort System, the country is more deeply valley bottoms further upstream towards the watersheds. Along river-banks I dissected but at the same time laterite cappings are both more abundant and f,; river gum (E. rudis) forms fringing forest, and paperbark (Melaleuca rhaphio­ more extensive. There is a well-marked catena with E. marginata­ phylla) forms a dense understory at the water's edge of the more permanent E. calophylla-E. wandoo woodland on the summit ironstone gravels, and rivers. In broad valley-bottoms and swamps, particularly in the~Collie Basin, woodland of E. calophylla and E. wandoo on the slopes. E. astringens may low woodland of Eucalyptus rudis, Melaleuca preissiana and/or Banksia spp. associate with E. marginata on breakaways. E. rudis occurs along minor is found. Composition of the sclerophyll understory of the jarrah forest has drainage. Major creeks are lined by E. rudis, and not been as intensively studied as in the Darling System, but is believed to be of M. viminea. substantially different composition. In the south, the jarrah-marri forest may improve locally to tall forest. 4.5 The Kwornicup System The Kwornicup System is situated on a swampy plain extending roughly 4.2 The Chapman System from the Muir Highway for 30 km northward, and from west of Rocky Gully The Chapman System is the vegetation of the Blackwood Plateau, laterite- · and Frankland to Kendenup. The plain forms the interfluve between the head­ capped and gently undulating, but locally dissected to reveal the underlying waters of the Kent and Hay Rivers and the Gordon, and is very poorly Mesozoic sediments. The general cover consists of jarrah-marri forest, fre­ drained, so that it is covered with lakes and swamps including Lake Muir, quently stunted by poor drainage conditions. Some of it was mapped as more Lake Kwornicup and Lake Poorarecup .. The vegetation system is a mosaic open (woodland) or less tall (low forest and woodland) by F. G. Smith with jarrah-marri forest as the dominant member, enclosing numerous patches (1972-3-4). Eucalyptus meiacarpa and E. patens may occur locally as in the of jarrah low-forest, paperbark low-forest and reed swamps. Owing to the flat Bridgetown System, while low woodlands of Melaleuca preissiana and Banksia swampy terrain, the jarrah-marri for-est is often mixed with yate (E. cornuta), spp. occupy damp sites. Where there has been dissection, a yellowish clay loam swamp yate (E. occidentalis) and wandoo (E. wandoo). Eucalyptus decipiens, is exposed on pediments and carries scrub of small stunted jarrah, numerous a small species between a tree and a mallee, comes in as an understory or shrubs and the grass tree Kingia australis. On the slopes of the Whicher Scarp becomes dominant in sandy-swampy places, with Xanthorrhoea and Hakea there are expanses of very sandy lateritic gravel, on which jarrah forms wood­ r~ varia. It forms mallee communities on the lunettes bordering lakes, as at L. land with Eucalyptus haematoxylon and Banksia spp. In the northwest, under Poorarecup. Banksia verticil/ata becomes common in swampy depressions, the lee of the Leeuwin-Naturaliste Ridge, Eucalyptus cornuta forms forest on and at the borders of swamps. Clay swamps usually acid grey earths (Gn2.94). contain stands of E. occidentalis with an understory of Melaleuca cuticularis and M. violacea. Sandy swamps may have dense M. cuticularis low-forest 4.3 The Beaufort System grading into reeds with scattered paperbark. The landscape is generally similar to that in the Williams System, except that the valley bottoms contain grey alkaline clays or clayey soils, where E. occi­ 4.6 The Narrikup System dentalis replaces E. loxophleba. Sandy deposits occur also along the main The Narrikup System extends inland of the Hay and Albany Systems to be­ course of the Beaufort River, some clearly of aeolian origin, and carry a tween Mt Barker and Woogenillup, and fi;:_om Kendenup more or less to the variety of plant communities. Kalgan River. The Porongurup System occurs as a small enclave. The Narri­ The principal elements of the catena are woodland of E. astringens and kup System lies upon a plain, little dissected except in the southeast along the E. wandoo on laterite residuals, occasionally also with E. marginata and/or Kalgan River and its tributaries, but not as swampy as in the Kwornicup E. gardneri, woodland of E. calophylla and E. wandoo on the undulating System. Lakes and swamps are few. Jarrah-marri forest was therefore almost country generally, and woodland of E. loxophleba and E. occidentalis on continuous before clearing for settlement. Eucalyptus occidentalis is present aeolian sand patches. There are small patches of scrub-heath, and around along minor creeks, E. rudis and E. patens along the Hay River. E. decipiens Fitzes Swamp an extent of woodland of E. marginata and E. wandoo along the comes in on wet places. Small patches of Banksia woodland occur on sand:

188 189 VEGETATION SURVEY SWAN Banksia attenuata, B. ilicifolia and Nuytsia floribunda. Towards the Kalgan With the decline in the rainfall to the northeast, the system is below the Plains patches of Eucalyptus tetragona mallee-heath begin to be seen, and 25-inch or 625-mm isohyet, and the forests therefore open out to woodland. towards the east and south increasing patches of jarrah and jarrah-Casuarina Jarrah is still present, but mixed with both marri and wandoo on upper slopes, low forest. On the dissected country of the Kalgan River, however, there is a whereas lower slopes have yate and wandoo. E. decipiens appears as usual in return to good jarrah-marri forest, as the soils are younger, less leached and depressions. There is some teatree along creeks, and as lower rainfall means better drained. There are swamps here in valley bottoms containing paper­ safinity, samphire appears to a limited extent. · barks and teatree (Melaleuca cuticularis, M. densa), Eucalyptus staeri and Geekabee Hill, 15 km west of Cranbrook, is in this area, and is of special E. decipiens. Agonis juniperina and Oxylobium lanceolatum line the river­ interest, as with the adjoining small hills it is an outlier of the Stirling Range, banks. of the same quartzite formation. It carries rather open jarrah low woodland (E. marginata but no E. calophylla) with a good heath layer 1.2 m tall. 4. 7 The Porongurup System This system is centred upon the Porongurup Range, one of the largest 4.9 The Kent System granite massifs in the state, where granite domes crowd upon one another over This comprises an area of extremely-poor country along the upper Kent and a length of 12 km and a breadth of 3 km, reaching a general height of 2000 feet Denmark Rivers, between Mount Lindesay and the Muir Highway. It is above sea-level (600 m), with a maximum of 670 mat the Devil's Slide. M~~t of characterized by shallow leached sands over rock or laterite, both of which fre­ the domes have bare summits, where the rock is smooth and thinly covered quently crop out. The country is gently undulating and poorly drained, with with lichens or mats of moss, or is irregularly covered with boulders and numerous large swamps. Jarrah low forest is the predominant formation, nor­ pockets of soil, in which scattered plants can take root. These summits are mally pure; there is little marri, and Casuarina only appears sparingly towards mapped as rock outcrops. The higher summits at the western end such as the south. On patches of better soil the cover improves to jarrah-marri forest Marmabup, Devil's Slide, Wall's Summit and Rock of Gibraltar tend to be the (medium height), and there are some small patches of karri on alluvial soil smoothest; those in the centre. of the Park-Morgan's View, Nancy Peak, along the . Swamps occur as narrow strips along drainage lines, Twin Peaks-are more bouldery; while the lower Castle Rock in the east or as larger expanses occupying broad flat valley bottoms; In the former case (570 m) carries gigantic perched boulders which are a scenic feature. they carry a mixed community of reeds and heath shrubs such as Beaufortia The bare domes rise from an encircling mass of karri (Eucalyptus diversi­ sparsa a:nd Kunzea ericifolia, in the second of reeds with scattered paperbark color) tall forest, whose enormous trees reaching 60 m in height form a striking trees (Melaleuca cuticularis). co·mposition in detail appears to be similar to the contrast with the scrubby rocks above. In this locality karri only occurs on the swamps described in the Warren Subdistrict. slopes of this range, and is an outlier from the main area .of karri forests The granite mass of Mt Lindesay is included in this system. Unlike the 100 km to the west. Eucalyptus cornuta forms a fringing forest between the Porongurup Range there are no stands of karri. It more resembles the Many­ karri and the rock slabs. peaks massif, with bare rock slabs rising out of a heath with Kingia, and this On the pediments of the range the soil becomes more leached and lateritized, . surrounded by jarrah-marri forest. and the forest cover changes to medium-height trees of jarrah (E. marginata) and marri (E. calophylla). On the northwestern flank of the range the laterite 4.10 The Hay System crust is very massive, and the jarrah are reduced to low trees

190 191 VEGETATION SURVEY SWAN ously described. Valley-floor swamps crossed on the Denmark-Mt Barker 5 Warren Subdistrict main road consist predominantly of reeds with scattered shrubs. Tall forest of karri (Eucalyptus diversicolor) on red earths, forest of jarrah­ 4.11 The Albany System marri (E. marginata-E. calophylla) on red and yellow podzolic soils. Extensive paperbark (Mela/euca} and sedge swamps in valleys and foot plains. The town of Albany lies in this system which stretches from Wilson Inlet to Climate: Moderate mediterranean; winter precipitation ranges from 650 to Oyster Harbour, and from the Warren Subdistrict boundary (roughly along 1500 mm per annum; essential feature is short dry season of only 3-4 dry the line of the South Coast Highway) inland to Millbrook Road. The country months. is a plain entrenched by streams draining south and east in flat-bottomed Geology: Archaean granite and infolded metamorphic rocks of the Yilgarn valleys, but the monotony is relieved by granite domes north of Princess Royal Block. Harbour and a single one further north near the King River. The upland soils Physiographic units: Darling Plateau, Albany Slopes, Scott River Plains, are excessively poor, leached and badly drained, so that more depauperate Leeuwin-Naturaliste Ridge. members of the low-forest mosaic are dominant, i.e. Casuarina fraserana on deep white sand, becoming mixed with Eucalyptus staeri where this overlies 5 .1 The Nornalup System laterite. At Albany airport there is only 20 cm of topsoil over laterite, water­ The karri (E. diversicolor) forest zone forms the Nornalup System. It logged in winter, and the cover seems to have been jarrah mallee only m in. 271. extends from northwest of Manjimup in the valleys of the Donnelly River height. System towards the south and southwest almost to the coast. The area com­ The valley swamps consist of dense reeds 1 m tall. Leptocarpus tenax is · prises a dissected laterite plateau sloping gently to the south. Vegetation is a dominant with numerous large and small woody plants. The granite domes mosaic controlled by topographic position and geology. Karri tall forest is must have been disturbed by cutting of timber and firewood. On Mount mainly restricted to red earths, which develop on basic gneiss on lower slopes. Clarence one finds the remains of jarrah-marri forest, becoming mallee among Marri becomes co-dominant further upslope with a change to podzolic soils, rocks at the top. and may become single-dominant. Jarrah becomes dominant on the ridge tops on most soils, generally with laterite or ironstone gravel present. Stature of 4.12 The East Kalgan Sj,.!tem jarrah forest varies from tall to low, according to soil depth, permeability and Lying mostly east of the Kalgan River, this system is the eastern extremity drainage. On the poorest (Dy5) soils ·known as 'high level flats' trees thin out of the Darling Botanical District and is already transitional to the adjoining leaving thickets of shrubs. on' the lower ground towards the footplains, there Eyre District. The western boundary follows the edge of good jarrah-marri is a sequence with worsening drainage comprising mixed forest with E. patens forest southwards from Stony Creek, 2-3 km east of the Albany-Borden road, and E. megacarpa, thickets with scattered small trees of these species, thickets to the Takenup Creek, where it crosses the Kalgan River and follows the edge with understory of reeds, and finally reed swamp. On small hummocks and of the plateau 2-3 km east or-theriver so~th to Oyster Harbour. The northern sand ridges the cover is jarrah-Banksia low woodland. and eastern boundary of the system is also the district boundary, a line In the southern part near the coast, in the Walpole-Nornalup area, both red along which mallee-heath becomes dominant. South of the Bremer Bay road tingle (E. jacksonii) and yellow tingle (E. guilfoylei) associate with karri in tall there is a sharp transition from woodland to open sandplain, but further forest. north there is a gradual transition with patches of mallee-heath increas­ ing in size and frequency, and the mapped boundary is therefore an arbitrary 5.2 The Denmark System line. The principal difference from the Nornalup System, -where karri typically The landscape is a plain, mostly poorly drained, dotted with a small fresh­ appears on the lower to mid-slope, is that now it appears on the highest water lakes and swamps. The vegetation is a mosaic of jarrah-marri forest, ground. Karri soils are associated with the outcrop of granite batholiths which jarrah low forest, jarrah-Casuarina and jarrah mallee-heath. The structural may or may not be exposed as bare rock at the summit. Karri is found growing adaptability of Eucalyptus marginata is here seen at its full range within a on typical red earth around such exposures, or on the hills and ridges which single system. Jarrah low forest seems to predominate· in the north, they underlie. Karri appears again on the alluvial soils along the streams, but jarrah-Casuarina in the south, jarrah-marri forest in the west and mallee-heath mid and lower slopes are usually occupied by jarrah or jarrah-Casuarina on in the east. Swamp vegetation is as noted under the Albany system. There are sand and/ or laterite. It appears that the latter soil material has been deposited two smali patches of karri, the most easterly known, on farms just south of in this position in the catena in the course of formation of the landscape, hav­ Circuit Road in the Manypeaks area. ing originated as laterite on the peneplain before dissection of the country. In

192 193 VEGETATION SURVEY SWAN and to the west of Denmark there is a belt of high ground culminating in rush- and sedge-filled swamps and lakes. Isolated hummocks of lateritic Mount Shadforth, where this catena is present, but most of the karri has been material support jarrah in forms from forest to low woodland, and sandy cleared for agriculture. Between the Wilson Inlet and Princess Royal Harbour ridges Banksia low woodland. At and to the north of the Scott River there is a the country is much lower, and while the same catena still exists on rising curious and unique Viminaria scrub on sheet laterite. ground, with karri on the hilltops, wide belts of swampland occupy flat valley bottoms. The massif of Torbay Hill replicates the Denmark country. Further 5.5 The Torndirrup System west of Denmark from William Bay to the Bow River the country is again This is very similar to the Boranup System, but the composition of some lower, with swampy flats, and gently undulating hilly country with karri only heaths appears to differ. It extends from Irwin Inlet to King George Sound. on isolated hilltops and along streams (as at the Kent River), most of the coun­ The geography of the south coast is controlled by granite outcrops, which try being sandy and originally under jarrah and Casuarina. rise as low domes and form capes and headlands. From one headland to the The other components of the vegetation system besides karri tall forest next the coast extends in shallow curving bays backed by sand dunes, which therefore are jarrah-marri forest on laterite and yellow podzolic soils, jarrah occupy belts 2-3 km wide. In addition to forming dunes on low country, this or jarrah-Casuarina low forest on bleached sands, and reed swamp. sand also mantles the granite headlands whose summits only may peep through it. Ponding of the rivers by the sand dunes has created lakes and 5.3 The Boranup System swamps behind them. The Boranup System extends from Cape Naturaliste to Irwin Inlet, and The heaths on slopes facing the sea belong to the Pimelea ferruginea associ­ covers the Leeuwin-Naturaliste Ridge and the coastal dunes of the Scott River ation as in the Boranup System, and there is the same range of Agonis and Plain. The former is partly mantled with calcarenite and unconsolidated sand, Banksia communities on the younger sands, with limited patches of marri or and its seaward slope is much exposed to prevailing storm winds and sea spray. karri on older weathered sands. In the Torndirrup National Park some heath Vegetation is an intricate mosafo controlled by the factors of soil and and scrub-heath communities of .distinctive composition have been shown to exposure. occur. On the exposed western slopes of the Ridge vegetation is heath of the Pimelea Jerruginea associaoion of Bridgewater and Zammit (1979). Its stature 6 Avon Botanical District improves locally to thicket. With decreasing exposure peppermint (Agonis The typical sequences of vegetation comprise scrub heath on sandplain, flexuosa) and/or Banksia spp. dominate a range of structural types, low Acacia-Casuarina thickets on ironstone gravels, woodlands of York gum forest, low woodland or open low woodland. Jarrah (Eucalyptus marginata) (Eucalyptus loxophleba), salmon gum (E. salmonophloia) and wandoo may associate in the low forest on leached sands, and once off the coastal lime­ (E. wandoo) on loams, halophytes on saline soils. stone develops into jarrah-marri forest. In the lee of the main Ridge, on Climate: Extra-dry mediterranean; winter precipitation 300-650 mm per deeply-weathered older coastal limestone red soil has developed, technically - annum; with 7-8 dry months. described as brown sands (Uc4.:i} by Northcote et al. (1967), which resembles Archaean granites with fnfolded metamorphics of the Yilgarn the red earths of the Nornalup System and similarly supports karri tall forest. Geology: Block. There are a few other small patches of karri on alluvial soils. Ph'ysiographic units: Meckering Upland, Yilgarn Plateau. The communities of the sand and calcarenite are repeated on the Scott River The Avon District is a large one and comprises 21 vegetation systems. There Plain section, including patches of karri tall forest. Forest of pure marri is thus some diversity. The Walebing, Goomalling, York, Meckering, Pingelly, (E. calophylla) and woodlands of E. cornuta and E. megacarpa also occur on Narrogin and Wagin Systems belong to the Meckering Upland and may per­ the brown sands. A stretch of prograding shoreline between the Meerup and haps be described as the inner wheatbelt. Drainage has been rejuvenated and Warren Rivers has become colonized by marram grass (Ammophila arenaria). the country is hilly. The Perenjori, Jibberding, Victoria Plains, Guangan, Mt Caroline, Pikaring, Corrigin and Dumbleyung Systems lie further inland, are 5.4 The Scott River System drier and noticeably less hilly. These constitute the outer wheatbelt. The On the extensive stretches of seasonally swampy flats between the forests of Wongan Hills System is a unique enclave. The Broome Hill and Tambellup the Chapman and Nornalup · Systems,· and the coastal sand dunes of the Systems of the far south have some characteristics of their own. Finally the Boranup System, there is largely jarrah-Banksia low woodland with Melaleuca Muntadgin, Moorine Rock and Skeleton Rock Systems are still drier and con­ and an understory of small shrubs and sedges. With a still higher water-table stitute the eastern wheatbelt. They have many characteristics in common with sedgeland occurs, and where water is trapped by the dunes, there are small the Roe District.

194 195 SWAN VEGETATION SURVEY 6.1 The Walebing System from Livesey Siding, which defines the change of country. This-is typical inner wheatbelt country, dissected, hilly, drained by creeks which flow regularly in The Walebing System straddles the Great Northern Highway from Moora winter. On laterite-capped residuals there are sandplains; these occur also as through Walebing to New Norcia in a belt 20km wide and extends south to small p~tches of reworked sand in the valleys. Most of the country is un­ Bolgart. The country is undulating and hilly. The catena comprises Casuarina dulating with loam soils originally covered by mixed woodland of Eucalyptus thicket or Dryandra heath on small relics of laterite on ridges, Eucalyptus wan­ /oxophleba and E. wandoo, with occasional E. salmonophloia. Eucalyptus doo woodland on summits and upper slopes, merging downslope into E. loxo­ loxophleba and E. wandoo tend to segregate topographically, the former on phleba, and this in turn, if there are extensive flats, into E. salmonophloia. the lower slopes and vice versa. Granite outcrops are common, and are vege­ Eucalyptus rudis appears on creek banks. There are samphire flats in some tated with Acacia acuminata low woodland or mixed A. acuminata and valley bottoms and some patches of Banksia-Xylomelum scrub-heath on low­ Casuarina huegeliana. Lateritic residuals have been so thoroughly cleared that level aeolian sandplains. one can only guess at their original vegetation. Probably there were patches of Eucalyptus astringens woodland and thickets featuring Casuarina campestris 6.2 The Goomalling System and Leptospermum erubescens, of which Eucalyptus macroc(lrpa was a com­ The Goomalling System extends south of the above system down to an ponent. Remnants of such thickets occur frequently on patches of gravelly approximate line from Bolgart to Meckering. There are very extensive sand­ soil. Sandplains apparently carried scrub-heath similar to that in the Goomal­ plains occupying perhaps half the area. They occu_r for the most part onJ.he ling System. higher ground, but appear to be substantially of aeolian origin, as they overlie metamorphic rocks not granite, and consist of yellow earthy sand of some 6.5 The Pingelly System depth. The original vegetation was scrub-heath or locally Banksia low wood­ The Pingelly System lies south of the York System, extending as far as_ land. In the valleys the soil is red loam developed on metamorphic rocks, with Wickepin. The eastern boundary (with the Corrigin System) extends from the a cover of woodland of Eucalyptus loxophleba and E. salmonophloia. Along eastern end of Yenyening Lakes via Kweda to Wickepin and the southern major drainage yellow alkaline loams support a teatree and samphire vegeta­ boundary (with the Narrogin System) from Karping to Wickepin. The land­ tion in extensive salt-flats. scape is undulating, hilly, deeply dissected, with remnants of laterite crust 6.3 The York System capping higher ground to form promi_ilent mesas. Large numbers of granite exposures also occur, forming-·conspicuous domes and tors. Deposits of The country owes its character to the underlying· predominantly gneissic aeolian sand are found on the lower ground near the rivers. rocks of the Jimperding Metamorphic Belt which have been readily eroded, so Most of the country was originally covered with w~odland, principally of that nearly all the laterite-crusted 'old plateau' surface has gone, the 'new' E. wandoo and E. /oxoph/ebq,,' sometimes in mixture, but frequently segre­ soils are relatively fertile red loams, and the surface is of gentle relief, except gated with E. wandoo on the more siliceous, eluviated soils of the upper slopes where local outcrops of granitic, quartzitic or some of the harder metamorphic and E. loxophleba ·on the red soils of lower slopes. E. salmonophloia•comes in rocks form hills, some still laterite-capped. The result of this geological struc­ locally on the heavier red soils. E. rudis ·lines major drainage channels, and if ture is a unique situation where York gum (Eucalyptus loxophleba) is no these are saline, it is accompanied by Casuarina obesa. In this system Eucalyp­ longer_ confined to the soils of lower slopes but may occur as the sole species tus astringens and E. accedens are at the limit of their range and descend from forming woodland over the whole landscape. Its usual associate E. wandoo is the lateritic plateau sites, with which they are normally associated further_west, confined in this system to the less basic rocks usually on quartzite hills. onto the moister pediments, abandoning the plateaux to heath with Dryandra Another associate, salmon gum (E. salmonophloia) is not common except spp. dominant. Stands of Eucalyptus accedens become lower and more open. locally where associated with some ultramafic rocks. Eucalyptus rudis and Low-level sandplains near the Avon River carry the Banksia-Xylomelum Casuarina obesa form riparian woodland along the Avon River and its major alliance as in the York System. The numerous massive granite outcrops may be tributaries. There are no salt-flats. ! surrounded by Casuarina huegeliana on sand, or if the soil is loamy, by Acacia acuminata. 6.4 The Meckering System The relatively small area occupied by this system extends from the Mortlock 6.6 The Narrogin System River East Branch along the main road and railway. southward tMortlock River South Branch. The eastern boundary is a line ,drawn south and Wickepin. The country is less _dissected, so that substantial areas of

196 197 VEGETATION SURVEY SWAN laterite-crusted plateau remain. As rainfall is higher than in the Pingelly south and southeast, extending to the south as far as Cranbrook and including System, these plateaux are covered by woodland of Eucalyptus astringens and the township of Tambellup, It is dissected country, almost entirely in the E. accedens instead of heath, except for local patches. Woodland of E. loxo­ drainage of the Gordon River, but is of low relief. There are a few laterite­ phleba and E. wandoo covers the dissected country below the breakaways, capped hills which carry woodland of blue and brown mallet, Eucalyptus gard­ with a tendency to topographic separation especially in the west, with E. wan­ neri and E. astringens. Predominantly the country is covered with woodland doo on the upper and E. loxophleba on the lower slopes. Outliers of E. calo­ i ! - of wandoo. (E. wandoo) and yate (E. occidentalis) which associate together. phylla, wh_ich regularly associates with E. wandoo in the Dryandra System They may become segregated on valley flats with E. wandoo alone on sandy immediately to the west, occur here and there in the wandoo. E. rudis lines soil and E. occidentalis on clay. York gum (E. loxophleba) comes in around major drainage channels. There is some teatree and samphire around Taarblin Pootenup in the lakes country. River gum (E. rudis) is present near the Gordon Lake and other small salt lakes below it, in the southeast of the system. There River in the western part, forming woodland with wandoo and yate, but along are few prominent granite outcrops. the upper Gordon drier and saltier conditions force a change to teatree (Mela­ leuca viminea) and samphire (Arthrocnemum, Sarcocornia). 6.7 The Wagin System The sandplain at Tambellup consists of wandoo with scattered patches of The Wagin System adjoins the Narrogin System on the south in a belt heath: this is on an aeolian sand-sheet blown out of the bed of the Gordon approximately 35 km wide from High bury to Katanning. Its boundary with the River. Dumbleyung System to the east runs roughly parallel to the Great Southern Railway 10 km to the east of it. The landscape is undulating, well dissected, 6.10 'rhe Perenjori System with only small remnants of laterite cappings on ridges and mesas, some A portion of the Perenjori System is situated between Marchagee and granite bosses and tors, and broad valleys containing salt marshes and small Wubin. The landscape undulates gently, and there is a simple catena of yellow round permanent salt lakes. The general catena comprises· woodland of E. sandy soils with ironstone gravel on the higher ground, red loams on the lower astringens and E. wandoo (replacing the E. accedens of the Narrogin System ground, and saline grey sandy soils along valley bottoms. The vegetation of which does not extend further south) on lateritic mesas a:nd breakaways, low these is respectively Casuarina campestris thicket, Eucalyptus loxophleba and woodland of E. loxophle!J..a and Casuar/na huegeliana on granite outcrops, E. salmonophloia woodland, and a complex of samphire, teatree thickets and woodland of E. loxophleba and E. wandoo on the slopes of the undulating scrub with or without succulent grm,rnd layers, and patches of woodland. country, and a mosaic of woodland, teatree scrub ;md samphire on salt flats. 6.11 The Victoria Plains System 6.8 The Broome Hill System Moora, Watheroo, Miling, Bindi Bindi and Piawaning are included in this This name is given to a distinctive area which includes Katanning, extending system, which is very similar to the Perenjori System, and might well have from there east to Ewly

6.9 The Tambellup System This system is the classical 'guangan' of James Drummond {cited by Erickson 1969) and is accordingly named with his original spelling. It is inter­ The Tambellup System surrounds the Broome Hill System on the west, esting that the locality Kwangan Plains appears on the Bencubbin 1: 250 000

198 199 11 i

VEGETATION SURVEY SWAN sheet just west of Koorda in an area also forming part of the Guangan System. Eucalyptus longicornis and E. salubris. Lighter red soils have E. loxophleba The system occupies country from Lake Hinds to Koorda and from Pithara to and E. salmonophloia. 'Mallee with a considerable number of component Dowerin. species is found on red soils with a surface layer of ironstone gravel. Finally, The country consists to a very large extent of residual sandplain dominated and extraneous to the catena, there is the open vegetation of rock slabs. by outcropping granite bosses. The valleys are saline and occupied by salt lakes and halophytes, with small areas of peripheral woodland and aeolian sand­ 6.14 The Jibberding System plain. This extensive system lies to the east of the Perenjori and Guangan Systems The residual sandplain is mapped as 'Mallee and Casuarina Thicket', since as far as an approximate north-south line midway between Marinda and the overall impression is one of thicket in which mallee ecualypts are more Beacon, which when continued south, curves slightly east and runs down the than normally abundant. On close examination there is found to be an intri­ centre of the salt valley lying just to the east of Bencubbin, overlooked by Mt cate mosaic, determined by soil variations. Small patches of yellow sand occur Marshall. The southern boundary lies just south of the railway from Korre­ here and there on higher ground, and carry the Banksia-Xylomelum flora of locking to Trayning. The country is slightly drier than the guangan and more the Marchagee System. These sand patches appear to be of aeolian origin. In dissected, so that broad valleys and interfluves alternate, the former occupied the residual sand plain proper, on deeper sand one finds the dominants to be by some major salt-lake systems. The vegetation units are broadly the same as · Acacia Jragilis, A. stereophylla, Casuarina acutivalvis, Eucalyptus oldfieldii, in the Guangan System but with some floristic changes, and the tendency to Grevil/ea excelsior and G. pterosperma. This is substantially the flor:M>f the form intricate mosaics remains, but there is now also a broad division of the thickets of the Jibberding System. On shallower sand over ironstone gravel the country into sandplains on the interfluves and red loam soils in the valleys, dominants are Casuarina campestris, mallee eucalypts and Grevi/lea petro­ which is expressed in the II_l.apping. Within this broad division which creates a philoides; mallees identified were Eucalyptus f oecunda, E. plenissima, -major catena an intricate mosaic pattern of soils and vegetation is typical of all E. redunca, E. rigidula and E. transcontinentalis. The mallees become more 'outer wheatbelt' systems. The writer noted in the course of a traverse in this exclusive and develop into a mallee formation on a pink duplex soil with sand system: over clay. Here they are joined-by E. erythronema. Woodland of E. loxo­ phleba, E. salmonophloia and E. salubris occurs on patches of red loam, or Sand and laterite may occur on low ground and red soils on high ground. Soil and there are thickets of Melaleuca uncinata and_ other Melaleuca spp. with scat­ vegetation types merge into one another, mallee and thicket are usually mingled, and the woodland occurs mixed with malle_e, and as patches in mallee and thicket. tered eucalypts. These soil types, even the red loams, occur in the mosaic and ,· not in the usual catenary sequence, indicating that they are probably linked This mosaic character has also been strongly emphasized in the work of with variations in the underlying rock. Muir (1976-8, 1978-9). The major catena comprises communities of granite outcrops, kwongan on 6.13 The Wongan Hills System sandplains, mallee on intermediate Dy5 soils, woodland on red podzolic soils, The W ongan Hills which _support a system all their own, form a small halophytic communities in saline bottomlands. enclave within the Guangan System. Resistant metamorphic rocks protruding Rock outcrops are complex mosaics of bare rock clad only with lichens, from the surrounding plain were at one time eroded into low whalebacks rock pavements carrying scattered clumps of the herbaceous Borya nitida and trending north to south and then southeast, and became thickly crusted with some shrubs in crevices, and some thickets on peripheral shallow soils or run­ laterite .. Subsequently the laterite has been substantially breached to form off zones. Casuarina campestris is typical in the former case, Acacia lasiocalyx mesas bounded by breakaways and scarp slopes. These special features- of in the latter. geology and landforms have been responsible for development of special Sandplain soils may be said to carry three basic kwongan communities features in the flora and plant communities of the hills, all of which have been which intergrade or are subject to local floristic variations: described by Kenneally (1977). (a) Acacia resinomarginea thickets on deep yellow earthy sand. The communities are arranged in catena. On the summit plateau there is a (b) The mixed kwongan association on yellow sandy soils containing iron­ Casuarina-Dryandra thicket with scattered emergent mallee in groups or as stone gravel. Acacia, Casuarina or more rarely Melaleuca species are individuals. On the scarp slopes immediately below breakaways there is a dominant. dwarf scrub of Melaleuca undulata. On the scree slopes below this with a sur­ (c) Melaleuca uncinata thickets on shallow or loamy sands, with impeded face covering of ironstone rubble there is again a thicket, of Casuarina cam­ drainage. pestris and Calothamnus asper. Below this the communities vary according to All of these belong broadly to an Acacia-CasuarinasMelaleuca alliance and soil. Heavy red soils developed on metamorphic rocks carry woodland of share a common associated flora.

200 201 VEGETATION SURVEY SWAN Mallee is limited to small patches unmappable even at 1 : 250 000. Dominant thickets. Patches of mallee; too small to be mapped, occur usually between the species are Eucalyptus loxophleba (now occurring as a mallee ecotype), kwongan and the woodland of the middle and lower slopes. Woodlands con­ E. ovularis, E. redunca and E. transcontinentalis. Woodland is formed by sist of Eucalyptus loxophleba, E. salmonophloia, E. salubris and E. wandoo. E. loxophleba (tree ecotype), E. gracilis, .E. salmonophloia and E. salubris. Eucalyptus wandoo is rare. 6.17 The Corrigin System Salt country includes samphire communites; scrub of Acacia, Hakea and The Corrigin System has a typical 'outer wheatbelt' landscape and lies be­ other specie~ over a ground layer of succulents including samphires; and tween the 'inner wheatbelt' Pingelly and Narrogin Systems and the mallee of woodland of Eucalyptus loxophleba, E. salmonophloia and/or E. gracilis over the Hyden System. A topographic change to a more hilly and deeply-dissected saltbush (Atriplex vesicaria) or mixed succulents. Some sandy dune ridges landscape· marks the boundary in the former case accompanied by vegetational adjoining salt lakes inay haveAtriplexwithout trees and shrubs. changes. It corresponds roughly to the 400-mm isohyet. The eastern ·boundary is drawn where t11allee becomes the dominant component of the vegetation. 6.15 The Mount Caroline System This line runs roughly north-south through Jitarning siding. This system occupies an area centred upon Kellerberrin. The country is The Corrigin System is drained by the upp~ reaches of the A van River, gently undulating and consists mainly of plains underlain by red and yellow there is a well-organized drainage_pattern, but dissection is shallow and slopes podzolic soils. Residual sandplains are confined to relatively small remIJa:nts, gentle. The higher ground is capped by large patches of sand and laterite. and their dissection and removal have exposed numerous granite bosses and Laterire usually appears at the surface at the edges of such sandplains, but tors which frequently form conspicuous features dominating the landscape. does. not always form breakaways. There are some salt lakes in the vicinity of These include Mt Caroline, south of Kellerberrin, from which the system is Yealering, with halophytes on adjoining flats, but other bottomlands are not named, and its adjacent Mt Stirling, two huge outstanding masses covering necessarily salt, though salinity is increasing. There are few granite outcrops in 350 and 225 hectares respectively. this system. The basic catena comprises the same elements as in the Jibberding System, The vegetation comprises kwongan (thickets and heath) on sandplains, but their relative proportions and floristic composition differ. On granite woodland on slopes and flats, patches of mallee intermediately, and in the bosses, low woodland of Acacia acuminata and Cas1Jarina huegeliana pre­ bottomlands teatree thickets or teatree and samphire. Kwongan communities dominates, sometimes with Eucalyptus loxophleba. Run-off communities reflect increases in rainfall. On laterite thickets show a mingling of Casuarina include Leptospermum erubescens thickets. In kwongan the Banksia­ campestris with Dryandra spp., and on the deeper sands the Banksia­ Xylomelum association replaces Acacia resinomarginea communities on deep Xylomelum association has merged into a scrub-heath which contains many of sand. Casuarina campestris thickets occur on dense laterite. These may occur . its floristic elements but ·has Grevillea hookerana as the most conspicuous with scattered wandoo trees. Mallee, woodland and halophytic communities species. appears in the 'mixed kwongan' association. are substantially as in Jibberding except that Eucalyptus wandoo is more com­ Mallee species are primarily E. redunca, E. incrassata, E. eremophila and mon, and Melaleuca spp. assume dominance in halophytic shrublands. E. pileata. Woodlands consist of E. wandoo, E. loxophleba, E. salmono­ phloia and E. longicornis, with E. rudis along creeks and E .. astringens on 6.16 The Pikaring System breakaways. The Pikaring System, named from a prominent granite hill, occupies the north-central portion of the Corrigin 1 : 250 000 sheet. Its southern boundary 6.18 The Dumbleyung System follows up the stream which drains into Lake Mears to pass just north of This system occupies country centred upon the town and lake of ,Dumble­ Corrigin, continuing to Bilbarin and then north to Ardath. The landscape, yung. It lies east of the Wagin System and receives a lower rainfall. The typical of the outer wheatbelt, is gently undulating, not deeply dissected and southern limit is at Lake Coyrecup, and. the eastern boundary is drawn on lacking pronounced topographic features. entering country where mallee is predominant. The country is gently un­ The systemlies mainly on high ground, so that there is a large proportion of dulating, with scattered residual laterite cappings. These are more frequent in residual sandplain and little low-lying salt country. Large prominent granite the north. Salt-flats and lakes occupy the principal valleys, sometimes with outcrops are plentiful. associated sand deposits. The general catena in the system is of Sandplains or kwongan · are ·a mosaic of Casuarina campestris thickets, Dryandra-dominated heath oil laterite residuals, woodland and low woodland Leptospermum-Melaleuca heath and other heaths. On some of the roughest · of the 'mallets' Eucalyptus astringens, E. falcata and E. gardneri on degraded stony country scattered Eucalyptus wandoo appear in Casuarina campestris laterites and laterite wash, woodland of. E. loxophleba, E. longicornis,

202 203 VEGETATION SURVEY SWAN E. salmonophloia and E. wandoo on the undulating country generally with and Southern Cross. The elements of the landscape are much the same as frequent small patches of mallee (E. eremophila, E. redunca;. E. incrassata), q, before but differently weighted. Compared with its adjoining systems to the teatree and samphire on salt-flats, scrub-heath and low woodland on low-level west, it is drier, with resulting floristic changes, and the landscape is more sandplains. precisely dissected into residual sandplains which are now usually bordered ·by distinct breakaways, and the red soil country of the valleys. Owing to the small 6.19 The Muntadgin System amount of clearing of the sandplains at the time of the aerial photography of 1962 it has been possible to differentiate on the vegetation inap between The Muntadgin System occupies the eastern portion of the Kellerberrin area granitic areas with shallow, grey, gritty sands over rock and much outcrop, to the south of the Moorine Rock System, which lies north of lakes Brown and and the deep wind-sorted sand sheets. The latter are normally underlain by Campion. The boundary of the Muntadgin System is formed by the salt chan­ laterite at variable depth. The woodland areas mapped include patches of nel running out of Lake Brown first to the southwest and the south to meet the mallee, and there are salt-flats in the main valleys in the south. main highway and railway at Hines Hill, after which it follows another salt Granite outcrops are normally well covered by shrubs including Casuarina valley southward to its head, and then coptinues south across country, passing campestris, Calothamnus asper and the succulent Calycopeplus helmsii. through the township of Bruce Rock. The Muntadgin System extends to the Casuarina campestris is dominant in thickets on granitic sandplains. On east as far as Westonia and Holleton and south to South Kumminin. The depositional and lateritic sandplains there are three associations as further country is slightly drier than that in the Mt Caroline System, and is relatively west: Acacia neurophylla thickets on dense laterite, the 'mixed kwongan' higher-lying and less reduced by erosion. There ar_e substantial ar;-as of association on gravelly sands, and Acacia resinomarginea thickets on deep residual sandplains dissected by shallow valleys leading to the west and north­ sand. The principal species in the mallee formation are Eucalyptus redunca, west. These sandplains were estimated to occupy 350Jo of the surface in the E. /oxophleba, E. sheathiana and E. transcontinentalis. In woodland E. loxo­ Merredin soil survey (Bettenay & Hingston 1961); further south the propor­ phleba is rare; E. wandoo is found on wash at the foot of breakaways; prin­ tion is much higher. There are many granite rock outcrops, some of them cipal woodland species are E. salmonophloia, E. salubris and E. longicornis. domes of substantial size, others merely slabs covered by shallow sandy and gritty soils. There are no playa lakes or salt-:flats in the system, except at its edges, where they are shareg with adjoining systems. 6.21 The Skeleton Rock System The vegetation differs substantially from that of the Mt Caroline System. This system is situated south of Southern Cross and extends into the Roe Granite outcrops are much less well vegetated and correspond more to the District further south. The country is high-lying, forms part of a watershed, Jibberding System. Kwongan is much more extensive and consists of different and is thus only partly dissected. About half of the land surface consists of associations. Mallee is also more extensive and can be mapped, both as pure residual sandplains with a vegetation of scrub-heath and thicket. On the re­ mallee adjoining sandplains on the upper slopes of the valleys and as maliee mainder of the land in the shallow valleys the vegetation is mallee, frequently with patches of woodland in the upper reaches of the main valleys. Woodland · with patches of woodland. as an extensive formation is limited_ to the lower parts of these valleys. York In the sandplains scrub-heath pre~ominates, covering usually the central gum (Eucalyptus loxophleba) virtually disappears from _the woodlands, occur­ portions where the sand is deepest, and grading into thicket towards the edges ring mainly as its mallee ecotype, whereas Morrell (E. longicornis) makes its where the sand is shallow and overlies ironstone gravel. This transition is appearance on the more calcareous of the bottomland soils. E. salmonophloia marked by the casuarinas, C. acutivalvis and C. corniculata, which are rare to and E. salubris are the principal species. absent in the heath, but become dominant with Acacia spp. in the thicket. As a In kwongan it is difficult to detect different associations related to soil types generalization these are mapped as Acacia-Casuarina thickets. as elsewhere; rather there are thickets dominated by Acacia spp. and The mallee is transitional in that Eucalyptus eremophila tends to dominance Casuarina acutivalvis, which correspond to the 'mixed kwongan' of other in the southern part of the system, while E. loxophleba and E. sl!eathiana systems. A component is the small mallee Eucalyptus burracoppinensis. In the appear in the northern part. Eucalyptus gardneri is.seen, but not apparently mallee formation E. redunca, E. cylindriflora and E. transcontinentalis are the E. falcata. E. spathulata is found in winter-wet places. E. flocktoniae is occa­ principal species. sional. Patches of woodland are formed of E. salmonophloia and E. salubris.

6.20 The Moorine Rock System 7 Roe Botanical District This system lies between the Jibberding and Muntadgin Systems, and the boundary of the South West Botanical Province, which mns close to Bullfinch The general cover is mallee, with Eucalyptus eremophila the most consistent

204 205 VEGETATION SURVEY SWAN species. Patches of eucalypt woodland occur on lower ground, and scrub­ 7 .2 The Forrestania System ,, heath and Casuarina thickets on residual plateau soils. The Forrestania System is developed on a greens.tone belt, and comprises a Climate: Extra-dry mediterranean; winter precipitation annual total 300- variety of communities which are controlled by the underlying geology largely 500 mm, with 7-8 dry months. in a mosaic form. The actual greenstones, which are of a basaltic nature, Geology: Archaean and Proterozoic granites overlain in the east by Early weather to form a somewhat flat tract of country with a heavy soil supporting Tertiary sediments. eucalypt woodland broken by numerous small salt lakes, but there are in­ Physiographic units: Ongerup Plateau (Pallinup and Chidnup Systems), cluded granites and quartzites ('whitestones') which form siliceous soils, fre­ Truslove Plateau (Lort, Oldfield, Salmon Gums Systems); Hyden Plateau, quently lateritic, accounting for areas of mallee, thicket an? scrub-~eath Forrestania Tableland and Lake Hope Uplands corresponding to like-named within the mosaic. In addition there are banded ironstones formmg promment systems. rocky ridges with distinctive associations of heath and thicket. 7 .1 The Hyden System The sclerophyll woodlands comprise only two major tree species, Eucalyp­ tus salmonophloia and E. longicornis. The Hyden System, is a very extensive one, occupying the eastern third of The small salt lakes have a samphire vegetation and are frequently sur­ the Corrigin 1 : 250 000 sheet south of South Kumminin, fully half of the rounded by a teatree belt (Melaleuca ?parviflora). Many local patches in the adjoining Hyden Sheet to the east and a like proportion of the Newdegate woodland with shallow or lateritic soil carry only mallee or casuarina thicket. sheet. It is one of the largest components of the Roe District. The landscape-,is Mallee included in this system is frequently of the same character and compo­ very gently undulating, with wide flat valleys and long gentle slopes. rising to sition as in the adjoining Hyden and Lake Hope Systems, where Eucalyptus broad interfluves. The latter are capped, as elsewhere, by residual laterite and eremophila is the most consistent species. sand, but these deposits have seldom any definite margins such as breakaways. On included granites there are certain areas of scrub-heath and thicket Perhaps due to the gentle slopes soils are very variable, and the highly-mosaic which are of the same character and composition as those in the Boorabbin character exhibited by the vegetation of the wheatbelt becomes even more pro­ System. A peculiar feature of the Forrestania System is the ridges of banded nounced. The plant cover varies in structure and composition every few yards. ironstones which form abrupt hills, rocky and with little soil. Mount Holland Mapping is complicated by this, and even more by the frequent fires which is clothed with a dense thicket 2 m tall, similar in composition to that of the take place and eliminate or obscure the vegetation patterns seen in aerial Bremer Range further east, the commm;iest species being Casuarina campestris photography. It is usually only possible to map accurately those categories and Calothamnus asper. which give pronounced photo-patterns, e.g. rock outcrops, woodland relative to shrublands, salt-flats and lakes. Types of shrubland may be difficult or impossible to distinguish from one another. However, on a broad scale it is 7 .3 The Lake Hope System possible to say that there is a characteristic catena in the Hyden System, com­ This system occupies a basin of interior drainage around a number of playa prising kwongan (scrub-heath and thicket) on sandplains, mallee on the slopes lakes, e.g. L. Hope, L. Tay, L. Sharpe and L. Mends. Slopes are gentle, duri­ covering the bulk of the area, mallee with patches of woodland on upper valley soils, woodland on lower valley soils, and in saline areas a mosaic of wood­ crust temnants are not extensive, so that ·most of the area is covered by mallee land, shrubland and samphire. Bare granite outcrops are a feature in any and woodland or with burnt-out woodland which has been reduced to the section of the catena. equivalent of mallee. The components of the catena are scrub-heath and Scrub-heath, where it occurs, is of very heterogeneous composition, but thicket. granite outcrops, mallee and woodland'. Scrub-heath in the north Grevillea hookerana is a reliable character species, also the peculiar Casuarina resembles that of the Boorabbin System but in the south that of the Esperance pinaster (Beard 1969c) and scattered mallees, especially Eucalyptus albida, System, with Eucalyptus tetragona conspicuous. In general mallee and wood­ which occur as emergents. Casuarina-dominated thickets comparable with the land resemble those of the Hyden System. E. diptera forms whipstick stands 'mixed kwongan' of the Avon District are less common. In the mallee forma­ on clay. The burnt-out woodland around Lakes Tay and Sharpe is on tion over 15 spp. of Eucalyptus have been recorded. E. eremophila and calcareous soil and consists of Eucalyptus oleosa and E. flocktoniae. E. redunca are the most consistent. The dense Melaleuca understory is charac­ teristic. Eucalyptus f alcata and E. gardneri form low woodland on irons_tone 7.4 The Salmon Gums System ridges; E. platypus, E. annulata and E. spathulata form low forest on patches Only a small area of this system, named from the town of Salmon Gums, is of low-lying clay. In woodland E. salmonophloia is the principal species with present at the margin of the Swan sheet. It consists of somewhat flat or gently E. salubris, joined by E. longicornis, E. gracilis and E. kondininensis in the undulating country covered with mallee of E. eremophila on Dy5 soils, or of vicinity of salt lakes. 206 207 I

I VEGETATION SURVEY SWAN E. oleosa-E. flocktoniae on Gel, with patches of woodland of the latter try constitutes the Oldfield system. The plain, due to its flatness, is winter-wet; species or of E. salmonophloia or E. diptera. the soil with its sand-over-clay mallee soil profile becoming readily water­ logged in the rainy season. The most swampy areas are 'gilgai', i.e. with a 7 .5 The Chidnup System hummocky surface. The general plant cover is mallee, but there are scattered The Chidnup System includes the area on the Dumbleyung 1 : 250 000 sheet granite outcrops, patches of sand with mallee-heath, clay patches with Euca­ which was described as the Ongerup System by Beard (1980d). It occupies a lyptus platypus low forest, and scattered lakes and pans which tend to carry or belt parallel to the coast and covering the high ground which forms the water­ be surrounded by stands of E. occidentalis. shed between the south coastal rivers and the Swan-Avon basin. Relief is very The mallee in this system is a distinct community, with E. eremophila domi­ subdued and the landscape is flat to gently undulating, dissected only margi­ nant in association with E. forrestiana. Strictly speaking, neither of the two nally by the headwaters of some of the south-draining streams. There are some dominants is a mallee, as they are killed by fire, regenerating each time from very low, long narrow ironstone ridges and very numerous small lakes and seed as a single-stemmed tree, as does E. platypus. It is convenient however to swamps. The structure of the high plain replicates that of the Broome Hill and regard this community as mallee rather than as a kind of very low forest. Other Kwornicup Systems. On the west it is bounded by a definite scarp overlooking casual mallee species include E. redunca, E. uncinata, E. goniantha and the town of Gnowangerup, but elsewhere its margin is less precise. E. f!ocktoniae. The trees reach 3-4.5 m in height, and have the usual dense Scrub-heath, usually with Eucalyptus tetragona conspicuous, appears on understory about I m. tall of melaleucas. broad sandy ridges. On laterite, low woodland of E. falcata is the climltx, though frequently burnt back to the stature of mallee. Small patches of wood­ 7.8 The Oldfield System land of E. occidentalis, joined sparingly by E. salmonophloia occupy depres­ There are places where the old land surfaces have been extensively breached sions on winter-wet grey clays and in swamps, low forest of E. platypus also on by the upper courses of rivers, giving rise to broken country with a close grey clays. Mallee covers the greater part of the area with a tendency to segre­ mosaic of different soil and vegetation types. Undissected plateau remnants. gate into E. eremophila-E. oleosa and E. redunca-E. uncinata associations. carry Eucalyptus tetragona mallee-heath similar to that of the Esperance System. On eroded surfaces, thin soil over bedrock carries Casuarina­ 7 .6 The Pallinup System Calothamnus thicket, loam carries mallee with Eucalyptus eremophila domi­ The area· described on the Albany-Mt Barker 1 : 250 000 sheet under the nant, clay low forest of E. platypus, E. spathulata and E. annula ta. Some Chidnup System (Beard 1979d) is now regarded as the Pallinup System. It patches of E. occidentalis woodland are found in valley bottoms. comprises the valley of the Pallinup River and adjoining plains, and extends north to include Gnowangerup .. The plains are occupied by mallee of the 8 Eyre Botanical District E. redunca-E. uncinata association with patches of low forest of E. flock­ toniae and E. gardneri on gravel, E. platypus and E. annulata on winter-wet Scrub-heath and mallee-heath on sandplain, with tallerack (Eucalyptus clay, and with small circular depressions containing E. occidentalis woodland, tetragona) as characteristic species. Mallee (E. redunca, E. incrassata) occu- Melaleuca low woodland or open water. Lakes are mostly saline and inter­ pies valleys incised in the plain. · mittent. Continuous woodland occurs in the larger valleys on young bedrock Climate:. Dry mediterranean; winter precipitation total of 500-700 mm per soils. Yate (Eucalyptus occidentalis) and York gum (E. loxophleba) are the annum; with 5-6 dry months. principal species with some E, wandoo, some marri (E. calophylla) near the Geology: mainly Eocene sediments, with outcrops of granites and quartz­ Stirling Range, and some morrell (E. longicornis) northwest of Borden. Along ites. the course of the Palliniip Casuarina obesa grows in the river bed, river gum Physiographic units: Jerramungup Slopes, Ravensthorpe Hills, Stirling and (Eucalyptus rudis) and yate on banks and levees. York gum and Casuarina Barren Ranges, Esperance Plains. huegeliana cover a sandy aeolian deposit. 8.1 The Jerramungup System 7. 7 The Lort System The Jerramungup System occupies the seaward slope of the continent The Lort System is named from the river which bisects it, and occupies the descending from the high plain along the watershed (Chidnup System) to the flat plain lying about 180 m above sea-level, which succeeds the gently-rising coastal plain on Tertiary sediments (QualupSystem). Soils in the Jerramungup coastal plain of the Esperance System. Where this flat plain has been dissected system are formed on granite and are mostly young to mature. The general by the rivers, especially by the Oldfield in the west, the resulting broken coun- plant cover is mapped as a mosaic unit of mallee and mallee-heath, with

208 209 ·«'·

VEGETATION SURVEY SWAN mallee, sometimes with patches of yate woodland, in valleys. In actuality, the mosaic is considerably more complicated, and is dictated by variations in soil depth and texture. The communities present were specially studied in a small E. marginata area close to the Phillips River, and have been dealt with in- a separate paper mallee-heath (Beard 1967). The pattern found there extends generally throughout the Jerra­ mungup system. The communities comprise mosaic of rock and thicket on granite outcrops, Casuarina-Melaleuca thicket on shallow soil over bedrock, heath on shallow bleached sand, mallee on Dy5 soils over extensive areas, mallee-heath on more sandy, leached Dy5 soils, Casuarina heath, Eucalyptus platypus low forest on patches of clay and E. occidenta/is woodland on creeks and lower valley slopes. Mallee is of the E. eremophila-E. oleosa association on upland soils containing ironstone gravel, and the E. redunca-E. uncinata associations in, the valleys without gravel. The two intergrade. Jarrah low woodland 8.2 The Ravensthorpe System The system is associated with the. outcrop of greenstone rocks around the town of Ravensthorpe where the settlement was directly due to the presence of E. marginata these rocks, which are metalliferous and also give rise to fertile, moisture­ mallee-heath retentive soils suitable for agriculture. Soil depth on the ·greenstone varies according to topography, shallow and rocky on the ridges. deeper on mid­ slope, very deep in the bottomlands. The vegetation types associated with this catenary sequence are thicke~, mallee and woodland or low forest. The thicket of the summit ridges of the Ravensthorpe Range and Mt Des­ mond is similar to that of the Barren Ranges, that is to say it is dominated by the low mallees Eucalyptus preissiana and E. lehmannii, with Dryandra quercifolia. The two most consistent and typical species in mallee are E. tetragona mallee-heath and E. gardneri, which in favourable places and given freedom from fire in­ crease in stature to form low forest. At least nine other species are known to Yale woodland occur, including the local endemic E. stoatei. Sedge swamp The woodlands occupy broad valleys, in which the soil is at its deepest, and , Yale woodland consist of E. loxoph/eba and E. salmonophloia.

E. tetragons mallee-heath 8.3 Stirling Range System on old lateritized plains soil This system is associated with the Range of that naine and covers the slopes, peaks and valleys. Surrounding plains and pediments are included in the Woodland on scarp Qualup System, where their vegetation is E. tetragona mallee-heath or mixed scrub-heath. Salt lake & samphfre Communities are arranged in a catena which consists of a mixed thicket on the summits, without clear dominance but 'Yith Dryandra formosa, Isopogon Sand ridges with mallee E. angu/osa, E. deciplens, Banksia latifolius and Oxylobium atropurpureum as the most conspicuous species; mallee-heath with jarrah (Eucalyptus marginata) in a mallee form as E. tetragons mallee-heath character-species on the lower slopes merging into jarrah low woodland on

210 211 .F

VEGETATION SURVEY SWAN footslopes, and this again into jarrah-marri woodland in the valleys, or some­ mallee-heath, dominated by Eucalyptus nutans and E. gardneri. The Barren times to wandoo. E. tetragona mallee-heath surrounds the range. Ranges are well known to harbour a considerable number of endemic species. Principal control of vegetation is by topography and soil. Owing to the The existence of these endemics is probably related to the unique habitats mountainous nature of the Range, topography exerts a very strong influence, afforded by the differing lithology in these mountains. and the relationships of the various units can be explained in terms of the On the pediments of the Barren Ranges the Eucalyptus preissiana-Dryandra catena, to which both geology and soils are also related. The rocks forming the quercijolia thicket merges gradually into Eucalyptus tetragona mallee-heath. as Stirling Range are of sedimentary origin, consisting of quartz sandstone at the the stony detritus gives way to sandy lateritic soil. base, overlain by phyllite and muddy sandstone. As the beds are mostly fairly The mallee in the valleys of rivers, which have cut through the ranges, flat-lying, this sequence exists throughout, and there is an absence of the litho­ belongs to the E. redunca-E. uncinata association. logical diversity which is marked in the Barren Ranges further east and has Coastal vegetation is similar to that in -the Bremer System, except for created ecological niches favourable to local endemic species there. Broadly, absence of Agonis flexuosa, which does not spread east of the Gairdner River. the thicket of the mountain tops is associated with phyllite and the mallee­ Cliffs and headlands exposed to the sea carry an open stand of low cushion heath of the lower slopes with quartz sandstone. Woodland in the valleys is plants. At Point Ann these are , , Calo­ associated with colluvium brought down from the mountains, forming rela­ thamnus pinijolius, Pimelea ferruginea, and at the mouth tively young, undeveloped soils. Although these may contain quantities of Pimelea ferruginea and Scaevola crassifolia. Stabilized dunesand at the latter laterite, it is in the form of transported nodules. On the other hand the J;;uca­ point is vegetated with Eucalyptus angulosa as mallee and an understorey of lyptus tetragona mallee-heath of the surrounding plains and pediments Mela!euca pentagona. (Qualup System), while it is also developed partly on colluvium, has a highly­ weathered soil profile, dating probably from the Early and Middle Tertiary. 8.5 The Qua/up System 8.4 The Barren Ranges System The Qualup System is very widespread, covering the sandy gravelly plains north and south of the Stirling Range and extending east to the Phillips River, This system covers the small mountains of the Barren Ranges group with beyond which it is continued by the very similar Esperance System to Cape their pediments, some smal_l adjacent portions of coastal plain on Plantagenet Arid and Israelite Bay. South of the Stirlings the Qualup gives way to the Cape rocks, river trenches where 'these are cut through, and some ininor areas of Riche System with a change in vegetation, which cannot now after land clear­ drift sand. The vegetation of these four types of country is respectively the ing be exactly traced by means- of aerial photo patterns and an arbitrary line Barren Ranges thicket, E. tetragona mallee-heath, mallee and coastal scrub. has been drawn. The composition of the Barren Ranges thicket varies locally. The most con­ The principal formation is mallee-heath in which the conspicuous tallerack sistent species are the mallee E. preissiana and the prickly shrub Dryandra (Eucalyptus tetragona) is taken as the character species, growing on plains of quercifolia, which dominate the 1.5 m thicket. Other typical components are sand overlying clay often with ironstone gravel. On deep sand the formation Eucalyptus lehmannii (rnallee form), Banksia lehtnanniana, Calothamnus changes to scrub-heath, in which mainly proteaceous shrubs, e.g. Banksia spp. pinifolius, Casuarina humilis, C. trichodon, Dryandra armata, Eucalyptus and Lambertia inermis largely replace mallee. Mallee itself occurs on the conglobata, Hakea crassifolia and . lunettes of lakes and in valleys entrenched into the plain. It belongs to the The effect of lithology is seen in certain distinct associations which follow Eucalyptus redunca-E. incrassata association. There is also limited woodland the outcrop of a particular rock type. Thus, a sandstone which produces a thin along creeks crossing the plain and along the Kalgan River. The plains are yellow sandy soil is characterized by stands of the whipstkk mallee Eucalyptus dotted with numerous salt lakes and pans, or simply swampy depressions sepulcralis. which contain E. decipiens mallee if sandy, E. occidentalis woodland if loamy. A certain very massive quartzite carries a typical association also: of Regelia velutina, Calothamnus validus, Melaleuca citrina, Banksia quercifolia var. integrijolia and Baeckea ovalifolia. This quartzite, from its nature, tends to 8.6 The Cape Riche System form the mountain summits, and is present in East Mount Barren, Annie Peak On crossing the bioclimatic boundary line on the Kalgan Plains to a shorter and West Mt Barren. However, it crops out also at lower elevations, when the dry season of under 4 months, the mallee-heath becomes dominated by identical plant association will be found with it. E. marginata instead of E. tetragona, and other species changes take place. The summits of the other mountains in the Barren Ranges, where not This mallee-heath association, similar to that on the slopes of the Stirling formed of this quartzite, also tend to show local peculiarities. Certain outcrops ·. Range, covers the greater part of the area, merging into a scrub-heath as of greenstone occur locally in the ranges and carry a distinctive association, a described in the Qualup System on deep sand. Some fairly large patches of

212 213 (·

SWAN VEGETATION SURVEY jarrah-marri woodland occur along the Bremer Hay Road and again near the 8.9 The Fanny's Cove System sea on Warriup Road. The plain is dotted as usual with small depressions filled The Fanny's Cove System occupies a narrow littoral plain between the sea with E. decipiens or E. occidentalis according to the degree of swampiness, or and the edge of the gently-rising old land surface of the Esperance System. The in some cases with sedges and . Fanny's Cove System has a young land surface of Quaternary sands, some of In the extreme south below the Bluff River and in the Waychinicup drainage it piled into dunes of various ages, mostly vegetated, but with some patches of Eucalyptus staeri replaces E, marginata, but no significant change in the loose drift sand. The dunes are almost everywhere present and frequently im­ associated flora was recorded. As before, there is a mallee phase and a scrub­ pound small shallow lakes and swamps or closed estuaries. In the west there is heath phase on deeper sand with banksias dominant. no topographic break on the inland sid~, but further east a decayed former sea-cliff becomes apparent which rises to become 30 m high still further east at 8.7 The Esperance System Esperance. On the seaward side of the dunes there is a low scrub in which As previously noted, the Esperance System continues eastward the coastal Scaevola crassifolia is dominant, otherwise the principal species are Eucalyp­ plain of the Qualup System developed on Tertiary Plantagenet sediments and tus angulosa and , with an understory of Melaleuca pentagona rising gently from sea-level to an altitude of 180 m in 30 km. The plain is or M. sclerophylla, The community is much burnt and rarely has a chance to trenched by the valleys of small seasonally intermittent rivers rising further develop any mature structure. Occasional big old specimens of Melalecua inland, and its surface is pocked with small round depressions which form pubescens suggest that that species might in time become dominant if fire were intermittent freshwater lakes or paperbark and yate swamps. Plant formations excluded. Old, well-consolidated dunes may develop a mallee-heath associ­ and their relationship to landscape units are the same as in the Qualup System, ation ~ith Eucalyptus tetragona and E. preissiana. but their floristic composition differs. Inland of the dunes there is a flat and swampy sandy plain carrying a scrub­ heath with Banksia speciosa dominant. Eucalyptus platypus var. heterophylla 8.8 The Bremer System may form patches of low woodland in depressions, while swamps are colo­ This system comprises the coastal complex of granite bosses and sandhills nized by the paper bark tree Melaleuca parviflora. stretching from Nanarup eastward to Point Hood. The granite masses of Mt Gardner, Mt Manypeaks and Bald Island are included, together with others further east, and the dune complexes between them. The granite is often partly THE SOUTHWESTERN INTERZONE mantled with sand, and the depth of soil and its degree of leaching is very vari­ able, so that exposed bosses carry an intricate mosaic of communities. On the 9 Coolgardie Botanical District dunes a mosaic character is imposed by fire as well as age of weathering of the sands. Predominantly eucalypt woodlands, becoming open and with saltbush­ On the dune sands the Pimelea ferruginea association of the Boranup bluebush understory on the more calcareous soils. Patches of shrub steppe System is still present facing the sea, or low wind-pruned heath as in the Torn­ adjoining the Great Victoria Desert. Scrub-heath and Casuarina thickets on dirrup System. Further away, or with more shelter, there is a scrub-heath with sandplains. · Agonisjlexuosa and Eucalyptus angulosa as the most conspicuous species. On Climate: Arid non-seasonal to semi-arid mediterranean; annual precipita- the better sites and with freedom from fire this is capable of developing into tion 200-300 mm. woodland of Agonis flexuosa 15 m tall. On leached grey sand Eucalyptus Geology: Proterozoic granite and gneiss of the Fraser Range Block; decipiens mallee dominates a heathland, and on limestone ridges there, are Archaean granite with infolded volcanics and metasediments of the Yilgarn thickets of Dryandra sessilis, Jackson fa and Acacia decipiens. Block. In exposed places on granite bosses there are communities of cushion plants Physiographic units: Boorabbin Plateau, Bungalbin Ridges, Parker Hills, such as Dryandra pteridifolia and , or with more soil Bremer Range, Coolgardie Plains and Hills. Banksia media, Darwinia diosmoides and Melaleuca pentagona. Bald Island has a unique vegetation due to isolation from fire, comprising a 9 .1 The Boorabbin System succulent mat exposed to salt spray, tussock-land of Poa caespitosa and Scirpus nodosus behind this, then heath and scrub of Agonis flexuosa. On the The Boorabbin System is the largest, and gives its name to the most exten­ sheltered side of the island there is low forest of Eucalyptus lehmannii with sive physiographic unit. It stretches from Southern Cross to Coolgardie, some Agonis and Callitris preissii, changing to Melaleuca lanceolata on cal­ northwards roughly to the line of the standard gauge railway, and south to the carenite. Bremer Range.

214 215 VEGETATION SURVEY SWAN At the highest points and in the centre of the widest interfluves, broad and Acacia thickets, shallow granitic soils on the middle slope with Acacia plateaux of deep yellow sand carry a scrub-heath association. Down-slope it scrub, and deep red loams in the bottom-lands carrying various woodland merges very gradually, so that sharp boundaries can never be drawn, into the associations.Ju the vicinity of salt lakes the soil may become sandy, in which Acacia-Casuarina thicket. There is at first a general mixture, then heath plants case there is a return to Acacia scrub, this time with a saltbush and succulent are relegated to an understory and finally disappear. Within these two zones ground layer. outcrops of granite occur with their rock pavement vegetation. Down-slope The thickets of the sandplains comprise Acacia neurophyl!a on dense under the thicket the yellow sand becomes shallower, and is bottomed by a laterite, 'mixed kwongan' on sandy-gravelly soil and Acacia resinomarginea lateritic hardpan which eventually comes to the surface, often with a small r on deep sand, as in systems further west. In Acacia scrub on granitic soil, scarp or 'breakaway'. Below this there is an abrupt change to woodland, at A, ramulosa is the principal species. Woodlands may be formed by Eucalyptus first the mixed association of Eucalyptus transcontinentalis and E, Jlocktoniae loxophleba with a sclerophyll understory, or by E. salmonophloia and on a relatively shallow red loam soil overlying granite. Further down in the E. salubris with either a 'broombush' understory (mainly Acacia and Eremo­ valley bottom, on deep alluvium there is a gradual change to the taller phila spp.) or a 'saltbush' understory (A triplex, Sclerolaena, other succulents). E. salmonophloia association. The latter species is general throughout on light Acacia ramulosa is back in scrub in salty country, this time with such salt­ loam. E. longicornis comes in on heavier soil, E. salubris on stiff clay and tolerant species as Eremophila oldfieldii, , Hakea preissii and E. melanoxylon where kunkar is abundant. A narrow band of mallee may Pittosporum phillyraeoides, and in the ground layer Atriplex, Frankenia, occur between the breakaway and the woodland. -· Carpobrotus, Disphyma and Maireana. The Bungalbin, Die Hardy and Highclere Systems are on metamorphic belts 9. 2 The Cave Hill System forming enclaves within the Jackson System. In the Cave Hill System there is very little scrub-heath due to dissection of the sandy plateau surfaces. The interfluves are mainly characterized by granite 9.5 The Bungalbin System outcrops surrounded by thicket growing on shallow decomposing rock or The Bungalbin System is the vegetation of the abrupt rocky ridges of banded residual ironstone. On the lower ground the same woodland types are found as ironstone seen at Bungalbin, Mt Jackson, Koolyanobbing and elsewhere. They in the Boorabbin System. have become sources of iron-ore. These ridges are very rocky, and there is little soil in the ordinary sense except on the footslopes. Thickets of Acacia quadri­ 9 .3 The Bremer Range System marginea are characteristic. Casuarina acutivalvis and C. campestris may be The Bremer Range is a greenstone belt and owes its topography to the more present also and may assume dominance locally. The associated flora is not resistant members of the metamorphic rocks. On the rocky knolls one finds a numerous. The ridges usually rise from woodland of Eucalyptus salmono­ broombush thicket of Casuarina campestris and Calothamnus asper. In local phloia and E. salubris. patches the thicket breaks away to a grassland with shrubs. Footslope areas carry a fine woodland of Eucalyptus dundasi and E. longicornis (both black­ 9.6 The Die Hardy System butts), with no other associated trees, except that where the woodland has been This system occupies a small area on the northern border of the map on the destroyed by fire, the regeneration in addition to the above two species con­ footslope of the Die Hardy Range which lies just off the map. The range con­ tains much E. corrugata. The latter species appears to be relatively short-lived sists of banded ironstones like Mt Jackson and Koolyanobbing, but owing to in competition with the others, and under undisturbed conditions appears to lower rainfall the vegetation is slightly different. Brachychiton gregorii is a be confined to a narrow belt between the woodland and the thicket. On low casual small tree, and Dryandra arborea occurs on rocks along the crest of the alluvial country there is the usual E. salmonophloia association. range. On the north face of the range there is an open scrub of Acacia aneura, A. linophylla, A. acuminata, A. tetragonophylla and Dodonaea spp. On the 9.4 The Jackson System south face there is a dense thicket of Casuarina acutivalvis and C. campestris The Jackson System lies north of the Boorabbin System. The landscape is mainly, with some of the acacias, and mallees such as Eucalyptus oleosa and somewhat more dis~ected, so that .residual sandplains are reduced iri relative E. J ormanii, Pti/otus obvatus is common as a ground plant. area. Where the duricrust has been removed by erosion, there is country of The footslope carries an outlier of the mulga formation (Acacia aneura low shallow soil developed on granite.with much rock outcrop, and this is charac­ woodland) whose proper boundary still lies 30km further north. A. aneura is teristic of the middle slope. The valley bottoms have deeper, more mature dominant, with scattered Casuarina cristata, and large shrubs of Acacia i soils. The catena therefore comprises fairly wide interfluves with lateritic soils ramulosa forming a lower layer.

216 217 11:,, i i VEGETATION SURVEY SWAN 9. 7 The Highclere System present. Mallee is of E. gardneri and E. redunca or of E. loxophleba and · The greenstone belt north of Bullfinch, comprising the Highclere Hills and J, E. sheathiana, mingling with Acacia-Casuarina thickets. A Casuarina-Calo­ the northern part of the Yilgarn Hills, has geological and vegetational features thamnus thicket similar to that of the Bremer Range covers the tops of knolls of its own which place it in a different system from the southern part of the and ridges. Yilgarn. Where outcrops of ironstone occur, they are of much more limited 9.10 The Karroun System extent than in the Bungalbin System, creating small rocky ridges 'in hilly coun­ try, and as in the Bungalbin System their vegetation is a thicket of Acacia This area lies north and east of the Jackson System and is uninhabited. The quadrimarginea with a few scattered trees of Casuarina cristata, Brachychiton landscape is similar to that elsewhere on the Boorabbin Plateau, gently un­ gregorii and Pittosporum phil!yraeoides. · dulating and of low relief, about equally divided into residual sand plains fre­ Hilly country on greenstone is covered with woodland of Eucalyptus longi­ quently bounded by breakaways up to 3 m high, and shallow valleys with red cornis and E. corrugata with an understory of saltbush, A triplex vesicaria and loam soils. There are substantial areas of outcropping granite, there is some A. nummularia. Occasional small trees may be Casuarina cristata, Brachy­ salt country along the boundary with the Jackson System, but virtually there chiton gregorii and Callitris columellaris, and among larger shrubs Acacia are only two components of the catena, kwongan on sandplains and woodland tetragonophylla, A. ramulosa and Santa/um spicatum. In places; particularly on valley loams. on the slope running out to Lake Deborah, this same Eucalyptus and saltbush Kwongan communities are much the same as in adjoining systems, e.g.: association persists on the adjoining lower country. Elsewhere, especially on (a} Acacia neurophylla thickets on dense laterite. · · the east and west flanks of the hills, the eucalypts may be replaced by (b) Mixed kwongan with Casuarina corniculata dominant. The soil is a E. salmonophloia, E. loxoph/eba, E. salubris and ·E. sheaihiana, the last lateritic gravel in a clay matrix; named not in its usual mallee form but as a large stout tree 12 m tall and 50 cm . (c) Acacia resinomarginea thickets up to 12 m tall, with associated in diameter. Casuarina acutivalvis and Melaleuca uncinata over a patchy ground layer of Ecdeiocolea monostachya on deep sandy yellow earths. 9.8 The Yilgarn System (d) Melaleuca uncinata thickets 2-3 m tau on sandy yellow earths. Woodland communities differ from those of adjoining systems. Three can This and the Parker Range System which follows are also developep. upon be recognized. On slopes with red Dr soils, there are low to medium-height greens tone country. In the Yilgarn System there is virtually no catena,' as the woodlands (8-15 m) of mixed and vegetation is entirely woodland except for the salt lakes at Southern Cross. Eucalyptus loxophleba Callitris columel­ with a scattered sclerophyll understory, mainly becomes There is only a change in composition on rising ground. The system comprises laris, Acacia. Ca/litris dominant or the sole species on red earth (Gn) soils, in low woodland of 5-8 m. three distinct areas: the Yilgarn proper from Marvel Loch through Southern On heavy clay flats there is open woodland of 10-15 m. Cross to Bullfinch, the Westonia outlier and the Holleton outlier. Eucalyptus salubris In the Yilgarn there are woodlands of E. longicornis, E. salmonophloia and 9.11 The Jaurdi System E. salubris, with E. corrugata coming in on rises. The understory is of either of two types: the boree type with and M. pauperiflora, and The Jaurdi System lies east of the Jackson System. It is all highlying country the saltbush type with the saltbushes A triplex vesicaria and A. nummularia. underlain by granite, and most of the surface is covered by residual sandplain In the W estonia outlier it is the same, except that the woodlan,ds haye been only slightly di~sected by the upper reaches of some shallow valleys. Granit; heavily cut over in the heyday of min\ng and now consist of young stands, rock outcrops are numerous. Topographic undulation is slight. In the sand­ some originating from coppice, some 9 to 12m in height. plain areas the soil consists of yellow sand at the surface which may be under­ At H9lleton the woodland is of more varied composition, as Eucalyptus lain _by laterite. at any depth. Deep sands exceeding 90 cm appear. to pre­ f alcata, E. flocktoniae and E. kondininensis have all been identified there, t dommate. Outside the sandplains, in topographically lower situations the soils while E. corrugata has not. The same understory types apply. are red in colour, usually sandy at the surface in situations closest to the sand­ I plain, becoming heavier in texture towards the valley bottom and at the same .I time more calcareous. 9.9 The Parker Range System The full catena of soil and vegetation types, of which not all members may Here the country is more hilly and the catena more varied, running from be present on any one transect, is as follows from the centre of the interfluve woodland to mallee or thicket on rises, and to thicket on ironstone ridges. outwards: Woodlands consist mainly of E. longicornis, E. salmonophloia and E. anceps Deep sand> 90 cm: Thickets with Acacia resinomarginea domi­ with patches of mallee. Saltbush, broombush and boree unµerstories are all nant.

218 219 VEGETATION SURVEY SWAN Sand over laterite: Mixed Acacia-Casuarina thickets ('mixed 9.13 The Kununalling System kwongan'). North of the Coolgardie System the country is drier, resulting in floristic Reddish sand, transitional: Thicket with scattered trees of E. loxophleba. changes, though topography and geology are similar. Thickets on ironstone Red sand: Mallee of E. loxophleba and E. sheathiana, or and other ridges are as before, but Eucalyptus torquata disapp~ars from the low trees of E. oleosa and spinifex (Triodia hill woodlands. There are some small areas of sandplains which are covered by scariosa). Acacia-Casuarina thickets of the 'mixed kwongan' type on yellow sand; how­ Red sandy loam: Woodland, of E, salmonophloia, E. salubris, ever, constant gradations to red sand occur and these patches carry shrub E. loxophleba and E. sheathiana. steppe of Triodia scariosa and mallee, Eucalyptus oleosa and E. concinna. In Granite rocks and salt lakes are interspersed irregularly. the north some of these are large enough to be mappable. Shallow granitic soils have a scrub of Acacia ramulosa as in the Jackson System, in which 9.12 The Coolgardie System mulga (A. aneura) begins to appear in the north. Woodlands are very mixed, principally Eucalyptus le souefii with The next three systems which follow are essentially on metamorphics and E. slilmonophloia, E. transcontinentalis, E, longicornis, E. campaspe and volcanics, so that their catenas are quite different from those on granite. The Casuarina cristata. The saltbush understory predominates in mid-slope, topography is controlled by the harder and more resistant strata among the changing to bluebush in the flats. Saline areas are as in the Coolgardie System metamorphics which form low ridges striking NNW-SSE with alluvial-.fl.ats between them. · 9.14 The Broad Arrow System The hardest strata are banded ironstones, which form the most prominent 1 ridges, and are covered with thickets in which Acacia quadrimarginea is domi­ Two hilly greenstone belts converge near the former mining centre of Broad nant. Arrow. The country is broken and hilly and consists mainly of stony ridges Other ridges, presumably of some different geological formation, carry with their intervening footslopes. There are no wide flats, bottomlands or 'I 'i thickets of Acacia acuminata and Eremophila oldfieldii. sandplains. Lower rainfall also effects differences from systems further west Ridges of a less abrupt nature formed by metaigneous rocks ('greenstones') ·and south. 11 carry a woodland, the Eucdlyptus torquata-E. le souefii association, which As elsewhere the stoniest ridges, frequently of banded ironstones, are occurs solely within the Coolgardie System. E. torquata and E. le souefii are covered with dense thickets of Acacia quadrimarginea or of Casuarina co-dominant, abundant and characteristic. Associated trees are E. c/elandii, campestris, Acacia. acuminata and Eremophila oldfieldii. The less rocky carry E. campaspe, Casuarina cristata and . There is an open open low woodland of Casuarina cristata with the above shrubs as understory. shrub understory, largely of Eremophila spp. In the northeastern sector of the Eucalypts appear where there is more soil, and the general cover is a mixed Coolgardie System the ridges feature Casuarina cristata instead of Eucalyptus woodland of Eucalyptus le souefii, Casuarina cristata, Acacia aneura, Euca­ torquata, and saltbush and bluebush join the understory. lyptus transcontinentalis and E. oleosa. In the deeper valleys one finds The woodlands of the middle slope are of rich and varied composition, con­ E. salmonophloia, E. sa!ubris and E. le. souefii. There is an almost universal taining mainly Eucalyptus le souefii with E. transcontinentalis, E. salmono­ bluebush understory of Maireana sedifolia. phloia, E. oleosa, and E. campaspe. There are two types of understory which may be characterized as the THE EREMAEAN BOT AN I CAL PROVINCE 'broombush' and 'saltbush', interchanging independently of the overwood and presumably controlled by soil pH. This is the Australian Arid Zone with annual rainfall below 250 mm and all Woodlands of the lower slopes and flats consist typically of Eucalyptus months classified as 'dry', i.e. with no assured growing season. A small salmonophloia, often with E. salubris, E. le souefii and E. longicornis. The portion appears on the Swan map, comprising the Kurnalpi System, and a part soil is very calcareous with a pH of 8, except superficially, where it may drop of the Broad Arrow System to 6, and is associated with a surface coating of moss and lichen. At the lowest points of the terrain there are a number of large salt-flats 10.1 The Kurnalpi System incorporating playa lakes. The playa lakes and numerous smaller salt pans, The communities within this system are transitional in character between the which are without vegetation, are surrounded by saltbush and bluebush flats Interzone and the Eremaea but are placed in the latter since they consist pre­ of Atriplex and Maireana, at times lightly wooded with Casuarina cristata, dominantly of low woodlands not exclusively dominated by eucalypts. Patches Myoporum platycarpum and some Acacia spp. of Eucalyptus le souefii woodland mixed with Casuarina cristata occur on

220 221 ------~------~------

VEGETATION SURVEY greenstones in the southern part, and constitute outliers from the Coolgardie System further south. As the greenstones are followed north E. le souejii is replaced by Acacia aneura (mulga). Areas of E. salmonophloia and E. oleosa forming medium-height woodland-generally rather open-are found on some bottomland soils around Lakes Goongarrie and Owen. Otherwise we have predominantly mixed and patchy woodlands and low woodlands, in

which the principal trees are Eucalyptus oleosa, Casuarina cristata and Acacia ! aneura. In the south these are taller and E. o/eosa is dominant, but further AA north height declines and E. oleosa becomes gradually less plentiful. One patch of pure mulga (A. aneura) has been mapped north of Lake Owen, and is an inlier from further north as, in general, mulga country is not entered for 15 km north of Goongarrie. Both broombush and saltbu.sh understory com­ munities are found but the latter predominates. Sandy patches in the wood­ lands bring in the mallee and spinifex community, ,and there are two large sandplains so covered. The soil consists of red sand overlying a calcarenus hardpan. Towards the north on some shallow granitic soils the cover consists of scrub of Acacia ramulosa with scattered low trees of sheoak; and mulga. On saline flats bordering the salt lakes and also to the east of the greens tone belt running north from Broad Arrow to Lake Goongarrie where the soil is evidently very alkaline, there· are scattered trees of A. aneura, Casuarina cristata, Pittosporum and Myoporum, with a well-developed ground layer mainly of A triplex• in the first case, Maireana in the second.

-~ i' I

222 ' II JI 1 11 I

UNIVERSITY OF WESTERN AUSTRALIA PRESS

ISBN O 85564 094 4