PRIME SEAL PRIME PRIME SEAL ISLAND Scientific Expedition

ISLAND

2008 Scientific Expedition Scientific

The Hamish Saunders Memorial Island Survey Program

HAMISH SAUNDERS MEMORIAL TRUST, NEW ZEALAND 2008

Biodiversity Conservation Branch Department of Primary Industries, Parks, Water and Environment Prime Seal Island Scientific Expedition 2008

A partnership program between the Hamish Saunders Memorial Trust, New Zealand and Biodiversity Conservation Branch, DPIPWE, Tasmania.

© Department of Primary Industries, Parks, Water and Environment

Book ISBN 13 978-07246-6510-5

Web ISBN 13 978-0-7246-6511-2

Cite as: Harris, S., Driessen, M. and Bell, P. (2009). Prime Seal Island Scientific Expedition 2008. Hamish Saunders Memorial Trust, New Zealand and Biodiversity Conservation Branch, DPIPWE, Hobart, Nature Conservation Report Series 09/3

This work is copyright. It may be reproduced for study, research or training purposes subject to an acknowledgement of the sources and no commercial use or sale. Requests and enquiries concerning reproduction and rights should be addressed to the Branch Manager, Biodiversity Conservation Branch DPIPWE or the Hamish Saunders Memorial Trust, Auckland, New Zealand. PRIME SEAL ISLAND Scientific Expedition 2008

A partnership program between the

Hamish Saunders Memorial Trust, New Zealand and

Biodiversity Conservation Branch, DPIPWE, Tasmania.

Editors:

Stephen Harris

Michael Driessen

assisted by Phil Bell. C ONTENTS

2 Photo by Rolan Eberhard.

FOREWORD 4

Hamish Saunders 6

Acknowledgements 6

Summary of Results 7

INTRODUCTION 8

GEODIVERSITY 10

VEGETATION 26

A REVISED FLORA 40

THE MAMMALS 60

THE REPTILES 66

THE DISTRIBUTION AND MANAGEMENT OF ENVIRONMENTAL WEEDS 76

INVERTEBRATE SURVEY 84

PRELIMINARY OBSERVATIONS OF THE SPIDERS 102

THE MOTHS 110

OBSERVATIONS ON ORTHOPTERA 114

BIRDS 120

NOTES ON NEARSHORE FISHES 128

BRIDGETTE MOFFAT Report of Hamish Saunders Memorial Trust Award Recipient 2008 132

DYLAN VAN WINKEL Report of Hamish Saunders Memorial Trust Award Recipient 2008 134

3 F OREWORD

4 Photo by Rolan Eberhard.

The Hamish Saunders The program aims to collect In this volume the results of the Memorial Island Survey scientific information on Tasmanian third expedition are reported. Prime and New Zealand islands as a Seal Island is one of the largest of Program was established contribution to the long term the Outer Furneaux Islands and the in 2005 as the result of management and conservation twelve papers in this volume cover a partnership agreement of their natural values. Islands diverse aspects of its natural values. not only hold a special romantic This will assist in the long-term between the Tasmanian and scenic attraction but are also management of the island by the Government and the Hamish regarded as scientifically important government and the lessees who Saunders Memorial Trust. repositories of biodiversity including currently occupy much of the island. biogeographically significant species. The program arose from The island survey program was Islands are also valuable areas that recently reviewed and both the the tragic loss of this young can be used as benchmarks against Tasmanian Government and New Zealand scientist while which wider threats and changes the Trust have re-affirmed their can be measured. They can also be he was assisting in Tasmanian commitment to building on the considered in some cases as playing Government research on work so far in both Tasmania and a role in quarantining insurance New Zealand. Apart from all the remote Pedra Branca Rock in populations of threatened species. practical benefits, the professional south western Tasmania. Since the partnership agreement and personal interaction that was signed in 2005 each of the this program generates between expeditions has resulted in a report scientists on both sides of the which the department has published Tasman will be one of the legacies of in the Hamish Saunders Memorial Hamish Saunders. Island Survey Program series.

Kim Evans Secretary Department of Primary Industries, Parks, Water and Environment Tasmania

David Saunders Hamish Saunders Memorial Trust New Zealand

5 Hamish Saunders in local cultures and people. Not Acknowledgements only did he travel to these places, Hamish Saunders was a New but he also took a great interest in We especially thank once again, the Zealand volunteer who died the people around him. He touched Hamish Saunders Memorial Trust tragically in 2003 while conducting many lives. Hamish was a remarkable for participating in the program, survey work on a Tasmanian and talented young man. The passion particularly Alan and David Saunders, endangered species program. and enthusiasm he engendered in and the Trust’s travel award Hamish graduated from Waikato those whom he met and the gentle recipients Bridgette Moffat and University with a First Class leadership he embodied is his legacy. Dylan van Winkel. Sincere thanks to Honours and Masters degree in George Jennings of Shaw and Sons marine geology. He later completed This island survey program is Pty Ltd. and John Cooper of Flinders a postgraduate GIS course with dedicated to the memory of Island who were supportive of the distinction. He also achieved Hamish Saunders and intended as study and provided background qualifications as a scuba dive a platform for emerging leaders in information as needed. James instructor, was a good sportsman marine conservation. The Tasmanian Luddington provided transport and was talented, not solely Government’s commitment and between Flinders Island and Prime academically, but as an all round long-term support for the program Seal Island and we are grateful for individual. was endorsed by the then Minister his logistical support in this regard. for Environment and Planning, The Penny Wells and Mike Pemberton As an explorer, Hamish achieved in Hon. Judy Jackson MHA, on 8 July provided Agency support. We also his 26 years much of which most 2005. thank Wayne Dick, the Parks and only dream. From Antarctica to the Wildlife Service Ranger on Flinders Galapagos, Central America, South Island for taking a keen interest in America, South-East Asia, Europe the study and for visiting the party and Australia, he combined his in the field. Wayne Warren of Parks passion for the natural world and and Wildlife Service, Lois Ireland and conservation with that of an interest Noel Whittaker of Flinders Island were helpful to the party.

We thank the many people who provided their time and expertise, some in a volunteer capacity, across the range of specialties dealt with in this report – they are acknowledged separately in the individual reports herein.

Thanks to Brett Littleton of the ILS Design Unit in the Department of Primary Industries, Parks, Water and Environment for his design and layout of the report.

6 Summary of Results 7. Prime Seal Island supports one 13. The survey resulted in the first of the greatest diversities of record of the spur-throated 1. Prime Seal Island comprises reptile species of all the Outer locust from eastern Tasmania and a granite basement overlain Furneaux Islands. The presence the first record of a raspy cricket by alkaline dunesands which of cats and house mice could from the eastern Bass Strait accumulated prior to the Last potentially have an effect on the islands. Glacial Maximum. Some dunes reptile fauna. are still mobile. 14. Several new species of 8. The introduced flora was invertebrates were discovered 2. There are a number of significant assessed for problem species. including a new species of geomorphic features, especially Seven of these were mapped centipede, and a possible new around the coast. These have and prioritized for action, 5 of species of bristletail. Over 7 000 been added to the Tasmanian which are high priority. specimens were collected from Conservation Database. the island. 9. The current occupants of the 3. The vegetation comprises 13 island have undertaken extensive 15. The invertebrate fauna of the vegetation communities, including control of boxthorn, with island is quite diverse and likely 3 listed as threatened: Eucalyptus evidence of manual removal to be relatively intact with fewer ovata forest and woodland across much of the island. exotic species than expected. (DOV), Heathland on calcarenite (SHC) and Seabird rookery 10. The mammal survey revealed 16. The invertebrate fauna of complex (SRC). five wild mammal species, one the island is likely to be best of which was the Tasmanian conserved by maintaining the 4. The native vegetation cover pademelon, common on the island in its present condition. has expanded over the last few island. Evidence of Brushtail 17. An undescribed geometrid moth decades. Possum was detected but is a new record for Tasmania. sightings not made. The most 5. An additional 40 species of common introduced mammals plants have been added to those 18. Forty-seven bird species were were house mice and feral cats. known for the island, taking the recorded for the island including wedge-tailed eagles. Although total to 193. 11. The first collection of spiders no presently used nest of the yielded 75 species, including 6. The island has populations of 10 species was found, a disused nest Tasmania’s largest wolf spider threatened plant species. Where was observed. Birds would be Tasmanicosa godeffroyi with a population estimates were favoured by eradication of cats, body length of 26 mm. carried out these demonstrated better fencing in some areas, and much larger populations than 12. A species of cave cricket careful fire management. previously thought. previously known only from 19. Fifty-one fish species were Flinders, Babel and Little Dog recorded inshore on a small Island was found in Manalargenna portion of the east coast of Cave. Prime Seal Island. The species are typical of what could be expected in this locality.

7 I NTRODUCTION

FLINDERS ISLAND

Whitemark PRIME SEAL ISLAND LOCATION CAPE BARREN IS

B ASS STRAIT

Launceston

Hobart

8 Prime Seal Island. Basemap: 1:25000 map Wybalenna 5656 (reproduced courtesy of TASMAP, DPIPWE).

Prime Seal Island, at 1221 limey sands were considered fairly information on which this expedition hectares, is one of the fertile compared with the granite has been able to build. There were islands and their infertile siliceous still many gaps in our knowledge of largest of the approximately soils. Consequently the more fertile the island. The size, and geographic one hundred outer islands islands were settled from the early location of the island, together with in the Furneaux Group in nineteenth century as farming and government’s joint management fishing took on more importance responsibility (a small part of the eastern Bass Strait. The island following the demise of the sealing island is outside the leasehold) with occurs at 40°03’45’’ latitude, period in about the 1820s. a private lessee, were amongst the 147°45’31’’longitude about factors that made this island an Much of the island is still operated ideal target of the Hamish Saunders ten kilometres to the west as a wool growing operation under Memorial Island Survey Program. of Flinders Island itself and is leasehold by the Crown to Shaw about ten times longer than and Sons Pty Ltd. In the 2008 The expedition party landed on shearing season 43 bales of medium Flinders Island on 13 October 2008 it is wide. The island has a to fine merino wool was taken off thence to Prime Seal Island the north-south orientation. the island. The lessees also carry following day. The team departed out infrastructure maintenance, Prime Seal Island on the 19 October Flinders, Cape Barren and Clarke weed control, game management 2008 and then Flinders Island on Islands are the three main islands and burning. There is a network 20 October. The expedition party in the Furneaux Group. Together of vehicle tracks on the island, an leader was Stephen Harris, joined with their outer islands and those airstrip, shearing, machinery and by Michael Driessen (mammals, of the Kent, Hogan and Curtis generator sheds, accommodation, reptiles), Nick Mooney (wildlife), Groups further north, they form water tanks and fencing. Clare Hawkins (mammals), Rolan an archipelago between Wilsons Eberhard (geomorphology), Emma Promontory in Victoria and the Islands are significant for biological Betts (geomorphology), Abbey Tasmanian mainland. These islands conservation and there have Throssel (invertebrates), Kevin have variously been part of a land been many practical examples Bonham (invertebrates), Sarah bridge at times of lower sea level of the role played by islands in Munks (mammals), Dylan van such as during the Last Ice Age prior being refuges for scientifically Winkel (Hamish Saunders Memorial to about 8 thousand years ago, or important biota, sometimes free Trust Travel Award Recipient 2008, separated as they are now by higher from feral or problem animals and wildlife), Bridgette Moffat (Hamish sea level. as potential sites for translocations Saunders Memorial Trust Travel or reintroductions of endangered The island is varied in topography Award Recipient 2008, natural species that might otherwise be and looks imposing with its three history), Micah Visoiu (vegetation/ under pressure in the rest of their rounded elevated hummocks visible flora) and Oliver Strutt (weeds). range. from a considerable distance. Like most of the islands in the group, it There had been very little focussed is composed mainly of granite with scientific exploration on Prime Seal a mantle of calcarenite, alkaline Island. Books on the flora and fauna sandy soils, and acid soils formed of the Furneaux Islands by Stephen directly over the granite exposures. Harris and Nigel Brothers and Islands in the Furneaux Group with colleagues assembled most of the

9 G EODIVERSITY

10 Plate 1 Quaternary sands exposed by erosion on the southwest coast. Photo by Rolan Eberhard.

By Rolan Eberhard mapping is limited to the the northwest coast, were covered. 1:250 000 Flinders Island sheet Sand samples were collected for Geologically, Prime Seal Island (Jennings and Cox 1978). thermoluminescence (TL) dating comprises a granite basement Geomorphological aspects are by David Price (University of overlain by Quaternary sediments, touched on in reports concerning Wollongong). This paper alludes to principally dunesands. Weathering of Mannalargenna Cave, the cultural the dating results, although this work the granite combined with aeolian significance of which was recognised will be described in detail elsewhere. and coastal processes have strongly in the late 1980s (Harris 1988; Geology influenced the geomorphology. Brown 1991). The island was visited Thermoluminescence dates for briefly during a reconnaissance Prime Seal Island is essentially a dunesands indicate an extended inventory of the geoconservation single large outcrop of granitic period of aeolian sedimentation values of Tasmania’s islands in the basement rock, probably in the period leading up to the mid 1990s. Some unusual karst granodiorite but referred to here Last Glacial Maximum. Sandy features were noted at this time as granite for simplicity. Although alkaline soils and calcrete duricrusts (Dixon 1996) and later listed in locally obscured by Quaternary reflect the role of calcareous the Tasmanian Geoconservation sediments, the granite crops out sand as the dominant soil parent Database as the Prime Seal Island extensively on all parts of the island. material. Prime Seal Island was Karst and Concretions site (http:// The rock is most likely a member of episodically connected to, and www.dpiw.tas.gov.au/inter.nsf/ the Wybaleena suite of granitoids, isolated from, adjacent land masses, WebPages/LBUN-6TY32G?open). which are widespread along the due to oscillating sea levels during The soils have been described only western side of the Furneaux Group Quaternary glacial-interglacial cycles. insofar as their agricultural capability (Reid 1987). Granitoids account for The most recent period of isolation is considered in unpublished approximately 70% of the Palaeozoic may have commenced around documents relating to the leasehold basement of the Furneaux Islands 8 000 years ago. The 2008 Prime arrangement for the island. The (ibid), part of a broader north- Seal Island expedition provided Hamish Saunders Memorial trip south oriented granitoid mass that information that will be used to was an opportunity for additional underlies much of eastern Tasmania. update the Tasmanian Shoreline observations on aspects of the These rocks are Devonian in age Geomorphic Types Digital Line geodiversity of Prime Seal Island. and were emplaced as a series of Map Version and the Tasmanian large magmatic intrusions into older Geoconservation Database. It sedimentary strata (Mathinna beds) highlighted the importance of METHODS and between 395 and 368 million years avoiding land management practices RESULTS ago (Seymour and Calver 1995). with potential to exacerbate soil Uplift and erosion over an extended erosion hazards on Prime Seal Island. This overview of the geodiversity period of geological time has of Prime Seal Island is based on an exposed the granite at the surface. examination of recent and historical INTRODUCTION air photos and 3 field days, during The Quaternary sediments are which time the main parts of the dominated by unconsolidated The geodiversity (geology, island, including most of the coast, dunesands of variable thickness. geomorphology and soils) of Prime major sandblows and features of These sediments are well exposed in Seal Island is poorly documented. interest reported previously, such as sandblows and erosion gullies on the The scale of available geological Mannalargenna Cave and karst on western side of the island (Plate 1).

11 Plate 2 Sandrock cropping out on the coast near Target Hilll. Photo by Rolan Eberhard.

A second specimen from the same general locality was a mixture of shell fragments up to 20 mm and poorly sorted subangular to angular siliceous grit ranging in diameter from about 0.25 to 7 mm. In this case the matrix, creamy amorphous material, was estimated to constitute about 50% of the rock.

These observations suggest that some rocks which have been referred to as limestone, such as the strata in which Mannalargenna Cave has formed, may be better described as calcareous sandstones or ‘sandrock’ 1. Secondary carbonate deposits on the cliff containing the cave, and within the cave itself, are potentially accounted for by leaching from overlying shell-rich sands (Plate 3). On the other hand, the degree of karstification at certain other locations indicates the presence of limestone sensu stricto (ie. >50% Older lithified sands are associated indicate a high siliceous content for calcium carbonate). The parent with aeolianite that crops out on or some aeolianite units. A sample material implies a form of limestone near the coast at many sites (Plate from near Mannalargenna Cave known as aeolian calcarenite ie. 2). The aeolianite is thinly bedded was found to consist mainly of lithified calcareous dunes. Aeolian with dips of 0-30° and frequent subangular to rounded siliceous calcarenite referred to as Palana cross bedding. The presence of grains typically about 1 mm in Limestone (Sutherland and Kershaw numerous shell macrofossils in strata diameter and, to a lesser extent, 1971) crops out extensively on at one or two sites on the east coast platey shell fragments of similar size. the eastern parts of Flinders Island. implies a marine or beach origin for These materials were cemented by Palana Limestone at Settlement some coquina-like facies, but the a meagre (<10%) whitish matrix of Point, 6 km from Prime Seal Island grain and bedding characteristics presumed carbonate. A sample of and the closest point to it on are clearly aeolian in the majority of pinkish sandrock from Peacock Bay mainland Finders Island, contains a cases. comprised well sorted subangular moderate to high calcium carbonate to rounded siliceous grains about content of 61-95% (Hughes 1957). Examination of hand specimens 0.25-0.5 mm in diameter. About The formation is evidently somewhat under low power optical microscope 30% of the rock was whitish matrix. heterogeneous, with some facies

1 Sandrock is a field term for sandstone that is not firmly cemented (Jackson 1997)

12 Plate 3 Secondary carbonate coatings on the cliffline containing Mannalargenna Cave. Photo by Rolan Eberhard.

reported to contain considerable is potentially consistent with the implying more stable conditions amounts of angular to rounded degree of lithification of at least by the mid-late Holocene. These quartz grit (Sutherland and Kershaw some aeolian formations on Prime results contrast with dates for 1971), suggesting possible parallels Seal Island, although evidence of dunesands in northwest Tasmania with sandrock units on Prime Seal truncation by a Last Interglacial of 24-22 ka (Duller and Augustinas Island. sea level is debateable. However, a 2006) and 29-14 ka (McIntosh thermoluminescence date of 56 ka et al. 2009). Tasmania-wide data Sutherland and Kershaw (1971) for cavernous sandrock on the west indicates a significant increase in argue that the Palana Limestone coast implies a post Last Interglacial landscape instability from 35 ka developed from late Tertiary to age in this case (Eberhard in prep.). onwards, although a number of early Pleistocene calcareous dunes, older dates for aeolian sediments suggesting ‘a Lower Pleistocene, Thermoluminscence dates have been reported (McIntosh et al. pre-Riss/Wurm age for most of it’ for unconsolidated dunesands 2005). The Prime Seal Island dates on the basis that the limestone is interbedded with slope deposits imply that the period of increased cut by what they regard as a Last from a site on the southwest coast aeolian activity recorded after 35 Interglacial sea level. Kiernan (1992) of Prime Seal Island suggest that ka elsewhere in Tasmania may have supports a pre Last Interglacial the sediment accumulated between commenced at about the same age for aeolian calcarenite at about 38 and 7 ka, with a strong time or somewhat earlier on the Fotheringate Bay on Flinders Island, aeolian contribution prior to the Furneaux Group. also on the evidence that it too was Last Glacial Maximum (Eberhard in planed off by Last Interglacial marine prep.). A buried soil horizon near erosion. A pre Last Interglacial age Target Hill was dated to 3-4 ka,

13 Plate 4 Granite tor near Sealers Cove. Photo by Rolan Eberhard.

Plate 5 Limestone shore platform, north of Peacock Bay. Photo by Rolan Eberhard.

swells reaching western Tasmania being refracted eastwards through Bass Strait. Accordingly, the western side of the island is considerably more exposed than the east. This is reflected in the character of coast on the respective sides of the island.

The western coast comprises a virtually continuous rocky shore dominated by broad shore platforms up to 100 m or more in width, with offshore reefs and occasional deeply Geomorphology and bluffs, another landform typical of indented coves and gulches. Strong granitic terrain, are present along the structural control of the coastline is Prime Seal Island is approximately 10 mid and upper slopes on the western clearly evident in air photos, which km long on the north-south axis and side of the island (Plate 4). typically about 1 km wide on the east- highlight the results of vigorous west axis. Four principal hills, rising to Prime Seal Island’s coast is mechanical erosion along frequent a maximum elevation of 155 m and approximately 29.2 km long. intersecting linear features such as separated by more-or-less equally Although its location within the conjugate joint sets. A few short spaced wind gaps, give the island its low-moderate wave energy zone sandy beaches account for less than characteristic humped profile, with of Davies’ (1978) qualitative 4% of the coast on this side of the some older publications referring to it classification of wave energy for island. Some of these are developed as Hummock Island. The bold domed Tasmania suggests a relatively quiet on the landward side of rocky shore form of the hills is typical of granitic coastal environment, mariners attest platforms. Minor boulder beaches terrains with widely spaced joint to Bass Strait as a stormy seaway are present. In contrast, about 20% fractures. Little evidence was seen not lacking in wave energy. This is of the relatively sheltered eastern of solutional features which often due to a combination of frequent side is sandy beaches, which tend to develop on granitic rocks, such as strong winds associated with passage be broader than those of the west. runnels and gnammas. However, some of low pressure weather systems Shore platforms are common, but small but spectacular isolated tors across the region and south-westerly rarely exceed 30 m in width 2.

2 A number of discrepancies were noted for shoreline geomorphic types attributed to Prime Seal Island on the Tasmanian Shoreline Geomorphic Types Digital Line Map Version 4.0 (Sharples 2006). For example: (1) shorelines mapped as upper intertidal cliffs between Spit Point and Peacock Bay, and at South Bay, are steeply inclined in places but rarely vertical, and better described as rocky (bedrock) shorelines; (2) a shoreline east of Target Hill is mapped as upper intertidal cliffs with no distinctly different lower intertidal shoreline element, whereas the shoreline actually comprises a well-developed lower intertidal shore platform in limestone below a rocky upper intertidal shore; (3) shorelines east of North Hill, and at Wolff Bay, mapped as upper intertidal shell, pebble cobble or boulder beaches or shorelines, are in fact sandy beaches; and (4) a shoreline south of Sealers Cove mapped as upper intertidal cliffs, is actually a shore platform backed by a steep slope formed in Quaternary sands. The Tasmanian shoreline geomorphic types map is based generally on a combination of published and unpublished sources, air photos and field verification in some places. Older unpublished maps based on air photo interpretation by Revel Munro, with no field verification, were the source in the case of Prime Seal Island (C. Sharples, pers. comm.). By convention, the geomorphic types map A number of discrepancies were noted for shoreline geomorphic types attributed to Prime Seal Island on the Tasmanian Shoreline Geomorphic Types Digital Line Map Version 4.0 (Sharples 2006). For example: (1) shorelines mapped as upper intertidal cliffs between Spit Point and Peacock Bay, and at South Bay, are steeply inclined in places but rarely vertical, and better described as rocky (bedrock) shorelines; (2) a shoreline east of Target Hill is mapped as upper intertidal cliffs with no distinctly different lower intertidal shoreline element, whereas the shoreline actually comprises a well-developed lower intertidal shore platform in limestone below a rocky upper intertidal shore; (3) shorelines east of North Hill, and at Wolff Bay, mapped as upper intertidal shell, pebble cobble or boulder beaches or shorelines, are in fact sandy beaches; and (4) a shoreline south of Sealers Cove mapped as upper intertidal cliffs, is actually a shore platform backed by a steep slope formed in Quaternary sands. The Tasmanian shoreline geomorphic types map is based generally on a combination of published and unpublished sources, air photos and field verification in some places. Older unpublished maps based on air photo interpretation by Revel Munro, with no field verification, were the source in the case of Prime Seal Island (C. Sharples, pers. comm.). By convention, the geomorphic types map records all rocky shore platforms as lower intertidal landforms, despite the fact that such features often extend into the upper intertidal zone. This is true of the majority of shore platforms on Prime Seal Island.

Plate 6 Limestone pinnacles 14 on beach, Peacock Bay. Photo by Rolan Eberhard. An exception to the generally limestone coasts (Trudgill 1985), beneath the case hardened caprock modest shore platforms of the implying that these features are (kankar) at several locations (Plate eastern side of the island is a feature partially karstic in origin. 7). The presence of an indurated developed in aeolian calcarenite capping layer provides the structural Karst has also developed on thin about 1 km south of Mannalargenna integrity necessary to support the (ca. 2 m thick) case hardened Cave. This shore platform is in the cave roof, a phenomenon that limestone that crops out at South order of 50 m wide, strikingly level has been noted in other aeolian Bay and intermittently between and covered by a dense mat of the calcarenite karsts (White 1994). Sealers Cove and the northern tip seaweed Hormosira sp. (Plate 5). It The entrances of larger examples of the island. A variety of karren bears comparison with the extensive tend to face west into the prevailing forms are present including pans, limestone shore platforms of the weather, suggesting that they may pits, rills and runnels. Pointy karst western coast of Flinders Island be less a product of solution than pinnacles (spitzkarren) protrude (Kiernan 1992). A combination of physical and/or chemical weathering, through sand on the beach north solutional lowering and mechanical under conditions of more or less of the camp on Peacock Bay (Plate abrasion are considered to account continuous assault by salt-laden wind 6). Small caves, generally shelter- for the formation of broad, flat shore and spray. A mantle of loose fine like cavities and arches, extend platforms that characterise many sediment on the cave floors would

15 Plate 7 Cave developed in case-hardened aeolian calcarenite. Plate 8 Tufa terraces on coast near Target Hill. Photo by Rolan Eberhard. Photo by Rolan Eberhard.

Plate 9 Relict aeolian sands deposited on the windward (western) side of the island. Note evidence of recent burning. Photo by Rolan Eberhard.

be consistent with the disintegration it appears, as archaeologists dug of cave pearls requires cave drips of the parent rock through a process through 4 m of sediment before to agitate the particles, preventing such as salt wedging. On the other encountering the sloping bedrock them from becoming cemented to hand, the deposition of speleothems floor of the inner chamber (Sim other surfaces (Hill and Forti 1997). such as stalactites and columns 1991). Mannalargenna Cave is A similar process can be ruled out implies either solutional erosion about 50 m above present sea level for the Prime Seal Island concretions, of the limestone above the caves and faces southeast. The site was as the size of the particles precludes or leaching of carbonates from occupied by Pleistocene humans agitation by wind or rain and the overlying shell-rich sands. This does between about 8 and 20 ka (Brown context is not a pool. An alternative not necessarily contradict a non- 1991). explanation is that the concretions karstic mode of cave formation. are a calcrete duricrust deposited The ‘knobbly concretions’ associated as a lag following deflation of the The sandrock in which it has with the karst reported by Dixon carbonate-rich sands in which they developed and domed internal form (1996) are typically about 30 mm formed. This explanation does not of Mannalargenna Cave, the only in diameter, near spherical in form account for the consistent size of cave of significance on the eastern with a rough botryoidal texture the concretions or their absence side of the island, suggests that it on the surface. They appear to be from other sites. Irrespective of their too is not primarily a karst feature, restricted to several square metres origin, the concretions are an unusual despite the presence within it of of limestone pavement a few metres feature of which Prime Seal Island is presumed carbonate speleothems. above sea level at one site on the the only recorded Tasmanian example. First reported by Harris (1988), this northwest coast. The mode of cave comprises a 6 m wide entrance formation is unclear. Concentrically Springs are common where the leading to a small inner chamber banded concretions in caves known contact between the granite (Figure 1). No part of the accessible as cave pearls develop in shallow basement and overlying calcarenite cave is more than about 6 m from pools where a mineral coating and/or Quaternary sands is the dripline. The full extent of the develops on a nucleus such as a sand exposed along the high water original cavity is more spacious than grain. The detached spherical form mark. Seventeen springs or

16 clusters of springs were counted (Plate 8). Water samples obtained These include linear transgressive in October 2008. Rapid infiltration from two springs on the southern dunes several hundred metres long of precipitation and the seaward coast were high in dissolved salts, and oriented east-west across the deflection of groundwater along the with sodium and chloride levels that wind gaps between Sealers Bay and geological contact account for both suggest a significant contribution Peacock Bay and between North the abundance of coastal springs from windblown spray off the sea Hill and Target Hill. As on Flinders and the paucity of surface runoff (Appendix 1). Calcium levels are Island (Kershaw and Sutherland and fluvial landforms. There is little towards the upper end of the 1972), the dunes are relict features, evidence of the latter barring some range reported for karst waters in being vegetated and no longer gully erosion on the southern part of Tasmania (Eberhard and Houshold mobile, despite localised sandblows. the island. 2002). Despite the salinity, Aeolian sands interbedded with the quality of water would not slope deposits crop out on the Many of the springs have necessarily be considered unsuitable western flanks of Prime Seal Island’s precipitated carbonate in the form for stock to drink. main southern hill. The sands are of tufa. A major example occurs incised by a few deep gullies of at the head of a small bay west of Aeolian landforms characterise those recent origin and truncated by Target Hill. Here, an impressive parts of Prime Seal Island which marine erosion near present sea series of tufa terraces has developed are mantled by Quaternary sands. level (Plate 9). Thermoluminescence

17 Figure 1. Extent of sand erosion on north Prime Seal Island in 1951 and 2003. Basemap: November 2003 air photo (reproduced courtesy of TASMAP, DPIPWE).

dates indicate that the sediment and harsh environmental conditions, pair of parallel sandblows which accumulated between about 38 ka particularly prior to the Last Glacial extend for ca. 0.5 km from near sea and 7 ka (Eberhard in prep.). The Maximum, when the bulk of the level to an elevation of ca. 70 m on age of the top of the sequence is sediment accumulated. Target Hill. To estimate the extent close in time to the culmination of and trajectory over time of actively Active sandblows are present the Holocene marine transgression eroding sand country on Prime Seal several locations on Prime Seal at 6 ka. The absence of buried soil Island, areas interpreted as bare or Island, mostly but not exclusively horizons within the profile suggests mobile sand (excluding beaches) on the more exposed western side a high level of landscape instability were digitised from scanned and (Figure 1). These include a notable

Table 1: Approximate extent in hectares of bare or actively eroding sand on Prime Seal Island, as interpreted from air photos between 1951 and 2003. Refer to Figures 1 and 2 for locations. Note that air photo coverage was not available for South Bay or the Lower South-west in 1986.

1951 1973 1974 1982 1986 1998 2003 North Hill 1.33 2.36 1.78 1.59 1.18 0.03 0.12 Target Hill 2.33 7.44 6.24 6.16 4.44 3.74 3.80 Sealers Cove 5.92 7.37 3.15 1.41 0.28 0.18 0.06 Lower South-west 2.12 0.92 3.39 3.86 - 1.53 5.39 South Bay 0.00 0.26 2.19 0.59 - 0.21 0.37 TOTAL 11.70 18.35 14.79 13.61 (>5.90) 5.71 9.74

18 Figure 2. Extent of sand erosion on south Prime Seal Island in 1951 and 2003. Basemap: November 2003 air photo (reproduced courtesy of TASMAP, DPIPWE).

orthorectified air photo mosaics favour of a lower result because air between 1973 and 1974. in a GIS (Figures 1 and 2). The photo coverage for the two more These results should not be methodology is subject to variations southerly sites was not available interpreted simply as evidence that in the quality of the images and for 1986. This trend was reversed land management practices over the light conditions at the time the between 1998 and 2003 when the the last 30+ years have reduced images were captured, both of which total eroded area is seen to expand the scale of erosion on Prime Seal affect the ability to accurately assess again, gaining 4.0 ha (71%) but still Island. In fact, the apparent increase erosion status. The area totals should remaining lower than results for in erosion post 1998, especially in therefore be considered indicative 1982 and earlier runs. The pattern the southern parts of the island, only (Table 1). is not consistent across the island as and field observations concerning a whole. For example, the eroded About 11.7 ha of the island appear active sandblows and deep gullying area in the lower south-west shrunk to have been actively eroding at on seaward slopes that had recently by 1.2 ha (57%) between 1951 and the time of the first air photos been burnt, suggest a more complex 1973 when eroded areas elsewhere in 1951. This increased by 6.7 ha scenario. on the island were expanding, (57%) between 1951 and 1973, although it later increased to gain Soils but then retreated between 1973 3.3 ha (154%) by 2003. Only the and 1998. By 1998 the total eroded sandblow at South Bay is not present The soils of Prime Seal Island are area had contracted by 12.6 ha, to some degree over the entire air dominantly well-drained loamy reducing it to about half what it had photo record. This feature developed sands or light sandy loams of been in 1951. Results in the latter between 1951 and 1973, expanding weak to moderate structure. Soil part of this period are skewed in rapidly to its maximum extent pH ranges from 8-9 (Poole et al.

19 Plate 10 Calcrete duricrust. Plate 11 Calcified tree roots in sandblow at Target Hill. Photo by Rolan Eberhard. Photo by Rolan Eberhard.

Plate 12 Residual pedestal formed by loss of soil around knobby clubsedge root ball. Photo by Rolan Eberhard.

2002), which is consistent with the southwestern coast, exacerbating of Tasmania from mainland Australia the alkaline soil parent material erosion hazards in areas that have about 38 million years ago. Since that – calcareous Quaternary sand. A been burnt. Up to 1 m of sediment time, eustatic fluctuations in sea level calcrete duricrust is widespread in has been lost from some sites, as have periodically exposed the land the form of hardpans and rounded indicated by the height of pedestals bridge, notably during Quaternary whitish clasts, often exposed by formed where soil has been retained ice ages, or flooded it (Jennings erosion or brought to the surface around knobby clubsedge root balls 1959). Prime Seal Island would have by anthropogenic disturbance (Plate (Plate 12). Numerous bones from first come into existence as an island 10). The calcrete results in stony soils seabird and small mammals litter the in its own right, as opposed to a on some parts of the island. surface of some deflated areas. range of hills on the eastern margin of the Bassian Plain, during one of The soils and sand units on which these sea level highs. Cainozoic they are formed are highly erodible, marine sediments up to 18 m as demonstrated by sandblows GENERAL above present sea level on Flinders and erosion gullies described DISCUSSION and Island (Sutherland and Kershaw elsewhere in this paper. Some of CONCLUSION 1971) imply that, on one or more these sandblows contain lags of Crustal deformation associated occasions, the wind gaps between calcareous pipes formed around with the separation of Australia and the hills of Prime Seal Island would plant roots (Plate 11), reminiscent Antarctica produced the Bass Basin, have been submerged, creating a of King Island’s Calcified Forest. into which the sea began to intrude minor archipelago of three or four Burrowing seabirds are a source of early in the Tertiary Period. This smaller islands. intense local bioturbation of soils on process culminated in the separation

20 The timing and duration of isolation level, due to sediment movement level, as land can be pushed up or events (islands) versus connectivity in the marine environment. This down through tectonic movement events (land bridges) can be is particularly pertinent around or isostatic pressure. However, modelled using bathymetry data Flinders Island, where strong although there is evidence that many and Quaternary sea level curves. currents have both scoured deep parts of the Tasmanian coast have An important caveat on this is that trenches and deposited extensive experienced Quaternary uplift, this it cannot necessarily be assumed sandy shoals (Jennings 1959). Nor does not appear to be the case on that submerged Quaternary land can it be assumed that the elevation Flinders Island in the latter part of surfaces have been preserved of the land relative to the sea is the Pleistocene (Murray-Wallace and following post glacial rises in sea affected only by fluctuations in sea Goede 1995).

21 Other factors being equal, the depth the presumed former land bridge at about 10-11 ka, while Prime of water overlying a former land between Tasmania and mainland Seal Island would have ceased to bridge is a threshold that determines Australia – is some 30 km offshore. be joined to Flinders Island at 8-9 whether a change in sea level has Consequently, below the 40 m depth ka. This potentially corroborates potential to expose the land bridge contour, a small change in relative the age of the youngest dated or drown it. In the case of Prime sea level would result in a major cultural horizon in Mannalargenna Seal Island, the channel between it shift in the position of the coastline. Cave, as it is plausible that humans and Flinders Island is shallow, being The 40 m depth contour is also the ceased to make use of the cave about 10-15 m deep (Australian approximate depth of the presumed when it became isolated by sea. Hydrographic Service 2002). This former land bridge between Flinders Sea level curves based on more would require only a modest fall Island and Tasmania, now Banks Strait. recent reviews of data from eastern in sea level to create a land bridge. Australia suggest that Prime Seal A post-glacial sea level curve based Within 1-2 km west of Prime Seal Island became separate from on dated marine sediments from the Island, the sea bed drops fairly Flinders Island around 8.5-10 ka eastern Australian region (Hopley rapidly to a depth of about 40 m, (Sloss et al. 2007). Differences 1987) suggests that the most recent due to the presence of a linear between these and other sea level major sea level transgression, which submarine feature interpreted as curves reflect the field data from commenced after 20 ka, would have a probable fault (Jennings 1959). which they are derived, which in turn overtopped the Bassian Rise around Further west, the gradient of the are affected by many local factors. 12-13 ka. The same sea level curve sea bed moderates, and the 60 m Blom (1988) argues that the Bassian suggests that the Flinders-Tasmania depth contour – the approximate Rise was not overtopped until as land bridge would have disappeared average depth of the Bassian Rise, late as 8 ka, based on a date for

Figure 3. Sketch plan of Mannalargenna Cave (from Harris 1988).

22 the first appearance of an oceanic Conclusions Island, the Prime Seal Island Karst facies in a sediment core from Bass and Concretions site. Strait. Thus, at present, the timing of Whereas a 6.4 km wide seaway While sand erosion has facilitated the most recent inundation of the currently separates Prime Seal access to valuable scientific evidence, presumed former land bridges can Island from Flinders Island, which the same process is depleting the only be constrained to within several in turn lies about 50 km off the overall scientific resource while thousand years. coast of northeast Tasmania, Prime Seal Island existed for extended creating a potentially serious source A sea level curve based on dates periods only as an outlying cluster of land degradation. Evidence of from uplifted coral terraces on of hills on the windy Bassian Plain, recent or ongoing sand movement the Huon Peninsula, Papua New overshadowed by the higher ranges can be observed on many parts of Guinea, is available from 260 ka to the east on present-day Flinders Prime Seal Island today, particularly onwards (Aharon and Chappell Island. The physiographic context where the land management 1986). Inferences made on the basis at this time was continental rather practices include grazing and burning of this curve would suggest that than maritime. Consistent with this on steep and/or exposed slopes. Prime Seal Island was rarely cut off is the presence on the island of relict In the interest of avoiding further from Flinders Island prior to the sandsheets and longitudinal dunes, a anthropogenic modification to relict most recent marine transgression. It legacy of the once extensive aeolian aeolian landforms and compromising was probably isolated for a period landscape that extended south to important sedimentary records, between about 118-135 ka and Tasmania across the Bassian Plain. these practices should be avoided. possibly briefly at around 106, 220 and 240 ka. The same sea level curve Despite strong similarities with suggests that the Bassian Rise was other parts of the Furneaux Group, ACKNOWLEDGEMENTS exposed on various occasions: prior the geodiversity of Prime Seal to 250 ka, around 190 ka, between Island includes features which are Thanks to the organisers and other about 170-140 ka, possibly briefly at particularly well developed or participants of the Hamish Saunders 110 ka, intermittently between 80-30 otherwise of considerable interest Memorial trip to Prime Seal Island ka and then again at around 29-12 for science and conservation. and to Emma Betts for assistance ka. The Flinders-Tasmania land bridge These include aeolianite karst in the field. Air photos used in this would have been dry for longer phenomena, which are common study were made available by Tasmap periods and may have escaped in parts of Bass Strait but poorly (DPIPWE) and orthorectified inundation for most of the period represented in Tasmania generally. by Bronwyn Tilyard (DPIPWE). 10-80+ ka. Although earlier sea level Additionally, eroded sections through Stephen Harris gave permission curves are available, these are more Quaternary sands provide access to use the map of Mannalargenna speculative still and their applicability to sedimentary sequences spanning Cave. Thermoluminescence dating to Prime Seal Island, where a mere a period of major environmental of sand samples was carried out 10 m rise or fall in sea level is critical, change during the late Pleistocene by David Price at the University of is questionable. However, the general and Holocene. These features Wollongong. Water samples were 3 pattern of episodic isolation and warrant consideration for listing analysed by Analytical Services connectivity events can be assumed in the Tasmanian Geoconservation Tasmania, a NATA accredited to have applied during earlier Database, which currently contains laboratory. Pleistocene glacial-interglacial cycles. only one reference to PrimeSeal

3 These have now been listed.

23 REFERENCES of linear dune activity in Tasmania Kiernan, K. (1992) Some coastal using optical dating, Quaternary landforms in aeolian calcarenite, Australian Hydrographic Service. Science Reviews 25: 2608-2618. Flinders Island, Bass Strait, Helictite (2002) Furneaux Group 1:150,000, 30(1): 11-19. Chart Aus 800, Australian Eberhard, R. and Household, I. (2002) Hydrographic Service, Wollongong. Water quality in karstlands at Mole McIntosh, P.D., Price, D.M., Eberhard, Creek, Tasmania, Pap. Proc. Roy. Soc. R. and Slee, A.J. (2009) Late Aharon, P. and Chappell, J. (1986) Tasm., 136: 159-172. Quaternary erosion events in Oxygen isotopes, sea level changes lowland and mid-altitude Tasmania in Harris, S. (1988) A Catalogue of Some and the temperature history of relation to climate change and first Cultural Relics in the Outer Furneaux a coral reef environment in New human arrival, Quaternary Science Islands, Report to the Australian Guinea over the last 105 years, Reviews 28: 850-872. Palaeogeography, Palaeoclimatology, National Parks and Wildlife Service. Palaeoecology, 56: 337-379. Murray-Wallace, C.V., and Goede, Hill, C. and Forti, P. (1997) Cave A. (1995) Aminostratigraphy and Minerals of the World, National Blom, W.M. (1988) Late Quaternary electron spin resonance dating of Speleological Society Inc., Huntsville. sediments and sea-levels in Bass Quaternary coastal neotectonism in Basin, southeastern Australia – a Hopley, D. (1987) Holocene sea- Tasmania and the Bass Strait Islands, preliminary report, Search 19(2): level changes in Australasia and the Australian Journal of Earth Sciences 42: 94-96. south Pacific, pp. 375-408 in Devoy, 51-67. R.J.N. (ed.) Sea Surface Studies, Bowden, A.R. (1983) Relict terrestrial Poole, L., Harris, S., North, J., P. Croom Helm, London. dunes: legacies of a former climate Stafford and Bayley, S. (2002) Prime in coastal northeastern Tasmania, Z. Hughes, T.D. (1957) Limestones in Seal Island Management Report, Geomorph. N.F. 45: 153-174. Tasmania, Tasmania Department of unpublished. Mines, Geological Survey Mineral Brown, S. (1991) Mannalargenna Reid, E.J. (1987) Furneaux Islands, Resources No. 10. Cave: a Pleistocene site in Bass Strait, pp. 261-266 in C.F. Burrett and E.L. pp. 258-271 in Smith, M.A., Spriggs, Jackson, J.A. (1997) Glossary of Martin (eds.) Geology and Mineral M. And Frankauser, B. (eds.) Sahul in Geology, 4th edition, American Resources of Tasmania, Geological Review, Department of Prehistory, Geological Institute, Virginia. Society of Australia Inc. Special ANU. Publication 15. Jennings, D.J., and Cox, S.F. (1978) Davies, J.L.(1978) Beach sand and King Island – Flinders Island 1:250,000 Sim, R. (1991) Archaeological wave energy in Tasmania, in: Davies, Scale Geological Map, Geological Excavations on Prime Seal Island and J.L. and Williams, M.A.J., (eds), Survey of Tasmania, Department of Badger Islands in the Furneaux Group, Landform Evolution in Australasia, Mines, Hobart. Bass Strait, report to the Tasmanian ANU Press, Canberra. Aboriginal Land Council, the Flinders Jennings, J.N. (1959) The submarine Island Aboriginal Association and the Dixon, G. (1996) A Reconnaissance topography of Bass Strait, Proc. Roy. Tasmanian Aboriginal Centre. Inventory of Sites of Geoconservation Soc. Vict. 71: 49-72. Significance on Tasmanian Islands, Seymour, D.B. and Calver, C.R. (1995) Parks and Wildlife Service Tasmania. Kershaw, R.C. and Sutherland, F.L. Explanatory Notes for the Time- (1972) Quaternary Geomorphology Space Diagram and Stratotectonic Duller, G.A.T. and Augustinas, P. of Flinders Island, Rec. Q. Vic. Museum Elements Map of Tasmania, Tasmanian (2006) Reassessment of the record 43: 1-28. Geological Survey Record 1995/01.

24 Sharples, C. (2006) Data Dictionary Appendix 1. Physico-chemical characteristics of two Prime Seal Island springs for the Tasmanian Shoreline Geomorphic Types Digital Line Map Spring 1 Spring 2 Version 4.0 (2006) (Tascoastgeo_ Location v4gda), report to the Department Easting (GDA) 562760 563630 of Primary Industries and Water, Northing (GDA) 5560890 5561210 Tasmania. Field measurements Sloss, C.R., Murray-Wallace, C.V. Temperature (°C) 14.8 13.7 and Jones, B.G. (2007) Holocene pH 8.70 - sea-level change on the southeastern Conductivity (mS/cm) 2.54 - coast of Australia: a review, The Analyte Holocene 17:999-1014. Bromide (mg/L) 2.9 3.1 Sutherland, F.L. and Kershaw, R.C. Chloride (mg/L) 513 631 (1971) The Cainozoic geology of Fluoride (mg/L) 1.09 0.98 Flinders Island, Bass Strait, Pap. Proc. Sulphate (mg/L) 179 342 Roy. Soc. Tasm., 105; 151-175. Ammonia (mg-N/L) 0.018 0.016 Trudgill, S. (1985) Limestone Nitrate (mg-N/L) 10.1 7.82 Geomorphology, Longman, London. Nitrite (mg-N/L) 0.029 0.005 Nitrogen (mg-N/L) 11 8.4 White, S. (1994) Speleogenesis in Phosphorus (mg-P/L) 0.237 0.362 aeolian calcarenite: a case study Silver (µg/L) <1 <1 in western Victoria, Environmental Geology 23: 248-255. Aluminium (µg/L) 2500 1880 Calcium (mg/L) 56.2 98.1 Cadmium (µg/L) <1 <1 Cobalt (µg/L) 1 <1 Chromium (µg/L) 6 6 Copper (µg/L) 1 3 Iron (µg/L) 2030 2030 Magnesium (mg/L) 37.4 42.4 Manganese (µg/L) 39 49 Sodium (mg/L) 445 611 Nickel (µg/L) <10 <10 Lead (µg/L) <7 <7 Zinc (µg/L) 5 6

25 V EGETATION

26 Photo by Micah Visoiu

By Micah Visoiu on the majority of Furneaux Islands was then mapped using 1998, 1:24 including Prime Seal Island was very 000 aerial photography, along with A survey of Prime Seal Island significant (Harris et al. 2001). Since field notes. This map and associated in October 2008 resulted in the arrival of sealers on the island vegetation descriptions of Harris et identification, description and in these early years, fire has been al. (2001) together with some new mapping of 13 TASVEG mapping a significant shaping influence on aerial photographic interpretation units (Harris & Kitchener 2005). the vegetation. Clearing through (using 2003 1: 42 000, air photos) The mapping units identified are burning and then the grazing of were used to classify and map the ‘Allocasuarina verticillata forest livestock has been a use of the island island’s vegetation within the 1:25 (NAV)’, ‘Eucalyptus ovata forest and for well over a century (Whinray 000 statewide Tasmanian Vegetation woodland (DOV)’, ‘Coastal scrub on 1971). Aerial photographs taken in map ‘TASVEG 2.0’ in 2008 (TVMMP alkaline sands (SCA)’, ‘Heathland on the early 1950’s show that woody 2009). The process of converting the Calcarenite (SHC)’, ‘Coastal Grass vegetation at that time covered original units into TASVEG mapping and Herbfield (GHC)’, ‘Seabird probably less than 20% of the island, units described in Harris & Kitchener rookery complex (SRC)’, ‘Saline this is a significant change to the (2005), is not straightforward sedgeland/rushland (ARS)’, ‘Lowland observations made by Campbell and may have resulted in some grassland complex (GLC)’, ‘Sand in 1828 who stated the island to translation errors. Mud (OSM)’, ‘Pteridium esculentum be ‘lofty and covered in trees’ (in The extensive ground survey work fernland (FPF)’, ‘Agricultural Land Harris et al. 2001). More recent on the island during the 2008 (FAG)’, ‘Weed Infestation (FWU)’ Aerial photographs show that the expedition provided an invaluable and ‘Regenerating cleared land cover of woody vegetation on the opportunity to ground truth the (FRG)’. Distinct facies within these island has increased markedly in the current vegetation mosaic, update communities have been described last 50 years. It would appear from the mapping and determine and related to previous literature the available aerial photographs the most appropriate TASVEG descriptions. (1951, 1974, 1982, 1998, and 2004) mapping units in which to place the that the vegetation is very dynamic. vegetation communities present. This The development from grassland paper therefore provides an updated INTRODUCTION then heathland, scrub and forest is vegetation map of Prime Seal Island, rapid, whilst fire is an ever present The first signs of human occupation along with detailed descriptions of stochastic factor that can halt this of Prime Seal Island has been the vegetation communities on the succession at any time. dated at 18 500 years BP, through island. Extent and occurrence of archaeological work undertaken at The first vegetation map of Prime threatened species and species of Mannalargenna Cave on the island’s Seal Island was published in 2001 biogeographic significance are dealt north east coast. The use of this (Harris et al. 2001) as part of a with elsewhere in this report, as is site continued until at least 15 000 volume that described and mapped the occurrence and extent of exotic years BP. However after this date it is the vegetation of islands within the species on the island. thought that rising sea levels reduced outer Furneaux Group in Bass Strait. and finally eliminated human Nineteen mapping communities influence from these islands until the were identified during several visits arrival of Europeans in the late 18th to the island in the early late 1980s and early 19th centuries. From this and early 1990s. The extent of time onwards the human impacts these mapping units on the ground

27 28 METHODS Species nomenclature follows Vegetation Map Buchanan (2005). Structural The island was comprehensively classification follows the National Community descriptions and traversed on foot. Composition of Vegetation Information System biogeographic notes floristic communities was noted in (NVIS) structural formations rule set The vegetation on Prime Seal has areas that were determined to be (Thackway et al., in Mackenzie et al. been categorised here into 13 representative of the vegetation 2008). TASVEG mapping units (Harris & on the island. Vegetation extent Kitchener 2005). Within several of and community boundaries were these mapping units there is more subsequently mapped using a variety RESULTS than one facies. The vegetation of remotely sensed imagery. The mapping units present are listed in most recent aerial photography was On-ground observations on Prime Table 1, along with the different at 1: 42 000 scale and dated from Seal Island over the course of floristic/structural associations 2003, the only 1:24 000 coverage the six day field trip provided a where present. Floristic communities was 1998 black and white imagery. good insight into the vegetation described elsewhere from statewide Examination of these two photo associations present. A number of surveys which are related to those runs suggested that the vegetation these associations would seem to seen on Prime Seal Island are also on the island was very dynamic, with be unique within Tasmania, primarily indicated. All the defined vegetation changes in vegetation extent in this due to Lasiopetalum discolor which associations which were noted on 5 year period obvious in several is extensively distributed over the the Island are described below. areas. Google Earth (www.earth. island and is dominant or sub- google.com 2009) was found to use dominant in several communities. 2009, 2.5 metre resolution SPOT This species, within Tasmania, is 5 imagery, which indicated further confined to this island. changes in vegetation community Examination of aerial photographs extents since 2003. The 2009 SPOT and satellite imagery, combined with 5 imagery was deemed to be of extensive field observations suggest high enough quality to map the that the vegetation is very dynamic. vegetation when used in conjunction An apparent reduction in the extent with the 1998 and 2003 aerial of grazing of the island in recent photography, ground observations years along with an associated and landscape photographs taken reduction in burning of some areas during the field trip. Mapping was has resulted in a significant increase carried out on transparency overlays in the cover of scrub communities, over ~1:15 000 sized SPOT 5 whilst some areas of Allocasuarina printouts from Google Earth. The verticillata forest also seem to be vegetation mapping units used are expanding. No vegetation was seen from Harris & Kitchener (2005). on the island that did not show signs Some of the floristic communities of fire in the past. (facies) within these mapping units were also described. The floristic communities have been described in Community descriptions and biogeographic notes.

29 Table 1: List of Mapping units and floristic associations observed on Prime Seal Island (2008)

TASVEG mapping Code Floristic/structural associations Similar described floristic Communities Unit Name distinguished Allocasuarina NAV Allocasuarina verticillata short 2. Allocasuarina verticillata forest verticillata forest open forest (Harris et al. 2001)

Coastal Allocasuarina low forest (Duncan & Brown 1985) Allocasuarina verticillata, Myoporum 2. Allocasuarina verticillata forest insulare, Bursaria spinosa short (Harris et al. 2001) closed forest Island Allocasuarina low forest (Duncan & Brown 1985) Eucalyptus ovata DOV Eucalyptus ovata, Allocasuarina forest and woodland verticillata short closed forest Coastal scrub on SCA Beyeria lechenaultii, Myoporum 17. Leptospermum laevigatum scrub (+/- alkaline sands insulare closed shrubland Leucopogon parviflorus, Bursaria spinosa, Dodonaea viscosa, Melaleuca ericifolia, (Melaleuca armillaris –Long Island only), Correa alba) (Harris et al. 2001) Leptospermum laevigatum, 17. Leptospermum laevigatum scrub (+/- Allocasuarina verticillata, Leucopogon parviflorus, Bursaria spinosa, Pomaderris paniculosa subsp. Dodonaea viscosa, Melaleuca ericifolia, paralias, Dodonaea viscosa, (Melaleuca armillaris –Long Island only), Correa Leucopogon parviflorus, Bursaria alba) (Harris et al. 2001) spinosa, Olearia ramulosa closed Dominance community 19. Leptospermum shrubland laevigatum scrub (Kirkpatrick & Harris 1995) Myoporum insulare tall closed 24. Myoporum insulare closed Scrub (Harris et shrubland al. 2001)

Dominance community 24. Myoporum insulare shrubland (Kirkpatrick & Harris 1995) Heathland on SHC Beyeria lechenaultii, Pimelea 11. Heathland on calcarenite Calcarenite serpyllifolia heathland (Harris et al. 2001) Lasiopetalum discolor heathland 11. Heathland on calcarenite (Harris et al. 2001) Acrotriche cordata, Lasiopetalum 11. Heathland on calcarenite discolor open heathland (Harris et al. 2001)

Floristic community 34. Spyridium vexilliferum- Acrotriche cordata heath (Kirkpatrick & Harris 1995)

30 TASVEG mapping Code Floristic/structural associations Similar described floristic Communities Unit Name distinguished Coastal Grass and GHC Fire disclimax Austrostipa stipoides 4. Austrostipa stipoides tussock grassland Herbfield closed tussock grassland (Harris et al. 2001)

Dominance community 30. Austrostipa stipoides tussock grassland (Kirkpatrick & Harris 1995) Austrostipa stipoides, Disphyma 32. Succulent herbfield (Tetragonia implexicoma crassifolium, Tetragonia implexicoma, / Disphyma crassifolia / Sarcocornia quinqueflora T. tetragonoides open tussock succulent herbfield) (Harris et al. 2001) grassland Floristic community 15. Austrostipa stipoides- Disphyma crassifolium tussock grassland (Kirkpatrick & Harris 1995) Seabird rookery SRC Leucophyta brownii, Tetragonia 18. Leucophyta brownii heathland complex implexicoma sparse shrubland (Harris et al. 2001)

Dominance community 7. Leucophyta brownii shrubland (Kirkpatrick & Harris 1995) Saline sedgeland/ ARS Juncus kraussii rushland 14. Juncus kraussii rushland (Harris et al. 2001) rushland Dominance community 16. Juncus kraussii rushland (Kirkpatrick & Harris 1995) Lowland grassland GCL Austrostipa flavescens complex Austrodanthonia spp. Poa labillardierei closed grassland Sand Mud OSM Pteridium esculentum FPF Pteridium esculentum closed 28. Pteridium esculentum fernfield fernland fernland (Harris et al. 2001) Agricultural Land FAG Improved pasture 9. Exotic grassland and improved pasture (Harris et al. 2001) Weed Infestation FWU Mesembryanthemum crystallinum closed forbland Regenerating cleared FRG Slashed scrub on alkaline sands 10. Exotic grassland and improved pasture land (FRG) dominated by Ficinia nodosa (Harris et al. 2001)

31 Allocasuarina verticillata the understorey. In gaps caused by viscosa, Leucopogon parviflora and forest (NAV) the breaking down of “old growth” Lasiopetalum discolour. The ground A. verticillata; Lasiopetalum discolour layer is quite dense with a cover The high fire frequency on the and Myoporum insulare occur, as do of grasses; predominantly Poa island since European discovery the short lived shrubs Apalochlamys labillardierei and Austrodanthonia has contributed to reduced tree spectabilis and Zygophyllum sp., and herbs such as Wahlenbergia cover. Harris et al. (2001) cites an billardierei. These disturbance gaps gracilenta, Daucus glochidiatus and early account by Campbell, who in would appear to be short lived Ajuga australis. Several orchid species 1828 described the island as lofty as regeneration of A. verticillata are also present; most commonly and covered in trees. This general was also apparent in many of the Caladenia latifolia and Microtis uniflora reduction in tree cover is well canopy gaps in which senescing however Cyrtostylis robusta and a illustrated by a 1951 aerial photo trees were observed. This facies of large stout fruiting specimen of a which clearly shows the Allocasuarina the community best matches the Pterostylis sp. were also encountered. verticillata forest extent on the island structure and habitat of “Coastal The facies of Allocasuarina verticillata (presumably A. verticillata was the Allocasuarina low forest” as described forest fits the floristic community only widespread tree species on the by Duncan and Brown (1985); “Island Allocasuarina low forest” island at this time), to be confined however the associated species (Duncan & Brown 1985). In the to two small patches and a number are different from the common description of this community it is of other areas of scattered trees. associates seen on mainland stated that this type of vegetation This forest type has since this time Tasmania. This is due to the flora of was probably extensive on Prime expanded considerably as shown by Prime Seal Island lacking many of Seal Island (amongst others) prior to more recent aerial photos. In several these species, and including many European use of the Island. stands large mature and often species that do not occur commonly Eucalyptus ovata forest senescing trees were located at on the Tasmanian mainland. the centre with younger individuals and woodland (DOV) found towards the outside. In some areas, primarily on the There is a small area of Eucalyptus large hill to the south of Peacock ovata forest and woodland (DOW) A. verticillata forest currently occurs Bay, a second facies of A. verticillata present on the large hill to the in stands on the more rocky areas forest has developed that is far south of Peacock Bay. It occurs on on the summits of the hills extending more species rich than the typical north easterly slope on deep limey down slope on the northern sides. form elsewhere on the island. sands overlain by a +/- 10 cm thick Patches also persist on well drained Contributory factors to this might layer of gray brown sandy loam. sandy rises, presumably in areas that include more recent fire disturbance This vegetation is floristically very have escaped high intensity burning as indicated in this area by the similar to the higher diversity facies regimes. These site characteristics are presence of fire scars on several of Allocasuarina verticillata forest, typical for the vegetation mapping larger trees and a single cohort however a sparse population of units in north eastern Tasmania regeneration of several species Eucalyptus ovata is also scattered (Harris & Kitchener 2005). In long including A. verticillata, two to three throughout forming a sub-dominant undisturbed areas on the island A. metres in height. The overstorey layer amongst the slightly taller A. verticillata forest is characterised by incorporates Myoporum insulare, and verticillata. This situation is quite complete dominance by A. verticillata occasionally Bursaria spinosa. A quite unusual and the resulting floristic underlain by a thick cover of leaf dense shrub layer is developed that community could be interpreted litter on the ground. Individual includes Pomaderris paniculosa subsp. as a facies of A. verticillata forest Pimelea serpyllifolia are occasional in paralius, Bursaria spinosa, Dodonaea

32 (NAV), however the significance of Coastal scrub on alkaline areas of exposed sand. In many areas the occurrence of E. ovata at this sands (SC A) this facies occurs in association with site warrants its separate mapping granite outcrops. However, the soil in unit (see other paper by Visoiu this This mapping unit incorporates these areas remains calcareous, often volume). The E. ovata at this site are much of the vegetation on Prime with calcarenite sheets developed low spreading +/- mallee form trees Seal Island, however the vegetation on the outcropping granite bedrock and are 1-2 metres shorter than the it covers is quite heterogeneous. where it meets the ground. surrounding overstorey and often The areas mapped as Coastal scrub Occasionally at the centre of these have no shrub layer beneath, with a on alkaline sands (SCA) are a fine outcrops there are areas where lush thick herbaceous ground layer. scale mosaic of scrub communities the calcium carbonate has been This community is floristically distinct delineated mainly by period since leached out. In these areas other from E. ovata described elsewhere last fire. They are however all similar species associations occur and would in Tasmania (Duncan & Brown in that they all occur on limey and be mapped as Dry scrub (SDU) 1985). It has similarities with “Island sometimes cemented sands with if they were sufficiently extensive Allocasuarina low forest” (Duncan characteristic species including to map, but their rarity and small & Brown 1985); however E. ovata Beyeria lechenaultii, Myoporum extent precluded them from being is not named as an associate in this insulare and Leptospermum distinguished in the mapping. Species community elsewhere, although E. laevigatum present in varying that occur in these areas are rare on globulus occurs commonly with it on combinations. This scrub complex the island and include Leptecophylla Flinders Island. fits loosely into mapping unit 17 juniperina subsp. oxycedrus, Pultenaea “Leptospermum laevigatum scrub daphnoides var. obcordata and Kunzea In the early 1950s, the site of the E. (+/- Leucopogon parviflorus, Bursaria ambigua. ovata population was located in a spinosa, Dodonaea viscosa, Melaleuca small forested remnant situated in ericifolia, (Melaleuca armillaris –Long A second more complex facies of an extensively cleared landscape, as Island only), Correa alba)” described scrub on alkaline sands is found shown in aerial photographs taken by Harris et al. (2001). on some areas of deeper sands. At early 1951. Since that time much of these sites Allocasuarina verticillata, the surrounding pasture has been In its simplest form the CS Leptospermum laevigatum, Pomaderris invaded by native vegetation with community on the island is paniculosa subsp. paralia, Dodonaea significant areas ofA. verticillata forest dominated by Beyeria lechenaultii viscosa, Leucopogon parviflora, and scrub on alkaline sands now and/or Myoporum insulare, the Bursaria spinosa and Olearia ramulosa surrounding this original remnant. dominance of which is determined also occur. Myoporum insulare Despite the significant expansion by the substrate, with B. lechenaultii is usually present, but Beyeria of this woody vegetation, the E. most prevalent on calcarenite and lechenaultii is often absent. There is ovata does not appear to have consolidated sands whilst M. insulare often no obvious dominant; instead spread from the original wooded dominates on deeper limey sands. there is a mixture of +/- even patch visible in 1951. Harris et al. Pimelea serpyllifolia, Lasiopetalum height individuals of a selection of (2001) suggested the confinement discolor and Pomaderris paniculosa the above species or a fine scale of this species to this site (only subsp. paralia are usually also present mosaic of small patches of those one individual was encountered as scattered midstorey shrubs. The species. The cover of any one of at that time) suggested a paucity dense nature of this closed scrub these species rarely exceeds 20%. of eucalypts on the island prior to usually prevents the development of Poa labillardierei, Austrostipa flavescens European use. a ground layer; instead leaf litter and and Austrodanthonia sp. often form detritus cover the ground along with

33 Photo by Rolan Eberhard.

a grassy ground cover. The shrubs Heathland on Calcarenite The second facies is generally found Apalochlamys spectabilis, Zygophyllum (SHC) on the steeper slopes in areas where billardierei, and herbs Parietaria outcropping rock is limited. The soil debilis, Dichondra repens, Senecio There is a reasonably large extent is comprised of a higher organic biserratus and Urtica incisa are all of heathland on calcarenite on content in the top 5cm, with limey commonly present amongst the Prime Seal Island. Patches are sands, mixed with granite gravels grass tussocks or in relatively bare primarily located on westerly to below this; fragments of calcarenite areas. No systematic survey and north-westerly facing slopes and are are also common. The overwhelming classification of scrub communities found on most of the hills along the dominant is Lasiopetalum discolor has been undertaken in Tasmania, length of the island. The substrate 50-80cm high and with 25-75% however areas of this facies may fit in all these areas is granite overlain cover. Beyeria lechenaultii var. latifolia into the dominance community “19. by a cap of calcarenite which is in and Pimelea serpyllifolia are both Leptospermum laevigatum scrub” places exposed as a sheet or as also prevalent with 10-30% cover (Kirkpatrick & Harris 1995). beds of broken and angular rubble, each. Hibbertia sericea is also present calcareous sands form the subsoil as is Zygophyllum billardierei. There A third floristic community that has with a thin (5 cm thick) layer of dark are few herbs and ground covers been mapped in the SCA mapping brown organically enriched top soil. and bare ground is common. This unit occurs in areas that have There are three distinct facies of this floristic community has not been remained undisturbed for a long heathland on the island which seem described specifically elsewhere. The time. This facies is predominantly to be determined by soil type. All dominance of L. discolor would make located on easterly facing slopes. three facies are included in mapping this community unique to Prime Seal In such areas Myoporum insulare unit 11 “Heath on calcarenite” Island. forms a more or less closed scrub (Harris et al. 2001). often with occasional Allocasuarina The third facies is associated with verticillata. The vegetation ranges The first facies is characterised by outcropping and broken surface from 3 to 6 metres in height with deeper limey sands with little organic calcarenite rubble with a matrix a +/- open understorey with a matter, there is little or no exposed of calcareous sand and low levels well developed ground layer of limestone, however fragments of organic matter. In these areas herbs, grasses and orchids. The best are scattered on the surface. This Acrotriche cordata commonly examples of this M. insulare closed soil type is generally found on the dominates with 10-50% cover. scrub are present on the eastern lower slopes and flats below hills. Lasiopetalum discolor and Beyeria slopes of the large hill to the south The dominant species is generally lechenaultii are always present, with of Peacock Bay. This vegetation short Beyeria lechenaultii var. latifolia Hibbertia sericea also usually present. type has been identified by Harris 0.5-1 metres high with 25-75% Spyridium vexilliferum and or Eutaxia et al. (2001) as mapping unit 24 cover. Pimelea serpyllifolia forms a microphylla are also occasionally “Myoporum insulare closed Scrub” 25-50% cover with bare ground present in these areas. This floristic and occurs on a number of the often prevalent (10-50% cover). community has affinities with Furneaux Islands. It has however Other species that are often present “Floristic community 34. Spyridium not been floristically described with lower covers are Pomaderris vexilliferum-Acrotriche cordata elsewhere. paniculosa subsp. paralia, Zygophyllum heath” described by Kirkpatrick & billardierei and stunted Myoporum Harris (1995), from north eastern insulare. This floristic community Flinders Island. It differs from this has not been specifically described community in that L. discolor makes elsewhere.

34 up a substantial proportion of the calcareous sands that are rich in to areas of saline sedgeland/rushland cover. A. cordata and E. microphylla sub-fossil bird and marsupial remains. in other coastal areas of Tasmania have been seen to have similar Bare sand with scattered sub fossil (Harris & Kitchener 2005) and the environmental preferences on remains comprises 30-60% of Furneaux Islands (Harris et al. 2001). Flinders Island, where they occur the ground cover. This community Lowland grassland complex together in the few sites they are is described as mapping unit 18 (GCL) known from (Underwood 1998). “Leucophyta brownii heathland” by Harris et al. (2001); however it has Seabird rookery complex There are several small patches not been floristically distinguished (SRC) of native grassland on the island beyond this. It would however fit that have developed in areas There are small areas of sea bird into the dominance community of previously improved pasture. rookery in the south western corner “7. Leucophyta brownii shrubland” These are generally openings of the island which are occupied by (Kirkpatrick & Harris 1995). in regenerating scrub and are a relatively small breeding colony of Saline sedgeland/rushland dominated by Austrodanthonia less than 3000 pairs of short tailed (ARS) racemosa, Austrostipa flavescens and shear waters (Puffinus tenuirostris) Poa labillardierei. Annual weed grasses (Brothers et al. 2001). These areas There are small patches of this are relatively common in these differ from the normal sea bird vegetation in the saddle to the areas however the native grasses rookery vegetation in the Furneaux south of North Hill. At this site are the dominant. This vegetation islands in that the dominant wind is funnelled inland bringing mapping unit is rare on the Outer species is Leucophyta brownii, with salt spray during onshore westerly Islands of the Furneaux Group interspersed Tetragonia implexicoma. weather. The facies is very species and may only occur on the biggest There are also large scattered poor, being dominated by Juncus islands. The site characteristics and individuals of South African boxthorn kraussii of around 50% cover, with floristics are typical of the vegetation (Lycium ferocissimum). The L. brownii bare red/orange soil exposed over types throughout the drier areas individuals are very large, some being much of the remaining area, often of the Tasmanian mainland (Harris up to 1.5 metres in height and 2 with a visible salt crust. Occasional & Kitchener 2005). The one slightly metres in canopy width. The colonies herbs are Gnaphalium indutum, unusual aspect of the community on are located on flats and steep slopes Vellereophyton dealbatum and Prime Seal Island is the presence of which are composed of consolidated Disphyma crassifolium. This is similar Austrostipa flavescens as one of the

35 dominants. This species is uncommon maintained by patch burning, with The second facies of Coastal grass away from coastal areas, with other fires set as soon as the vegetation and herbfield (GHC) appears to be Austrostipa species more common in will hold a fire which is usually the more natural of the two. It is less Lowland grassland complex (GCL) every three to four years (J. Cooper fire dependent gaining disturbance within its primary occurrences’, pers comm). This type of grassland instead from salt spray and coastal which is in the northern and is common and extends several processes. This facies has higher southern midlands. hundred metres inland in many areas. species diversity. Typically there is In some places there is an obvious a 25-50% cover of A. stipoides, with Coastal Grass and succession between this community inter-tussock spaces covered by Herbfield (GHC) and the SCA community. Where the mats of Tetragonia implexicoma and Coastal grassland and herbfield is fire frequency is lower, Myoporum to a lesser extent T. tetragonoides, widespread along the western and insulare and Beyeria lechenaultii begin Disphyma crassifolium, and short southern coast of Prime Seal Island to overtop the grass tussocks and spreading Myoporum insulare. Poa where it is primarily located on the conversion to scrub is rapid. poiformis is scattered and occasional alkaline sands which are in varying Examination of historical aerial throughout the grassland and stages of calcarenite formation. There photos (1951, 1974, 1982, 1998) herbfield. The best examples of this are two main facies represented indicates the boundaries between herbaceous community are located in this mapping unit, both of which these two communities are quite in the north western eastern tip of fit into mapping unit 4 “Austrostipa dynamic and are often represented the Island, where extensive beds stipoides tussock grassland” by wide ecotones. of Disphyma crassifolium occur. This described by Harris et al. (2001) for vegetation fits floristic community Just to the south east of Sealers the Furneaux Islands. 15 “Austrostipa stipoides-Disphyma Cove on a steep dune face an crassifolium tussock grassland” as interesting example of the fire The first and most widespread facies described by Kirkpatrick and Harris disclimax community occurs with is a fire disclimax community, being (1995). Areas of it are mapped Pultenaea tenuifolius and Eutaxia characterised by large tussocks of as unit 32 “Succulent herbfield microphylla common amongst the A. Austrostipa stipoides with few other (Tetragonia implexicoma / Disphyma stipoides tussocks in otherwise bare species present. These areas are crassifolia / Sarcocornia quinqueflora sand.

36 Zygophyllum billardieri in flower on a limestone cliff, western side of Prime Seal Island. Photo by Micah Visoiu

succulent herbfield)” by Harris et al. to the south of Sealers Cove and increasing the salinity of the soil (2001). Peacock Bay. The majority of the area (Vivrette & Muller 1977). This makes that has been converted to this land the habitat unsuitable for all but the Sand Mud (OSM) use is underlain by deep alkaline most salt tolerant species and allows There are a number of areas along sands with occasional limestone and a new generation of M. crystallinum the western coast of the island granite outcrops. The floristic make- seeds to germinate with little where sand blows have occurred. up of the pasture varies depending competition (Bohnert & Cushman The cemented and semi-cemented on the level of improvement. 2000). M. crystallinum is a rare weed nature of the sands has caused Common pasture grasses are Lolium in Tasmania (Harris et al. 2001, NVA several of these blows to form perenne and Bromus diandrus. A 2009), and is not known to have vertical sides, exposing a multitude of number of Trifolium species are also formed any other infestations of a bird and marsupial sub-fossil remains widespread and dominant in places. mappable size anywhere else in the some of which are from species Annual weed grasses including state. Parapholis incurva, Lagurus ovatus and no-longer present on the island. Regenerating cleared land Catapodium rigidum are common Occasional shrubs of Leucophyta (FRG) brownii, Ozothamnus turbinatus and widespread as are herbaceous and Olearia axillaris are present in species Geranium molle, Cerastium The vegetation on Prime Seal Island stabilising areas. glomeratus and Arctotheca calendula. shows signs of having undergone In many less improved areas native significant changes in land use in the Pteridium esculentum species persist or continue to past. Aerial photos taken in 1951 fernland (FPF) invade. These include Apalochlamys show that substantially more of spectabilis, Bulbine semibarbata, On the south eastern slopes of the the island was cleared at that point Lasiopetalum discolor, Ficinia nodosa, large unnamed hill to the south of than now. Slashed regrowth scrub in Austrostipa stipoides and Pimelea Peacock Bay there are several large areas that have reverted to native serpyllifolia. patches of Pteridium esculentum. vegetation occur in the southern These have apparently invaded areas Weed Infestation (FWU) part of the island. There are several previously cleared and converted large areas around the shearing shed for agricultural use and are on deep There are scattered weeds present where this has recently occurred. alkaline sands. Pteridium esculentum in various places on Prime Seal The resulting vegetation is rapidly dominates with close to 100% cover; Island. The weed issues and mapping re-sprouting and numerous seedlings there are occasional pasture species of these species are dealt with of native shrubs are quickly growing. present. This is a typical community by Strutt (this volume). The only These areas have been mapped as of disturbed sandy areas throughout infestation large enough to be regenerating cleared land, although Tasmania (Harris et al. 2001, Harris mapped as a distinct patch is located it is unclear whether they will and Kitchener 2005). on the south western tip of the regenerate fully to scrub or be island. At this site the succulent further improved and converted Agricultural Land (FAG) halophyte Mesembryanthemum back to improved pasture. crystallinum is dominant over an area Agricultural land of varying levels of of between one and two hectares. improvement covers much of the The species is annual to biennial Island. The largest patches occur and forms a dense mat in the area. along the east coast and cover the M. crystallinum accumulates salt. The majority of the large unnamed hill salt is released once the plant dies,

37 GENERAL DISCUSSION marginata, Leptospermum scoparium, It would be beneficial if fire was & MANANGEMENT and Leptospermum glaucescens. This excluded from the reserve in RECOMMENDATIONS species list would suggest that the the north of the island, and the vegetation type is situated on less vegetation in this area was allowed There is incomplete correspondence fertile substrates with a lower pH to continue to grow older. Likewise of the mapping units from Harris than those that are typical of Prime it would be a priority to keep et al. (2001) with TASVEG mapping Seal Island. fire out of the scrub and forest units (Harris & Kitchener 2005) communities on the large hill to The two other mapping units used in resulting in the allocation of the the south of Peacock Bay. The TASVEG 2.0 have been reallocated. scrub communities on the island Eucalyptus ovata in this area is of high Succulent saline herbfield (ASS) on to “Acacia longifolia coastal scrub conservation significance within the the island has been absorbed into (SAC)” and “Heathland scrub mosaic outer islands and it would benefit “Coastal grass and herbfield (GHC)”. on Flinders Island (SHF)” in TASVEG greatly from being left unburnt. The The Coastal heathland (SCH) has 2.0. In the vegetation mapping Allocasuarina verticillata forest on the been reallocated to Coastal scrub presented in this paper the areas hills through the centre of the island on alkaline sands (SCA). mapped as these two mapping should also be left unburnt. units have been incorporated under The rapid development of the “Coastal scrub on alkaline sands The dynamic nature of the vegetation, combined with the (SCA)”, which was deemed to vegetation on Prime Seal Island removal of African boxthorn be warranted by the floristics and mean that this description is a (Lycium ferocissimum) infestations substrate on which they occurred. snapshot in time. It will continue to by the land manager and some change and develop, and burn, and small amounts of scrub clearance, The fast rate of vegetation start again. progression on the island has have all contributed to changes in also meant that the TASVEG 2.0 vegetation boundaries since the TASVEG 2.0 mapping (based on mapping of vegetation extent was ACKNOWLEDGEMENTS already out of date when it was 1998 1:24 000 aerial photos and previously mapped due to the lack 2003 1:42 000 photos). In general Stephen Harrris provided advice of contemporary aerial photographs. the Lycium ferocissimum is no longer in the field and in the preparation mappable as weed infestations in of this paper. Winston Smith kindly Acacia longifolia coastal scrub (SAC) the north eastern part of the island, prepared the vegetation map. is a distinct vegetation assemblage scrub communities have expanded of A. longifolia and Leucopogon significantly, Allocasuarina verticillata parviflorus. However, A. longifolia forest has expanded noticeably and a was found to be extremely rare small amount of scrub in the centre on the island, only being seen at of the island has been slashed. The one site with less than 5 individuals. extent of Heathland on calcarenite Heathland scrub mosaic on Flinders (SHC) is not as extensive as was Island (SHF) is a mosaic of scrub thought in the south of the island, and heath that is characterised due probably to over-mapping of it by a group of species that are previously rather than clearance. This not present on Prime Seal Island. vegetation type was however found These include Eucalyptus nitida, to be under mapped in the central Xanthorrhoea australis, Banksia and northern part of the island.

38 Photo by Emma Betts

REFERENCES Harden G.J. (Ed) (1990) Flora of New Thackway, R., Neldner, V.J. & Bolton, South Wales, volume 1, UNSW Press. M.P. (2008) Vegetation, In: Mackenzie, Bohnert, H.J. & Cushman, J.C. (2000) Sydney N.J., Grundy, M.J., Webster, R. & The Ice Plant Cometh: Lessons in Ringrose-Voase (eds) (2008) Harris, S. & Kitchener, A. (2005) From Abiotic Stress Tolerance. Journal of Guidelines for Surveying Soil and Land Forest to Fjaeldmark: Descriptions of Plant Growth Regulation 19, 334-346. Resources, Second Edition. CSIRO Tasmania’s Vegetation. Department publishing, Victoria. Brothers, N., Pemberton, D., Pryor, of Primary Industries, Water and H. & Halley, V. (2001) Tasmania’s Environment. Printing Authority of Underwood, S 1998, Synecology Offshore Islands: Seabirds and Other Tasmania. Hobart. & Conservation of Vegetation on Natural Features. Tasmanian Museum Aeolian Calcarenite, Flinders Island, Harris, S., Buchanan, A. & Connolly, and Art Gallery, Hobart, Tasmania. Bass Strait, BSc thesis, University of A. (2001) One Hundred Islands: Tasmania. Buchanan, A.M. (2005) A Census The Flora of the Outer Furneaux, of the Vascular Plants of Tasmania, DPIWE, Hobart. Vivrette, N.J. & Muller, C.H. (1977) Fourth Edition. Tasmanian Herbarium Mechanism of Invasion and Kirkpatrick, J.K. & Harris, S. (1995) Occasional Publication No. 7. Dominance of Coastal Grassland The conservation of Tasmanian dry Tasmanian Museum and Art Gallery. by Mesembryanthemum crystallinum. coastal vascular plant communities. Hobart Ecological Monographs 47, 301-318. Wildlife Scientific Report 95/1. Parks Duncan, F. & Brown, M.J. (1985) Dry and Wildlife Service. DELM, Hobart. Whinray, J.S. (1971) A note on Prime sclerophyll vegetation in Tasmania, Seal Island, The Tasmanian Naturalist, extent and conservation status of No. 27, Hobart the communities, Wildlife Division Technical Report 85/1. National Parks and Wildlife Service, Tasmania

39 A REVISED FLORA

40 Photo by Micah Visoiu

By Micah Visoiu INTRODUCTION Spyridium vexilliferum var. vexilliferum and Zygophyllum billardierei). A survey of Prime Seal Island in Prime Seal Island has been known Taraxacum cygnorum which is listed October 2008 resulted in 40 species for some time to have an interesting under the Environment Protection of vascular plant being added to and in some ways unique flora when and Biodiversity Conservation Act those previously recorded. These compared to the other Furneaux 1999 (EPBCA 1999) has also been comprise 13 exotic species and 27 Islands and mainland Tasmanian. In recorded there in the past. species that are native to Tasmania. the first half of the 19th century the This takes the known flora of island was visited by at least two well The Hamish Saunders Memorial the island to 193 taxa. The island known Tasmanian naturalists, those expedition to Prime Seal Island provides habitat for populations of being R.C. Gunn and J. Milligan both in October 2008 provided the the threatened taxa Lasiopetalum of whom recorded the presence of opportunity to complete a more discolor, Pomaderris paniculosa subsp. Lasiopetalum discolour, amongst other thorough examination of the island’s paralia, Eutaxia microphylla var. things (Tas. Herbarium data, Whinray vegetation and flora, and improve microphylla, Spyridium vexilliferum 1971). The first vascular plant species population estimates for threatened var. vexilliferum, Zygophyllum list for the island was published J. or biogeographically interesting plant billardierei, Acrotriche cordata, Whinray in 1971 and contained 66 taxa on the island. It is hoped that Parietaria debilis, Stellaria multiflora, taxa. A second, more comprehensive the information presented here will Cyrtostylis robusta, and Leucopogon list was published in 2001 (Harris be of value for future conservation lanceolatus. Biogeographically et al.) and contained 143 taxa. Both management planning on this and significant taxa encountered were: of these lists were based on the other Bass Strait Islands, as well as Threlkeldia diffusa, Eucalyptus authors’ ground surveys; with the being relevant to future assessment ovata, Convolvulus erubescens and exception of one historical record and monitoring for threatened Asplenium trichomanes. An exotic of Taraxacum cygnorum (J. Milligan flora inhabiting Prime Seal Island. species, Orobanche minor sensu 1844) included by Harris et al. The information provided here lato, is included in this section as its (2001). Combining the lists provided also adds to the understanding of presence on this island intriguing. a total known flora of 155 taxa, biogeographic relationships in the Callitris rhomboidea was previously including 50 exotic species and two flora of Bass Strait recorded but was not encountered endemics. in this survey. The population size and extent of each threatened or Harris et al. (2001) produced METHODS otherwise significant taxa were a vegetation map of the island, described on the basis of the 2008 descriptions of the vegetation and The island’s vegetation was sampled and previous surveys. preliminary estimates of some by means of traversing along a populations of threatened taxa. number of routes over the six day At that time eight species listed period. The island was only sampled under the Tasmanian Threatened and this incomplete coverage of Species Protection Act 1995 the island is a limitation of the (TSPA 1995) were known from survey. Data were recorded during the Island, (Acrotriche cordata, the survey of all plant species and Eutaxia microphylla var. microphylla, vegetation formations observed. Lasiopetalum discolor, Leucopogon Data on the habitat preferences lanceolatus, Pomaderris paniculosa and distributions of particular target subsp. paralia, Parietaria debilis, taxa were used to estimate the area

41 of occupancy for these taxa on the RESULTS the South Australian border and is Island. Vegetation maps (Visoiu this listed as Rare under the Advisory volume) also assisted in determining An updated species list for Prime List of Rare or Threatened Plants in habitat availability. Population Seal Island is located in Appendix Victoria 2005 (ALRTPV 2005). The counts/densities of target species one. It contains 193 taxa which population in Tasmania is confined were estimated by counting or include 66 introduced species and to a localized area in the Furneaux estimating the number of individuals 127 native taxa of which two are Islands approximately 800 km from within a small sample area and endemic to Tasmania. Forty species the South Australian and Victorian extrapolating average densities to were observed for the first time on populations. Within the islands it the total area of occupancy. In some Prime Seal Island during the 2008 is known only with certainty from instances belt transects were used survey, 27 of these were indigenous Flinders and Prime Seal Island to determine population densities. Tasmanian taxa, while 13 were (NVA July 2009). There is also one Error ranges were included in exotics that have become naturalised specimen held in the Australian assessments; these were subjective in Tasmania (Buchanan 2005). National Herbarium (Canberra) and based on the confidence in which may have been collected on Populations of nine threatened the population estimate. This was one of the Sisters Islands which species were located during the deemed to be a more reliable and are off the north coast of Flinders 2008 survey; two other species accurate representation of the true Island. The grid accuracy and location have been recorded from the island population given the limitations of notes of this specimen are, however, in the past but were not located the survey than would an arbitrary inconclusive (Unit ID 668889, during the 2008 survey. Six species error percentage. ANHSIR July 2009). Acrotriche of biogeographic interest within cordata is one of a group of taxa, The species records from the 2008 the Furneaux Islands were also the populations of which in Tasmania survey of the island were compared observed. The species for which are regarded as southern outliers with the two previous published lists population information is described of the Australian mainland core for the Island (Whinray 1977, Harris are summarised in Table 1. distributions (Underwood 1998). et al. 2001) as well as records held by the Tasmanian Herbarium, and On Prime Seal Island Acrotriche data available online on the Natural Threatened taxa cordata was first collected in the Values Atlas (NVA July 2009) and mid 1960’s and has been collected Australia’s Virtual Herbarium (AVH Acrotriche cordata several times since however no July 2009). This information was used Acrotriche cordata is a small heath population data has been provided to create the most comprehensive (up to 50cm tall and 80cm broad) in until now. During the 2008 survey A. list so far prepared for Prime Seal the family ERICACEAE, and is listed cordata was determined to be locally Island (Appendix 1). as Vulnerable in Tasmania (TSPA common on westerly to north 1995). It has a disjunct distribution, westerly facing slopes in ‘Heathland Taxonomic nomenclature for plant its western most populations on calcarenite’. The species is known taxa follows Buchanan (2005). The occurring around the south west to occur on the same substrate on nomenclature adopted here for coast of Western Australia where Flinders Island (Underwood 1998). vegetation communities follows it is considered relatively common. On Prime Seal Island the species Harris and Kitchener (2005). It is also considered common in tends to be concentrated in the the south east of South Australia. It rockier facies of the heathland where occurs sporadically in Victoria near plant cover is lower and sandy

42 Table 1: Plant taxa for which population distributions and estimates were determined.

Threatened taxa Common name Family Distribution Status First Recorded Acrotriche cordata# coast groundberry EPACRIDACEAE WA, SA, VIC, TAS Vulnerable 1966 Cyrtostylis robusta large gnat-orchid ORCHIDACEAE WA, SA, VIC, TAS Rare 2008 Eutaxia microphylla spiny bushpea FABACEAE WA, SA, VIC, NSW, Rare 1986 var. microphylla# TAS Lasiopetalum coast velvetbush STERCULIACEAE WA, SA, TAS Rare Mid 19th century discolor# Leucopogon lance beardheath EPACRIDACEAE SA, VIC, NSW, QLD, Rare Early 1990’s lanceolatus* TAS Pomaderris shining dogwood RHAMNACEAE WA, SA, VIC, TAS Rare 1966 paniculosa subsp. paralia Parietaria debilis shade pellitory URTICACEAE All states Rare 1966 Spyridium vexilliferum helicopter bush RHAMNACEAE SA, VIC, TAS Rare Mid 19th century var. vexilliferum Stellaria multiflora rayless starwort CARYOPHYLACEAE WA, SA, VIC, NSW, Rare 2008 TAS Taraxacum coast dandelion ASTERACEAE WA, VIC, TAS Vulnerable (EPBCA Mid 19th century cygnorum*# 1999) Zygophyllum coast twinleaf ZYGOPHYLACEAE WA, SA, VIC, TAS Rare billardierei# Taxa of biogeographic significance Asplenium maidenhair ASPLENIACEAE WA, VIC, NSW, TAS 2008 trichomanes spleenwort Callitris rhomboidea oyster bay pine CUPRESSACEAE SA, VIC, NSW, QLD, 1965 TAS Convolvulus blushing bindweed CONVOVULACEAE WA, SA, VIC, NSW, 1965 angustissimus subsp. QLD, TAS angustissimus Eucalyptus ovata black gum MYRTACEAE SA, VIC, NSW, TAS Mid 1980’s Orobanche minor lesser broomrape OROBANCHACEAE WA, SA, VIC, NSW, Mid 1980’s sensu lato QLD, TAS Threlkeldia diffusa# coast bonefruit CHENOPODIACEAE WA, SA, VIC, TAS Mid 1980’s

* Taxa that were not observed during the survey # Taxa with highly restricted distributions within Tasmania

43 coloured broken limestone covers around the east and northern coastal FABACEAE. It generally grows to the ground. A. cordata dominates areas of Tasmania and it is listed as 5-10cm high and can get up to one these heaths providing 10-50% of Rare (TSPA 1995). On the Furneaux metre in diameter, although some the vegetation cover. Lasiopetalum islands C. robusta is known from Australian mainland populations discolor and Beyeria lechenaultii Flinders, Babel, Badger and Vansittart grow as small upright shrubs. Eutaxia always co-occur with A. cordata in islands (Harris et al. 2001, NVA July microphylla is widespread and locally this community. 2009). It has also been collected common in the southwest of Western from Inner Sister Island and the Kent Australia, it is also common in There are three locations on the Group of Islands (National Herbarium southern South Australia, throughout island where Acrotriche cordata was of Victoria, AVH July 2009). Victoria and in the southern half of found to be densely populated. New South Wales. It is listed as Rare At North Hill there are a number Cyrtostylis robusta was first recorded in Tasmania (TSPA 1995). of small patches of A. cordata on Prime Seal Island during the dominated vegetation, which are 2008 survey. It was found in the Within Tasmania the Eutaxia occupied by 750 mature plants grassy herbaceous understorey microphylla is usually associated with (plus or minus 250). Similarly on of Allocasuarina verticillata and Tertiary limestone and limey sands the small hill to the south of Target Myoporum insulare open forest in close proximity to the coast. It is Hill where three distinctive patches (‘Allocasuarina verticillata forest’). It known from a number of sites on the were observed to include 750 was located in free draining site on a west coast of Flinders Island, and on mature plants (plus or minus 250). substrate of calcareous sands with a Cape Portland. Two populations are The largest population was observed layer of organically enriched top soil. known from the South East, one on on the unnamed large hill south of The site had a north easterly aspect the Forestier Peninsula and one near Peacock Bay. In this area there are and gentle (four degree) slope. The Midway Point (Lynch 1993). When 2300 mature plants (plus or minus colony occupied an area of one Lynch (1993) surveyed the majority 700). Therefore the total estimated square metre and was composed of of known populations in the early population of A. cordata on Prime about 15 leaves. No plants were in 1990s, all populations contained less Seal Island is 3800 mature plants flower at the time however several than 100 individuals each with the (plus or minus 1200). individuals had maturing fruit present. exception of the Forestier Peninsula The habitat and leaf morphology population which was estimated at Cyrtostylis robusta combined with residual floral 200 while a loose estimate of 1000 Cyrtostylis robusta in the family features present on the maturing individuals was given for Prime Seal ORCHIDACEAE is a geophytic fruit were sufficient to identify the Island (Lynch 1993). colony forming terrestrial orchid. It taxa. Time constraints prevented During the recent trip to Prime has a single ground hugging reniform further extensions surveys for the Seal Island Eutaxia microphylla was leaf and a six to 25cm high scape with species in the immediate vicinity. surveyed more extensively. Akin to up to seven insignificant brownish There were at least several hectares the Flinders Island populations, it red flowers (Jones et al. 1999). It is of similar habitat in the local area was found to occur in areas mapped regarded as common and widespread that may support further colonies. as ‘Heathlands on calcarenite’, and in the south west of Western Eutaxia microphylla var. also in calcareous sand dunes. It was Australia, Likewise on the south east microphylla noted as being present just inland coast of South Australia. It is scattered of Wolff Bay on the west coast, at in Victoria where it is regarded as not Eutaxia microphylla in Tasmania is a this site there were only a handful threatened. In Tasmania it is distributed spiney prostrate shrub in the family of plants seen. In dunes just to the

44 Lasiopetalum discolor in flower. Photo by Micah Visoiu

southeast of Sealers Cove 300 (plus or minus 100) smallish plants were encountered growing with Austrostipa stipoides and Pultenaea tenuifolia in an area that appears to have a high fire frequency (in the vicinity of five to ten year fire intervals). Several hundred metres south of this site there is a large patch of ‘Heathland on calcarenite’ growing on the western slope of a large un-named hill. At this site Acrotriche cordata, Lasiopetalum discolour and Beyeria lechenaultii co-dominate on broken limestone and shallow soil, 1500 (plus or minus 500) Eutaxia microphylla were estimated to be present. At this site plants were large and well established with some reaching a While there are several historical the ground. In these areas it grows metre in diameter. records from north western with Acrotriche cordata. At one site The total estimated Prime Seal Island Tasmania there is some doubt on North Hill plants were counted population of Eutaxia microphylla is about the accuracy of the locality in a transect measuring135 metre therefore 1800 (plus or minus 600) descriptions for these collections long and ten metres wide through mature plants more than double the (see discussion below). Lasiopetalum a patch of heathland dominated population estimate (500 plants) for discolor is listed as Rare in Tasmania by Lasiopetalum discolour. A total the rest of Tasmania (Lynch 1993). (TSPA 1995). of 674 plants were counted. The heathland extent at this site was On Prime Seal Island this species Lasiopetalum discolor 4.5 ha and was likely to contain a is the dominant in most areas of population of about 22 500 plants Lasiopetalum discolor is a medium ‘Heathland on calcarenite’ (Harris & (plus or minus 2 500). The species sized multi-stemmed shrub (one Kitchener 2005). In particular those attained a similar density in the metre by one metre) in the family areas on the steeper slopes which other areas mapped as ‘Heathland STERCULIACEAE. It is common have lower amounts of limestone on calcarenite’ and also occurred along the south coast of Western outcropping and incorporate some extensively, although not so densely, Australia and in coastal areas of granite gravels and dark coloured in areas of ‘Coastal scrub on alkaline South Australia where is extends organic matter is more prevalent in sands’. In these two vegetation nearly as a far as the Victorian the soils. In such areas Lasiopetalum units this species was found to Border. The only known extant discolor reaches up to 75% total be very common over much of population in Tasmania occurs on cover. It often dominates in the the Island. Extrapolation from the Prime Seal Island which is around rockier facies of the heathland where survey at North Hill suggests that a 800km east and 200km south of the plant cover is lower and sandy conservative estimate of 20 hectares nearest South Australian population. coloured broken limestone covers

45 of ‘Heathland on calcarenite’ on the however suitable habitat was noted Island. It occurs in ‘Heathlands on Island could support approximately to be present on the hill to the calcarenite’ and ‘Coastal scrub 100 000 (plus or minus 10 000) south of Peacock Bay, in herbaceous on alkaline sands’. This species is plants. The less dense but far more ‘Allocasuarina verticillata forest’. This a significant component of these extensive occurrence outside of this site had similarities to Robin Hill heathlands, especially in areas with vegetation would at least double if and Steep Hill on Clarke where L. higher disturbance regimes. Seedlings not triple this number, producing a lanceolatus occurs commonly (pers and individual bushes were also conservative estimate of 200 000 obs., Harris & Reimer 1994). It is encountered in areas of cleared land. (plus or minus 50 000) individuals on likely that further surveys in this No calculation of the population on Prime Seal Island. area would re-locate the species. the island was made however it is However the fact that the species likely to be in the order of tens of Leucopogon lanceolatus was not observed during the six day thousands. survey of the island in 2008 suggests Leucopogon lanceolatus is a tall Parietaria debilis narrow-elliptical shrub to three that the total population for the metres high (Curtis 1963). Its most species is likely to be low. Parietaria debilis is a small soft noticeable feature is the bright red Pomaderris paniculosa light green annual herb in the colouration of the young stems subsp. paralia URTICACEAE family. It is quite and narrow lanceolate leaves. L. widespread but not common, in lanceolatus occurs extensively Pomaderris paniculosa subsp. paralia all temperate areas of Australia, on the eastern side of the Great is a medium sized shrub in the family occurring in all states. It also occurs Dividing Range from Fraser Island RHAMNACEAE. It grows up to in New Zealand. It favours well in Queensland, through New South two metres tall and can form dense drained and often alkaline soils Wales and into eastern Victoria. thickets. It is often associated with (Harden 1990). In the Furneaux It is further scattered throughout limestone, coastal dune systems Islands it occurs in shady sites under southern Victoria, occurring in the and cliff lines (Walsh & Entwistle scrub and heath in slightly damp border area with South Australia 1994). This taxon occurs on the areas (Harris et al. 2001). Parietaria with an outlying population further south coast of Western Australia debilis is listed as Rare in Tasmania north west on Kangaroo Island. It and is not considered threatened (TSPA 1995). It occurs sporadically is listed as Rare in Tasmania (TSPA in that state. It is common in South throughout the coastal areas of the 1995) due to its limited distribution Australia and Victoria. It is listed State, with the majority of known in Tasmania. In the state it occurs on as Rare in Tasmania (TSPA 1995), populations in the Bass Strait islands. King Island and the Furneaux Islands. where it occurs predominantly in During the 2008 survey of Prime the Furneaux Islands and north On the Furneaux Islands L. Seal Island Parietaria debilis was east Tasmania, with one confirmed lanceolatus occurs on Flinders, Cape occasionally encountered around the outlying population on King Island Barren, Long, Inner Sister, Badger and southern coast of the island. It was (NVA July 2009). Clarke islands (Harris et al. 2001,Tas. usually under Myoporum insulare in Herbarium specimens). It has also On Prime Seal Island Pomaderris areas of sandy soil around granite been recorded once from Prime paniculosa subsp. paralia is tors and on the landward edge of Seal Island by Harris et al. (2001), widespread and common in a granite coastline. It was also found although no herbarium specimen number of heath, scrub and forest growing in dense ‘Scrub on alkaline was collected. It was not recorded communities throughout the sands’ in the flat plain between from the island on the present trip; areas of native vegetation on the Sealers Cove and Peacock Bay. No

46 population counts were made of this had recent or ongoing disturbance, Stellaria multiflora is listed as rare in species during the 2008 survey but it such as slashed areas and vehicle Tasmania (TSPA 1995). On the Bass is likely that the population is in the track edges. Strait Islands it is known from Flinders order of tens of thousands. Island, Babel Island, the Kent Group, Spyridium vexilliferum was observed Curtis Island and Three Hummock Spyridium vexilliferum var. at three sites in 2008. The largest Island. The first record of species on vexilliferum population was encountered in an Prime Seal island was made during area of broken rocky ground in an Spyridium vexilliferum var. vexilliferum the present survey. area of regularly slashed heathland is usually a small open shrub 200 metres to the south east of Stellaria multiflora was found (30-90 cm tall) in the family Wolff Bay. At this site approximately growing on a granite rock plate RHAMNACEAE. The taxon is fairly 400 (plus or minus 100) plants were approximately 200 m south west common and widespread in South present in an area of about half a of the shearing shed, and was most Australia and Victoria. In Tasmania it hectare. Associated species were prevalent in partial shade around the occurs in sandy heaths and on rocky Acrotriche cordata, Beyeria lechenaultii edges of Myoporum insulare shrubs outcrops in the east, north and west and Pimelea serpyllifolia. A handful of that overhung the rock plates. The of Tasmania (Curtis & Morris 1975). plants were also seen on the eastern vegetation in the surrounding area On the Bass Strait islands it has been face of North Hill in ‘Heathland on was ‘Regenerating cleared land’, recorded and collected several times calcarenite’. A similarly small group with the areas around the rock from Prime Seal Island. There is one of less than ten plants were seen on plates retaining some shrubs and mid 19th century specimen collected the western face of the hill to the native vegetation. Associated species by J. Milligan attributed to Flinders south of Peacock Bay. All plants seen were Cotula australe, Gnaphalium Island. Although no specimens have on the island were characterised by indutum and Galium murale. The subsequently been collected from a low dense spreading habit, with population was not fully surveyed Flinders Island (Tas. Herbarium most plants being less than 30 cm but would have been in the range records, AVH July 2009, NVA July tall and up to one metre in diameter. of 70 individuals (plus or minus 2009) it is reported to still occur This is unusual for the species; but 30). There were numerous other there in several localities associated exposure to sea breezes may go similar rock plates in the surrounding with calcarenite (S. Harris pers com.). some way to explaining this growth area that may also have harboured Spyridium vexilliferum is listed as rare form. populations of this species. in Tasmania (TSPA 1995). Stellaria multiflora Taraxacum cygnorum This species was first collected from Prime Seal Island in the Stellaria multiflora is a tiny annual Taraxacum cygnorum is a rosette mid 19th century and has been herb that grows 2-5 cm tall. It has forming herb in ASTERACEAE. It observed there several times since. a scattered distribution across is very similar in appearance to the Observations during the 2008 the southern half of Australia. It is introduced dandelion (Taraxacum survey indicated that this species occasional on the south coast of officinale). It was first described from is quite restricted in its distribution Western Australia and is listed as rare specimens collected in Western on the island. It was observed most under the National Parks and Wildlife Australia; however it is now listed as often in areas of thin sandy soil Act 1972 (NPWA 1972) in South extinct in that state. It occurs in four over granite and limestone, within Australia. It also occurs in Victoria small populations in south western SHC and SCA. The majority of and New South Wales. In Tasmania Victoria where there is believed to populations of Spyridium vexilliferum it is widespread but very occasional be significantly less than 1000 plants seen on the island were in areas that from sea level to the Central Plateau. and it is listed as endangered under

47 the State Act there (Carter 2004). Kent and Hogan groups Zygophyllum Taxa of biogeographic Taraxacum cygnorum is also listed billardierei can be locally very significance nationally as Vulnerable (EPBCA common after disturbance (Harris et 1999). It is not listed in Tasmania al. 2001). Asplenium trichomanes (TSPA 1995). On Prime Seal Island Zygophyllum Asplenium trichomanes in the family There are three herbarium specimens billardierei was first recorded in the ASPLENIACEAE, is a small fern of Taraxacum cygnorum collected in mid 1960s (Whinray 1971), and with a cosmopolitan distribution Tasmania in the mid 19th century has been observed there several in temperate areas of the world; (Harris et al. 2001). They are from times since (NVA, May 2009). At occurring in Australia, New Zealand, King Island, Flinders Island and Prime the time of the 2008 survey this Africa, Europe, Asia and North Seal Island. The taxon has not been species was locally dominant over America. Within Australia it is listed collected in Tasmania since this time, quite extensive areas, predominantly as rare in Victoria (ALRTPV 2005) despite some efforts to relocate it. in disturbed areas such as scrub that and South Australia (NPWA 1972), In Victoria Taraxacum cygnorum is had been slashed within the last it also occurs in New South Wales associated with near coastal grassy two years and along slashed fence and Western Australia. Within woodlands on limestone and limey lines. It also occurred commonly Tasmania the subspecies Asplenium sands (Carter 2004). A small area of within ‘Heathland on calcarenite’. trichomanes subspecies quadrivalens such habitat does still exist on Prime The largest single patch observed has a localised distribution Seal Island which may be worth was on the north face of the large predominantly on Ordovician targeting in future surveys of the hill to the south of Peacock Bay. limestone (Harris et al. 2001). It island at a different time of year or At this site approximately one has in the past been identified after a wet spring. hectare of regenerating cleared land as significant on the Furneaux had been slashed and had been Islands where it occurs on Tertiary Zygophyllum billardierei colonised by Zygophyllum billardierei limestone. There is one record from Flinders Island where the population Zygophyllum billardierei is a sprawling where it provided 70-90% of the size is unknown. It has been succulent perennial herb with bright vegetation cover. Estimating a density recorded from a limestone outcrop yellow flowers growing up to 40 of 0.75 plants per square metre, this on Badger Island where less than 20 cm high and one metre wide. It is population contained about 7 500 individuals are estimated to occur (S. in the family ZYGOPHYLLACEAE. individual plants (plus or minus 750). Harris pers com.). The specimen from It occurs along the southern coast A less dense population occurred Prime Seal Island has not yet been of Australia from Western Australia along several hundred metres of identified to subspecies, however through South Australia and along fence line just inland from Wolff geographically it is likely to be this the Victorian coast. It is listed as rare Bay. At this site 1000 mature plants taxon. in Victoria and not threatened in the (plus or minus 250) were estimated to occur. Other populations of this other states. In Tasmania Zygophyllum This is the first record of this species were commonly encountered billardierei is confined to disturbed species from Prime Seal Island. over most of the island. A estimate of area on calcareous sands and The population is located the total population of Zygophyllum limestone’s on the islands of eastern on a south easterly facing billardierei on the island at the time Bass Strait (Underwood 1998, Harris limestone cliff face just north of the visit would be 30 000 (plus or et al. 2001). Zygophyllum billardierei of Mannalargenna Cave. Only minus 10 000) mature individuals. is listed as rare in Tasmania (TSPA a handful of individuals (5-10) 1995). On islands of the Furneaux, were present at this site. Associated

48 Callitris rhomboidea. Illustration by Brett Littleton

species were Galium australe and Tasmania C. rhomboidea is confined During the 2008 trip to Prime Plantago bellidioides. to dry areas on the east and north Seal Island a small population of east coast and it is also widely Convolvulus angustissimus subsp. Callitris rhomboidea distributed on the Furneaux islands angustissimus was located at the Callitris rhomboidea is a medium including a number of the larger northern end of the leasehold, on the sized tree up to 10 metres in high outer islands. flats just to the south of North Hill. At with fine dark green foliage (Harris this site vegetation was rough pasture Callitris rhomboidea was recorded et al. 2001). It is in the family with a mix of native and exotic from Prime Seal Island in 1965 CUPRESSACEAE. It occurs down grass as well as emergent saplings of (Whinray 1971). It has not been the eastern seaboard of Australia Pomaderris paniculosa subsp. paralia, recorded since despite active from Queensland through New Myoporum insulare and Ficinia nodosa. searching for this species by S. Harris South Wales and Victoria This is currently the only population in the late 1980s and early 1990s and into South of this taxon that is known from the and during the 2008 survey, see Australia. In outer Furneaux Islands. discussion. Eucalyptus ovata Convolvulus angustissimus subsp. angustissimus Eucalyptus ovata is a medium sized tree in the family MYRTACEAE. It Convolvulus angustissimus occurs throughout south eastern is a small twining pink Australia on damp to wet fertile flowered herb in the family soils. It is locally common in South CONVOVULACEAE. It is locally Australia, Victoria, New South common in all states of Australia Wales and Tasmania. Very few of except Northern Territory. Within the outer islands have any eucalypts, Tasmania it is common in native presumably because those that were grasslands and grassy woodlands present at the time of European throughout the midlands and along settlement were eliminated by a high the east coast. There are no records fire frequency (Harris et al. 2001). of this taxon from the Furneaux Eucalyptus ovata occurs on the larger Islands held at the Tasmanian Islands of Flinders, Cape Barren and Herbarium, nor are there any records Clarke however Prime Seal Island on the Tasmanian Natural Values would appear to be the only known Atlas (NVA July 2009). However the site where this species occurs on an National Herbarium of Victoria hold outer Island. three specimens, two from Flinders Island and one from Prime Seal Eucalyptus ovata has previously been Island (Royal Botanic Gardens Board, recorded from the Island; however Melbourne, MELISR database, 27th this record from the mid 1980’s was March 2009). The Prime Seal Island of a single tree stumbled upon whilst specimen was collected by J. Whinray forging through dense Allocasuarina sometime in the 1960s, however verticillata forest (S. Harris pers com.). it is not included in his species list The approximate site of this tree published in 1971 (Whinray 1971). on the north face of the large hill

49 to the south of Peacock Bay was with dead wood present at their over the last few years. A small seed approached from the top of the hill extremities and often with one or collection was made and has been during the 2008 survey. The species two dead trunks, the open areas lodged with both the Tasmanian was re-located in dense scrubby around these individuals was much Seed Conservation Centre and ‘Allocasuarina verticillata forest’. The smaller than for the larger trees. The Millennium Seed Bank. dense understorey of Myoporum third size class was comprised of Orobanche minor sensu insulare, Bursaria spinosa, Pimelea scattered saplings up to one metre lato serpyllifolia and Leucopogon parviflora in height. The population size was created difficulties in ascertaining the estimated at 20 large trees (plus or Orobanche is a genus of holoparasitic extent and size of the population. minus 3), 45 mallee trees (plus or herbaceous plants in the family minus 5) and 25 saplings (plus or ORABANCHACEAE. Species have Exploration of the immediate area minus 5). no photosynthetic pigments and revealed the population to be are only present above ground made up of three quite distinct size The surrounding vegetation of when they are flowering and classes. The first of these were large large Allocasuarina verticillata and fruiting. All records of this genus in mature trees up to five metres in Myoporum insulare were a single Tasmania have been determined as height with two to three spreading cohort that regenerated after a the introduced European species trunks diverging within a metre of major fire event. The tallest of these Orobanche minor. Despite its the ground with the larger trunks trees were seven metres in height, introduced status, the occurrence being 20-40 cm in diameter. These overtopping the E. ovata formed the of the species on Prime Seal Island trees were large enough to inhibit mid-storey in this vegetation. The is of biogeographic interest (see the growth of other woody plants majority of trees showed significant discussion). beneath their canopy and generally signs of stress, with almost all trees were underlain by a herb rich Poa having numerous dead branches and The site that this taxa was found labillardierei grass sward. The second had generally sparse foliage. Mature on Prime Seal Island during the size class was characterised by fruit were only found on a handful present trip was on an old track lignotubers 20-40 cm in diameter of the larger trees, with flower buds on limey sand soils in the northern supporting 3-7 slightly spreading also present on these and several side of North Hill. Approximately small mallee trunks 3-10 cm in others. Very few old fruit were seen, 5 patches of plants were seen, all diameter. These mallee trees were indicating seed production in this of which were growing in open usually around four metres in height population has been limited by stress

50 Orobanche in native vegetation. Photo by Micah Visoiu

sandy areas on the track through GENERAL less at that time. The expansion of native vegetation. The only species DISCUSSION native vegetation may account for growing within one metre of these the apparent population increase in patches were the annual lily Bulbine The known flora of Prime Seal Island this species. Harris et al. (2001) also semibarbata and the native daisy comprises 193 taxa which include gave a considerably lower estimate bush Olearia ramulosa. It seems likely 68 introduced species and 130 of the population for this species that the host for the Orobanche native taxa of which 2 are endemic on the island, suggesting there were plants was O. ramulosa given that to Tasmania. Thirteen threatened only 20 plants in the late 1980s and the species has a known preference species have been recorded from early1990s. for ASTERACEAE. ASTERACEAE the island. The estimated Prime Seal Island and FABACEAE are the two most The populations of Acrotriche population of Eutaxia microphylla of common host families for Orobanche cordata, Eutaxia microphylla, about 1800 mature plants comprises minor sensu lato (Rumsey & Jury Lasiopetalum discolor on Prime Seal two to three times more plants than 1991). Island comprise a very significant the total estimated population of Threlkeldia diffusa proportion of the total estimated this species for the rest of Tasmania populations of these taxa in (Lynch, 1993). This is an increase Threlkeldia diffusa is a low Tasmania. on the estimates of 600 and 1000 growing succulent plant in the individuals on the island made in CHENOPODIACEAE. It has a mainly There are no size estimates for the early 1990s (Harris et al. 2001, coastal distribution from around the the Flinders Island populations Lynch 1993). It is unlikely that the 20° line of latitude on the Western of Acrotriche cordata, however increase that was made in the Australian coast right around the anecdotally it would seem that estimated population is a result of south west coast, entire coast of the population on Prime Seal population increase; rather it is a South Australia and western coast of Island which is 3800 mature plants factor of increased survey effort. The Victoria. It reaches its most easterly constitute a large percentage of extensive survey effort on the island distribution in Tasmania’s Furneaux the total Tasmanian population of during the 2008 trip failed to find Islands. It also occurs sporadically and this species. Anecdotal evidence new population locations. probably ephemerally on Tasmania’s suggests this taxon has increased in north coast. Threlkeldia diffusa is not abundance on Prime Seal Island in Lasiopetalum discolor would appear listed as threatened in any of the the last 30 years. Whinray (1971) to be confined to Prime Seal states in which it occurs. However it noted that only three plants were Island within Tasmania, although has a very restricted distribution in seen on the northwest side of several herbarium specimens have Tasmania. North Hill in the mid 1960s. The low been regarded as coming from vegetation that this species occurs other localities historically. There On Prime Seal Island Threlkeldia in and distinct colour it has amongst are two early collections made diffusa was observed occasionally as other vegetation tend to make it by J. Milligan held in the Australian single plants or small groups of plants quite noticeable where it grows. On National Herbarium in Canberra in areas that had been exposed to the present survey this same site which have been attributed to recent disturbance. No population on the northwest side of North Hill Three Hummock Island in western counts were made, however the was estimated at about 750 mature Bass Strait (ANHSIR July 2009). population on the island would be plants. Aerial photographs taken in This location seems to have been reasonably small with a high turnover. 1974 show the native vegetation extrapolated from the tag which extent in this area was substantially denotes the locality as “Hummocky

51 Island”. Prime Seal Island has in the extant population in Tasmania. The a component of dry vegetation on past been known as “Hummock population on the island is large a number of the Furneaux Islands; Island’ (Whinray 1971, Harris et with an estimated 250 000 mature however it is killed outright by fire. al. 2001), so it would seem more individuals and would seem to be Fire also triggers the mass dispersal probable that it was this locality that secure. Examination of historical and germination of seed. Therefore Milligan referred to. Indeed, J. Milligan aerial photographs from the 1960s the period between fires needs to made a number of collections from 70s and 80s show that the extent be greater than eight years to allow “Hummock Island” in the 1840s that of native vegetation in those areas maturation of a new cohort of are held at the Tasmanian Herbarium now dominated by this species has individuals and production of new which have been determined as increased significantly since that time. seed. Any shorter period between coming from Prime Seal Island. It is therefore reasonable to assume fires and the species is lost from the that the population of L. discolor has area (Harris 1989). It is possible that There is one undated herbarium increased over that period. this species survived until the mid specimen of L. discolor collected by 1960s and has since become extinct Leonard Rodway, who collected in There were two threatened species on the island due to several fires in Tasmanian from the 1890s until the that have been recorded from short succession (fires are regular 1930s , which has been regarded as Prime Seal Island in the past, were on the island and the extent of them coming from Sisters Beach (North not recorded during the 2008 trip. is not mapped). However it is also West Tasmania). The specimen, which Taraxacum cygnorum has not been possible that intensive surveying of is held at the Tasmanian Herbarium recorded in Tasmania since the those areas that are visible as forest has very little original collection 1840s. Descriptions of the habitat in aerial photographs in the 1950s information recorded. Other than where this species occurs in Victoria and 1970s (vegetation cover has the collectors name it says ‘the (Carter 2004), would suggest expanded significantly since this sisters, north _____ coast’, the that there is still a small amount time) may enable this species to be largely illegible word between ‘north’ of suitable habitat for this species relocated. and ‘coast’ has been interpreted as present on Prime Seal Island. This ‘west’, although this is by no means area which is located in the area of The presence of Orobanche minor explicit. The Sisters Beach and Rocky Eucalyptus ovata on the large hill to on Prime Seal Island is a curiosity. Cape areas have been surveyed the south of Peacock Bay should be Within its native range it is often extensively since this time and this surveyed more thoroughly for this referred to as Orobanche minor sensu species has never been relocated, species at a time when it is likely to lato and is regarded as presenting indeed it is uncertain what locality in be in flower. This area is also likely significant taxonomic difficulties, this area that is known as ‘the sisters’. to be the habitat for Leucopogon with morphologically reduced No other collections by Rodway lanceolatus which was also not diagnostic characters combined have been located that have this recorded on the present trip. with unknown host specific effects, same collection locality, which could and the unrepresentative nature of The serotinus conifer, Callitris give further clues to the original dried specimens making determining rhomboidea, was recorded form locality. It would be reasonable to this and a raft of closely related Prime Seal Island in the mid 1960s conclude therefore, that the origin species very difficult (Rumsey & (Whinray 1971), and has not been of this particular L. discolor specimen Jury 1991). Orobanche minor sensu relocated since, despite active is unknown. This would make the lato shows unusually low host searching by S. Harris in the late Prime Seal Island population of specificity for the genus Orobanche, 1980s and early 1990s and also on Lasiopetalum discolor the only known the majority of species of which the 2008 expedition. This species is

52 show high host specificity. This has of the other unusual weed on dune areas and inland sandy places led to the idea that Orobanche minor these two islands, Brassica oleracea, (ARBCP July 2009, EFSA July 2009). sensu lato is a species aggregate, which is the wild form, from which The taxon Orobanche cernua var. with morphological characters of kale, Chinese broccoli, cauliflower, australiana is regarded as native in lower selective importance than cabbage, kohlrabi and broccoli have Australia but is poorly defined with the physiological characteristics that all been bred. It is one possible origin no definitive diagnostic characters determine host and habitat range of an introduced Orobanche species. yet provided (EFSA July 2009). It is (Rumsey & Jury 1991). That is to However, Orobanche minor sensu however very similar to Orobanche say that morphologically similar lato does not seem to have been minor sensu lato. The previously populations that parasitise different recorded in Tasmania before the described issues with determining species or families in different 1960s, or within Australia before the Orobanche taxa combined with habitats may in fact be genetically 20th century (AVH July 2009, NVA the habitat of this taxon on Prime distinct taxa. The fact that species July 2009). On Prime Seal Island Seal Island and presumably also of Orobanche are largely inbreeding Orobanche was seen in an area of Christmas and New Year Islands lends credence to this theory. native vegetation along a sandy track would suggest a close look at fresh edge, and apparently parasitising material from these locations is Despite the introduced status of Olearia ramulosa. Historical aerial warranted. Orobanche in Tasmania, the taxon has photographs show the locality of the some curious distributions within Prime Seal Island is a site of very population has regenerated from the state. The majority of records high conservation significance within pasture in the last 25 years. and specimens are from the fertile Tasmania. The expansion of native vegetable growing and dairy farming Harris et al. (2001) has invoked the vegetation in the last 40 years areas on the central north coast and lithological and climatic similarities contains important populations of in the north west. Specimens have of islands in eastern Bass Strait and a range of threatened flora species also been collected from Christmas the coasts of South Australia and and is the only known site in and New Year Islands off the north south west Western Australia as Tasmania where Lasiopetalum discolor west coast of King Island, and Prime an explanation for the high floristic is known to occur. It also harbours Seal Island on the opposite side of congruity across these areas. They a number of species that are Bass Strait. These island occurrences postulated that the very alkaline biogeographically significant in their are interesting as they all occur in substrate in conjunction with a occurrence on an outer island of the +/- native vegetation and in offshore Mediterranean climate, explained Furneaux Group. It is probable that island habitats. Christmas and New the distribution of such species other plant species both threatened Year islands lie within a couple of as Lasiopetalum discolor, Acrotriche and non-threatened remain to be hundred metres of each other in cordata and Threlkeldia diffusa. These found on this unique island. western Bass Strait. They are both in species have their strongholds on the a largely natural state (Brothers et limestone coasts of South Australia al. 2001). New Year Island is reputed and Western Australia. This habitat ACKNOWLEDGEMENTS to have been the site of a short in South Australia also supports lived market garden set up in the populations of the Rare (NPWA I would like to thank Jayne Balmer early 1860s by two Chinese men 1972) native taxa Orobanche cernua for comments on the drafts, Stephen from Geelong; to where produce var. australiana (ARBCP July 2009). Harris for general guidance, field was regularly shipped (Hooper In this area it is thought to parasitise data, advice in the field, editing and 1973). This is the most likely origin ASTERACEAE species in coastal comments, Oliver Strutt for help in field work, and all others involved in

53 the Prime Seal Island expedition. I Brothers, N., Pemberton, D., Pryor, Group, Parks and Wildlife Service would in particular like to thank the H. & Halley, V. (2001) Tasmania’s report. DELM, Tasmania. family of Hamish Saunders, who set Offshore Islands: Seabirds and Other Hooper, R.H. (1973) The King Island up the memorial fund that made this Natural Features. Tasmanian Museum Story. Peko-Wallsend, Sydney. expedition possible. and Art Gallery, Hobart. Jones, D., Wapstra, H., Tonelli, P. & Carter, O. (2004) Draft Flora Harris. S. (1999) The Orchids of and Fauna Guarantee Action Tasmania. Melbourne University REFERENCES Statement, Coast Dandelion Press. Victoria. ALRTPV: Advisory List of Rare or Taraxacum cygnorum. Department Threatened Plants in Victoria - of Sustainability and Environment. Lynch, A.J.J. (1993) Conservation 2005. Victorian, Department of Melbourne. Biology and Management of 16 Rare Sustainability and Environment, East or Threatened FABACEAE Species Curtis, W.M. (1963) The Student’s Melbourne, Victoria. in Tasmania, Australian National Flora of Tasmania, Part 2, Government Parks &Wildlife Service Endangered ANHSIR: Australian National Printer, Hobart. Species Program Project No. 4, Parks Herbarium Specimen Information Curtis, W.M. & Morris, D.I. (1975) The & Wildlife Service, Hobart. Register, IBIS database, Australian Student’s Flora of Tasmania, Part 1, National Herbarium, Australian NVA: Natural Values Atlas, Government, Canberra, viewed July EFSA: Electronic Flora of South Australia Biodiversity Conservation Branch, 2009. Loefl. Department for Environment Parks, Water and Environment, and Heritage, Adelaide, viewed July Tasmanian Government, Hobart, ARBCP: Adelaide Region Biodiversity 2009. viewed July 2009. Conservation Program, Threatened < https://www.naturalvaluesatlas. species Profile, Orobanche cernua Harden, G.J. (Ed) (1990) Flora of New dpiw.tas.gov.au/pls/apex/f?p=200:1:> var. australasica, Department for South Wales, volume 1, UNSW press. Environment and Heritage, Adelaide, Sydney. Royal Botanic Gardens Board, viewed July 2009. Melbourne, MELISR database, 27th Harris, S. (1989) The Ecological < http://www.environment.sa.gov.au/ March 2009 Biogeography of Callitris Vent. in biodiversity/pdfs/regional_recovery/ Tasmania. M.Sc. thesis. University of Rumsey, F.J. & Jury, S.L. (1991) An flora/orobanche-cernua-var- Tasmania. account of Orobanche L. in Britain australiana.pdf> and Ireland. Watsonia 18, 257-295. Harris, S. & Kitchener, A. (2005) From AVH: Australia’s Virtual Herbarium, Forest to Fjaeldmark: Descriptions of Underwood, S. (1998) Synecology via Centre for Plant Biodiversity Tasmania’s Vegetation. Department & Conservation of Vegetation on Research, Council of Heads of of Primary Industries, Water and Aeolian Calcarenite, Flinders Island, Australian Herbaria, viewed July Environment. Printing Authority of Bass Strait, BSc thesis, University of 2009. Tasmania. Hobart. Tasmania. Buchanan, A.M. (2005) A Census Harris, S., Buchanan, A. & Connolly, Walsh, N.G. & Entwistle, T.J. (eds) of the Vascular Plants of Tasmania, A. (2001) One Hundred Islands: The (1994) Flora of Victoria, Volume 2, Fourth Edition. Tasmanian Herbarium Flora of the Outer Furneaux, DPIWE, Inkata Press, Melbourne. Occasional Publication No. 7. Hobart. Tasmanian Museum and Art Gallery. Whinray, J.S. (1971) A note on Prime Hobart Harris, S. & Reimer, A. (1994) Flora Seal Island, The Tasmanian Naturalist, and Fauna of Clarke Island, Furneaux No. 27, Hobart.

54 Appendix one Prime Seal Island vascular plant species list

The ‘*’ in the right hand columns indicate where the records have come from. There are a number of species that were not seen in the current survey. In most cases this is due to the season in which the survey was undertaken. There are also a number of unverified records, which may have been recorded in error, namely Hibbertia prostrata, Hibbertia riparia and Lasiopetalum macrophyllum. Pomaderris oraria has been recorded in the past, however this taxon has not been included on the list as it is most likely that this refers to Pomaderris paniculosa subsp. paralia which is common on the island.

FAMILY SPECIES NAME COMMON NAME Whinray Harris et Other Current 1971 al 2001 survey DIOCOTYLEDONS AIZOACEAE Carpobrotus rossii native pigface ** * AIZOACEAE Disphyma crassifolium round-leaved pigface * * * AIZOACEAE i Mesembryanthemum iceplant * * crystallinum AIZOACEAE Tetragonia implexicoma bower spinach ** * AIZOACEAE Tetragonia tetragonoides new zealand spinach * * APIACEAE Apium insulare island sea-celery * * APIACEAE Apium prostratum subsp. slender sea-celery * prostratum var. filiforme APIACEAE Hydrocotyle hirta hairy pennywort * * APIACEAE Lilaeopsis polyantha jointed swampstalks * APOCYNACEAE Alyxia buxifolia seabox ** * ASTERACEAE Actites megalocarpa dune thistle * * ASTERACEAE Apalochlamys spectabilis sticky firebush ** * ASTERACEAE i Arctotheca calendula capeweed * * ASTERACEAE Brachyscome diversifolia var. tall daisy * maritima ASTERACEAE i Carduus tenuiflorus winged thistle * * ASTERACEAE Cassinia aculeata dollybush * * ASTERACEAE i Centaurea melitensis malta thistle * ASTERACEAE Cotula australis southern buttons * ASTERACEAE Cymbonotus preissianus southern bears-ears * * ASTERACEAE Euchiton collinus cudweed * * ASTERACEAE i Gamochaeta calviceps grey cudweed * ASTERACEAE i Gamochaeta purpurea purple cudweed or * spiked cudweed ASTERACEAE Gnaphalium indutum tiny cottonleaf ** * ASTERACEAE Helichrysum leucopsideum satin everlasting ** * ASTERACEAE i Hypochoeris glabra smooth catsear * * ASTERACEAE i Hypochoeris radicata rough catsear * * ASTERACEAE i Leontodon taraxacoides hairy hawkbit * * ASTERACEAE Leucophyta brownii cushionbush * * ASTERACEAE Olearia axillaris coast daisybush ** * ASTERACEAE e Olearia phlogopappa var. dusty daisybush ** * brevipes ASTERACEAE Olearia ramulosa twiggy daisybush ** * ASTERACEAE Olearia stellulata sawleaf daisybush * * ASTERACEAE Olearia viscosa viscid daisybush * *

55 ASTERACEAE Ozothamnus turbinatus coast everlastingbush * * ASTERACEAE Pseudognaphalium luteoalbum jersey cudweed ** * ASTERACEAE Senecio biserratus crosscut fireweed * ASTERACEAE Senecio glomeratus purple fireweed * * ASTERACEAE Senecio pinnatifolius var. groundsel * lanceolatus ASTERACEAE i Silybum marianum variegated thistle * * ASTERACEAE Taraxacum cygnorum VU coast dandelion * ASTERACEAE i Vellereophyton dealbatum white cudweed * * BORAGINACEAE Cynoglossum suaveolens sweet houndstongue * * BRASSICACEAE i Cakile edentula searocket * BRASSICACEAE i Cakile maritima american searocket * * BRASSICACEAE i Hymenolobus procumbens oval purse ** * CAMPANULACEAE Lobelia anceps angled lobelia * * CAMPANULACEAE Wahlenbergia gracilenta annual bluebell * CAPRIFOLIACEAE Sambucus gaudichaudiana white elderberry * * CARYOPHYLLACEAE i Cerastium glomeratum sticky mouse-ear ** * CARYOPHYLLACEAE i Minuartia mediterranea fineleaf sandwort * CARYOPHYLLACEAE i Petrorhagia nanteuilii proliferous pink * CARYOPHYLLACEAE i Polycarpon tetraphyllum fourleaf allseed ** * CARYOPHYLLACEAE i Sagina apetala annual pearlwort * CARYOPHYLLACEAE i Sagina maritima sea pearlwort * * CARYOPHYLLACEAE i Stellaria media garden chickweed ** * CARYOPHYLLACEAE Stellaria multiflora r rayless starwort * CASUARINACEAE Allocasuarina verticillata drooping sheoak ** * CHENOPODIACEAE Atriplex cinerea grey saltbush ** * CHENOPODIACEAE i Chenopodium glaucum pale goosefoot * * CHENOPODIACEAE i Chenopodium murale nettleleaf goosefoot * * CHENOPODIACEAE Rhagodia candolleana subsp. coastal saltbush ** * candolleana CHENOPODIACEAE Sarcocornia quinqueflora beaded glasswort ** * CHENOPODIACEAE Threlkeldia diffusa coast bonefruit ** * CONVOLVULACEAE Convolvulus angustissimus var. blushing bindweed * angustissimus CONVOLVULACEAE Dichondra repens kidneyweed ** * CRASSULACEAE Crassula decumbens var. spreading stonecrop * * decumbens CRASSULACEAE Crassula sieberiana subsp. wiry stonecrop ** * tetramera DILLENIACEAE Hibbertia prostrata prostrate guineaflower * DILLENIACEAE Hibbertia riparia erect guineaflower * DILLENIACEAE Hibbertia sericea var. sericea silky guineaflower * * EPACRIDACEAE Acrotriche cordata v coast groundberry * * * EPACRIDACEAE Leptecophylla juniperina subsp. coastal pinkberry * oxycedrus r EPACRIDACEAE Leucopogon lanceolatus var. lance beardheath * lanceolatus EPACRIDACEAE Leucopogon parviflorus coast beardheath ** *

56 EUPHORBIACEAE Beyeria lechenaultii var. latifolia pale turpentine-bush * * * EUPHORBIACEAE i Euphorbia paralias sea spurge * EUPHORBIACEAE i Euphorbia peplus petty spurge * * EUPHORBIACEAE Phyllanthus gunnii shrubby spurge ** * FABACEAE Eutaxia microphylla var. spiny bushpea * * microphylla r FABACEAE i Melilotus indicus sweet melilot * * FABACEAE Pultenaea daphnoides subsp. heartleaf bushpea * obcordata FABACEAE Pultenaea tenuifolia slender bushpea ** * FABACEAE Swainsona lessertiifolia coast poisonpea * * FABACEAE i Trifolium campestre hop clover * FABACEAE i Trifolium glomeratum cluster clover * * FABACEAE i Trifolium stellatum star clover * * GENTIANACEAE i Centaurium tenuiflorum slender centaury * * GENTIANACEAE Sebaea ovata yellow sebaea * GERANIACEAE i Erodium cicutarium common heronsbill * * * GERANIACEAE i Geranium molle soft cranesbill * * GERANIACEAE Geranium potentilloides mountain cranesbill * GERANIACEAE Pelargonium australe southern storksbill * * LAMIACEAE Ajuga australis australian bugle * * LAMIACEAE i Marrubium vulgare white horehound ** * MALVACEAE Lawrencia spicata candle saltmallow * MALVACEAE i Malva dendromorpha tree mallow * * MALVACEAE i Malva parviflora smallflower mallow * * MIMOSACEAE Acacia longifolia subsp. sophorae coast wattle * * MYOPORACEAE Myoporum insulare common boobialla * * * MYRTACEAE Eucalyptus ovata var. ovata black gum * * MYRTACEAE Kunzea ambigua white kunzea * * MYRTACEAE Leptospermum laevigatum coast teatree ** * MYRTACEAE Melaleuca ericifolia coast paperbark * * ONAGRACEAE Epilobium billardierianum willowherb * * OROBANCHACEAE i Orobanche minor lesser broomrape * OXALIDACEAE i Oxalis corniculata subsp. yellow woodsorrel * * corniculata OXALIDACEAE Oxalis perennans grassland woodsorrel * * PAPAVERACEAE i Glaucium flavum yellow poppy * PITTOSPERACEAE Bursaria spinosa subsp. spinosa prickly box ** * PLANTAGINACEAE e Plantago bellidioides herbfield plantain * * PLANTAGINACEAE i Plantago coronopus subsp. slender buckshorn * * coronopus plantain POLYGALACEAE Comesperma volubile blue lovecreeper ** * POLYGONACEAE i Accetosella vulgaris sheep sorrel * * POLYGONACEAE Muehlenbeckia adpressa climbing lignum ** * POLYGONACEAE Rumex brownii slender dock * * PORTULACACEAE Calandrinia calyptrata pink purslane * * PRIMULACEAE i Anagallis arvensis subsp. arvensis scarlet pimpernel * * PRIMULACEAE Samolus repens creeping brookweed * *

57 RANUNCULACEAE Clematis microphylla small-leaf clematis ** * RHAMNACEAE Pomaderris apetala dogwood * RHAMNACEAE Pomaderris elliptica yellow dogwood * RHAMNACEAE Pomaderris paniculosa subsp. shining dogwood ** * paralia r RHAMNACEAE Spyridium vexilliferum var. helicopter bush * * vexilliferum r ROSACEAE Acaena novae-zelandiae common buzzy ** * ROSACEAE Acaena pallida dune buzzy * ROSACEAE i Aphanes arvensis parsley piert * RUBIACEAE Galium australe tangled bedstraw * * RUBIACEAE i Galium murale small bedstraw * RUBIACEAE i Sherardia arvensis field madder * RUTACEAE Correa alba var. alba white correa ** * RUTACEAE Correa backhouseana var. velvet correa * * backhouseana RUTACEAE Correa reflexa common correa ** * SAPINDACEAE Dodonaea viscosa subsp. broadleaf hopbush * * * spatulata SCROPHULARIACEAE Mimulus repens creeping monkeyflower * SOLANACEAE i Lycium ferocissimum african boxthorn ** * SOLANACEAE Solanum laciniatum kangaroo apple * * SOLANACEAE i Solanum nigrum blackberry nightshade * * SOLANACEAE Solanum vescum gunyang * STERCULIACEAE Lasiopetalum discolor r coast velvetbush ** * STERCULIACEAE Lasiopetalum macrophyllum shrubby velvetbush * THYMELAEACEAE Pimelea serpyllifolia subsp. thyme riceflower ** * serpyllifolia URTICACEAE Parietaria debilis r shade pellitory ** * URTICACEAE Urtica incisa scrub nettle ** * URTICACEAE i Urtica urens stinging nettle * VALERIANACEAE i Valerianella eriocarpa italian cornsalad * * ZYGOPHYLLACEAE Zygophyllum billardierei r coast twinleaf ** * PTERIDOPHYTES ADIANTACEAE Pellaea falcata sickle fern * ASPLENIACEAE Asplenium flabellifolium necklace spleenwort * ASPLENIACEAE Asplenium trichomanes subsp. limestone spleenwort * quadrivalens DENNSTAEDTIACEAE Pteridium esculentum bracken * * GYMNOSPERMS CUPRESSACEAE Callitris rhomboidea oyster bay pine * MONOCOTYLEDONS ARACEAE i Zantedeschia aethiopica arum lily * * CENTROLEPIDACEAE Centrolepis polygyna wiry bristlewort * CENTROLEPIDACEAE Centrolepis strigosa subsp. hairy bristlewort * * strigosa CYPERACEAE Carex breviculmis shortstem sedge * CYPERACEAE Ficinia nodosa knobby clubsedge ** *

58 CYPERACEAE Isolepis cernua nodding clubsedge * * CYPERACEAE Isolepis marginata little clubsedge * CYPERACEAE Isolepis platycarpa flatfruit clubsedge * * CYPERACEAE Lepidosperma ensiforme arching swordsedge * CYPERACEAE Lepidosperma gladiatum coast swordsedge * * JUNCACEAE Juncus bufonius toad rush * * JUNCACEAE Juncus kraussii sea rush * * LILIACEAE Bulbine semibarbata smallflower leeklily * * LILIACEAE Dianella brevicaulis shortstem flaxlily * * LILIACEAE Hypoxis glabella var. glabella tiny yellowstar * ORCHIDACEAE Caladenia latifolia pink fairies * * ORCHIDACEAE Cyrtostylis robusta r large gnat orchid * ORCHIDACEAE Microtis uniflora onion orchid * ORCHIDACEAE Pterostylis sp. greenhood * POACEAE i Aira caryophyllea annual hair grass * POACEAE i Ammophila arenaria marram grass * POACEAE Austrodanthonia racemosa var. stiped wallabygrass * * racemosa POACEAE Austrofestuca littoralis coast fescue ** * POACEAE Austrostipa flavescens yellow spear-grass * * POACEAE Austrostipa stipoides coast speargrass ** * POACEAE i Briza minor lesser quaking-grass * * POACEAE i Bromus diandrus great brome * * POACEAE i Bromus hordeaceus soft brome * * POACEAE i Bromus sterilis barren brome * POACEAE i Catapodium rigidum ferngrass ** * POACEAE Distichlis distichophylla australian saltgrass * * POACEAE i Holcus lanatus yorkshire fog ** * POACEAE i Hordeum murinum subsp. bluish barleygrass * * glaucum POACEAE i Lagurus ovatus harestail grass ** * POACEAE i Lolium loliaceum stiff ryegrass * POACEAE i Lolium perenne perennial ryegrass * * POACEAE i Parapholis incurva coast barbgrass * * POACEAE Poa labillardierei tussockgrass * POACEAE Poa poiformis blue tussock grass * * POACEAE i Polypogon maritimus coast beardgrass * POACEAE i Polypogon monspeliensis annual beardgrass * * POACEAE i Rostraria cristata annual catstail * * POACEAE i Secale cereale rye * POACEAE Spinifex sericeus spinifex ** * POACEAE i Stenotaphrum secundatum buffalo grass * * POACEAE i Vulpia myuros fescue * *

59