I ' , - PLANT COMMUI{ITIES OF TF{E BEI{ LOMOND PLATEAU I I i -li L\ l I !i Legges Tor L_ Stacks Bluff Cotton Moor I I li l I I I ] I I L- I I I L I I L I I I. B. Davies I I J M.]. Davies i I I l t PTANT COMMUNITIES i OF THE BEN LOMOND PLATEAU john B. Davies Margaret J. Davies I I I L- Consultant Bobnists for the Queen Victoria Museum and Art Callery and the Plomley Foundation I I Davies,l.B., & Davies, M.I. (1989) Plant Communities of The Ben Lomond Plateau. OccasionalPaper No. 1 Queen Victoria Museum and Art Gallery, LauncestoryTasmania. I I Cover: Three dipensional plot of the Ben Lomond Plateau from the i southwest. Note the lower Southern plateau surface (RHS) and the higher altitude Northern plateau sn.face (Left Background). (Plot provided by the Department of Parks,Wildlife I and Heritage). I ! i j I I L- CONTENTS Foreword 6 1. Backgrourrcl 7 I Obie'ctivesof the Study 7 I Locationand Topography 7 Cmlory ard Cmrnorpholory 9 Soils 10 ' climate I -- .. L_ ,. Generar 11 Rainfall 11 i Temperature 72 I I . SnowCover t2 Dishrrbancr General 13 Developmental l3 Trampling l3 Slope- Grooming 13 Fire 13 Previous Vegetation Studies 14 2. Vegetation of Ben Lomond Plateau 15 . .-r'* .r_ .E '.. , . ..- Sumrnaqy Species 15 PlantCommunities t6 ConservationStatus 15 I Descriptionsof the Plant communitiesand ReservationStatus l8 " 3. Brief Comlnrison of the Atpine Vegetationof the BenLomond Ptateau and Mt Field 49 4. Imolicationsof introducedEucalyptus coccifera Seedlingsat Ski Village 50' 5. Eviderrceof Dsturbancr causedbv LiehtnineStrike 51 Aptrpndix 1. Survey Method and Analysis of Data. 53 2. Summaryof Plant Communitiesand Their Dstribution and Habitat. 55 3. List of VascularPlants for the BenLomond Plahau. 57 4. Tableof Speciesin Community Groups. 63 5. List of Sites,Grid Referencesand Altituder. 6 6. VegetationMap of the BenLomond Plateau. i 68 l L* 6. Bibliography r t_- J ACI(NOWLEDGEMENTS Thanks are due to the Dreclor of tlre QueenVictoria Museum ard Art Gallery, Mr Chris fal5l-L and the present Acting Dr''ector,Mn Rhonda Hamilton for administrative assistance, to Ms Unda Bowen ,lPi"g and fgt editing the script, Mrs Carolyn Coert for t"yo.tl Mr Brian Allison for printing the photographs. The proiectwas funded by the plomley Fo;Luor1"rra Field assistance and:o-mPanywere provided by Mrs Kath Daviesand Dr Brad potts, and in partiorlar Dr rerry 9*laner whose expertiseand familiarity with venomonr t jtim added an extra dimension to field work. Acknowledgementil:.t: qrr to the pa+ia,nger, Mr lan Marmion, and the Departnent of Lands Parksand Wildlife for the use oi their hit and permission to collect botanical specirnens. o9ertise Iy9"94: yP qPydd bylrtt Mary C-arneron(Honorary ResearchAssociate, eueen Victoria Museum and Art Galleqy)ard Dr tony orchara, Mr Alex Buchananand Mr D.I. Morris and Dr Winifu Curtis from the TasmanianHerbarium. Acknowtedgerrent is alsoglven to Mr Mike Brouderand the ForestryCommission for the use of 120 000colour aerial photoqplt lf the plateau,and to Ms RosernaryCordy, Mr Dave peters, Mr StephenHarris and Mr Martin Gay, Departmentof lands, Parkgand Wiianf" for the production of th9 vetetation and community distribution rnaps. Mr StephenHarris provided constructivecriticism of the manurript Finally thanks arc due to Dr Brad Potts (BotanyDepartment, University of Tasmania)for assistancewith data and table production,ind to prof. Kirkpatrick (Gmgraphy 1*ly:r Jamie Dept- University of Tasmania)for the use of his alpine species rnasterfile. The rcport was printed by the Departmentof parks,wildlife and Heritage. t I I jr I '.i:.:jli,i i j l PHOTO 1: General view to the southeastof the subdued topography of the lower Ben Lomond plateau surface from PiesseVale. Bare boulderfields in the Rodway Valley can be seen in the central left of the photo wiih rocky outcrops visible in the background. The plateau terain lacks the deep "[J-shaped" valleys, prominent cols, hanging valleys and moraines typical of more i severely glaciated areas in Tasmania such as Mt. Field. I I L I l (, FOREWORD The Queen victoria Museum and Art Gallery and the Plomtey Foundation are glad to be able to Prcs€nt- Plant cumunities of the Bm Lonrond plateau, By fohn B. Davies and Margaret f. Davies. This is the first of what is hoped will be an authoritative series of publications on topics of public interest, to be issued in a new series, occasional Papers of the Quem victoria Museum and Art Gallery. The interest of the Plomley Foundation is at present concerned with ecological reearch in Tasmania' with a bias towards studies relating to the northern parts of tlie Sate. In this regard it is appro'priate to present thd present stuay of plant communities of the Ben lomond Plateau by two experienced botanise. The Fourdation is now giving special attention to ecological research, and hopes to fund a number oJ such projects over the years. There is a paticilar need in Tasmania to undertake ecological studies carried out by fully qualified persons. ., {t RhondaHamilton # Acting Drector QueenVictoria Museum N.I.B.Plomley Honorary ResearchAssociate QueenVictoria Museum I 7 1. BACKGROUND : OBIECTIVES OF THE STUDY I Tlre authors received a brief from the Queen Victoria Museum and Art Gallery and the Plomley I \- Foundation to conduct a botanical survey of the Ben Lomond Plateau. The Survey was to list the plant communities and varular speciesand indicate the conservation significance of the area. The mapr obiectives of the study wert:- I (1) To document the flora Ql To describe and map Oreplant cmrmunlde* I I (3) To identify and describe the maior patterns of variation in the vegetation. LOCATION AI{D TOIOGRAPT{Y Ben lomond is situated in north-easternTasmania, at latitude 41" 32'S,longitude 147" 39'E, I 50 kilometres south-eastof launceston. It forms the southem boundaqy of the north eastem i massif, which is bounded to the north-west by Mt. Arthur and by Mt. Victoria in the north -east. I The plateau is a roughly rectangular area of approximately 6500 hectares,ranging in altitude from 1200m to over 1500m. The northern half of the plateau maintains an altitude of 140Om, while the southern half rangesbetween 1300mand 140Omalt. LeggesTor at the northern end of the plateau is the second highest point in the State at 1572m. Stacks Bluff at 1527mis the highest point at the southern end. Rodway Valley dissectsthe plateau and derends to an altitude of 1240m.(See Map 1) l I Lake Youl is the largest lake on the plateau, and is drained by the Nile River which flows in a southerly direction from the plateau through SpekeGorge. The eastem side of the plateau is slightly elevated resulting in a predominantly westerly to north-westerly drainage pattern. i I i I I L MAP 1 The Ben Lomond plateau study area showing locations and numbers of plot sites 3ao l1 o18 )919 I o+ o12 o25 q o P*o. o, ol o24 + 9/ I e ol4 q3 I I ---^_--\ N lkm o s I i* l- p \ I r- o45 o4g o62 * "oo s \\\ -'-..ttj o 35 044 o49 o6l ._---,._ o50 o60 064 o71 tt.-.-.... frt.N o37 o42 -l c\ o59 o69'*.'$o o72 \h. 3/ L \J -r// oA o4l o52 \J o58 066 0 69 o73 0 cotton M oor \ / ,,} KNUCKL '$6b /;^l o53 4r o57 067 0 o74 </ 55 l 9 I L GEOLOGY AND GEOMORPHOLOGY Broadly speaking the mountains of Tasmania are of two types (Davies 1965). In the centre, east and southeast, they tend to be plateau-like in character, whereas in the west, they tend to be ridge'like. This difference is caused by the underlying rocks - folded pre{arboniferous I rocks in the west, and post{arboniferous rrnre or less horizontal sediments, intruded by granite and dolerite in the east. The basement rocks of the northeastern massif atr slates, siltstones, gleywackes and quartzite of the Mathinna Beds (Fish & Yaxley 1966). These were folded intensely during the Devonian Period, and su@uently intruded by granite. Pmeplanation followed and later Permian and I Triassic tocks were deposiFd. Ttrcse were intmded by dolerite during tlre |urassic period with I sills up b 3mrn thick. The igneous rccks conform to and mimic the sedimentary struchrre, and while maintaining a generally horizontal structure, these rocks were extensively faulted and uplifted (C-aine1983). The resulting mountains have the tabular form of the Fault-Structure Province, and are the sources of the North and South Esk Rivert and the Forester, Pipers and Ringarooma Rivers. Geologically the Ben Lomond Plabau is predominantly dolerite. The only exception is a I highly localised area of exposure of the ParmeenerSuper4roup (Forsyth et al 1974)in the creek bed of Rafferty Creek under Coalmine Crag. This exposure consists of the sedimentary tocks, sandstone, siltstone and mudstone, with a nanow coal sequence. This was once worked commercially (Plomley 1989). Immediately upslope of this exposur€ on the lower slopes of Coalmine Crag, hornfels (xcurs mixed with dolerite, but the actual zone of contactmetamorphism is not exposed. An aboriginal quarry was dirovered in this region during field work for the present study. 'sorted Scatter€d occurences of hornfels are also found associated with polygons' in the upper catchment of Storys Creek. i L- In the highlands of Tasmania there is ample evidence of glacial and periglacial activity during the Pleistoceneepoch (Fish & Yaxley 19ffi), when approximately one fifth of the area l of the State was covered with ice. A small icecap existed on Ben l-omond, which was the only plateau in the north east to be glaciated.