Tt. tz-' A GEOBOTANICAL STUDY OF THE REMNANT NATURAL VEGETATION OF TEMPERATE SOUTH AUSTRALIA. by Ashley Dean Sparrow. Department of Botany University of Adelaide. A thesis submitted to the University of Adelaide for the degree of Doctor of Philosophy. January 1991. VOLUME 1: TEXT AND REFERENCES. CONTtrNTS List of Abbreviations lv Summary v Declaration vi Acknowledgements .. vii Chapter 1. BACKGROUND AND AIMS 1.1 INTRODUCTION 1 1.2 REVIBW OF PHYTOSOCIOLOGY: THEORY AND MtrTHODS , 4 1.3 VEGETATION STUDIBS IN SOUTH AUSTRALIA .. 8 1.4 BUT WHY CLASSIFY VEGBTATION ? 11 1.5 SPECIFIC AIMS ... l2 Chapter 2. STUDY AREA. 2.1 INTRODUCTION .... t4 2.2 LOCATION . t4 2.3 GBOLOGY, TOPOGRAPHY AND SOITS . .... 15 2.4 CLIMATE ..... 19 2.5 VEGETATION .. 2I 2.6 LAND-USB 25 Chapter 3. SURVEY METHODS AND DESCRIPTION OF THE DATA SET. 3.1 INTRODUCTION .... 29 3.2 DBFINITION OF THE SCOPB OF THE SURVtrY . 30 3.3 SURVEY STRATBGY 32 3.4 SAMPLING DENSITY 33 3.5 DBSIGN OF THE SAMPTING GRID .... 34 3.6 LOCATION OF SITES 36 3.7 POSITIONING OF QUADRATS AT SITBS 38 3.8 VEGETATION DATA 39 3.8.1 Measurements at the Sites . 39 3.8.2 Voucher Identification and Taxonomy .... 40 3.8.3 Data Collation 47 3.9 ENVIRONMENTAL DATA ... 4I 3.9.1 Measurements at the Sites .. .. 41 3.9.2 Soil Analyses 43 3.9.3 Climatic Data 44 3.9.4 Data Collation 45 Chapter 4. VEGETATION ANALYSIS I: SBLECTION OF ANALYSIS METHODS AND PRELIMINARY STATISTICS 4.1 INTRODUCTION 46 4.2 MULTIVARIATE ANALYSIS: REVIEW AND CRITIQUB 46 4.2.1 Ordination 47 4.2.2 Classification 50 4.2.3 Analysis of Vegetation-Environment Relationships ... .... 53 4.2.4 Summary 55 4.3 ANALYSIS METHODS 55 4.3.1 Selection Of Multivariate Methods 56 4.3.2 Analysis Approach ....... 5B 4.4 PRELIMINARY STATISTICS . 60 Chapter 5. VtrGETATION ANALYSIS II: REGIONAL ANALYSBS - RESULTS AND DISCUSSION. 5.1 PREAMBLE . 62 5.2 SOUTH-EAST REGION 63 5.3 MURRAY MALLBE REGION .. .. 68 5.4 I(ANGAROO ISLAND RtrGION 74 5.5 SOUTHERN MOUNT LOFTY RANGES REGION /t) 5.6 NORTHERN MOUNT LOFTY RANGES REGION 81 5.7 YORKE PENINSULA REGION 84 5.8 EYRE PENINSULA RBGION 87 Chapter 6. VBGBTATION ANALYSIS III: STUDY AREA SYNTHESIS - RESULTS AND DISCUSSION. 6.1 PREAMBLE . 93 6.2 CTASSIFICATION 94 l 6.2.1 Definition of Complexes 94 6.2.2 Regional Distribution of Complexes 96 6.2.3 Mallee Complexes .. 98 6.2.4 Northern Mt Lofty Ranges and Yorke Peninsula .. 101 6.2.5 Relationships Between Complexes r02 6.3 ORDINATION 104 6.4 PARTIAL ORDINATIONS 108 6.4.1 Sclerophyllous Woodlands and Heathlands 109 6.4.2 Coastal Poredune Scrub and Subcoastal Mallee 111 6.4.3 Mallee Complexes r72 6.4.4 Semi-Arid Mallee and Arid Shrublands II4 6.4.5 Savannah Woodlands 115 6.5 MULTIPLtr DISCRIMINANT ANALYSIS ..... tI7 6.6 SUPRASPECIFIC ANAtYStrS .... 118 ll 6.7 DISCUSSION 120 6.7.1 Appraisal of Analysis Methods ., 120 6.7.2 Comparisons with Earlier Studies 124 6.7.3 Summary of Habitat Gradients r29 Chapter 7. DIRECT GRADIENT ANALYSIS: RtrSPONSE MODETS OF PRBDOMINANT SPECIES. 7.1 INTRODUCTION 131 7.2 METHODS 133 7.3 RESULTS .... t34 7.3.1 Signifi.cant Environmental Variables as Predictors t34 7.3.1.1 Rainfall, SoiI Texture and Soil pH 135 7.3.I.2 Altitude and Longitude 139 7.3.1.3 Other Variables .. I43 7.3.2 Significance of Models .. r44 7.4 DISCUSSION .. 147 Chapter 8. IMPLICATIONS OF THB STUDY FOR ENVIRONMENTAL MANAGBMENT AND CONSBRVATION 8.1 INTRODUCTION 754 8.2 MBTHODS 156 8.2.1 Rarity of Species 156 8.2.2 Remnancy of Vegetation Types 158 8.3 RESULTS .... 159 8.3.1 Species Rarity 159 8.3.2 Vegetation Type Rarity ... t64 8.3.3 Ordination Overplots of Remnancy ... 168 8.4 DISCUSSION 1,7t Chapter 9. CONCLUDING DISCUSSION. 9.1 REVIEW OF THE STUDY ... 177 9.1.1 Sampling Strategy . .. 177 9.1.2 Multivariate Analysis of Floristic Data .. .... 179 9.1.3 A New, Floristic Classification . 181 9.1.4 Description of Environmental Gradients . ... 182 9.1.5 Relevance to Conservation Assessment .. ..... 183 9.2 CONTRIBUTION TO VEGETATION THEORY . 184 9.3 AVtrNUES FOR FURTHER RBSEARCH .. ..... 185 REFBRENCES. 187 [Al1 flgures, tables and appendices are contained in Volume 2]. LIST OF ABBRE\/IATIONS BMDP Biomedical Data Analysis Package (Dixon 1981) b.p. before present CCA canonical correspondence analysis C.P. Conservation Park (N.P.\M.S.) C.S.I.R. Council for Scientific & Industrial Research, Australia (superseded) C.S.I.R.O. Commonwealth Scientific and Industrial Research Organization, Australia (current) DCA detrended correspondence analysis GLIM Generalised Linear Modelling (McCullagh & Nelder 1983) hc half-change unit MDA multiple discriminant analysis NMDS non-metric multidimensional scaling N.P. National Park (N.P.W.S.) N.P.W.S National Parks & Wildlife Service, South Australia NTP Numerical Taxonomy Package (Belbin et aI. 1984) PCA principal component analysis RA reciprocal averaging SPSS-X Statistical Package for the Social Sciences, Version 10 (SPSS Inc. 1986) T.S.S. total soluble salts TWINSPAN two-way indicato¡ species analysis (Hill 1979b) UPGMA unweighted pair-group method using arithmetic averages (Sneath & Sokal 1973) [SI units of mensuration are used throughout.] 1V SUMMARY A floristic survey of the temperate parts ("Agricultural Districts") of South Australia was undertaken, with emphasis on the semi-arid "mallee" regions which have been relatively poorly studied in the past. Semi-quantitative data for native perennial angiosperms and gymnosperms were collected at 744 sites, each of 0.1 ha and regularly distributed over the 151 000 km2 survey area. A total of 545 species were encountered at an average of 13.4 species per site. A combination of multivariate clustering (Bray-Curtis/UPGMA) and ordination (DCA) methods were used to produce a two-tiered hierarchical floristic classiflcation and to examine the patterns of intergradation between these groups. Although there were few discontinuities and a high degree of gradation at both classification levels, 164 vegetation types were defined in 38 major complexes. There is general agreement between this classifi.cation and earlier studies of more restricted scope, but the new classification is the first to have a quantified hierarchical structure and gives greater detail of mallee vegetation types and patterns than does any of the previous physiognomic/floristic classifications available for South Australia. Many vegetation types (mallee or otherwise) have geographically restricted distributions clearly reflecting the biogeographic cline spanning southern South Australia. Relationships between vegetation and climate, geology and soils were investigated by correlation of vegetation ordinations with abiotic environmental factors, by catenation of complexes using multiple discriminant analysis, and by logistic regression of the environmental responses of individual species (selected, dominant tree and shrub species). Seasonal and tidal flooding, annual rainfall, soil texture, and soil pH, total soluble salts and calcium carbonate were the most significant correlates. The interaction of rainfall with soil texture indicated the importance of soil water relations in determining species distributions at the scale of the survey. For a number of mallee eucalypt species, the addition of longitude as an environmental variable improved response models, suggesting that these species experience some genetic cline which modifies their "environmental behaviour" east-west across their ranges. The applications and implications of the results to vegetation management were considered. The survey provides new data on the rarity of species and vegetation types, criteria which are often used in conservation management. Continuity of floristic composition, occurrence of biogeographic variants and the mosaic nature of the landscape at all scales lead to difficulties with the concept of vegetation type rarity. This remains one of the problems of conservation management based on rarity. a DECLARATION This thesis contains no material which has been submitted or accepted for a degree or any other award in any university. To the best of my knowledge and belief, the thesis also contains no material previously published or written by another person, except where due reference is made in the text. I consent to the thesis being made available for copying and loan, if accepted for the award of the degree. Ashley Sparrow. vl ACKNOWLtrDGEMENTS I would very much like to thank the following individuals and organisations for their contributions to the progress and completion of this thesis: o Bob Lange - as sometime supervisor, spiritual leader, business manager and provider of footsteps in which to follow. o Russ Sinclair - as stand-in supervisor upon Bob's retirement and continual source of encouragement. o Kingsley Turner, Bob Inns and fellow offcers of the Native Vegetation Management Branch, Department of Environment and Planning - for access to their facilities, including aerial photo mosaics, LANDSAT imagery and remnancy data. r and Richard Payne for hospitality at Naracoorte during survey Cathy - work. ¡ Jansen and Fleur Tiver for assistance and companionship on field Loraine - trips. ¡ Enid Robertson, Peter Lang, David Whibley and Bill Barker for help with identification of voucher plant specimens, sometimes of scant -non-florvering material. o Ari Verbyla, Phil Leppard and Bill Venables - for advice on statistical matters and instruction on getting computer software packages to do what was needed. o Marcus Brownlow, Jill Sparrow, Ray Sparrow and Andrew Rowett for - invaluable assistance during the last-minute rush of thesis preparation. ...and all my fellow research students, past and present especially - Loraine Jansen, Bruce I{arvke, Stuart Manson, Fleur Tiver, Noelene Wotton, Marcus Brownlow, Merrick, Andrew Chester Rowett and Angela Renfrey - from whom I not only learned a great dea1, but benefltted in ways best summed up by Boccacio: I have on occasion derived much relief from the agreeable conversation and the admirable expressions of sympathy offered by friends, without which I amfirmly convinced that I should have perished..