Research Library Resource management technical reports Natural resources research 8-1994 Floristic survey of Northern sandplains between Perth and Geraldton Edward Arnold Griffin Follow this and additional works at: https://researchlibrary.agric.wa.gov.au/rmtr Part of the Natural Resources and Conservation Commons, and the Plant Sciences Commons Recommended Citation Griffin, E A. (1994), Floristic survey of Northern sandplains between Perth and Geraldton. Department of Primary Industries and Regional Development, Western Australia, Perth. Report 144. This report is brought to you for free and open access by the Natural resources research at Research Library. It has been accepted for inclusion in Resource management technical reports by an authorized administrator of Research Library. For more information, please contact [email protected]. ISSN 1039-7205 DEPARTMENT OF AGRICULTURE WESTERN AUSTRALIA FLORISTIC SURVEY OF NORTHERN SANDPLAINS BETWEEN PERTH AND GERALDTON Compiled by: E.A. Griffin In association with the Spatial Resource Information Group Department of Agriculture Western Australia South Perth, Western Australia 6151 August 1994 2,CDU_Iq' Vin,H L_ __) ICK MU 144 RESOURCE MANAGEMENT TECHNICAL REPORT series Information for contributors Scientists who wish to publish the results of their investigations have access to a large number of journals. However, for a variety of reasons the editors of most of these journals are unwilling to accept articles that are lengthy or contain information that is preliminary in nature. Nevertheless, much material of this type is often of interest and value to other scientists and to administrators, and should be published. The RESOURCE MANAGEMENT TECHNICAL REPORT series provides an avenue for dissemination of such material. It is a series of occasional papers in the general subject area of resource management and is jointly published by the Resource Science and the Land Management Branches of the Department of Agriculture, Western Australia. Intending contributors should contact the convenor of the RESOURCE MANAGEMENT TECHNICAL REPORT series Publication Committee. All papers will be considered by the Publications Committee and appropriate referees. Published by and available from: Resource Science Branch and Land Management Branch, Department of Agriculture-Western Australia 3 Baron-Hay Court, South Perth, Western Australia 6151. FLORISTIC SURVEY OF NORTHERN SANDPLAINS BETWEEN PERTH AND GERALD TON prepared by E.A. Griffin E.A. Griffin and Associates Consultant Botanist 402 Berwick St., St James, W.A. 6102. in association with the Spatial Resource Information Group, Regional Operations Department of Agriculture, Baron-Hay Court, South Perth, W.A. 6151 This project was funded under the National Estate Program, a Commonwealth financed scheme administered by the Australian Heritage Commission (Federal Government) and the Heritage Council of W.A. (State Government). ISSN 1039-7205 Northern Sandplains (Perth - Geraldton) E.A. Griffin & Associates E.A. Griffin August, 1994 This report may be freely used for management and research purposes and should be quoted in the following way: Griffin, E.A. (1994) Floristic Survey of Northern Sandplains between Perth and Geraldton. Unpublished Report to the Heritage Council of WA. The written permission of the author must be obtained before including original material contained in this report in all other publications. E.A. Griffin & Associates Northern Sandplains (Perth - Geraldton) CONTENTS page ABS TRACT . SUMMARY 2 RECOMMENDATIONS 3 . INTRODUCTION 4 . STUDY AREA 4 . Geology 4 . Physiography 4 . Soils 6 Drainage 6 . Climate 6 . Vegetation 6 Land 9 use . METHODS 11 FLORA 11 SITE DATA 11 • Existing Data 11 . Field Observations 11 . Analysis and Summary of Data from Sites 13 RESULTS 15 FLORA 15 Alien Species 16 . Rare and Geographically Restricted Taxa 16 . Species List Updates 16 . FLORISTIC ANALYSIS 17 . Classification of Stands 17 . Regional Patterns 40 . DISCUSSION 62 . Database 62 . Flora 62 Floristic Patterns 62 . A Lesueur Botanical District? 63 . Conservation Significance 64 . ACKNOWLEDGEMENTS 64 Northern Sandplaists (Perth - Geraldton) E.A. Griffin & Associates . page REFERENCES 65 . APPENDICES 68 List of Tables Table 1 Summary of Taxa by Families, Priority, Geographic Restriction 15 Table 2 Summary of Homotoneity 17 . List of Figures Figure 1 Location Map 5 . Figure 2 Soils Map 7 . Figure 3 Vegetation Systems Map 8 . Figure 4 Crown Land 10 . • Figure 5 Location of Previous Studies Included 12 . Figure 6 Distribution of sites used in study 14 . • Figure 7 Dendrogram Displaying Fusion of Sites from 20 Group level 18 . Figure 8 Simplified Minimum Spanning Tree 19 . Figure 9 Distribution of the 20 Floristic Groups 20 maps . • Figure 10 Distribution of Floristic Groups with similar Geographic Patterns 41 . Figure 11 Tentative Biogeographic Boundaries 61 . List of Appendices Appendix 1 Research Projects Utilised Appendix 2 Database Codes and Definitions Appendix 3 Field sheet Appendix 4 Muir Vegetation Classification Scheme Appendix 5 List of Species Amalgamated Appendix 6 Species List Appendix 7 Name Changes for Previous Studies Appendix 8 Dendrogram Displaying fusion of Sites from 200 Group level Appendix 9 Landform by Group 100 Summary Appendix 10 Summary description of the 500 groups Appendix 11 Species by Group 100 Summary Appendix 12 Geographic Ranges of Floristic Groups E.A. Griffin & Associates 1 Northern Sandplains (Perth - Geraldton) ABSTRACT A database of plant lists from over 2,500 sites was compiled from the Northern Sandplains between Perth and Geraldton. Over 2,500 plant taxa were recorded from the area. Preliminary classification revealed in the order of 500 different floristic types. Analysis of these demonstrated strong regional patterns of floristic composition related to geology and soils. Consistencies in these patterns indicated a need to review the location of some of the botanical district boundaries. Northern Sandplains (Perth - Geraldton) 2 E.A. Griffm & Associates SUMMARY A project to update and integrate a number of earlier site based vegetation surveys between Perth and Geraldton is described. Corrections to species lists in fourteen of these are provided. The focus of the study, the Perth Sedimentary Basin between Gingin and the Irwin River, proved rich in native vascular plant flora with almost 2000 taxa recorded. About 15 percent were either rare or geographi- cally restricted. The integrated database was subjected to preliminary numerical classification of the floristic composition of stands of vegetation. The analysis of the lists of taxa from 2522 sites demonstrated the floristic composition of stands of vegetation in the area was highly diverse. It was estimated that over 500 different types would be recognisable after more detailed interigation of the data was performed. The classification demonstrated that the major floristic groupings related to geological, soil and/or landfonn types. Strong regional patterns were highlighted with some being directly related to locally distributed soil types (e.g. Quindalup Dunes). A preliminary analysis of the distribution patterns of 500 floristic groups defined highlighted some patterns consistent across major vegetation types. A number of common boundaries were highlighted e.g. the Darling Fault. It was concluded that geology and soil factors were a much greater influence on these regional patterns than was climate. The significance of these regional patterns and possible boundaries to the existing definitions of Botanical Districts is discussed. Some suggestions for modifications are made. The potential to reinstate the Lesueur Botanical District is discussed. A brief assessment of the significance of these patterns for conservation highlighted the need to protect representative remnants in two areas in particular; nor-nor west of Mingenew and east of Watheroo. The data collation and analysis highlighted gaps in the database. The most obvious was the poor representation of the enormous variation in the wetlands. Also the areas north of Mingenew and east of Watheroo are poorly documented. E.A. Griffin & Associates 3 Northern Sandplains (Perth - Geraldton) RECOMMENDATIONS The collation of a substantial database has been a major achievment. However, its value is more in the potential than in the achievment. Deficiencies in the data have been identified. To maximise the opportu- nities further maintenance and integration with other sources is essential. The database is a tool to identify the adequacy of representation of floristically based vegetation types in conservation reserves and other protected remnants. It is also a very powerful tool in understanding the basis of biogeographic patterns in the kwongan dominated areas of Western Australia. This will improve the basis for regional classifying the vegetation. RECOMMENDATIONS: 1. The database should be integrated with similar data from other parts of Western Australia and that from the Western Australian Herbarium in a way which will maximise the taxonomic validity of the taxa recognised. 2. Further sampling should be undertaken on the flora of the diverse wetland communities. 3. A sampling programme in the area north of Mingenew should be initiated, potentially with one of the very poorly known Yuna area. 4. The identification and description of ecologically meaningful floristic types in the present study area should be undertaken with a view to assessing their representation in areas of pretected vegetation. 5.