DDAARRLLIINNGG RRIIVVEERRIINNEE PPLLAAIINNSS BBIIOORREEGGIIOONN BBaacckkggrroouunndd RReeppoorrtt NSW BIODIVERSITY STRATEGY [JULY 2002] DARLING RIVERINE PLAINS BACKGROUND REPORT DARLING RIVERINE PLAINS BIOREGION A project undertaken for the NSW Biodiversity Strategy For more information data contact the: Western Regional Assessments Unit, NSW National Parks and Wildlife Service PO Box 2111 DUBBO NSW 2830 Ph: (02) 6841 9200 Fax: (02) 6841 9222 www.npws.nsw.gov.au © Crown copyright [July 2002] New South Wales Government ISBN 0731365305 This project has been funded by the NSW Biodiversity Strategy and coordinated by Western Regional Assessments Unit, NSW National Parks and Wildlife Service This report was produced by Anne Kearle, Carl Gosper, Helen Achurch and Tania Laity. Maps in the atlas were produced by Fiona Ross. Thanks to Gary Saunders for managing the project and providing valuable input. For their comments: Bill Johnson, NSW National Parks and Wildlife Service; Mike Maher, NSW National Parks and Wildlife Service; Murray Ellis, NSW National Parks and Wildlife Service; Mike Fleming, NSW National Parks and Wildlife Service; Steve Lewer, NSW Department of Land and Water Conservation; Darren Shelley, NSW Department of Land and Water Conservation; Terry Mazzer, NSW Department of Land and Water Conservation; and Patrick Tap, State Forests of New South Wales. Disclaimer While every reasonable effort has been made to ensure that this document is correct at the time of printing, the State of New South Wales, its agents and employees, do not assume any responsibility and shall have no liability, consequential or otherwise, of any kind, arising from the use of or reliance on any of the information contained in this document. CONTENTS PROJECT SUMMARY 1 INTRODUCTION 14 1.1 The Background Report 14 1.2 The DRP Biodiversity Conservation Assessment Project 15 1.2.1 Objectives of the DRP project 15 1.2.2 Funding for the DRP project 15 1.2.3 Associated projects 16 1.3 The Darling Riverine Plains Bioregion 18 1.3.1 Location and area 18 1.3.2 Human history 18 1.3.3 Land tenure and administrative boundaries 22 2 ABIOTIC FEATURES 29 2.1 Introduction 29 2.2 Climate 29 2.2.1 Rainfall: temporal and spatial variation 30 2.2.2 Winds 36 2.2.3 Temperature and evaporation 37 2.3 Geology, Topography And Soils 39 2.3.1 Geological history 39 2.3.2 Topography and geomorphology 41 2.3.3 Soils 41 2.4 Hydrology 42 2.4.1 Surface waters: rivers, catchments and wetlands 42 2.4.2 Groundwaters 49 2.5 Land Condition 51 2.5.1 Land degradation 51 2.5.2 River and wetland degradation 52 2.5.3 Salinity 53 2.6 Boundaries Within the DRP 55 2.6.1 Provinces 55 2.6.2 Land systems 58 2.7 Summary and Proposed Further Work 58 2.7.1 Summary 58 2.7.2 Proposed further work 59 3 VEGETATION 60 3.1 Vegetation in 1750 and Subsequent Modification 60 3.2 Vegetation Mapping and Description in the DRP 62 3.3 Plant Community Descriptions 64 3.3.1 Forests and woodlands 70 3.3.2 Shrublands 73 3.3.3 Grassland and wetland communities 74 3.3.4 Plant communities of major DRP wetlands 76 3.4 Conservation Status of Vegetation Communities in The DRP 80 3.4.1 Corymbia tessellaris (carbeen) open forest 81 3.4.2 Acacia loderi (nelia) shrublands 81 3.4.3 Artesian springs ecological community 82 3.4.4 The community of native species dependent on natural discharge of groundwater from the Great Artesian Basin 83 3.4.5 Acacia harpophylla (brigalow dominant or co-dominant) 83 3.5 Summary And Proposed Further Work 84 3.5.1 Summary 84 3.5.2 Proposed further work 85 4FLORA 86 4.1 Available Information 86 4.1.1 Sources of data 86 4.1.2 Plant species diversity of the DRP 87 4.2 Species of Conservation Concern 88 4.2.1 Threatened and ROTAP species 88 4.2.2 Predicted threatened species 89 4.2.3 Extinct species and historical records 90 4.2.4 Regionally endemic species and significant populations 91 4.3 Weed And Introduced Species 91 4.4 Summary And Proposed Further Work 91 4.4.1 Summary 91 4.4.2 Proposed further work 92 5 TERRESTRIAL VERTEBRATE FAUNA 93 5.1 Available Information 93 5.1.1 Sources of data 93 5.1.2 Species diversity of terrestrial vertebrates in the DRP 94 5.2 Amphibians 95 5.2.1 Known species diversity and distribution 95 5.2.2 Species of conservation concern 95 5.2.3 Regionally endemic species and significant populations 96 5.3 Reptiles 96 5.3.1 Known species diversity and distribution 96 5.3.2 Species of conservation concern 97 5.3.3 Regionally endemic species and significant populations 99 5.4 Birds 99 5.4.1 Known species diversity and distribution 99 5.4.2 Species of conservation concern 101 5.4.3 Regionally endemic species and significant populations 105 5.4.4 Introduced and pest species 106 5.5 Mammals 106 5.5.1 Known species diversity and distribution 106 5.5.2 Species of conservation concern 107 5.5.3 Regionally endemic species and significant populations 108 5.5.4 Introduced and pest species 109 5.6 Summary and Proposed Further Work 110 5.6.1 Summary 110 5.6.2 Proposed further work 111 6 OTHER FAUNA 112 6.1 Invertebrates 112 6.1.1 Aquatic invertebrates 112 6.1.2 Terrestrial invertebrates 113 6.2 Fish 113 6.2.1 Known species diversity and distribution 113 6.2.2 Species of conservation concern 114 6.2.3 Regionally endemic species and significant populations 116 6.2.4 Introduced fish species 116 6.3 Summary and Proposed Further Work 118 6.3.1 Summary 118 6.3.2 Proposed further work 118 7 ECOLOGICAL AND THREATENING PROCESSES 119 7.1 Ecological Processes 119 7.1.1 Nutrient cycling and soil formation 119 7.1.2 Hydrological regimes 120 7.2 Listed and Potential Threatening Processes 121 7.2.1 Listed Threatening Processes 121 7.2.2 Potential Threatening Processes 126 7.3 Weeds and Pest Animals 127 7.3.1 Weeds 127 7.1.2 Dense tree and shrub regeneration 128 7.3.2 Kangaroos 129 7.3.3 Feral animals 129 7.4 Other Threats to Biodiversity 129 7.4.1 Firewood collection and timber harvesting on private lands 129 7.4.2 Grazing 130 7.5 Summary and Proposed Further Work 130 7.5.1 Summary 130 7.5.2 Proposed further work 130 8 EXISTING CONSERVATION MANAGEMENT 131 8.1 Existing Conservation Assessments 131 8.2 Formal Reserves and Other Crown Lands 134 8.2.1 National Parks and Nature Reserves 134 8.2.2 Other Crown lands Managed For Conservation 139 8.3 Off-Reserve Conservation 141 8.3.1 Voluntary Conservation Agreements 141 8.3.2 Wildlife Refuges 141 8.3.3 Forest Management Zones 141 8.3.4 Catchment Blueprints 142 8.3.5 Water Management Plans 143 8.3.6 Regional Vegetation Management Plans 144 8.3.7 Salinity Management Plans 145 8.4 Areas of Biological Significance 145 8.4.1 Key areas 145 8.4.2 Refugia 146 8.4.3 Centres of endemism 147 8.4.4 Areas of high biodiversity 148 8.5 Wilderness Values in the DRP (NSW) 148 8.6 Summary and Proposed Further Work 148 8.6.1 Summary 148 8.6.2 Proposed further work 149 9 REFERENCES 150 10 APPENDICES 166 ACLIMATIC DATA B LAND SYSTEMS C PLANT SPECIES LIST D EXOTIC PLANT SPECIES E NATIVE FAUNA F WATERBIRD SURVEY DATA G INVERTEBRATE TAXA List of Tables Chapter 1 Table 1.1 NPWS estate in the DRP ...............................................................................................................................22 Table 1.2 State Forests in the DRP................................................................................................................................23 Table 1.3 State government electorates within the DRP ...............................................................................................24 Table 1.4 DLWC regions within the DRP.....................................................................................................................24 Table 1.5 NPWS administrative boundaries within the DRP ........................................................................................24 Table 1.6 SFNSW administrative boundaries within the DRP ......................................................................................25 Table 1.7 RLPBs within DRP .......................................................................................................................................25 Table 1.8 RVCs within the DRP ...................................................................................................................................26 Table 1.9 Water Management Committees within the DRP..........................................................................................26 Table 1.10 CMBs within the DRP...................................................................................................................................26 Table 1.11 Local Government areas which intersect the DRP ........................................................................................27 Table 1.12 Aboriginal Land Councils within the DRP....................................................................................................28 Chapter 2 Table 2.1 DRP meteorological stations used in this analysis.........................................................................................29 Table 2.2 Wetlands identified within each catchment of the DRP ................................................................................44 Table 2.3 River catchments intersecting the DRP .........................................................................................................45 Table 2.4 Groundwater resources of the Lower Namoi Catchment...............................................................................51 Table 2.5 Actual and predicted average salinity levels for major rivers in the DRP .....................................................54