New South Wales South West Slopes Bioregion Scoping Study NSW BIODIVERSITY STRATEGY Draft Report June 2001 © NSW National Parks and Wildlife Service, 2001. EXECUTIVE SUMMARY............................................................................................ 6 1. INTRODUCTION .................................................................................................... 8 Objectives of bioregional assessments.................................................................................... 8 Objectives of the scoping exercise........................................................................................... 9 Project management ................................................................................................................ 9 2. THE STUDY AREA .............................................................................................. 11 Climate .................................................................................................................................... 13 Geology.................................................................................................................................... 13 Tenure ..................................................................................................................................... 14 Environmental provinces or landscapes .............................................................................. 15 Native vegetation .................................................................................................................... 16 Major vegetation communities............................................................................................. 17 Clearing patterns .................................................................................................................. 21 Threatened flora..................................................................................................................... 24 Fauna....................................................................................................................................... 25 Amphibians .......................................................................................................................... 26 Reptiles................................................................................................................................. 28 Birds ..................................................................................................................................... 30 Mammals (bats).................................................................................................................... 32 Mammals (excluding bats)................................................................................................... 33 3. GAPS IN MAJOR DATA-SETS ........................................................................... 36 Vegetation mapping ............................................................................................................... 36 Fauna....................................................................................................................................... 37 2 Amphibians .......................................................................................................................... 38 Reptiles................................................................................................................................. 38 Birds ..................................................................................................................................... 38 Mammals.............................................................................................................................. 38 Overall.................................................................................................................................. 39 4. THREATENING PROCESSES ............................................................................ 40 Clearing................................................................................................................................... 40 Salinity..................................................................................................................................... 44 Simplification of the ground stratum ................................................................................... 45 5. A PRELIMINARY ASSESSMENT OF CONSERVATION PRIORITIES............... 47 Overall conservation options................................................................................................. 47 Formal reserves ...................................................................................................................... 48 State Forests............................................................................................................................ 49 Other crown land ................................................................................................................... 50 Leasehold land........................................................................................................................ 51 Freehold land.......................................................................................................................... 51 Summary................................................................................................................................. 52 6. TOWARDS A CONSERVATION ASSESSMENT OF THE SWS......................... 53 Suggested criteria for a conservation assessment of the SWS ........................................... 53 Comprehensiveness.............................................................................................................. 53 Functional importance.......................................................................................................... 53 Vulnerability to threatening processes ................................................................................. 54 Options for a conservation assessment of the SWS............................................................. 54 Undertake a detailed assessment over the entire study area................................................. 54 3 Undertake an assessment over the Upper SWS Province based on vegetation community mapping................................................................................................................................55 Confine assessments to strategic areas................................................................................. 55 Undertake assessment over entire bioregion using existing datasets................................... 55 Recommended option............................................................................................................. 56 Preferred option.................................................................................................................... 58 7. REFERENCES ..................................................................................................... 60 MAPS ....................................................................................................................... 63 A SUMMARY OF DATA LAYERS RELEVANT TO THE NSW SOUTH WEST SLOPES BIOREGION. ............................................................................................ 89 Abiotic data-sets with broad coverage across bioregion..................................................... 89 Major vegetation mapping projects...................................................................................... 91 APPENDIX 2 ............................................................................................................ 94 Bird records held for the study area..................................................................................... 94 APPENDIX 3 .......................................................................................................... 100 A STUDY OF THE IMPORTANCE OF ISOLATED TREES AND SMALL REMNANTS UNDERTAKEN AS PART OF THE SCOPING EXERCISE.............. 100 A DISCUSSION PAPER FOR CONSIDERATION BY THE RIVERINA HIGHLANDS REGIONAL VEGETATION COMMITTEE ............................................................................................................................... 101 Philip Gibbons......................................................................................................................... 101 SUMMARY............................................................................................................... 102 4 INTRODUCTION ...................................................................................................... 103 Connectivity ....................................................................................................................... 103 Comprehensiveness adequacy and representativeness....................................................... 104 Use of paddock trees by fauna ........................................................................................... 104 Resources provided by native paddock trees not provided by pine plantations................. 105 Other ecosystem services provided by paddock trees........................................................ 105 Paddock trees in the Riverina Highlands........................................................................... 105 DISCUSSION ......................................................................................................... 111 Conclusions ..........................................................................................................................