Vegetation Survey and Mapping (Stage 1)
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VVEEGGEETTAATTIIOONN Brigalow Belt SSUURRVVEEYY AANNDD South MMAAPPPPIINNGG ((SSTTAAGGEE 11)) NSW WESTERN REGIONAL ASSESSMENTS OCTOBER 2000 Resource and Conservation Assessment Council VEGETATION SURVEY AND MAPPING STAGE 1 REPORT WESTERN REGION Doug Beckers - National Parks and Wildlife Service Doug Binns - NSW State Forests A project undertaken for the Resource and Conservation Assessment Council NSW Western Regional Assessments Project number WRA 13 3 For more information and for information on access to data contact the: Resource and Conservation Division, Department of Urban Affairs and Planning GPO Box 3927 SYDNEY NSW 2001 Phone: (02) 9228 3166 Fax: (02) 9228 4967 © Crown copyright May 2000 New South Wales Government ISBN 1 74029 1549 This project has been funded and managed by the Resource and Conservation Division, Department of Urban Affairs and Planning The project was also overseen and developed through the Resource and Conservation Assessment Council. The authors would like to thank the following people without whose help the project would not have been possible; Jon Alexander, Janet Beckers, Warwick Bratby, Mark Cannon, Geoff Carr, Murray Ellis, Peter Ewin, Mark Fisher, Wendy Harding, Craig Harré, John Hunter, Peter Lezaich, Catriona Mackenzie, Jamie Molloy, Brent Marchant, Alex Maric, Rob McCosker, Julie Read, Geoff Robertson, Rachel-Anne Robertson, Gary Saunders, Rob Streeter, Patrick Tap, Nicki Taws, Steve Thornton, Matt White, Eric Whiting, Bob Wilson. The authors would also like to thank Marianne Porteners and Elizabeth Norris who refereed the report and provided many useful comments and constructive criticism. 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. 4 CONTENTS VEGETATION SURVEY AND MAPPING PROJECT SUMMARY i Background 1 1.1 Western Regional Assessments 1 1.2 Brigalow Belt South Bioregion 1 1.3 Objectives of the Vegetation Survey and Mapping Project 3 1.4 Ecologically Sustainable Management 3 1.5 Plot Based Sampling 3 1.6 Vegetation Mapping 4 Vegetation Survey (Floristic Plots) 5 2.1 Existing Plot Data 5 2.2 Methods 8 2.3 Data Analysis 10 2.4 Results 11 Vegetation Mapping 19 3.1 Approach 19 3.2 Methods 19 3.3 Results 21 Discussion 25 4.1 New Information about the vegetation of the bioregion 25 4.2 Gaps in our knowledge of flora and vegetation within the Bioregion 31 Key Results 35 References 37 5 Figures 1 Bioregional context map. 2 Locations of existing plot-based surveys in the bioregion. 3 The proportion of weed species in each survey according to cover score categories. 4 The percentage of flora species according to frequency category. 5 The relationship between number of plots (log10) and area sampled (log10) in existing surveys carried out in western NSW. Tables 1 Plot based vegetation surveys undertaken within the Brigalow Belt South Bioregion. 2 Planning areas surveyed and the number of plots completed. 3 Contractors, number of plots sampled and areas sampled. 4 The number of native and introduced species recorded within each survey, both existing and new plots. 5 The twenty most frequent native plants in plots. 6 The twenty most frequent weed plants in plots. 7 The number of plant species unique to each area, including the proportion of native plant species and weed species. 8 Threatened plants, Rare Or Threatened Australian Plants (ROTAP) and Protected plants found within plots. 9 Data capture and mapping contractors. 10 Vegetation mapping with plot-based sampling within or overlapping the bioregion. 11 Total extent and reservation status of broad overstorey types within the areas mapped within this present study. 12 Plot-based vegetation surveys conducted in western New South Wales. Appendices 1 State Forest and National Parks and Wildlife Service areas within the Bioregion. 2 Floristic plot sampling intensity. 3 Floristics recording sheet. 4 Vegetation structure recording sheet. 5 Site feature recording sheet. 6 Coding explanation sheet. 7 Opportunistic plant recording sheet. 8 Plot species list and frequencies. 9 Existing vegetation mapping within State Forests and National Parks and Wildlife Service estate within the Bioregion. 10 Aerial photograph overlay development procedure. 11 Eucalypt and related API polygon codes. 12 Rainforest, Special features and Exclusions (RSX) polygon codes. 13 API reliability polygon codes. 14 API guidelines for assigning polygon codes. 15 Data capture project brief. 16 Metadata statement for the Arc-view vegetation data. 17 Vegetation types within the bioregion grouped according to broad categories, their total extent and extent within Nature Reserves. 18 Vegetation types developed within Stage 1. 19 Existing vegetation types within State Forests and National Parks and Wildlife Service estate within the bioregion. 6 October 2000 Vegetation Survey and Mapping Stage 1 Report PROJECT SUMMARY This report has been prepared for the Resource and Conservation Assessment Council (RACAC) as part of the preliminary (Stage 1) Western Regional Assessment of the Brigalow Belt South bioregion. The Western Regional Assessments are to be carried out across the Western and Central Divisions of NSW with the Brigalow Belt South bioregion being the first. The assessments will provide scientific information on which to base Forest Agreements, as well as providing information for the use of other regional planning organisations such as Regional Vegetation Management Committees and Catchment Management Boards. Due to the short time available to undertake these preliminary (Stage 1) projects, this report must only be considered a brief summary of the results of initial surveys and analyses. This report can provide precautionary recommendations subject to further detailed assessment. A comprehensive (Stage 2) assessment will be undertaken to verify this preliminary assessment. Project objectives The project had three major objectives: ■ to provide a GIS based vegetation map at 1:50 000 scale of State Forests, National Parks estate and crown land within or directly adjacent to the Brigalow Belt South bioregion (south of Narrabri), suitable for use in conservation and resource assessment, planning and management; and, ■ to collect plot-based floristic data which will underpin the mapping data and enable floristic comparisons to be made both within and between forest areas; and, ■ to provide a basis for the development of conservation and resource strategies including assisting in; the identification of conservation values, the identification of a Comprehensive, Adequate and Representative Protected Area Network (see the NSW Biodiversity Strategy 1999) and developing conservation criteria, targets and protocols. Methods Existing mapping data were assessed for suitability in meeting the project objectives, by examining the floristic attributes, the age of the mapping and the mapping methodology. New mapping was conducted in some areas that were previously unmapped, or over some areas that required updating and/or upgrading. New mapping was facilitated with aerial photograph interpretation using aerial photographs at the most detailed scales available (1:25 000 or 1:50 000). Polygons were attributed according to a mapping pathway protocol which included an index of reliability, floristic type and special features attributes. Existing floristic sampling data were collected and an analysis was undertaken regarding the adequacy of the data. New floristic sampling was undertaken in some areas where no previous floristic sampling had been undertaken, or within some areas that had been undersampled. Sample sites were selected using stratified random sampling with sampling intensity being restricted to one plot per 1 000 hectares. Full floristic data, with an estimate of cover/abundance of vascular plants were collected at each standard 0.1 hectare plot. Plant community structure data and biophysical features data, were also collected at each plot. Key results and products A diverse range of plant species and vegetation communities occur within the Brigalow Belt South Bioregion with over 1 850 native plant species recorded in the current project, including 16 Threatened species and 17 Protected species. Plot data collected from each area surveyed within the Bioregion contained species that were unique to the dataset of each area. The large forest areas of the Pilliga and Goonoo State Forests were found to have low weed levels when compared to surveys conducted across other broad areas. Vegetation overstorey types of Poplar Box/Pilliga Box (which occur within west Pilliga) and Blue- leaved ironbark (which occur within Goonoo, Lincoln, Eura and Breelong State Forests) were found to be poorly represented in existing National Parks and Nature Reserves. The Rare, threatened or highly cleared and modified vegetation overstorey types; containing, Ooline, Semi-evergreen Vine thicket, Carbeen, Plains Grass, Green Mallee, White Mallee, Brigalow, Yellow Box, Fuzzy Box and River Red Gum were also found to have low levels of reservation. i October 2000 Vegetation Survey and Mapping Stage 1 Report BACKGROUND 1.1 WESTERN REGIONAL ASSESSMENTS Western Regional Assessments are being carried out across the Western and Central Divisions of New South Wales with the Brigalow Belt South Bioregion