NT Reporting Change in the Rangelands (PDF
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Australian Collaborative Rangeland Information System, Reporting Change in the Rangelands – 2007 NT Information for the National Report Rangelands 2007 – Taking the Pulse October 2007 Data and Information Contributed by: Debbie Mullin and Kate Richardson NT Department of Natural Resources, Environment & the Arts With additional input by: Gary Bastin and Melissa Schliebs CSIRO Sustainable Ecosystems & ACRIS Management Unit 1 TABLE OF CONTENTS List of Tables...........................................................................................................................................3 List of Figures..........................................................................................................................................3 Summary.................................................................................................................................................4 Acknowledgements .................................................................................................................................4 Introduction .............................................................................................................................................5 Reporting Area ....................................................................................................................................6 Report Contents ..................................................................................................................................6 Seasonal Quality as Context for Reporting Change ...............................................................................7 Method.................................................................................................................................................7 Assigning Causality to Change ...........................................................................................................9 Pastoral Monitoring Activity...................................................................................................................10 Landscape Function..............................................................................................................................10 Sustainable Management .....................................................................................................................11 Critical stock forage...........................................................................................................................11 Woody Cover.....................................................................................................................................11 Distance from Water..........................................................................................................................12 Land Values ..........................................................................................................................................13 Photos Showing Change.......................................................................................................................15 Darwin Coastal IBRA.........................................................................................................................15 Darwin Coastal IBRA.........................................................................................................................16 Sturt Plateau IBRA ............................................................................................................................17 Ord Victoria Plain IBRA .....................................................................................................................18 References............................................................................................................................................19 Appendix One: GIS Analysis of Distance from Water...........................................................................20 Rationale ...........................................................................................................................................20 Datasets ............................................................................................................................................20 Data Analysis.....................................................................................................................................21 Results...............................................................................................................................................21 Proportion of sub-IBRA analysed ..................................................................................................21 Proportion of land in each distance from water class ....................................................................21 Comments: .................................................................................................................................21 Water remoteness index:...............................................................................................................23 Comments ..................................................................................................................................23 Attachment 1: Theme 1 – Change in Landscape Function...................................................................25 Attachment 2: Theme 2 – Change in Sustainable Grazing Management ..........................................142 LIST OF TABLES Table 1. Number of cattle stations and percentage area of pastoral lease tenure for bioregions where land values are being reported...............................................................13 Table 2. Change in average unimproved value of pastoral land by bioregion. Values are CPI adjusted to 2005 dollar values. .......................................................................14 Table 3. Percentage area of each sub-IBRA covered by the distance-from-water layer. .......22 Table 4. The percentage of land per sub-IBRA in each distance from water class. The percentages are based on the proportion of area that was analysed in the NT. ................24 LIST OF FIGURES Figure 1. Bioregions in the NT. ................................................................................................5 Figure 2. Matrix for filtering seasonal effects on change. ........................................................9 Figure 3. Rate of clearing (%) in ‘Top End’ bioregions of the Northern Territory for 2004 and 2005. ...................................................................................................................12 Figure 4. Geographical extent of the distance from water layer available for the NT. ..........20 Figure 5. Mapped remoteness-index values based on the percentage of sub-IBRA area that is >8 km from permanent and semi-permanent sources of stock water....................23 ACRIS Rangelands 2007 – Taking the Pulse; NT contribution to national reporting, October 2007 3 SUMMARY This document integrates reports provided by the Northern Territory Department of Natural Resources, Environment and the Arts (NRETA) that contribute to the NT’s reporting of change in Australia’s rangelands for the period 1992 to 2005. A national synthesis (Rangelands 2007 – Taking the Pulse) has been compiled from relevant jurisdictional and national data by the Australian Collaborative Rangeland Information System (ACRIS). Taking the Pulse will be printed by the National Land and Water Resources Audit and will be released in the early part of 2008. Information in this (NT) report relates to: • Change in landscape function, as Attachment 1 to this report (pages 111 to 226). This attachment is also available as the separate Word document, NT ACRIS Theme 1 - Landscape Function.doc. • Change in critical stock forage, as Attachment 2 to this report (pages 227 to 284) and also in the separate Word document, NT ACRIS Theme 2 - Sustainable Management.doc. • Other components of the sustainable pastoral management theme, i.e. change in woody cover and distance from water (refer to table of contents at the start of this report). • Change in unimproved pastoral land values. • Landscape photos from Tier 1 and Tier 2 monitoring sites showing typical changes. Reporting is mainly at bioregion level (version 6.1 of the Interim Biogeographic Regionalisation of Australia, IBRA). Where available data are limited spatially, reporting is confined to relevant sub IBRAs of bioregions. The ACRIS Biodiversity Working Group has compiled data and information for the 2007 report based on ten indicators. NRETA, and particularly Alaric Fisher, has contributed biodiversity information for the NT (but that information is not included in this report). ACKNOWLEDGEMENTS Cameron Yates as the former NT representative on the ACRIS Management Committee initiated this work. Graeme Fagan provided oversight and support to the reporting of NRETA staff. We thank both for their input and support. Vanessa Chewings produced the site seasonal quality scores and provided general GIS support and advice. Again, our thanks to Vanessa for her valuable contribution. Members of the ACRIS Management Committee provided more general direction and guidance with jurisdictional contributions to the 2007 national report. NT reporting was supported by Natural Heritage Trust funding administered by the Desert Knowledge CRC. We thank the DK-CRC Secretariat, and Ange Vincent in particular, for their contribution by way of implementing and managing contractual arrangements. ACRIS Rangelands 2007 – Taking