Research and the collation of information presented in this report was undertaken with funding provided by the Biodiversity Group, Environment Australia. The project was undertaken for the National Reserve System Program (Project N204).
The views and opinions expressed in this report are those of the author and does not reflect those of the Commonwealth Government, the Minister for the Environment, the Director of National Parks and Wildlife or the State of New South Wales.
This report may be cited as:
Eardley, K. A. (1999) - A Foundation for Conservation in the Riverina Bioregion. Unpublished Report, NSW National Parks and Wildlife Service.
Limited copies of this report are held by:
Biodiversity Group, Environment Australia GPO Box 636 CANBERRA ACT 2601 AUSTRALIA and
NSW National Parks and Wildlife Service Land Assessment Unit PO Box 1967 HURSTVILLE NSW 2220 AUSTRALIA
1 1. ACKNOWLEDGMENTS
Major Contributors Lisa Metcalfe (NSW NPWS): Stage 2 Project Officer - Collection and input of data, review of vegetation status and developing vegetation retention targets, initial analysis of data. Sandra Whight (NSW NPWS): Stage 1 Project Officer - Data collection, literature review. Christopher J. Togher (NSW NPWS): Establishment of database. Steve Meredith (NSW NPWS): Liaison with Aboriginal Land Councils. Murray Robinson (NSW NPWS): Conversion of data from ERMS to Arcview, preparation of figures and editing. Julianne Smart (NSW NPWS): Editor. John Benson (Royal Botanic Gardens, Sydney): Extension vegetation mapping. John Brickhill (NSW NPWS): Extension vegetation mapping.
Additional Support I wish to acknowledge the assistance provided to this project by the following people: Liz Ashby Royal Botanic Gardens, Sydney Felicity Brandsema NSW NPWS Andrea Burns NSW NPWS, Griffith Tom Barrett NSW NPWS GIS Consultant, Armidale Peter Creaser NSW NPWS Rob Dick NSW NPWS Martin Driver Greening Australia Paul Flemons NSW NPWS Paul Foreman Victorian Department of Natural Resources and Environment Andrew Knight NSW NPWS Ross McDonnell NSW NPWS, Griffith Evelyn Maher NSW NPWS, Dubbo Steve Naven NSW NPWS Mike Nolan NSW NPWS Roger Oxley DLWC Rob Price Victorian Department Natural Resources and Environment Jo Priori formerly NSW NPWS Mark Rowe Western Riverina Vegetation Management Committee Murray Schofield formerly NSW NPWS Matthew Watts NSW NPWS, GIS Consultant, Armidale
2 TABLE OF CONTENTS
1. ACKNOWLEDGMENTS...... 2
2. ABSTRACT...... 6
3. GLOSSARY...... 7
4. INTRODUCTION...... 9
4.1 BACKGROUND TO THE RIVERINA PROJECT...... 9 4.2 EMERGENCE OF REGIONAL CONSERVATION PLANNING...... 9 4.3 THE APPLICATION OF DECISION SUPPORT SYSTEMS...... 11 4.4 SUPPORT FOR SYSTEMATIC REGIONAL CONSERVATION PLANNING ...... 12 4.5 THE DEVELOPMENT OF BIOREGIONALISATION ...... 12 4.6 DEVELOPING A BIOREGIONAL PLANNING FOUNDATION FOR THE RIVERINA BIOREGION ...... 13 4.7 AIM AND OBJECTIVES ...... 14 4.8 REPORT COMPONENTS ...... 14 4.9 TIME AND FUNDING ...... 15 4.10 MANAGEMENT STRUCTURE ...... 15
5. BIOLOGICAL, SOCIAL AND ECONOMIC OVERVIEW OF THE BIOREGION...... 17
5.1 LOCATION ...... 17 5.2 CLIMATE ...... 20 5.3 GEOMORPHOLOGY ...... 20 5.4 SETTLEMENT AND LAND USE...... 21 5.5 IMPACTS OF EUROPEAN SETTLEMENT AND LAND USE ON THE BIOLOGY OF THE RIVERINA ...... 23 5.5.1 Clearing and Grazing ...... 23 5.5.2 River Regulation ...... 24 5.5.3 Cropping ...... 25 5.5.4 Salinity ...... 25 5.6 CURRENT FLORA AND FAUNA OF THE RIVERINA ...... 25
6. A SYSTEMATIC APPROACH TO CONSERVATION PLANNING...... 28
6.1 CONSERVATION GOAL...... 28 6.2 SELECTION UNIT ...... 29 6.3 ACHIEVING THE CONSERVATION GOAL - IRREPLACEABILITY ASSESSMENT...... 29 6.4 ASSESSING THE DEGREE OF URGENCY - VULNERABILITY ...... 30 6.5 CONSERVATION PLANNING SOFTWARE - C-PLAN...... 31
7. METHODS ...... 32
7.1 COMMUNITY AWARENESS...... 32 7.1.1 Steering Committee...... 32 7.1.2 Catchment Management Committees...... 33 7.2 TECHNICAL COMPONENT ...... 34 7.2.1 Database Development ...... 34 7.2.1.1 DATA AUDIT ...... 34 7.2.1.2 COMPILATION OF PRIMARY DATA SETS ...... 35
8. ANALYTICAL METHODOLOGY ...... 44
8.1 THE GEOGRAPHIC INFORMATION SYSTEM ...... 44 8.2 THE DATABASE MANAGEMENT SYSTEM...... 45 8.3 IRREPLACEABILITY...... 45
3 8.3.1 C-Plan...... 45 8.3.2 Selection Unit...... 45 8.3.3 Identifying the Conservation Goal and Targets...... 46 8.4 VULNERABILITY TO CLEARING...... 47 8.4.1 Historic Clearing Patterns of Geomorphic Units ...... 48 8.4.2 Rural Land Capability ...... 50 8.4.3 Vulnerability - The Two Measures Combined...... 50
9. ASSUMPTIONS AND LIMITATIONS UNDERLYING THE ANALYSIS...... 51
10. RESULTS AND DISCUSSION...... 53
10.1 COMMUNITY AWARENESS...... 53 10.2 DATA AUDIT AND COMPILATION...... 54 10.2.1 Outcomes ...... 54 10.2.2 Discussion...... 58 10.3 VEGETATION TYPES AND VEGETATION MAP...... 60 10.3.1 Outcomes ...... 61 10.3.2 Discussion...... 66 10.4 STATUS OF RESERVATION WITHIN THE RIVERINA BIOREGION ...... 67 10.4.1 Area of Riverina Bioregion within Dedicated Reserves...... 67 10.4.2 The Status of Vegetation Types within Dedicated Reserves...... 68 10.4.3 Discussion...... 69 10.5 CLEARING STATUS ...... 71 10.5.1 Outcomes ...... 71 10.5.2 Discussion...... 71 10.6 VEGETATION RETENTION TARGETS...... 74 10.6.1 Outcomes ...... 74 10.6.2 Discussion...... 74 10.7 IRREPLACEABILITY ANALYSIS ...... 78 10.7.1 Discussion...... 82 10.8 VULNERABILITY ASSESSMENT ...... 85 10.8.1 Outcomes ...... 85 10.8.2 Discussion...... 86 10.9 CONSERVATION MANAGEMENT PRIORITY AREAS...... 90 10.9.1 Outcomes ...... 90 10.9.2 Discussion...... 93
11. TOWARDS CONSERVATION PLANNING - GENERAL DISCUSSION...... 95
11.1 TECHNICAL COMPONENT ...... 95 11.1.1 Data Audit and Database Construction...... 95 11.1.2 Communicating Results...... 97 11.2 METHODOLOGY ...... 98 11.2.1 C-Plan...... 99 11.3 COMMUNITY AWARENESS...... 101 11.4 PROJECT MANAGEMENT AND STAFFING...... 102
12. CONCLUSIONS AND FUTURE WORK...... 104
12.1 FUTURE DIRECTIONS...... 105
13. REFERENCES...... 107
14. ADDITIONAL READING ...... 112
15. APPENDICIES...... 116
4 15.1 APPENDIX 1 - COMMUNITY AWARENESS PACKAGE (1996, 1997)...... 116 15.2 APPENDIX 2 - CONSERVATION STATUS OF VEGETATION ...... 124 15.3 APPENDIX 3 - DERIVING NSW RIVERINA VEGETATION TYPES BY MERGING THE ROYAL BOTANIC GARDENS MAPPED VEGETATION CATEGORIES...... 141 15.4 APPENDIX 4 - MERGING THE VICTORIAN STRUCTURAL VEGETATION CATEGORIES WITH NSW VEGETATION TYPES ...... 144 15.5 APPENDIX 5 - LAND COUNCIL INFORMATION PACKAGE ...... 147 15.6 APPENDIX 6 - ENDANGERED SPECIES RECORDED FOR THE RIVERINA BIOREGION ...... 149 15.7 APPENDIX 7 - VEGETATION TYPES ATYPICAL OF THE RIVERINA BIOREGION AND THEIR DISTRIBUTION WITHIN AND OUTSIDE OF THE RIVERINA BIOREGION...... 151
LIST OF TABLES TABLE 1. IBM COMPATIBLE PERSONAL COMPUTER SPECIFICATIONS FOR OPERATING C-PLAN...... 31 TABLE 2. DATES AND DETAILS OF PROJECT STEERING COMMITTEE MEETINGS...... 32 TABLE 3. DETAILS OF CATCHMENT MANAGEMENT COMMITTEE MEETINGS ...... 34 TABLE 4. DATA USED TO COMPILE VICTORIAN STRUCTURAL VEGETATION MAPPING (SVEG100)...... 40 FIGURE 5. THE PERCENTAGE CLEARING FOR EACH GEOMORPHIC TYPE WITHIN THE VICTORIAN RIVERINA, MURRAY FANS AND MURRUMBIDGEE PROVINCES AND THE CORRESPONDING VULNERABILITY CLASS WHICH WAS EXTRAPOLATED TO APPLY ACROSS THE ENTIRE BIOREGION...... 49 TABLE 6. THE AREA OF CLEARED LAND WITHIN EACH RURAL LAND CAPABILITY CLASS FOR THE MURRAY FANS AND MURRUMBIDGEE PROVINCES...... 50 TABLE 7. DATA SETS FOR THE RIVERINA BIOREGION...... 55 TABLE 8. THE PROPORTION (HA) OF VEGETATION TYPES WITHIN EACH OF THE PROVINCES OF THE RIVERINA BIOREGION...... 63 TABLE 9. STATUS OF DEDICATED RESERVES IN THE RIVERINA BIOREGION...... 67 TABLE 10. THE AREA OF LAND IN DEDICATED RESERVES FOR EACH PROVINCE...... 68 TABLE 11. NATIVE VEGETATION TYPES WITHIN CONSERVATION RESERVES BY AREA (HA) AND PERCENTAGE (%)...... 70 TABLE 12. THE PROPORTION OF NATIVE VEGETATION CLEARED IN THE RIVERINA BIOREGION BY STATE AND PROVINCE...... 71 TABLE 13. THE AREA OF CLEARED LAND (NOT INCLUDING DEGRADED CATEGORIES) WITHIN EACH LAND CAPABILITY CLASS FOR THE MURRAY FANS AND MURRUMBIDGEE PROVINCES...... 72 TABLE 15. THE 87 GRID CELLS CONSIDERED AS TOTALLY IRREPLACEABLE...... 79
LIST OF FIGURES FIGURE 1. RIVERINA BIOREGION LOCATION MAP...... 18 FIGURE 2. LAND TENURE OF THE RIVERINA BIOREGION ...... 19 FIGURE 3. THE PROCESS OF DATA ACQUISITION...... 36 FIGURE 4. GEOMORPHOLOGY OF THE RIVERINA BIOREGION ...... 37 FIGURE 5. RIVERINA BIOREGION VEGETATION MAP...... 61a FIGURE 6. AMALGAMATED VEGETATION TYPES OF THE RIVERINA BIOREGION...... 62 FIGURE 7. CLEARING IN THE RIVERINA BIOREGION ...... 73 FIGURE 8. RESULTS OF THE IRREPLACAEBILITY ANALYSIS FOR THE RIVERINA BIOREGION ...... 81 FIGURE 9. VULNERABILITY TO CLEARING...... 88 FIGURE 9A.VULNERABILITY TO CLEARING (CLEARED LAND SHOWN) ...... 89 FIGURE 10. CONSERVATION MANAGEMENT PRIORITY AREAS ...... 91 FIGURE 11. HIGH PRIORITY AREAS FOR CONSERVATION MANAGEMENT...... 92 FIGURE 12. CONSERVATION PLANNERS ARE RELIANT ON THREE FORMS OF DECISION SUPPORT SYSTEMS.100
5 2. ABSTRACT A systematic conservation assessment approach was applied to the Riverina Bioregion for identifying a set of nominal conservation management priority areas. The report documents the development of a regional planning framework for conservation in the Riverina Bioregion and discusses many of the issues associated with this exercise such as the approach towards community awareness, analytical concepts and processes used to analyse the available data, methodological difficulties and results. The results on the reservation and protection status of native vegetation in the Riverina, the status of environmental and other data and the gaps in the current information base are presented.
The nominal conservation management priority areas were identified with the aid of a computer decision support system (C-Plan). The approach used for conservation assessment for this project was based on the relationship between the conservation value of an area (measured by its relative irreplaceability - the likelihood that a given area will need to be protected to ensure the achievement of a set of regional conservation targets) and its vulnerability to threatening processes (in this case native vegetation clearing). The combination of which determined the location of conservation management priority areas.
The strengths of the approach include its bioregional perspective, explicitness, evaluation of large and multiple data sets and the flexibility of C-Plan. The main constraints include its reliance on existing data and the high level of skill, experience and technical support required by the users of computer-aided systems. The report documents, in plain English, the methodology used as well as what worked and what didn’t.
The results of this project provide the foundation upon which more detailed information on ecosystems and species can be used to make conservation planning decisions, and in addition form a basis for monitoring the progress in conservation in the Riverina. With respect to conservation assessment C-Plan is a highly desirable new tool to be mastered, further developed and applied increasingly to conservation planning in conjunction with an ongoing reliance on detailed systematic regional and local surveys, expert knowledge. As such further work would include ground validation of priority areas, refinement of data sets, and re-analysis.
6 3. GLOSSARY
Adequacy The provision of sufficient lands, managed for conservation purposes, to allow for the maintenance of the ecological viability and integrity of populations, species and communities.
Bioregion Biogeographic Region - see IBRA
CAR Reserve System A system of protected areas that is comprehensive, adequate and representative (CAR) of all its component ecosystems
Conservation Goal In protected area planning, goals are usually set in terms of the extent or number of occurrences of each feature that should be represented. The goals usually vary according to perceived need for protection (i.e. with regard to susceptibility to loss or degradation).
Comprehensiveness Inclusion of the full range of ecosystems recognised at an appropriate scale within and across each bioregion.
Dedicated Reserve Reserves where the management regime equates to specific protected area management categories [Categories I, II, III, IV] defined by the IUCN Commission for National Parks and Protected Areas (1994) in which extractive activities, either for subsistence or commercial purposes, are absent or minor. In NSW the categories include national park, nature reserve, and flora reserve. In Victoria they include state park, reference area, flora, fauna, bushland and wildlife reserve.
Ecosystem A mapped unit comprising a description of floristic composition in combination with substrate and position within the landscape, including other components of the biota where available.
Interim Biogeographic Interim Biogeographic Regionalisation of Australia, is a Regionalisation of Australia - bioregional framework delineating “natural” regions throughout IBRA terrestrial Australia based on biophysical, environmental and vegetation considerations (eg. climate, lithology, landform, vegetation, flora, fauna and land use) and irrespective of State borders. “Bioregion” refers to the IBRA regionalisation.
Irreplaceability Is a measure of a site’s potential to contribute to achieving a conservation goal. That goal can only be achieved through conservation management of lands from each category of irreplaceability. However, while all or most lands might be required from the totally or highly irreplaceable categories, considerably less land should be required for conservation management from the low irreplaceability categories.
7 IUCN Categories for National Commission for National Parks and Protected Areas (1994). Parks and Protected Areas Ia - strict nature reserve - managed mainly for science Ib - wilderness area - managed mainly for wilderness protection II - national park - managed mainly for ecosystem protection and recreation III - national monument - managed mainly for conservation of specific natural features IV - habitat/species management area - managed mainly for conservation through management intervention V- Protected landscape/seascape - managed mainly for landscape/seascape conservation and recreation VI - managed resource protected area - managed mainly for sustainable use of natural ecosystems
Protected Area - An area of land/sea especially dedicated to the protection and maintenance of biological diversity, and of natural and associated cultural resources, and managed through legal or other effective means (IUCN, 1994).
Province A sub region within a bioregion that reflects the environmental attributes that influence the occurrence of ecosystems.
Reservation Status A measure of the area of land (or attribute such as vegetation type) within the Riverina Bioregion which is within a dedicated reserve.
Threatening Processes The dominant factors impacting on and acting against the conservation of biodiversity. Threatening processes could potentially include land clearing, logging, feral pests, grazing, change in the fire and hydrological regimes from the ‘pre European’ situation (i.e. through water flow regulation irrigation and raising saline water tables).
Representativeness The principle that those sample areas that are selected for inclusion in a protected area system reasonably reflect the biotic diversity of the ecosystem from which they derive.
Vulnerability The predisposition of an area to a threatening process. Vulnerability can be expressed in terms of (1) likelihood of an area being affected by the process; or (2) the time frame within which the area is expected to be affected.
4.
8 INTRODUCTION
4.1 BACKGROUND TO THE RIVERINA PROJECT
The Riverina Bioregional Conservation Planning Project, referred to henceforth as the ‘Riverina Project’, is a project which approaches conservation planning with the aid of a computer decision support system to identify a set of nominal priority areas for conservation action. In addition, this report describes the conservation status of the Riverina Bioregion, the status of environmental and other data, concepts and processes used to analyse the available data and our approach towards community awareness. The Riverina Bioregion as described and delineated by Thackway and Cresswell (1995) was chosen for study in 1994 because of its high natural resource use, limited area protected within conservation reserves, restricted extent of remaining native vegetation in the landscape and the need for a region wide perspective and regional planning foundation to aid conservation decision making. The Riverina Project had its genesis in: 1. the development and acceptance, in Australia, of the concept of regional conservation planning; 2. the development by NSW National Parks and Wildlife Service (NPWS) of a computer assisted decision support system which allows the systematic assessment of conservation choices using geographic information systems (GIS) (ie. the answers to difficult questions could now be retrieved from complex data layers); 3. Federal Government support and funding opportunities for the development of systematic regional conservation planning programs to meet Australia’s commitments under the National Strategy for the Conservation of Australia’s Biological Diversity and its international agreements on nature conservation; and 4. the development of the Interim Bioregionalisation of Australia “IBRA” (Thackway and Cresswell, 1995) and the need to provide a more detailed picture of the progress toward establishing a comprehensive, adequate and representative reserve (CAR) system within each bioregion. A discussion of each of the four catalysts for the project is discussed below.
4.2 EMERGENCE OF REGIONAL CONSERVATION PLANNING There is general agreement that a landscape or bioregional approach to conservation planning is essential to ensure that land use planning takes into account biodiversity conservation, as well as cultural and economic considerations. This approach involves the division of the landscape into units or “bioregions” which are representative of an area’s ecological processes rather than into administrative or political units. The processes which endanger species are largely triggered by landscape degradation such as vegetation clearing, which are generally more closely related to ecological boundaries. Thus, conservation decisions developed within a reliable bioregional framework can be expected to carry far more logic and legitimacy than might be achieved through any alternative regional breakup.
Integrated bioregional planning, however involves the equal consideration of natural,
9 cultural and economic factors in decision making. The complexity of this and the requirement to accommodate a diversity of stakeholder interests means that sufficient time, resources and social structure tends not to be available to undertake conservation planning in an integrated capacity.
Regional conservation planning, in its simplest outline, involves four steps: 1. assessment of conservation values and levels of threatening processes and the establishment of regional conservation priorities in space and time; 2. determining what conservation mechanisms are needed and/or available in the region; 3. development of procedures and protocols for the application of appropriate conservation mechanisms to various parts of the landscape; and 4. establishment of an integrated network of areas protected by a variety of conservation mechanisms across the landscape.
For the purposes of this project a distinction is made here between Steps 1-3, termed ‘plan-making’ and Step 4, termed ‘plan-implementing’. It is important to make this distinction, because both are equally fundamental for any planning enterprise, neither is of much use without the other, and many conservation initiatives fail to address both adequately.
An important component of the plan making exercise is to establish where conservation effort should be directed and where this need is most critical (ie. identifying priorities). Plan implementation then involves the employment of the range of conservation initiatives from formal dedication of reserves through to property management such as the fencing of population of a rare plant or a vegetation remnant from land in agricultural production.
Maintaining a healthy bioregion which has the capacity to remain viable and diverse beyond the next 10-100 years through ecologically sustainable development and regional planning requires more complex assessment. Such an implementation strategy may require cultural and administrative structural change and this may never be within our capacity.
Projects such as the Riverina Project therefore importantly contribute towards bioregional planning by providing advice to government and the community with regard to: S the relative value in biodiversity conservation terms of different parts of the landscape - ie. what to conserve ; S appropriate conservation mechanisms, or management types, necessary for each area - how to conserve; S how much land is needed under each conservation mechanism to meet the goals of arresting / minimising biodiversity decline - how much and where to conserve; and S the relative urgency required to implement conservation mechanisms for each area (usually related to threat) - when to conserve.
These concepts are not new ones, but the advancement of computer-aided decision
10 support tools allows for a greater scope in systematically answering the questions posed above and allows for the development of optimal regional conservation scenarios.
4.3 THE APPLICATION OF DECISION SUPPORT SYSTEMS The opportunity for NPWS to initiate conservation assessment at the bioregional scale was underpinned by the NPWS development of a systematic integrated decision support system for conservation planning in the form of a computer software package referred to as C-Plan (Pressey et al., 1994). C-Plan is based on procedures which are flexible and iterative. It is suited for use in a biogeographic context and works within a GIS. The interactive nature of the program with the GIS provides the flexibility and opportunity for viewing the spatial relationships within the bioregion by examining relevant data layers. The software uses a set of selection rules together with biological and environmental data to derive a conservation value known as irreplaceability, for all sites within the study area. The irreplaceability value provides an indication of how many other sites in the bioregion have the same or similar values. The analysis is mechanised by the conservation planning software and is dependent upon the quality of the information available and the criteria applied. The results of the analysis provide a basis for considering conservation priorities and exploring alternative landscape conservation options.
This conservation assessment approach is systematic because the methodology is applied in a consistent way across a bioregion and is explicit when the rules and decisions taken are fully documented. The analysis is repeatable and is capable of refinement as new data becomes available. The GIS and the iterative nature of the software allow the data to be constantly updated and the rules to be altered as the need arises. The analysis is re-run each time adequate conservation of a new area/s are secured, this ensures that the goals are achieved with a minimum area affected. Thus, as the area subject to protection of a bioregion changes with time, the rules can be modified accordingly. This approach to conservation assessment can utilise limited conservation resources more efficiently, highlight land use conflicts and assist their resolution by identifying areas desirable for conservation, and provide defensible arguments for conservation (Pressey et. al., 1994).
The Riverina Project, applied C-Plan to an agriculturally productive semi-arid environment which has a long history of intensive land use. Prior to this project, C-Plan had not been applied to this type of environment at the bioregional scale. In an operational capacity, NSW recently used C-Plan as a decision support system, for refining forest conservation options for the NSW Eden, Upper North East and Lower North East Regional Forest Agreements under the National Forest Policy Statement. This integrated process used extensive data sets of biological and economic data and industry stakeholders to integrate environmental objectives with timber harvesting economic targets.
In comparison with the Regional Forest Agreement process, the Riverina Bioregion lacks the multiplicity of data, the political imperative and the availability of lands owned by the Crown to drive an integrated bioregional planning process which may lead to altering land use. The Riverina Project therefore provided an opportunity to apply C- Plan and demonstrate a regional conservation planning approach that defines
11 spatial and temporal priorities for the Riverina Bioregion.
4.4 SUPPORT FOR SYSTEMATIC REGIONAL CONSERVATION PLANNING The national context for undertaking bioregional planning is the National Strategy for Ecologically Sustainable Development (Commonwealth of Australia, 1992); the National Strategy for the Conservation of Australia’s Biological Diversity (Commonwealth of Australia, 1996) and the National Forest Policy Statement (Commonwealth of Australia, 1992), all of which support the integration of biodiversity conservation with sustainable development. In NSW, the support for these strategies is being implemented through actions defined in the NSW Biodiversity Strategy (NSW NPWS, 1999), the Comprehensive Regional Assessment Process for Crown forests and the Native Vegetation Conservation Act, 1997.
In 1994, at the time the Riverina Project was proposed, there was active support by way of funding opportunities from the Federal Government for the development of systematic regional conservation planning programs. In particular, the systematic planning of a national system of conservation reserves to meet Australia’s commitments under the National Strategy for the Conservation of Australia’s Biological Diversity and its international agreements on nature conservation.
The National Reserve System (NRS) Program, with the aim of building a comprehensive national park and nature reserve system across Australia, provided NSW with an opportunity for involvement in the development of regional conservation planning techniques. Whilst the focus of the National Reserve System program is on the permanent protection of lands within a dedicated reserve system, the basic tasks for undertaking this, such as the collection of natural heritage data and the assessment of conservation value, are common to most conservation programs. Therefore, the regional conservation planning methodologies developed here are applicable to a range of conservation programs which aim to apply protection measures across the landscape.
Accordingly, the Riverina Project is seen as the foundation of information and methodology which can be used in more broadly focused conservation planning programs than the National Reserve System program and will provide a basis from which more detailed work can follow.
4.5 THE DEVELOPMENT OF BIOREGIONALISATION The development of the interim biogeographic regionalisation of Australia (IBRA) provided both a framework and impetus for assessing progress in conservation across Australia in a systematic fashion.
The IBRA framework (Thackway and Cresswell, 1995) is based largely on biophysical features for which each bioregion represents homogenous environment types at the landscape scale. The assessment and comparison of conservation values, threats and reservation status within and between IBRA regions is valuable in determining gaps in the system of protected areas across NSW and Australia. A conservation perspective at the bioregional level is beneficial because often the processes which endanger species and ecological communities are operating at the landscape scale. They include salinisation, vegetation degradation and habitat fragmentation.
12 Bioregions are used to assess the performance of Australia’s commitment to the protection of biodiversity, particularly within the protected area system. To undertake this assessment Thackway and Cresswell, (1995) compared the reservation status of each bioregion across Australia against a reservation goal of 10% of the area of each bioregion. Of the 80 bioregions within Australia, 23 had greater than 10% of their area within conservation reserves and 21 had less than 1% of their area reserved (Thackway and Cresswell, 1995). The bioregions with less than 1% reservation status were consequently identified as having a 'high priority' which means additional assessment and conservation action is required for a comprehensive national reserve system to be achieved. The Riverina Bioregion was identified as one of these high priority bioregions.
4.6 DEVELOPING A BIOREGIONAL PLANNING FOUNDATION FOR THE RIVERINA BIOREGION
A modest budget dictated that this project would initiate work and develop a foundation of information which would contribute towards bioregional conservation planning. The key features of the regional conservation planning approach adopted included: S a bioregion wide assessment; S the use of computer-based spatial data systems to store and analyse data; and S analysis of that data in a systematic and repeatable fashion. In particular the Riverina Project addressed the: S documentation and collection of region wide data sets (for 2 state jurisdictions); S analyses of available region wide data to indicate nominal areas of conservation significance; and S an attempt to involve elements of the regional community, regional administration and other state government agencies in these early data collection stages of regional conservation planning. The Riverina Project was not intended to produce a comprehensive conservation plan for the Bioregion but to develop a solid foundation and framework for future systematic conservation planning. Not surprisingly, therefore, the reporting for the project not only displays the outcomes of data audit, data sets collated and constructed, and the analyses and community presentations undertaken; but seeks to also report in such a way as to provide guidelines to conservation planners in terms of: S what worked and what didn’t; S unresolved issues; S pitfalls and limitations of the bioregional planning approach; and S approaches and techniques recommended, based on the Riverina Project experience.
13 4.7 AIM AND OBJECTIVES The aims of the Riverina Project were to: 1. develop a foundation for undertaking systematic conservation assessment in the Riverina Bioregion. The objectives here were to: S develop an information system on a bioregional scale for natural and cultural heritage data, so that consistent and relevant technical information is available for input into policy and operational decision making; S review the current state of natural and cultural resource data for the Riverina; and S identify gaps in the information base. 2. determine the relative conservation value of areas across the Bioregion and identify priority areas for conservation effort. Using the best available information, the objectives were to: S review the level of reservation status and broad scale clearing patterns across the Riverina; S assess conservation value through the application of the NPWS developed conservation planning software (C-Plan) to the Riverina Bioregion; S identify relative vulnerability to clearing of native vegetation cover across the Bioregion; and S identify priority areas for conservation effort. 3. make information available to local communities to aid regional management strategies.
The Riverina Project was not intended to definitively identify areas of high conservation value, but to point the conservation planner towards areas of likely high conservation value, where more detailed analyses is required before final decisions are made on the application of appropriate protection measures. As outlined previously, a definitive conservation plan based on the bioregional planning principles of integrating natural, cultural, economic and social factors in the planning process was not an objective of the Riverina Project. The Riverina Project primarily focused on biodiversity values, within the limitations of the available data and establish a solid foundation and framework for additional systematic conservation planning for biodiversity.
4.8 REPORT COMPONENTS
The primary components of the report are: 1. Regional Overview. This provides background information about the Riverina Bioregion, issues and influences which affect biodiversity. 2. Community Awareness. Interwoven throughout the report is the account of community interaction (Catchment Management Committees and Aboriginal Land Councils) in relation to information sharing. 3. Technical. This describes the principles of conservation planning and conservation priorities. This section addresses the methodology associated with conservation assessment, including data gathering and analysis. Although the report is largely technical in nature, and is directed to those who have a working knowledge of the principles of conservation planning, an attempt has been
14 made to present the information in plain English in order for it to be of use to a broader audience.
4.9 TIME AND FUNDING The project was undertaken by the NPWS with support from Environment Australia (EA) under the National Reserve System Program by way of $103,000 funding for the employment of one project officer for 18 months and a technical officer for 9 months.
The technical components of the project commenced in May 1996 and were finalised in December 1997. This project report was prepared during 1998.
4.10 MANAGEMENT STRUCTURE The project was based from the NPWS Head Office, Land Assessment Unit, in Sydney. This arrangement provided the project team with ready access to the necessary computer hardware and software, as well as, information technology and GIS support.
The project was supported by a project steering committee. The steering committee size was limited to seven people to minimise administrative costs and to ensure maximum attendance at meetings. Steering committee members were selected on the basis of their access to and knowledge of available biological data, assessment and planning skills, understanding of land use issues in the Riverina Bioregion and access to information networks. The steering committee comprised: S Project Supervisor - NPWS, Karen Eardley. Role: to provide organisational support and guidance; interpretation of results; and report preparation. S Project Officer - NPWS, Sandra Whight (1996/97)/Lisa Metcalfe (1997). Role: to undertake project actions, test assessment methodologies; establish standards and processes. S NPWS Western Zone Natural Heritage Manager - Dr Mike Fleming. Role: to communicate detailed knowledge of western NSW into the assessment process. S NPWS Research Scientist - Dr Bob Pressey. Role: to provide advice on the conservation planning software and associated reserve selection methodology being applied within NSW. S NSW Royal Botanic Gardens Ecologist- John Benson. Role: to provide knowledge and experience regarding vegetation communities in the Riverina. S State Forests of NSW District Forester, Deniliquin - Mike Thompson. Role: to provide input with respect to forestry and other vegetation issues in the Riverina. S Mark Rowe - Landholder and representative of the Western Riverina Vegetation Committee (from 1997). Role: to provide a local perspective of conservation issues and to provide advice on the applicability of the project for use within the local community.
The Victorian Department of Natural Resources and Environment (DNRE) declined representation on the steering committee because the Victorian Government is already committed to implementing a public land planning strategy for the Murray Valley Area which had been recommended by the Victorian Land Conservation Council in 1985.
15 Broad community representation on the steering committee was not sought because the project was primarily technical and designed to develop the foundation of a conservation strategy for the Riverina and would not immediately result in land use changes.
16 5. BIOLOGICAL, SOCIAL AND ECONOMIC OVERVIEW OF THE BIOREGION There are many individual factors which can be used to describe the environment of the Riverina Bioregion but it is the interrelationship of environmental, social and economic factors which have shaped the landscape and the current distribution of flora and fauna across the Bioregion. This section of the report provides an overview of some of these influencing factors.
5.1 LOCATION The Riverina Bioregion (also referred to as the “Riverina” or the “Bioregion”), as defined by Thackway and Cresswell (1995), covers an area of about 9 million hectares (90,000 sq. km), of which 77% (7 million ha) lies in south-west New South Wales, and the remaining 23% (2 million ha) in central-north Victoria (Figure 1). It extends from Narrandera in the east to Balranald in the west, and from Bendigo in the south to Ivanhoe in the north. The Bioregion encompasses outlying fragments from the Murray Darling Depression Bioregion in the west, and the Victorian Midlands Bioregion in its south.
About 96% of the Riverina Bioregion is in freehold (privately owned) or leasehold (leased from the government for private use) tenure. The remaining 4% is managed by the Crown (governments of NSW and Victoria) as state forest, conservation reserves, travelling stock reserves, highway parks, historic areas and other public use areas (Figure 2).
The Riverina Bioregion is characterised by a riverine plain. The Murray and Murrumbidgee Rivers and their major tributaries, the Lachlan and Goulburn Rivers flow westward from the Eastern Highlands across the Plain. The Riverina Bioregion within NSW has been divided into three natural sub regions (ie. provinces) based on the nature of the alluvial fans (Morgan and Terrey, 1992): S Lachlan Province (2,145,081 ha) which is characterised by a broad grey clay plain, with frequent low depressions. S Murrumbidgee Province (3,043,775 ha) which is characterised by extensive coarse deposits which have formed red-brown earths. In this province low source bordering dunes and sand dunes are common. S Murray Fans Province (1,703,110 ha) which is characterised by a series of fans developed from sediment derived from the steep slopes of the Snowy Mountains which is deposited by the Murray River. The fourth province referred to in this report comprises the part of the Riverina Bioregion which lies in Victoria, the Victorian Riverina Province (2,146,600 ha).
The provinces allow for the comparison of protection status within the Bioregion.
17
5.2 CLIMATE The Riverina Bioregion has a semi-arid climate, with hot summers and cool winters. Temperatures are fairly uniform across the Bioregion, with a tendency towards slightly higher temperatures in both summer and winter in the north. January is the hottest month with average summer temperatures over 30°C. July is generally the coldest month and winter temperatures can average as low as 4°C (Rhodes, 1990).
Annual rainfall increases from west to east and from north to south. Rainfall peaks occur in May and September. Summer rainfall is generally from localised thunderstorms, the more reliable rainfall coming in winter as a result of cold fronts moving in an easterly direction. Average annual rainfall ranges from 370 mm in the north west to 800 mm in the south east. Rainfall reliability decreases into the north- west of the Bioregion, and drought periods are not unusual (Dalton, 1988).
5.3 GEOMORPHOLOGY The Riverine Plain lies in the south-eastern part of the Murray Basin which extends over 300,000 km2. The Murray Basin is a closed groundwater basin and consists of unconsolidated sediments and sedimentary rocks. These sediments fill a low lying saucer-shaped depression rimmed and underlain by folded and partly metamorphosed basement rocks ranging in age from 230 million to 1 billion years ago (Butler et. al., 1973; Rutherford, 1990, Evans et. al., 1990).
In the case of the Riverina Bioregion the sediments are largely fluvial in nature, with some lacustrine and aeolian elements (Butler et. al., 1973). Fluvial sediments were sourced from the Eastern Highlands and deposited over millions of years. The deposition of Quaternary sediments, riverine and aeolian, by prior streams, ancestral rivers and the contemporary rivers resulted in a series of very gently sloping alluvial fans and floodplains (Butler et. al., 1973).
At a more detailed level, sand was deposited from prior streams into the stream channels while clay was deposited between the channels onto the floodplain when rivers overflowed their banks. The fluvial forces produced alluvial plains with features such as channels, drains and depressions. These were and are overlaid with the aeolian features of lunettes, source-bordering dunes and scalds (Butler et. al., 1973).
Prior streams had well defined sandy levee banks which today stand as ridges above the plain. Aeolian features mainly comprise lunettes and source-bordering dunes. Lunettes are crescent shaped and fits the curvature of the lake basin situated to their west. Sand lunettes formed from beach sand which was blown into a dune by prevailing westerly winds. Clay lunettes formed when lakes dried and produced clay pellets which were then blown onto the eastern shore of the lake forming sheets and building a smooth ridge. Source-bordering dunes are associated with prior streams and are ovoid in shape and formed where sand from dry stream beds was blown into nearby dunes (Butler et. al, 1973). Scalds, bare areas where the wind has removed surface soil, also occur on the Plain. The typical lacustrine features of the Riverina are lakes which tend to be shallow with flat floors and are subcircular, elliptical or kidney-shaped (Butler et. al, 1973).
20 The soils of the Riverina are associated with the levee-floodplain features of the prior streams. The soils of the levees are red-brown earths, sandy on the crest and loamy on the backslopes. The soils of the floodplain are grey, brown and red clays. The Paleozoic rocky outcrops which occur on the periphery of the Bioregion are features more representative of adjacent bioregions.
The Murray, Murrumbidgee, Lachlan, Goulburn, Loddon and Campaspe Rivers and their tributaries are the contemporary rivers of the Riverine Plain which continue to shape the nature of the Riverina. The flow of the Murray River varies from virtually nil during drought times up to 44,000 gigalitres during a wet year (Mackay, 1990).
The sedimentary layer of the Murray Basin is water saturated. Consequently, the water table lies close to the surface of the Basin and holds little capacity for storing additional groundwater. The groundwater trapped within the aquifer flows in an east – west direction. Any increase in infiltration results in a rapid rise in the water table to the surface where it can only be removed by evaporation from the ground surface or seepage into the river system (Rutherford, 1990).
5.4 SETTLEMENT AND LAND USE Hope (1995) suggests that Aboriginal people have occupied the Murray-Darling Basin for at least 40,000 years. Evidence of “the long human association with the land” is suggested by the burial sites such as those found in Lake Mungo, dated at about 26,000 years ago. Several large Aboriginal communities lived around the rivers and on the Hay Plain including the Wiradjuri, Nari-Nari, Mudi-Mudi, Gurendji and the Yida-Yida. Along the Murray there were the Banggarang, Yorta-Yorta, Baraba-Baraba, Wamba- Wamba, Wadi-Wadi and the Dadi-Dadi (NSW Department of Lands, 1987).
Hope (1995) claims that rivers were central to the Aboriginal way of life providing a rich concentration of food resources and Pardoe (1988) suggests that communities living along the rivers would have controlled access to the water and its resources, the rights to this occupation handed down from ancestors. Human burials and other Aboriginal occupation artifacts such as camping sites, middens, and scarred trees are common along the river systems (NSW NPWS Aboriginal Sites Register; Donovan, 1997). Aboriginal Reserves were established during the late 1800’s, and while some of these have since been revoked, small pockets of land are held by Aboriginal Land Councils and other Aboriginal groups (McGuigan, 1986; NSW Department of Lands, 1987).
The Riverina was first explored by Europeans in 1817 when John Oxley followed the Lachlan downstream below Booligal, but the lack of continuous streams and dense Lignum swamps prevented progress further west. In 1836 Thomas Mitchell reached the junction of the Lachlan and Murrumbidgee Rivers while Charles Sturt explored the Murrumbidgee and lower Murray Rivers between 1828 and 1831. He noted,
“It is impossible for me to describe the kind of country we were now traversing, or the dreariness of the view it presented. The plains were still open to the horizon, but here and there a stunted gum-tree, or a gloomy cypress, seemed placed by nature as mourners over the surrounding desolation” (Sturt, 1833, quoted in Porteners, 1993).
21 Sturt’s observations of the desolation encouraged graziers, who were lured into the region by descriptions of treeless plains and good water sources. Between 1835 and 1839, pastoral runs of between twenty and forty thousand hectares were established around Yanco, and along the Murray and Murrumbidgee Rivers, as far west as Hay. By 1845 around the Murray-Murrumbidgee junction an average pastoral property stocked mainly with cattle, comprised eighty thousand hectares (Semple, 1990). During the 1860's the predominant stock was sheep.
In 1915 the River Murray Waters Agreement provided for the construction of 26 weirs with locks to provide permanent navigation to Euchuca. Once riverboat travel declined, supply of water for irrigation became the main river focus (Margules et al., 1990). In 1912 the Murrumbidgee Irrigation Area was established by the diversion of water from the Murrumbidgee River, east of Nerrandera. The construction of the Hume Dam on the Murray River near Albury, the Burrinjuck Dam in 1928 on the Murrumbidgee River and the Blowering Dam in 1968 on the Tumut River, coupled with State-sponsored irrigation schemes enabled rice growing to develop into a highly productive regional industry (Humphries et. al., 1994).
The intensity of rice growing was subject to the availability of water. Pressey (in Margules et al., 1990) reported that about 52% of the Murray River between the Hume Dam in Albury and Wellington in South Australia comprises weir pools for storage and supply of water. With the introduction of tradeable water rights, the pumping of water away from rivers, access to bore water, increasing river regulation and new agricultural technology, crops are being grown outside the traditional irrigation areas (M. Rowe, pers. comm.). Irrigated crops are now evident in the plains around Hay, Deniliquin and Darlington Point. Large scale rice farming and rice production technology is driven by export opportunities to Japan.
More recently another water intensive crop, cotton, is being established in the Riverina Bioregion. Sheep grazing continues on land not suitable for cropping. Potato farming occurs on the fast draining sand hills (Jones, 1993).
The use of the land for the conservation of biodiversity is being promoted and administered through a number of mechanisms, namely reservation and management by Crown authorities, establishment of private protected areas, and landholder participation in community oriented programs.
Within New South Wales, dedicated conservation reserves include Morrisons Lake, Goonawarra, Yanga and Lake Urana Nature Reserves; Willandra National Park; Sanddune Pine, Toupna Creek, Moira Lakes and Billabong Flora Reserves; and Snake Island, Native Dog, Hay, Narrandera, Pollack and Bullatale Forest Reserves. The reserves within Victoria are Barmah State Park, Top Island, Top End and Killawarra Reference Areas and a number of smaller flora, fauna and wildlife reserves. There are also a number of private protected areas which contribute to conservation through the placement of a land use covenant on the property title.
There are three wetland areas of international significance in the Bioregion. These are the Barmah Forest (28,500 ha), Gunbower Forest (19,450 ha) and Kerang Wetlands
22 (9,172 ha) (Australian Nature Conservation Agency, 1996). They are internationally recognised as Wetlands of International Importance especially as Waterfowl Habitat (Ramsar Convention). Whilst these are not within dedicated conservation reserves the Australian Government has international obligations to ensure the identified wetlands are managed so as to maintain their ecological character.
Outside the conservation reserve system, there are Government lands for which protection of biodiversity is a secondary consideration such as lake reserves, education areas, state forests and regional parks. Within regional communities, landholder participation in conservation activities such as fencing and revegetation projects promoted in Bushcare and Landcare programs contribute to the protection of remnant vegetation.
5.5 IMPACTS OF EUROPEAN SETTLEMENT AND LAND USE ON THE BIOLOGY OF THE RIVERINA The availability of water and the highly fertile nature of the soils of the riverine floodplain make the area productive for plant growth. These factors have influenced human activities and land use in the region, particularly over the last one hundred and fifty years. The impact of land use has been an extensive modification of the natural distribution and condition of vegetation cover. Grazing and more recently insect related dieback, has modified the saltbush plains. Access to water for irrigation allowed for intensive agricultural production on lands adjacent to the Murray, Murrumbidgee and Lachlan Rivers which has resulted in a complete modification and fragmentation of the landscape. This is particularly noticeable around the Murrumbidgee, Hay, Coleambally and Tullakool Irrigation Areas and several irrigation districts around Deniliquin. In turn, the modification of the river systems to support intensive agriculture has resulted in altered hydrological regimes, water logging, salinity, land degradation, vegetation decline and fragmentation which has directly impacted upon and continues to threaten biodiversity.
5.5.1 Clearing and Grazing Native vegetation clearance is the single greatest threat to terrestrial biodiversity (EPA, 1997). Vegetation clearing and grazing reduce or modify natural habitat. The effect of this combined with the introduction of competitive herbivores (sheep and rabbits) and carnivores has been a general decrease in the number and species of flora and fauna. For example, the small mammals have most obviously been affected such that Bridled Nail-tail Wallaby (Onychogalea fraenata) which is now rare and the Eastern Hare- wallaby (Lagorchestes leporides) which is extinct.
In general, Australian woodlands contain the highest concentration of extinct and threatened birds (Garnett, 1992 and Robinson and Traill, 1996) with at least 46 south- eastern Australian woodland birds known to be declining in part of their range, towards a threatened status (Robinson, 1994). Cogger (1991) estimates that between 1,000 - 2,000 birds are killed for every 100 ha of woodland cleared and it is not only habitat loss from clearing which causes the decline, but also fragmentation of habitat. Fragmentation results in the fauna increasingly relying on smaller patches of habitat for survival and may lead to habitat simplification and habitat degradation. Those species which can compete successfully for reduced nesting sites, adapt to more open conditions
23 and co-exist with feral predators tend to survive.
The proliferation of rabbits from the 1870’s combined with overgrazing and droughts between 1883-85 and 1890-95 severely reduced the extent and condition of saltbush and grassland pastures (Semple, 1990). The selective nature of grazing animals resulted in a change in the composition of native plant species. For example, the chenopod shrublands were reduced to either ephemeral grasslands or shrublands, perennial species were replaced by annuals, and the more palatable species like Bladder Saltbush (Atriplex vesicaria) were replaced by less palatable species such as Roly Poly (Sclerolaena spp, formally Bassia) and Dillon Bush (Nitraria schoberi) (Leigh and Noble, 1972). Selective grazing has also hindered the regeneration of plant populations (Smith and Smith, 1990) and in particular, reduced the extent of the saltbush community across its natural range. Many of the saltbush associated plant species such as Swainsona recta, Winged Peppercress (Lepidium monoplocoides) and Psorlea parva are now considered to be threatened with extinction (Smith and Smith, 1990; Porteners 1993).
While some species have reacted adversely to land modification, some have found it to be beneficial. A species which may have actually increased in range due to vegetation clearance is the Fat-Tailed Dunnart (Sminthopsis crassicaudata) which prefers the low and open shrublands of saltbush and grasslands for feeding on invertebrates. Likewise, the abundance of the house mouse (Mus musculus) provides a good food source for small raptors such as Australian Kestrel (Falco cenchroides), Brown Falcon (Falco berigora) and Black-Shouldered Kite (Elanus notatus).
Despite these species specific increases there has been an overall decline in biodiversity quality and quantity coupled with regional extinctions since European development.
5.5.2 River Regulation River regulation, while providing a reliable and constant source of water for growing crops has altered the delicate balance of the natural wetting and drying cycle and extent and duration of flooding. These changes have affected native flora and fauna habitat.
For example, of the 17,101 hectares of Murray River floodplain vegetation identified and mapped by Margules et al. (1990) 39% was dead or severely degraded due to either increased or reduced flooding events. Water regulation has promoted a compositional change of riverine vegetation by the expansion of some communities to the exclusion of others (Margules et al., 1990). For example, the River Red Gum - Paspalidium - Couch Grass (Cynodon) community is cited as having been largely replaced by River Red Gum - Cyperus and River Red Gum - Common Reed (Phragmites) communities, while in the Great Cumbung Swamp the dominant plant Cumbungi (Typha orientalis) has now been replaced by the salt tolerant Common Reed (Saintly and Jacobs, 1990).
High summer river levels have led to the development of semi-permanent wetlands in some low lying areas. While this provides habitat for waterbirds during dry seasons it results in the death of River Red Gum (Smith and Smith, 1990), Black Box (E. largiflorens ) and Lignum (Muehlenbeckia florulenta) which require periodic drying events and are used by fauna as habitat for breeding. Elsewhere the reduced frequency
24 and duration of flooding has resulted in the spread of River Red Gum, for example from the Barmah State Forest into the Moira Grass Plains in Victoria.
Water regulation and altered hydrological regimes have impacted on wetland habitats and in particular waterbird breeding cycles. Australia wetlands have a natural process of drying and refilling to which native flora and fauna have adapted. The increase in water flow during dry periods stops the natural drying of rivers and breaks the wet/dry cycle favoured by fauna for breeding while the reduced height, frequency and duration of inundation of low to medium floods have in turn reduced waterbird breeding opportunities.
A continuing effect of river regulation is the expansion of irrigation agriculture away from the rivers and the associated clearing and further fragmentation of natural vegetation.
5.5.3 Cropping Apart from the impacts of clearing, cropping practices cause substantial changes in soil structure. Tillage machinery pulverises the soil aggregates and compacts the soil, and associated with this is a reduction in soil organic matter and soil fertility. This limits habitat opportunities for a number of sub-ground dwelling species, namely reptiles such as the Bandy Bandy (Vermicella anulata) and Blind Snake (Ramphotyphlops spp) which can not tolerate soil disturbance. Species such as the Curl Snake (Suta suta) and Hooded Scaly-Foot (Pygopus nigriceps) actually lose their grey cracking soils habitat when an area is cultivated and the cracks in the soil are compacted.
5.5.4 Salinity A serious impact associated with irrigation is rising water tables and increasing salinity. The clearing of native vegetation across the riverine plains has allowed more rainfall to move down through the soil, filling the underground gravel and sandbeds until they overflow and force saline groundwater to the surface where salt is concentrated upon evaporation. The Riverina is susceptible to salinity problems because the natural water table is relatively close to the surface and the soil is mainly imperviable clay.
Salinisation affects about 16% of the Murray River in NSW and Victoria (Margules et. al., 1990 ). Margules et al. (1990) have noted the range of effects of salinity on vegetation from the death of trees to a change in the composition of vegetation communities by colonisation of salt tolerant species. For example, Lignum (Muehlenbeckia) - Halosarcia shrubland gradually loses salt sensitive species, and the community changes to a lower more open and depauperate Halosarcia shrubland. The final impact being a loss of species, the simplification of vegetation composition and change in structure.
5.6 CURRENT FLORA AND FAUNA OF THE RIVERINA Geomorphology, topography, soils, climate and human activities have influenced the biodiversity of the Riverina Bioregion. Clearing and cropping has resulted in a fragmentation and modification of the remaining native vegetation. Some flora and fauna species have largely disappeared, others have been severely restricted in range,
25 while a few have tolerated the cleared and modified agricultural landscape.
The sandy soils of the riverine floodplain are dominated by Riverine Forest with River Red Gum (Eucalyptus camaldulensis) as the predominant tree species. The flooding requirements of this community means its distribution is restricted to the floodplains of the main river systems and their tributaries. The River Red Gum understorey is largely herbaceous comprising perennials, annuals and post flooding ephemerals. The understorey species composition alters across the floodplain with changes in topography and flooding frequency and duration.
The Riverine Forests form a relatively narrow strip of wetland habitat along the river system, and are particularly important habitat features in a landscape largely lacking tree cover. The Riverine Forest provides habitat for those species dependent upon trees for food, cover and nesting sites. Significant species known to inhabit the Riverine Forests include the Superb Parrot (Polytelis swainsonii), Sugar Glider (Petaurus breviceps), Feathertail Glider (Acrobates pygmaeus), Squirrel Glider (Petaurus norfolcensis), Brush-tailed Phascogale (Phascogale tapoatafa), Koala (Phascolarctos cinereus), Carpet Python (Morelia spilota), Freckled Duck (Stictonetta naevosa) and Peregrine Falcon (Falco peregrinus).
Adjacent to rivers and creeks, the flats and low lying swamps are dominated by shrublands of Lignum and Nitre Goosefoot which have been largely cleared for irrigation. The wetlands and floodplains are important for waterbird conservation. The Murrumbidgee / Lachlan Confluence, Barmah-Millewa Forest, Edward River and Murrumbidgee River floodplains are known to be able to support in excess of 20,000 waterbirds each (Kingsford et. al., 1996). These wetlands support a diversity of waterbirds many of which are migratory, and several which are listed as vulnerable under the NSW Threatened Species Conservation Act, 1995 such as the Australasian Bittern (Botaurus poiciloptilus), Freckled Duck and Painted Snipe (Rostratula benghalensis).
Adjacent to the River Red Gum on the higher, more saline heavy grey and brown clays of the outer parts of the floodplain is Black Box Woodland (Eucalyptus. largiflorens). The Black Box understorey comprises salt tolerant grasses, daisies and saltbushes. The common understorey shrubs include Lignum (Muehlenbeckia florulenta) and Nitre Goosefoot (Chenopodium nitrariaceum), Old Man Saltbush (Atriplex nummularia) and Bladder Saltbush (Atriplex vesicaria). It is a community which has been extensively cleared for cropping.
The Black Box Woodlands provide important habitat for a variety of birds such as the Bush Thickknee (Burhinus magnirostris) and in particular the Superb Parrot, which will only nest, where Box Woodland occurs within 10 km of the nest trees which are usually River Red Gum.
Away from the current river system, the Riverina is characterised by saltbush shrubland comprising Bladder Saltbush, Old Man Saltbush, Boree (Acacia pendula) shrubland, Cotton Bush (Maireana aphylla) and native grasslands (Danthonia spp. and Stipa spp.) (Leigh & Mulham, 1977). These generally occur on the red-brown earths (sandy loams
26 or loams) with a shallow A horizon, or grey and brown clays which are less well drained sites.
Cypress Pine (Callitris glaucophylla), Grey Box (Eucalyptus microcarpa) - Yellow Box (Eucalyptus melliodora) survives above the level of the floodplain on lighter textured soils and sandhills (Porteners, 1993, Margules et. al., 1990). These communities are of particular concern because of vegetation loss associated with over grazing and undermining by rabbits which leads to erosion of the sandy soils.
The native grasslands of the Riverina are nationally important because the lowland grasslands of south-eastern Australia are among the most threatened and poorly conserved ecosystems. The Riverina Grasslands occur on red-brown and grey clays and are considered extensive compared to other temperate grassland regions of Australia (Benson et. al., 1996). The Riverina Grassland community is quite variable in structure, composition and extent of modification across the Bioregion. Relatively undisturbed and species rich remnants occur (Benson et. al., 1996) as do a number of rare and threatened associated plant species such as the endemic Red Swainson Pea (Swainsona plagiotropis), Swainsona murrayana, Sclerolaena napiformis, Brachycome papillosa, Brachycome chrysoglossa and Lepidium monoplocoides.
Grasslands and shrublands provide food and shelter habitat for a number of species including the Plains-wanderer (Pedionomus torquatus), Bush Thicknee, Striped Legless- lizard (Delmar Impar) and Fat-tailed Dunnart (Sminthopsis crassicaudata).
Less characteristic of the Riverina Bioregion but common on the Bioregion periphery is Belah (Casuarina cristata) - Rosewood (Alectryon oleifolius) and Mallee (E. socialis, E. dumosa) which occurs on the calcareous, sandy soils more typical of adjacent bioregions (Semple, 1990; Porteners, 1993).
27 6. A SYSTEMATIC APPROACH TO CONSERVATION PLANNING Within most landscapes choices exist with regard to which areas should be subject to a high level of protection. Often these choices are made in a decision environment lacking adequate data to form a reasonable regional context. This can lead to inefficient decisions with respect to meeting conservation goals. Moreover, with increasingly limited government and community resources to undertake conservation action it has become clear that priority areas for immediate conservation action need to be identified with greater confidence to streamline the conservation effort.
The importance of conservation planning is highlighted in bioregions such as the Riverina, where the land is predominantly held in private ownership and economic viability is linked to agricultural productivity and natural resource utilisation. In landscapes such as this, conservation action does not occur quickly but rather in a series of slow punctuated steps (ie. for example, as properties are purchased for reservation or conservation agreements are entered into). For this reason there is an urgency to direct conservation resources to those ecosystems which will benefit most, or be lost if protection is not implemented in the short term. Our first steps must be efficient steps.
A systematic approach to conservation assessment can promote efficient conservation planning. The approach adopted for the Riverina Project involved: S the identification of a conservation goal; S the identification of sites which would efficiently achieve that goal; and S determining the urgency for conservation action to be applied to those sites.
6.1 CONSERVATION GOAL The principal element in determining priority areas for conservation action (such as by reservation, environmental zoning or community conservation measures) is the establishment of a conservation goal against which relative conservation values can be measured. This means defining 'what' and 'how much’ is to be conserved.
The conservation goal will reflect the conservation values and vulnerability of attributes requiring protection such as, vegetation types, environmental units and species. In deciding on this attribute, the objective is to obtain a comprehensive, adequate and representative sampling of biodiversity. This is achieved by adopting the principles of comprehensiveness (protecting a sample of each element of overall biodiversity), representativeness (ensuring that the variety within each element of biodiversity is also given protection) and adequacy (‘how much’ is to be conserved under any given mechanism to ensure future viability of the targeted element).
The conservation goal is usually defined by the area of the attribute, as a percentage or total area. For example, the national conservation target used as a baseline for the reservation of forest ecosystem types is 15% of the pre-European extent of each forest ecosystem type (JANIS, 1997).
28 6.2 SELECTION UNIT To implement a conservation planning process incorporating the principles identified above, the practitioner will need to systematically partition the landscape into manageable planning units. Referred to as ‘selection units’ these parcels represent the basic building blocks of the assessment process and can be derived from cadastral boundaries (eg. properties), land management units (eg. forestry management compartments), catchment boundaries, remnant vegetation or an arbitrary grid of cells which have no biological or administrative basis.
The choice of selection unit will depend upon the reason for analysis as well as the availability of a suitable selection unit. Some issues to be considered with respect to selection units (Pressey and Logan, 1998) include: S the number of selection units which can be reasonably analysed within time constraints; S the size of the selection unit compared to the extent of the features being analysed. For example, if the features are small vegetation fragments and the size of the selection unit is larger than the fragments, then the vegetation is likely to be masked; S Consistency of unit size across the landscape. For example, property sizes in urban areas tend to be considerably smaller than nearby agricultural properties. For a comparative analysis, the selection unit must be as standardised as possible to allow for the derivation of a continuum of areas from relatively high value to lower value. For this reason, a rectangular grid is often used; and S Importance of translating selection units into an on-ground implementation / management unit.
The ability to effectively achieve the conservation goal will be affected by the size, location and orientation of selection units. Overly large selection units are inefficient in representing all features in the smallest number of sites and will lead to an over representation of common attributes (Pressey and Logan, 1995 & 1998). This inefficiency is particularly important at the implementation stage when the real costs of conservation such as fencing, land purchase or revegetation are considered. Thus, small selection units relative to the target attribute such as a vegetation community will be more efficient for achieving and implementing conservation goals.
6.3 ACHIEVING THE CONSERVATION GOAL - IRREPLACEABILITY ASSESSMENT Once decisions are made on what attributes are to be targeted for protection, the conservation planner is then faced with choices as to where in the landscape protection can be achieved. A relative measure of the importance of each site in the study area can aid in the decision making process. The approach for conservation value adopted for the Riverina Project is the measure of ‘irreplaceability’.
Irreplaceability measures an area’s (ie. selection unit's) relative contribution to achieving the conservation goal. Irreplaceability values are derived by a mathematical algorithm which calculates the relative contribution each area makes to satisfying the nominated conservation goal (Ferrier et al., in prep).
There are a range of values for irreplaceability; totally irreplaceable, Ir1, Ir2, Ir3, Ir4, Ir5
29 and no contribution. Sites identified as ‘no contribution’ do not contribute to the conservation goal because they do not contain attributes of conservation importance (eg. cleared land). Sites identified as totally irreplaceable have the highest irreplaceability value and if the conservation values within that site are lost, then the conservation goal will be impossible to achieve. This is because within a study area there are no or very limited alternative sites which contain the same or similar values (ie. they have no replacement sites) Sites identified as Ir5 exhibit the lowest irreplaceability value and which means there are many similar sites within a study area which can contribute to achieving the conservation goal. Nevertheless some Ir5 sites will probably be required in order to achieve the conservation goal.
Thus, the irreplaceability value can be used to guide where the priorities are within a region because the higher the irreplaceability value, the fewer the options for replacement, and the higher the priority.
An irreplaceability analysis provides a means of demonstrating the implications of alternative conservation goals. It is a relative and dynamic measure. A change in conservation goal (eg. % of an area of vegetation community) will alter the results of the analysis. It is valid and indeed necessary to alter the conservation goal over time, particularly as natural and administrative landscape changes are made and areas are protected or destroyed. As discussed earlier, the implementation of conservation management actions in order to satisfy the conservation goal will take time and so the conservation planning tool must remain in service until such time as all the goals have been satisfied. The planning algorithm must be rerun as the data set is further refined or as significant changes occur in the landscape (i.e. further habitat may be lost or adequate conservation management of other areas may be secured).
6.4 ASSESSING THE DEGREE OF URGENCY - VULNERABILITY The purpose of conservation is to ensure that features being selected for conservation are likely to persist. Whilst the irreplaceability analysis identifies the location of the sites requiring conservation action, an assessment of the time factor within which to initiate this action is also required. In a conservation planning context, assigning a priority or time frame for conservation action involves the concept of vulnerability.
Vulnerability is an estimate of the degree of threat of destruction or degradation an area, species, community, ecosystem faces. This information can guide decisions on the amount of protection necessary and the urgency of that protection. Measures of vulnerability can include the current rate of clearing, predicted rate of clearing, land capability, predicted patterns of habitat loss, predicted extent of extractive land use or land modification. The measure is usually applied relatively across the landscape to indicate areas of high, moderate or low vulnerability. In this project, the vulnerability of the Riverina is assessed on the basis of the likelihood of vegetated areas being cleared for cropping.
Our capacity to understand and measure vulnerability change at a regional level is limited to measuring extreme changes brought on by habitat loss and predictive mapping of threats such as clearing, cropping and grazing often based on past trends. To a degree an understanding of these extreme changes will be sufficient to initiate conservation action. What is not understood is the cumulative nature of these threats.
30 We know enough to initiate urgent work but our ability to design a functional landscape, which includes some human/agricultural systems and is also viable for all remaining biodiversity, requires further exploration.
6.5 CONSERVATION PLANNING SOFTWARE - C-PLAN The conservation planning software (C-Plan) (Pressey et. al., 1995) is a Windows based conservation planning decision support system software package which can be linked to a GIS. Its value lies in the capacity to evaluate multiple data sets within a regional context and the capability to allow interactive exploration of these data sets. Furthermore, its capacity to calculate irreplaceability allows the user to explore the options for achieving a conservation goal and consider the implications associated with each option. The software has been extensively tested (Pressey, in press) and information on the software is currently available from the C-Plan Internet home page (www.ozemail.com.au/~cplan).
C-Plan has the capability to fully document all site selection decisions and the flexibility to redisplay the new pattern of landscape conservation options resulting from previous user decisions. This means that it is a technique which is explicit and repeatable. In addition, decisions can be refined as new data becomes available. This is particularly valuable in situations where sites selected as irreplaceable are found to be unavailable or contentious and the location of replacement sites is required (refer to Pressey et al., 1993; Pressey et al., 1994; Pressey et al., 1995; Pressey and Logan, 1997).
The software is based on a numerical algorithm (referred to as a 'predictor') which uses information on the frequency distribution of the area of occurrence of each attribute (eg. vegetation types) and the total extent of the attribute in the data set (Ferrier et al., in prep). The irreplaceability value is influenced by the degree to which an area contains a small or large occurrence of an attribute relative to its target and the distribution of these attributes within the Bioregion (Ferrier et al., in prep). The irreplaceability values generated are target specific and are a measure of the contribution of each selection unit to achieving the nominated targets.
The hardware required to run C-Plan is shown in Table 1.
Table 1. IBM compatible personal computer specifications for operating C-Plan. Hardware Riverina Project Recommended Operating System NT4 NT4 or Windows 95 Graphical interface Windows Environmental ERSI ArcView3 GIS Resource Mapping System (WinERMS) Processor Pentium Pentium RAM 32 Mb = or > 64 Mb – increasing the RAM will reduce calculation time for large databases. Hard Drive C-Plan uses 12 Mb when fully installed. For large databases (>20000 sites) 200 – 800 Mb of free disk space is required.
31 7. METHODS
7.1 COMMUNITY AWARENESS
7.1.1 Steering Committee The committee convened regularly over the 18 month period to provide advice on project direction and methodologies. The key objectives and outcomes of the steering committee meetings are outlined in Table 2.
Table 2. Dates and details of project steering committee meetings. Meeting Meeting Key Objectives/Outcomes Date Location 19 June NPWS S Discuss the project aims/objectives 1996 Hurstville S Consider suitable applicants for steering committee S Discuss best approach for the project, particularly data gathering 27 August NPWS S Inaugural meeting of steering committee (SC) 1996 Hurstville S SC support for project aims/objectives S Endorsement of SC representation, roles and responsibilities S SC support for proposed approach to stage 1 - data collection, methodology review S SC endorsement of community awareness approach via catchment management committees 27 NPWS Dubbo S Report on general progress November S Discuss paucity, bias in existing Aboriginal heritage data 1996 S Preparation of progress report to Environment Australia (EA) 11/12 Denilquin S Project update March 1997 S Discussion and general agree upon: data layers, selection units, conservation targets to be used S Recognition of the technical limitations of the project (namely data) S Proposal to obtain additional EA funding to undertake liaison and data collection with Aboriginal communities S Discuss expected project outcomes S Field inspection
(Participants included representatives from DNRE, NSW DLWC, NPWS - Griffith, Greening Australia - Deniliquin and the Western Riverina Vegetation Committee) 22 July Hurstville S Discussion of Stage 1 report 1997 S Confirmation of conservation targets S Demonstration of C-Plan S Discussion of Aboriginal heritage data collection S Community awareness progress 15 October Nerrandera S Confirmation of final data layers 1997 S Agreement to refine vegetation retention targets based on Catchment Management Committee’s review S Discussion on final outcomes of Aboriginal Heritage data collation S Review and discussion of preliminary results S Discussion of final report content and layout
32 7.1.2 Catchment Management Committees With ninety six percent of the Bioregion in private land management or ownership it was evident that the landholders within the Riverina are the primary custodians of biodiversity. For conservation of biodiversity to occur, agricultural production and conservation needs to be integrated. Support for this integration currently occurs through a variety of community oriented programs such as Total Catchment Management, Bushcare, Landcare and Farming for the Future. It was therefore apparent that sections of the community needed to be made aware of the aims, objectives and expected outputs of the Riverina Project, so that the outputs could contribute to the preparation of local and regional land management strategies.
The project adopted two approaches for obtaining and sharing information with the community. The first involved integration with the NSW Total Catchment Management Program (subject to the NSW Catchment Management Act 1989) via the Catchment Management Committee (CMC) network. The second involved an attempt to integrate aboriginal cultural information into the planning process by documenting and clarifying aboriginal issues through liaison with representatives of Local Aboriginal Land Councils. This is documented elsewhere in the report.
The principles of total catchment management are supported through a network of CMC's which are represented by local landholders and government authorities. CMC's are responsible for identifying catchment needs and preparing and implementing catchment management strategies.
The link between government and the community through the CMC network provided a conduit for information exchange with a subset of the broader community. Within the Riverina the NPWS was already represented on the Murray, Murrumbidgee and Lachlan CMC's. This provided an opportunity for the Riverina Project to be introduced into a sector of the community via a well established network. It is acknowledged that the Lower Murray Darling CMC and the Victorian community had no direct association with the project.
The approach adopted was to provide the CMC's with an understanding of the Riverina Project aims, objectives and outputs. This was considered important because the project would produce baseline data and information on conservation values and priorities across the Bioregion. The bioregional perspective would provide a context with which to compare and consider the importance of natural values located within and between neighbouring catchments of the Bioregion.
There was no intention for the project to undertake a fully consultative program with all interest groups and stakeholders in the Riverina. This was because the project sought to establish an information database and develop a good foundation for further conservation assessment and planning. The project sought to provide information and assessment tools (by way of assessment methodology) which could be widely applied rather than to advocate land use change. As discussed previously integrated conservation planning and land use change requires consideration of biodiversity, social and economic factors. Such integration was beyond the scope of the Riverina Project.
33 The following Table 3 documents various meetings held with the CMC’s. In all cases verbal project briefings were presented and written material (refer to Appendix 1, a and b) was made available for CMC coordinators and any interested members. Verbal presentations were the preferred method of communication so that the information could be explained accurately and efficiently. This also provided the NPWS with an opportunity to immediately respond to any questions or concerns raised.
Table 3. Details of catchment management committee meetings Date CMC NPWS Project Action Representative October Murrumbidgee Riverina Project S Verbal briefing 1996 Officer S Introductory information package (Appendix 1a) November Murray NPWS Griffith S Verbal briefing 1996 District, Manager S Introductory information package (Appendix 1a) November Lachlan NPWS Griffith S Verbal briefing 1996 District, Manager S Introductory information package(Appendix 1a) March 1997 Western Riverina Riverina Project S Verbal project briefing Natural Grassland Officer Committee (sub- committee of Murrumbidgee, Murray and Lachlan CMC's) August 1997 Murrumbidgee NPWS Griffith S Brief verbal project update District, Manager S Written update package (Appendix 1b) S Request for CMC to review and comment on nominated vegetation retention targets August 1997 Murray NPWS Griffith S Brief verbal project update District, Manager S Written update package (Appendix 1b) S Request for CMC to review and comment on nominated vegetation retention targets August 1997 Lachlan NPWS Griffith S Brief verbal project update District, Manager S Written update package (Appendix 1b) S Request for CMC to review and comment on nominated vegetation retention targets
7.2 TECHNICAL COMPONENT
7.2.1 Database Development
7.2.1.1 Data Audit All conservation assessment procedures rely on access to information. As populations of species are the fundamental planning entities for conservation, access to primary biological data provides the best detail upon which to base conservation decisions. However, for the Riverina Bioregion primary biological data has not been consistently collected. The geographic coverage of biological data is generally poor and the data that does exist is patchy or incomplete. Consequently, land classification maps based on biological attributes such as vegetation and land systems are used as surrogates for
34 primary biological data. At the coarse scale, these surrogates can represent distribution and extent of biodiversity.
The first and most critical step in the project was to undertake a data audit of existing information, obtain the information and assess its suitability for use in a bioregional conservation assessment process. To answer the question of ‘where’ the high conservation priority lands were in the landscape, spatial information in mapped format was required. In particular, information that would typify the Bioregion with respect to its ecological processes, biological attributes and land use pressures. Information that when combined spatially would illustrate the distribution of plants and animals across the Bioregion, as well as any human induced impacts on such distributions. Information such as: S plant and animal distributions; S physical attributes such as geology, geomorphology, rivers and the extent of salinisation; S land uses which could be used to predict vulnerability such as rural land capability, irrigation areas, urban areas; and S administrative features to characterise influence on land use such as tenure, roads, and government boundaries. 7.2.1.2 Compilation of Primary Data Sets Conservation assessment involves a comparative analysis and for this reason data coverage needs to be consistent across the area of analysis (ie. the Riverina Bioregion). Thus, the criteria used to select suitable data sets for inclusion in the Riverina Database were: S completeness of coverage across the entire Bioregion, S consistency of the data within the coverage, and S understanding the limitations and applicability of the data coverage.
Once suitable data sets were identified, the process of data acquisition was initiated. This process is outlined diagrammatically in Figure 3. All data layers used in the analysis were ‘clipped’ to the Riverina Bioregion boundary.
35 Figure 3. The process of data acquisition
Literature review and consult personal contacts
Contact authors/ department/ authority
and identify the custodian of the data
Negotiate with the custodian for data use and obtain a licenced agreement
Acquire and review the data not Reject data for its reliability and suitability for use in the context of the project. suitable
Convert data to a suitable format
Incorporate data into the database
A discussion and explanation of the primary data sets follows.
Geomorphology The hard copy geomorphology maps for the Riverine Plain, as described and mapped at 1:500,000 scale by Butler et. al, (1973) were borrowed from the Australian National University. Permission to digitise and utilise the data was obtained from one of the original authors, J.M. Bowler. A copy of the digital layer was forwarded to the Australian National University.
This mapping covers the entire Riverina Bioregion and depicts the geomorphic features of riverine and aeolian origin (Figure 4). Geomorphic attributes reasonably predict vegetation distribution (Semple, 1990 and Porteners, 1993) and agricultural land use (Butler et. al, 1973) throughout the Bioregion. The mapping was therefore used to support the vegetation mapping and predict areas suitable for agricultural production.
The reliability of the mapping is high, with interpretation of geomorphology from 1:50,000 or 1:100,000 air photos or photomaps. The main limitation of the map recognised by the authors was the transient nature of the aeolian features such as scalds, and the change in extent of these features due to the effect of wind erosion.
36
Vegetation Vegetation coverage was paramount to the conservation assessment process because it provided a biological foundation upon which to develop a conservation goal for the Riverina Bioregion.
A vegetation coverage for the Riverina was derived from a number of map sources. These sources were: S the Royal Botanic Gardens, Sydney (Porteners, 1993) Hay Plain: Booligal-Hay and Deniliquin-Bendigo 1:250 000 maps; S the Royal Botanic Gardens, Sydney (Porteners et. al., 1997) Pooncarie 1:250,000 map; S the Royal Botanic Gardens, Sydney (Scott, 1992) Balranald - Swan Hill 1:250,000 maps; S the Victorian Department of Natural Resources and Environment (1993) structural vegetation mapping (1:100,000); and S NPWS NSW “extension mapping” from Landsat imagery for the northern periphery and eastern portion of the Bioregion within NSW.
The combination of these mapping sources provided a complete but reasonably coarse, vegetation coverage for the Bioregion. This was not previously available. The map was reliable for information regarding woody vegetation but was limited in its capacity to describe native Grasslands. The coarse scale of the map means that any natural variation within vegetation communities was not depicted, nor were those vegetation types with small patchy occurrences. This means that the true diversity of vegetation communities within the Riverina may be concealed by the current mapping and consequently not taken into account in subsequent analysis.
Notwithstanding the limitations of the vegetation map it currently represents the best mapped information available for the entire Riverina Bioregion.
The Royal Botanic Gardens Mapping The Royal Botanic Gardens (RBG) mapping covers Balranald-Swan Hill (Scott, 1992), Deniliquin-Bendigo and Booligal-Hay (Porteners, 1993) and Pooncarie (Porteners et al., 1997) which represents 70% of the New South Wales portion of the Bioregion. This mapping is at a 1:250 000 scale and is derived from 1:50,000 and 1:100,000 aerial photographs and satellite imagery.
To combine the various RBG map sheets, the original authors undertook minor modification of coding and linework along the map sheet edges to ensure a consistency of coverage across the map sheets. This edge matching involved reference to aerial photography but was not field verified. The naming of the vegetation types and the coding of the polygons was also standardised between map sheets to ensure consistency of terminology across the Bioregion.
The RBG mapped 256 vegetation categories based on floristic and structural composition from 30 main vegetation communities. Limited detail of some of these communities is listed in Appendix 2, otherwise refer to Scott, 1992; Porteners, 1993; Porteners et al., 1997.
38 For practicality, comprehension and implementation of project outcomes, the degree of detail provided by the vegetation categories was simplified into 'vegetation types'. Vegetation types were derived by omitting structural detail and grouping common floristic categories. For example, Scattered Black Box Woodland was merged with Black Box Woodland (RBG codes 2sc with 2) to become Black Box Woodland (Appendix 3 details the combination of the categories). Likewise, vegetation types in mosaics were merged, such that Black Box/Lignum; Lignum/Black Box; and Lignum/Scattered Black Box (RGB codes - 2/18, 18/2, 18/2sc) became ‘Black Box Woodland/Lignum’. Mosaics are a combination of vegetation types that are recognised and mapped as one unit, usually because the constituent components are too small to be independently mapped. A mosaic therefore comprises one or more vegetation types, in which the order of description does not imply the dominance of any one constituent vegetation type.
This merging provided consistency between the various maps and enabled comparison at the coarse level without losing floristic detail. Nevertheless, it is acknowledged that the removal of the structural and species dominance information reduces the usefulness of the mapping for predicting species and habitat distribution. For example, it could not be used to predict Plains Wanderer habitat because this species is reliant upon vegetation structure as well as floristic composition (Baker-Gabb, 1998).
NPWS NSW Extension Mapping Porteners (1993) states that vegetation communities identified in the survey of the Booligal - Hay and Deniliquin - Bendigo map sheets extend beyond those map sheet boundaries. Thus, a coarse, rapid, extension vegetation mapping exercise was undertaken by John Benson (RBG, Senior Ecologist) and John Brickhill (NPWS, Naturalist, Griffith District) to provide coverage for the 30% of the Bioregion in NSW not currently mapped by the Royal Botanic Gardens.
The unmapped vegetation of the Conoble map sheet was classified from 1:250,000 Landsat TM satellite imagery (1995) whist the remaining vegetation was mapped from georeferenced 1:100,000 Landsat TM satellite imagery (1991) from the Hillston, Merriwagga, Kooroongal, Griffith, Colleambally Yanco, Jerilderie, Urana, Berrigan, Buraja and Walbundrie 1:100 000 map sheets. This extension mapping was completed with reference to existing RBG mapping, RBG preliminary mapping, existing broad scale mapping (Beadle, 1948; Moore, 1953; Leigh and Mulham, 1977) and geomorphology (Butler et al., 1973).
Sixteen vegetation communities were derived from the extension vegetation mapping, of which 12 were equivalent to the vegetation communities described by Porteners (1993). The remaining four communities; Grassland, Callitris Woodland on Prior Streams, Grey Box / Blakely’s Red Gum / Callitris, and Dwyer’s Red Gum / Callitris / Grey Box are new categories and are described in more detail in Appendix 2.
The mapping is very broad due to the rapidity with which it was undertaken and the constraints associated with visual interpretation of satellite imagery and the lack of field survey. The eastern extent of the mapping was field verified by John Brickhill in September 1997 which resulted in minor modifications to a few vegetation codes for the
39 Jerilderie and Narrandera map sheets.
The main limitations to the extension mapping are: S the grouping of all Grassland communities into one category. The constraint with using satellite imagery meant that native grasslands could not be accurately distinguished from improved pasture nor could the identification or composition of the main grass species. Therefore, the 'Grassland' vegetation type includes the continuum from relatively undisturbed native grassland to improved pasture with few native species; S the classification of Boree Woodland (Acacia pendula) with scattered individuals, as Grassland; S the development of additional vegetation types such as the ‘Callitris Woodland on Prior Streams’ which could not be classified as ‘Callitris Mixed Woodland’ or ‘Prior Stream Remnant Woodland’ without ground survey.
Combination of the RBG Mapping and the NPWS NSW Extension Mapping Due to the differences in the mapping techniques and the effort to minimise error from additional data re-interpretation, the linework and coding at the map edges between the RBG mapping and the NPWS NSW extension mapping were not united. The result of this is demonstrated by the noticeable straight edged delineation in vegetation mapping in the eastern section of the Bioregion (refer to Figure 5). On one side of the line, the vegetation is described by RBG as Boree Woodland (scattered Boree trees with grassy understorey) and the extension mapping classified this as Grassland and delineated individual clumps of Boree. The methods are different and both are valid, but this illustrates a real difficulty with joining maps derived using different vegetation interpretation and classification techniques.
Victorian Vegetation Mapping The vegetation mapping compiled by the Department of Natural Resources and Environment (DNRE) is the structural vegetation mapping, SVEG100. This is derived from 1:25,000, 1:50,000 and 1:100,000 aerial photographs and satellite imagery and is compiled from three sources of vegetation mapping: existing digital data; existing hard copy maps and primary data for new mapping. The sources are summarised in Table 4.
Table 4. Data used to compile Victorian Structural Vegetation Mapping (SVEG100). Type of Data Source Scale Digital Land Conservation Council Vegetation Maps 1:100 000 Digital Box Ironbark structural vegetation mapping 1:100 000 Digital River Murray Riparian Vegetation Data 1:25 000 Digital Tree 100 1993 1:50 000 Hard copy Forestry maps and undigitised Land Conservation 1:100 000 Council Vegetation Maps New data 1993 Landsat TM imagery 1:100 000
The vegetation map from these data sources is classified according to the dominant overstorey species, height class, density class and vegetation form class. This layer basically represents woody tree cover.
For Victoria, the Structural Vegetation Mapping depicts 21 vegetation classes within the
40 Riverina Bioregion. Only 9 classes were compatible with the NSW vegetation communities. The remaining 12 classes were retained as unique categories specific to the Victorian portion of the Bioregion. Nine of these unique classes are restricted to the periphery of the Riverina Bioregion and considered representative of vegetation types typical of the tertiary sands, Palaeozoic granites and sediments, and sediments which, as noted previously are associated with the alluvial-colluvial slope aprons of the adjoining bioregion. Appendix 4 shows the Victorian vegetation classes and their classification with NSW vegetation types.
Grasslands and shrublands are not mapped and therefore can not be incorporated into the assessment process. The lack of mapping of these categories is due in part to the limited extent of native shrubland and grassland in Victoria.
The mapping does not include non-dominant species associated with the dominant overstorey species. For example, there is no distinction between the E. camaldulensis dominated Riverine Forest and Riverine Forest/Black Box Woodland, as is the case for NSW mapping. The lack of floristic detail means that the mapping does not represent the diversity of existing habitat types and is therefore not a good surrogate for fauna distribution. It also implies that the assessment of irreplaceability will not be based on a consistent level of vegetation detail across the Bioregion.
Rural Land Capability Mapping Rural Land Capability Mapping was prepared at a scale of 1:100,000 in the early 1970 - 80’s for the Central Administrative Division of NSW by the NSW Soil Conservation Service (Emery, undated). The mapping was prepared to aid land use planning decisions and is based on an assessment of the biophysical characteristics of the land such as climate, geology, geomorphology, soils, soil erosion, soil drainage and existing land use to determine appropriate land use and the land management practices required to prevent soil erosion and maintain land productivity (Emery, undated).
The rural land capability mapping presents the best available agricultural land use predictor for the Central Division of NSW Riverina Bioregion. The land capability is based on soil types and terrain and is broadly classified as: 1. Suitable for regular cultivation (combination of rural land capability mapping classes I, II, III and flood irrigation). These lands were considered to be suitable for frequent growing of crops which use tillage practices. 2. Suitable for grazing with either occasional cultivation or no cultivation (combination of rural land capability mapping classes IV, V, VI). The land is capable of infrequent growing of crops using tillage practices. The land was considered best used for grazing with occasional cropping. 3. Not suitable for cropping or grazing (combination of rural land capability mapping classes VII, VIII). Land clearing should not occur due to extreme erosion hazard.
Review of Aboriginal Heritage Data The Aboriginal community holds a unique perspective of the land, based on experience, traditional knowledge and resource management practices. Coupled with their social, spiritual, cultural and historic links it is important that the interests of the Aboriginal community be considered in conservation planning and management (Dale, 1997). This
41 component of the project involved seeking information on areas of interest for the local Aboriginal groups.
Aboriginal Sites Register Under the National Parks and Wildlife Act 1974, the NPWS has responsibility for the protection of Aboriginal artifacts. In order to fulfill this responsibility NPWS administers the Aboriginal Sites Register (the Register), a state-wide database of recorded Aboriginal sites. It is a point-locality data set with descriptive site information. It has limited value for indicating the aerial extent of places of Aboriginal cultural or archaeological significance as it is far from exhaustive in its current listing of sites.
Currently, the Register has a strong bias to sites of archaeological significance as described by the physical feature (midden, scar tree, open site etc.). Sites of social significance to the community are largely absent from the Register as is an understanding of the site within the context of the wider environment. The bias in archaeological sites is due to a lack of systematic regional surveys, instead they are associated with development proposals or are opportunistic sightings such as along rivers or roads and data from selective survey areas. The fact that no sites are recorded for an area is more likely to reflect the absence of field survey than an absence of sites.
Due to the lack of comprehensive information and extreme bias in the Register for the Riverina, NPWS Aboriginal officers advised against the use of incomplete information in any conservation assessment which would be based on comparing the relative value of one Aboriginal site over another.
Aboriginal Consultation and Survey In an attempt to fill some of the gaps in the Register, Aboriginal communities within the Riverina were approached with the idea of locating areas of importance to Aboriginal communities and gaining an understanding of their issues of conservation concern. This was to be achieved by: S documenting places of significance to Aboriginal communities such as archaeological sites, places of cultural, ceremonial or spiritual significance, areas that were important for supply of resources such as food or medicines. The places could be delineated by broad areas or specific sites; S identifying land management issues and threats that may be associated with these places; and S validating existing sites in the Register and recording any new sites.
With limited availability of time (10 weeks) the NPWS Aboriginal Sites Officer approached the 13 Local Aboriginal Land Councils (LALCs) within the Riverina to determine their willingness to participate. Although the LALCs do not represent all sectors of the Aboriginal community, it provided an established network and access to elders and members of the community. The 13 Local Aboriginal Land Councils in the Bioregion are Albury and District, Balranald, Deniliquin, Griffith, Hay, Ivanhoe, Leeton and District, Moama, Murrin Bridge, Narrandera, Yorta-Yorta and Wamba-Wamba.
An information package (Appendix 5) was distributed to each of the LALCs. This was
42 to provide an overview of the project, an explanation of the gap in the existing information, request for access to additional information at the broad scale, and explanation of how the information would be used and subsequently stored.
Over a period of eight weeks, the nine LALCs which expressed an interest in discussing the project were provided with Aboriginal Sites Register maps, showing recorded sites, which were used to focus discussion. The LALC representatives were encouraged to identify new sites or areas of importance and to discuss land management issues associated with existing or new sites.
Unfortunately there was an overall reluctance by the Aboriginal representatives to provide any new information to this project. However, 297 recorded sites, which amounts to 37% of sites for the Riverina in the Register were validated. These were validated either by a review of the LALC records or field verification in the presence of a LALC representative or a community elder. Thus, the integrity of the database has been improved.
Regrettably, the Register remains incomplete. Many sites on both public and private land are unrecorded. The obvious lack of data, remaining bias in the data set and the inability to further document areas of interest or to rank sites of significance means that the sites within the Register are not sufficiently comprehensive to include in an analysis which requires the setting of conservation targets. Therefore, the inclusion of existing Aboriginal heritage information within the analysis remained beyond the scope of this project.
Species Based Data Flora and fauna species constitute the basic planning entities for biodiversity conservation. Species based data relies on a knowledge of species ecology and or distribution, to be utilised. However, this type of information is lacking for many species. In an assessment such as this, a species by species approach could be used in one or all of the following ways: S to focus on species of interest (eg. threatened species or declining species); S to identify particular habitats or habitat conditions using species which can be considered a surrogate for habitat type or condition (eg. keystone species); S to supplement an ecosystem approach where the ecosystem classification has not been able to fully represent the requirements of all species.
For the Riverina Project, the distribution of flora communities across the Bioregion is represented by the vegetation mapping. The NPWS Atlas of NSW Wildlife database holds spatial information on 11 vulnerable and endangered (Briggs and Leigh, 1995) plant species in NSW Riverina: Brachycome papillosa, Lepidium monoplocoides, Lepidium hyssopifolium, Callitriche cyclocarpa, Maireana cheelii, Sclerolaena napiformis, Swainsona murrayana, Swainsona plagiotropis, Stipa wakoolica, Stipa metatoris and Solanum karsense. The 88 sites recorded for these species represent opportunistic sightings. There has been no comprehensive or known systematic survey of the region for species of significance. The inconsistency of the data did not allow for its use as part of the comparative bioregional analysis.
43 The NPWS Atlas of NSW Wildlife database provides fauna records for the region. The Atlas is sourced from government, institutions and the public and collects both systematic and opportunistic records. The records for the Bioregion are largely opportunistic and are therefore biased to transport corridors such as roads and rivers (favourite places for local naturalists) or within production forests.
Within the NSW component of the Bioregion there are 290 recorded species of birds of which 36 are listed under the Threatened Species Conservation Act, 1995 as endangered or vulnerable, 41 species of mammals, 11 endangered or vulnerable and 6 extinct and 42 amphibian and reptile species recorded of which 2 are listed as either endangered or vulnerable. These endangered and vulnerable species are listed in Appendix 6. Although the records seem to indicate a reasonable species diversity, at least for birds, many of the recordings are for single individuals. In the case where species are in abundance they tend to be restricted to specific locations such as wetlands and tend to be migratory.
Survey and data collection has been carried out for two bird species, the Superb Parrot (Polytelis swainsonii) (Webster and Ahern, 1989) and the Plains-wanderer (Pedionomus torquatus) (Baker-Gabb, 1998). Species recovery and management planning for these species has either been prepared or is in preparation. Due to the absence of adequate systematically surveyed data for other fauna in the Bioregion and the fact there is no support for the use of these two species as indicator species, the use of their data is likely to significantly bias the analysis rather than add to a consistent bioregional overview.
Therefore, fauna data has not been used for this particular analysis for identifying irreplaceability, however it could be incorporated in a decision making process when selecting areas for protection which have equal irreplaceability. That means, where sites of equal irreplaceability exists, and all other factors being equal, the decision is taken to select the site/s with the known location of the species. The same principle would apply to otherwise unincorporated data such as areas of Aboriginal interest.
At the moment, the paucity of species data represents a major gap in the level of current biodiversity knowledge. As adequate species data becomes available this can be incorporated into a systematic conservation assessment.
8. ANALYTICAL METHODOLOGY
8.1 THE GEOGRAPHIC INFORMATION SYSTEM GIS’ are designed to integrate geographic or spatial data sets (ie. maps) and have interrogation capabilities allowing the spatial relationships of the data to be analysed, described, modelled and displayed in map form. This means, where appropriate, multiple themes mapped for the one area can be viewed simultaneously, amalgamated in to one theme or analyse one with respect to another. In a GIS, the patterns, points or colours of a map are replaced by codes. These coded areas can be points which represent the location of a feature, lines (vector) which represent linear features, grid cells or irregular polygons which represent area features or some combination of these.
44 The advantage of GIS is that very large data sets can be readily stored and accessed, manipulated, analysed and viewed.
The data incorporated into the GIS had a number of different origins. Some were imported and converted from other GIS and hard copy maps were digitised into GIS. The GIS used for this project was the Environmental and Resource Mapping System (E- RMS) (Ferrier, 1988) which is a square grid (ie. raster based) system and operates within a Microsoft Windows environment (WinE-RMS version 1.0b) on an IBM 330- Pentium 75 personal computer. This was the GIS in use by NPWS at the time of analysis.
Data was recorded at a resolution of 100 metre by 100 metre grid cells (1 ha). Analyses involved the interrogation of data using E-RMS. Specific questions were answered by overlaying and combining data layers such as vegetation, geomorphology, tenure, and land use. The results of analyses were retrieved in both map and report formats.
For presentation purposes (all figures presented in the report) and computation of some statistics the data layers were converted into the ESRI ArcView format.
8.2 THE DATABASE MANAGEMENT SYSTEM The GIS and the conservation planning software (C-Plan) are linked to a database management system. The database management system stores spatial data (grid cell, point, vector and polygon) and tabular data relating to information on sites, attributes (such as vegetation types) and conservation targets. The database management system allows the user to select sites and access information from the GIS display, by double clicking on the screen for those sites of interest. After analysis, the database management system links the site summary table, containing site status, with the GIS, allowing the display to be updated.
8.3 IRREPLACEABILITY The irreplaceability analysis required the C-Plan software, GIS data coverages, selection units and retention targets.
8.3.1 C-Plan The C-Plan version 2 was used in November 1997 to calculate irreplaceability. The algorithm specification (refer to Ferrier et. al., in prep.) used was predictor 4 and the combination size was 1874.
8.3.2 Selection Unit As this project is based on a comparative analysis, a rectangular grid configuration was used to provide a standardised selection unit.
Due to the maximum processing capability of the computer hardware the smallest grid configuration that could be analysed was 5km by 5km. There were 3942 grid cell squares covering the Bioregion, each grid cell comprising 2,500 ha. The grid cells on the periphery of the Bioregion will lie partly within and partly outside the Bioregion boundary, thus the area of the Bioregion calculated for irreplaceability (9,855,000 ha) is
45 larger than the area calculated for the Bioregion (9,042,182 ha).
All grid cells within the Bioregion were equally available for selection which means no areas were excluded from the analysis on the basis of tenure or current management regime. Often cells are tagged for calculation selection purposes as 'compulsory' because they comprise part of the existing conservation reserve system and form a starting point for analysis. However, the reservation status of the Riverina is negligible, therefore this analysis treats all grid cells as equally available for selection (ie. without bias).
8.3.3 Identifying the Conservation Goal and Targets Conservation assessment relies on defining attributes that are valued or in need of protection, that is, ‘what to conserve’. Additionally, computer based planning techniques including C-Plan, require the setting of specific goals or targets for each attribute, ie. ‘how much to conserve'. By establishing and documenting these criteria the assessment process is clear and repeatable.
In the Riverina the retention of remaining vegetation is identified as a fundamental component of biodiversity conservation (King, 1983; Brickhill, 1985; Benson, 1989; Roberts and Brickhill, 1992; Scott, 1992; Webster and Ahern, 1992; Bowen and Pressey, 1993; Cohn, 1995; Benson et. al., 1996; Porteners, 1993; Porteners et al., 1997 and Diez and Foreman, 1996). Thus, the conservation goal for the Riverina Project was described as the continued existence of the diversity of vegetation types currently found in the Riverina. The conservation goal was to be satisfied by achieving an individual retention target for each vegetation type. The nominated target represented the percentage area of each remaining vegetation type considered necessary to ensure its persistence in the landscape.
The allocation of retention targets involved the lumping of the vegetation types into the 30 vegetation communities described by Scott (1992), Porteners (1993) and Porteners et al. (1997). The conservation status of the 30 vegetation communities were reviewed and a retention target was assigned to each community (refer to Appendix 2). Each vegetation type lumped into a broad community was assigned the same retention target. This method was chosen because conservation status information was more readily available for vegetation communities than for the specifics of vegetation associations, or species.
The vegetation retention targets were based on: S the extent to which the vegetation community persists in the Riverina (ie. in absolute terms) and conversely it’s extent of relative decline; S the threat of clearing, which can be linked to knowledge of rural land capability , geomorphology substrates suitable for agricultural production; land tenure and management (Crown tenure usually has greater restrictions on clearing and use than freehold tenure); and S opinions of expert botanists and representatives of catchment management committees who manage native vegetation and/or have a good understanding of vegetation in the Riverina.
46 The setting of conservation targets elsewhere for vegetation has been based on the current extent of vegetation coverage relative to the pre-European extent of vegetation coverage (ie. Target = % of pre-European extent). For the Riverina, however, the pre- European vegetation coverage has not been extensively mapped, thus this procedure could not be quantitatively applied.
A sliding scale of retention target values was used to indicate the “high”, “medium”, “low” and “zero” relative levels of retention required. The retention targets are not an absolute measure but, are an expression of the level of retention considered to be required to ensure persistence of each vegetation type in the Bioregion. Four target categories were selected to provide a level of flexibility to reflect the intensity of factors (social, economic and ecological) influencing the persistence of each vegetation type. The retention target categories are as follows:
Vegetation Description Retention Target High - 90% Where 90% of the remaining extent of the vegetation type requires retention. This represents vegetation types that have been largely cleared and are faced with ongoing threats. A 90% target is assigned to compensate for their much reduced extent. Medium - 50% Where 50% of the remaining extent of the vegetation type requires retention. This represents those vegetation types that are widely distributed but still subject to threatening processes. Low - 15% Where 15% of the remaining extent of the vegetation type requires retention. The native vegetation is still extensive and/or not greatly threatened or existing in areas where management is compatible with persistence in the landscape. Zero - 0% Where none of this category will contribute to meeting a conservation goal. Non native vegetation types or vegetation types extensively modified by past activities and considered unworthy of protection.
The conservation goal is now defined by these vegetation retention targets, the allocation of which have satisfied the criteria of what and how much to conserve in the Riverina Bioregion.
8.4 VULNERABILITY TO CLEARING Clearing of native vegetation has been a key threatening process operating on biodiversity in the Bioregion. For this reason it is important to consider the vulnerability of the remaining vegetation in the Riverina with regard to its likelihood of being targeted for clearing. A predictive tool such as this is useful for setting priorities across the Bioregion for conservation action.
Within the Riverina there are two dominating land tenure types. The Lachlan Province is currently leasehold tenure, administered by the State Government. The other provinces are primarily freehold tenure. Leasehold lands are subject to land use restrictions, particularly with regard to broad scale vegetation clearing. As a result the Lachlan Province, while suffering varying degrees of disturbance, is still largely
47 covered with native vegetation.
The approach adopted was an assessment of vulnerability to clearing only in relation to inherent physical land use constraints. This approach is less subject to politics, but also explicitly ignores the current administrative constraints on land use in the west.
A high, moderate and low vulnerability ranking was derived to show those areas most likely to be targeted for clearing for agricultural purposes. This vulnerability ranking was derived from: S a primary data layer based on the relationship between clearing and the various geomorphic units (i.e. this layer covers the whole Bioregion). S a supplementary layer based on rural land capability mapping for the Central Division of NSW (i.e. this layer in some respects may be considered a more reliable layer but is restricted to the Murray Fans and Murrumbidgee Provinces and 11% of the Lachlan Province).
The two coverages were combined to provide a single vulnerability layer for the whole Bioregion. The data show the areas mapped as high, moderate and low vulnerability, for this layer, have experienced 74%, 21% and <1% clearing respectively.
8.4.1 Historic Clearing Patterns of Geomorphic Units Geomorphic units represent areas of homogeneous landform, soil and hydrology. Thus, some geomorphic units across their range, can be expected to be consistently more arable than others. As a consequence, clearing and cropping is expected to be more extensive with these more arable geomorphic units. These units can be expected to remain among the preferred targets for future clearing and are therefore considered most vulnerable.
GIS was used to overlay the geomorphic layer with clearing. For the purposes of this study it is assumed that native vegetation cover, prior to the introduction of ‘European’ farming practices, extended across the Bioregion (i.e. inclusive of areas currently cleared). The resulting data provides an indication of which geomorphic types have been targeted for clearing and are therefore most vulnerable to further clearing.
The vulnerability layer for the Bioregion was modeled based on the clearing across the southern three provinces. The decision to exclude the northern (Lachlan) province was due to the fact that this province has by comparison been subject to relatively little clearing, largely confined to its eastern end. It is likely that controls associated with the leasehold tenure have limited the clearing in this Province. The inclusion of the Lachlan Province was considered likely to bias the suggested trends.
The following rules were applied in developing this component of the vulnerability layer: S In the first instance geomorphic type mapping was used to provide the mapping units for vulnerability. S The various geomorphic types were considered to exhibit low, moderate or high vulnerability according to the proportion cleared (refer to Table 5). Greater than 20% cleared suggests an interest in clearing that geomorphic type and is therefore
48 considered moderately vulnerable. Greater than 50% cleared suggests a strong interest in clearing so the geomorphic type is considered highly vulnerable. S One geomorphic type, Depression Plain, within the Riverina is confined to the Lachlan Province and therefore a vulnerability rating could not be extrapolated from data held for the other three provinces. As a consequence the vulnerability rating for this geomorphic type was based on Lachlan data which suggests low vulnerability because little or no clearing undertaken. However, as previously discussed, clearing in the Lachlan is not considered to be a good predictor of vulnerability and, in time, may turn out to be far more vulnerable than indicated.
Figure 5. The percentage clearing for each geomorphic type within the Victorian Riverina, Murray Fans and Murrumbidgee Provinces and the corresponding vulnerability class which was extrapolated to apply across the entire Bioregion. Inclusive of the Lachlan Province Geomorphic Type Area of Geomorphic % of each Vulnerability Type in Victorian Geomorphic type Class for entire Riverina, Murray Fans cleared in Victorian Bioregion and Murrumbidgee Riverina, Murray Based on Provinces Fans and Clearing Murrumbidgee Provinces Confined Traces 393772 42 Moderate Plain with Depressions 1192335 41 Moderate Plain 1660244 90 High Plain with Scalds 877345 56 High Plain with Channels 760107 72 High Plain with Drains 468906 27 Moderate Depression Plain 103 0 Low Scalded Plain 594340 31 Moderate Channelled Plain 472984 32 Moderate Indistinct Dunefield on 40664 84 High Aeolian Sediments Dunefield 46073 84 High Source Bordering Dunes 67418 62 High Lunettes 38599 58 High Lake 36220 69 High Intermittent Lake 13553 50 High Swamp 20310 67 High Alluvial Colluvial Slope Apron 46620 96 High Hilly Terrain developed on 12760 99 High Tertiary Basalts Tertiary Sands and Gravels 10271 82 High Palaeozoic Granites 26725 93 High Palaeozoic Sediments 119335 86 High 6,898,684 Source: Butler et. al., 1973; Riverina Vegetation Map NPWS.
It is recognized that some may consider that the proportion of highly vulnerable lands has been underestimated. It should be born in mind, however, that one of the purposes of this vulnerability mapping is to assist in providing a guide to priority for conservation action. This aim can only effectively be achieved if the vulnerability mapping is more relative rather than absolute.
49 8.4.2 Rural Land Capability Land capability is a measure of the potential of the land to support agricultural production. Rural land capability classification is based on biological and physical properties making it a relatively reliable indicator of potential land use. It is also at a finer scale (1:100,000) than the geomorphic mapping and thus provides greater detail. However, the Rural Land Capability mapping is only available for the NSW Central Division (Murrumbidgee and Murray Fans Provinces and 11% of the Lachlan Province) of the Riverina. Therefore it was not suitable for use as a primary layer for predicting vulnerability across the whole Bioregion.
For the Central Division of NSW the rural land capability categories were combined according to the potential of the land to support cultivation. These were then assigned a vulnerability class, such that the greater the potential for cultivation, the greater the likelihood for clearing of native vegetation and the higher the vulnerability rating. Lands mapped as not suitable for cultivation were assigned a low vulnerability, lands suitable for grazing or occasional cultivation were assigned a moderate vulnerability and lands identified as suitable for regular cultivation were assigned a high vulnerability.
Measurements of clearing within each land capability type suggest that, in relative terms, some types have been more extensively cleared than might be expected from their ‘land capability’ (refer to Table 6). Reasons for this may include (a) the development of irrigation channels which allows irrigation cropping further from rivers, (b) access to ground water supplies; and (c) use of less arable land such as sand dunes for growing non irrigated crops such as potatoes.
Table 6. The area of cleared land within each rural land capability class for the Murray Fans and Murrumbidgee Provinces. (where HC = High Capability, MC = Moderate Capability, LC = Low Capability). Province Area of HC Land Area of MC Land Area of LC Land Cleared (ha) Cleared (ha) Cleared (ha) Murray Fans 900,299 (96%) 324,693 (63%) 65,414 (28%) Murrumbidgee 370,285 (83%) 301,451 (15%) 63,479 (13%)
8.4.3 Vulnerability - The Two Measures Combined Both vulnerability measures have their strengths and weaknesses. Thus, the mapping of vulnerability classes based on land capability has been used to supplement, rather than dominate over, the vulnerability mapping based on clearing within geomorphic types. That is, the vulnerability rating for any point within the Riverina is based on the higher value from the two rating systems(eg. where one measure suggests an area has moderate vulnerability and the other high vulnerability, the vulnerability rating for the area is taken to be high). This approach was taken in recognition of the complementary nature of the two vulnerability mapping methods and in order to ensure a precautionary approach to the determination of vulnerability.
50 9. ASSUMPTIONS AND LIMITATIONS UNDERLYING THE ANALYSIS The conservation goal is to ensure the continued existence of the diversity of remaining native vegetation types within the Riverina Bioregion. Prior to presenting the results it is first worth summarising the assumptions and limitations of the analyses.
Assumption: The IBRA regionalisation as described by Thackway and Cresswell (1995) adequately represents the biophysical characteristics of the Riverina Bioregion. Limitations: S The IBRA boundaries have not been systematically revised. In developing IBRA state nature conservation agencies used different attributes for different purposes and at different scales (Thackway and Cresswell, 1995). S At the broad (bioregional) scale, generalisation of information conceals any finer scale landscape patterns and much of the internal heterogeneity. S There are edge effects along the boundary which are attributed to characteristics of adjoining bioregions.
Assumption: The vegetation type map derived for the project characterises the diversity, extent and distribution of vegetation within the Riverina Bioregion. Limitations: S The map is only as valid and current as the original mapping from which it is derived. S The scale of mapping at 1:250,000 will conceal some of the complexity observed in the real world. S The map was derived from data sets that were produced at different times using various methodologies and scales. S The map more accurately represents the extent and distribution of woody vegetation than non-woody vegetation, such as Grasslands. S The map infers that the vegetation condition is consistent and not significantly degraded across the Bioregion. While this is known to be incorrect, there is no qualitative data on vegetation condition to supplement the map. S While there are questions as to the capacity for the vegetation map to adequately reflect the distribution patterns of flora across the landscape, the suggestion that it reflects fauna distribution is even more tenuous.
Assumption: That native vegetation originally covered the extent of the Bioregion.
Assumption: Nominated vegetation retention targets are rational and satisfactorily reveal the irreplaceability of sites across the Bioregion. Limitations: S The lack of information available prevented targets taking into account factors such as endemicity.
51
Assumption: Native vegetation clearing is a key threatening process in the Bioregion and therefore provides an adequate broad measure of the vulnerability. Limitations: S The extent of non-native vegetation coverage across the Bioregion was used to provide an indication of the extent of clearing across the Riverina. This is a problem in so far as habitat degradation may have occurred, for example, through attempts to improve grazing (ie. retaining areas of native understorey species while removing the overstorey species). S Vulnerability tends to be based on historic trends which is largely due to the issue of data availability. S The vulnerability layer only takes into account the threat of broadscale clearing (for cultivation). There is no feasible way to incorporate grazing pressure information into the layer, nor at this point is information available to predict the extent of other processes such as salinisation which would affect native vegetation extent.
Assumption: Non-native vegetation does not contribute to the conservation of biodiversity. Limitation: Non native vegetation does provide habitat for biodiversity. However, the focus of this project is on the relative priorities for native vegetation because natural vegetation supports the maintenance of natural ecological processes. In addition, detailed information relating to the tolerance of individual species (particularly fauna) to landscape modification, particularly the cumulative effects are largely unknown. While some native species may thrive within an area following habitat modification, this is invariably at the expense of biodiversity in the area as a whole.
Assumption: That conservation assessment and action should initially occur on those areas of the landscape which make the highest contribution to regional biodiversity and are the most threatened (ie. those areas of high irreplaceability and high vulnerability).
52 10. RESULTS AND DISCUSSION
10.1 COMMUNITY AWARENESS A general awareness of the project aims and objectives was raised through the use of the Catchment Management Committee network within the Bioregion and in this respect the project succeeded in its intent. Enquiries arising from individuals outside of the CMC’s also tended to suggest that information about the project had diffused widely, thus indicating that the approach adopted met with some success.
The Murrumbidgee, Murray and Lachlan Catchment Management Committees were generally supportive of the project and acknowledged the opportunity to integrate regional conservation assessment with community based strategies and projects, particularly projects based on vegetation mapping.
Community interaction in regional planning is a learning process for both NPWS and the community. It is obvious that there is an interdependency between government and the community for information. The question becomes one of how to access the information so that all benefit equitably. This requires trust by all parties and importantly, a willingness to recognise and preferably understand the issues involved. This level of trust is slowly developing as community and government work together to achieve good environmental outcomes.
Some of the main issues raised during the course of the project are discussed below.
Location of the Project It was suggested by the CMC’s that the project should have operated from within the Bioregion. The NPWS understood these concerns however, it was not practicable technically because the computer hardware and technical expertise necessary to run C- Plan was based in NPWS Head Office, Hurstville. However, to ensure that there was an interchange with the community by people familiar with local issues, the NPWS Griffith District Office offered a point of contact for CMC enquiries. This also permitted a consistent approach within the region.
The tiered location / operation of the project within NPWS required good communication and commitment to this ‘team’ approach from all NPWS operational areas and had a number of advantages. The developmental nature of the project meant that this tiered approach was an enhancement to efficiency as access to essential GIS and information technology support was expedited. New techniques and standards were well understood by NPWS Head Office allowing information to be disseminated rapidly to similar projects across NPWS. Thus, the benefit of not only the results, but the methodology and experience was shared within the agency.
Awareness Versus Consultation A perceived lack of 'consultation' was an issue raised by members of the CMC’s as a result of a media article in the Sydney Morning Herald (18//1997), followed by regional papers. These articles suggested that land allocation decisions on red gum forests would
53 arise from the project. Land management decisions such as this were not within the scope of the project, stakeholder consultation was therefore not necessary or appropriate.
Part of the original intent of the project was to make members of the community aware of the project, its aims and outcomes, and to encourage an open exchange of information. The interest surrounding the media story acted to cast doubt and speculation on this project and as a result valuable project time was diverted into addressing people’s concerns.
This incident however, demonstrates the potentially explosive nature of the issue of land use allocation with respect to private land and the ease with which misinformation can disperse through local communities raising unwarranted suspicion of government action. Unfortunately, unforeseen incidences such as this, increases the time involved to complete the project because time and resources are directed to re-building community or stakeholder confidence.
Community Representation on the Steering Committee In retrospect, at least two community representatives with access to wide regional networks should have been sought to be represented on the Steering Committee. Depending on the skills and resources of the representatives, this may have allowed a championing of the project outside of the government arena to enable a rapid assessment of a community position and response to questions or issues raised by members within the broader community.
However, greater stakeholder participation would incur a real increase in time, effort and money. Funding would need to be carefully allocated to ensure that costs associated with the steering committee meetings (travelling, time and conference costs) could be realistically met. Money would also need to be allocated for the preparation of more sophisticated information packages and opportunities provided to discuss the project at community forums.
Increased stakeholder participation means that greater effort is required to maintain a focus on the project to ensure it operates efficiently. As the number of stakeholders increase, more individual interests are identified and expectations diversify.
10.2 DATA AUDIT AND COMPILATION
10.2.1 Outcomes The data audit process involved the identification and collation of data sources for mapped biological, physical, land use and administrative information in the Riverina Bioregion. Whilst the focus of this data audit was map based information there exists a wealth of text based information, often site specific, which is contained in both government and community reports. Some text based information was used to guide project decisions particularly in the setting of the vegetation retention targets. The remainder of the information was largely not utilised.
The results of the data audit and subsequent data acquisition significantly influenced the
54 potential scope of the project by determining which data layers were ultimately available for analyses. Table 7 lists the information known to be available for the Riverina Bioregion in hard copy map or digital format, the scale of the mapping and the data custodian. The shaded boxes in Table 7 depicts the data used in analysis.
Notably, most of the digital data was acquired from government sources and is generally at a coarse scale. While fine scale mapping would have been desirable with respect to accounting for real world heterogeneity across the landscape, the coarse scale of the actual data available allows the development of a landscape perspective and shows trends across the Bioregion.
Table 7. Data sets for the Riverina Bioregion. (The 'shaded' boxes depict those used in analysis). Data Type Description Custodian Scale Available from NPWS RBG Vegetation Mapping NSW mapping of Pooncarie, Balranald- RBG 1:250,000 Swan Hill, Booligal-Hay, Deniliquin- Bendigo 1:250,000 map sheets Victorian Structural Structural vegetation mapping of forests DNRE 1:100,000 Vegetation in Victoria based on the Land Conservation Council vegetation classification scheme. Primarily based on satellite image interpretation. NPWS NSW Extension Interpretation mapping - Connoble map NPWS 1:250,000; 4 Mapping sheet 1:250,000 Landsat TM satellite 1:100,000 imagery (1995) & Hillston, Merriwagga, Kooroongal, Griffith, Colleambally Yanco, Jerilderie, Urana, Berrigan, Buraja and Walbundrie 1:100 000 map sheets. Landsat TM satellite imagery (1991) Riverina Bioregion Compiled vegetation map from RBG NPWS 1:250,000 4 (NSW Vegetation Map mapping, NPWS NSW extension only) mapping and Victorian structural vegetation mapping Geomorphology Combination of soils and riverine and University 1:500,000 aeolian structures. Applicable across of entire Bioregion Melbourne Rural Land Capability Central Division of NSW. Derived DLWC 1:100,000 layer describing the physical capabilities of land units for agricultural production Murray Darling Basin Woody Vegetation coverage (Basincare MDBC 1:100,000 In Part Commission Vegetation - attributed polygon data of entire study (DLWC/ Mapping (M305) area) Accuracy and reliability not tested NPWS) (refer to Andrews and Flemons, 1997) Grassland Sites Sites used for survey of Grasslands RBG Point Data within the Riverina (Benson et. al., 1996) NSW Forest Type & River Red Gum Forest mapping (not NSWSF 1:15,000 & Management Mapping available at time of project) 1:100,000 Victorian Forest Types Coverage showing forest types. DNRE 1:500,000
55 Data Type Description Custodian Scale Available from NPWS Distribution of Rare or Location of rare and threatened flora for DNRE Point data Threatened Flora in flora and fauna management Victorian. Victorian Tree Cover Coverage showing tree cover as defined DNRE 1:100,000 by woody vegetation greater than 2 m in height and with a crown cover greater than 10%. Victorian Wetlands Coverage showing current extent of DNRE 1:250,000 wetlands in Victoria based on 1970- 1980s air photos. Lachlan River Mapping Riparian vegetation mapping along the DLWC (Wetland Vegetation) Lachlan River and its confluence. Murray Riparian Vegetation Vegetation and land use categories MDBC 1:100,000 along the Murray River (polygon data) Important Wetlands Important NSW wetlands in the NPWS 1:100,000 Riverina Bioregion &1:50,000 Roadside Vegetation Vegetation maps and conservation value Shire 1:50,000 Mapping assessment of roadside vegetation in Councils several NSW Shire Council areas. of Conargo, Deniliquin, Wakool, Corowa. NPWS Wildlife Atlas Recorded flora and fauna locations in NPWS Point Data 4 NSW Plains-Wanderer Habitat Plains-Wanderer identified habitat RAOU 1:50,000 Mapping Waterbirds Waterbird records for selected wetlands NPWS Point data in the Riverina Floodplains Data delineating the extent of DLWC floodplains for the Murray-Darling Basin Rivers NSW rivers LIC 1:250,000 Identified Wild Rivers Identified Wild Rivers. Derived from DLWC the Wild Rivers Report 1987 Topography Digital elevation model (10M) LIC 250M Grid Climate Data (Rainfall) Average annual rainfall for the NPWS 6 min. grid Bioregion Aboriginal Cultural Recorded NSW Aboriginal heritage NPWS Point data Heritage Sites sites - NPWS Aboriginal Sites Register. Water Table Mapping depicting the height of the DLWC water tables Irrigation Structures Shows the location of regulators, DLWC Various drainage channels and supply structures associated with irrigation Irrigation Salinity Predicted salinity in irrigation areas DLWC only (not currently available) Area Erosion and Land Use Data delineating the extent of erosion DLWC Various Irrigation Area Location of NSW irrigation areas DLWC 1:100,000
56 Data Type Description Custodian Scale Available from NPWS Victorian Hydrology Location and identity of hydrological DNRE 1:100,000 features including; rivers, wetlands, channel, anabranch, stream and breakaway streams. Victorian Land use Broad agricultural land uses in Victoria DNRE 1:250,000 Town Layer Point data of the locations of all major Captured Point Data and minor towns for Project Roads NSW roads network LIC 1:250,000 Victorian Roads Victoria road network DNRE 1:500,000 Travelling Stock Reserves Location of travelling stock reserves DAg 1:50,000 & 1:100,000 NSW Local Government NSW local government boundaries LIC 1:250,000 Boundaries NSW State Electoral State electoral boundaries LIC 1:250,000 Boundaries NPWS Estate Land administered by NPWS under the NPWS 1:50,000 4 National Parks and Wildlife Act as at November 1996 Catchment Boundaries NSW catchment boundaries of major DLWC rivers Catchment Management NSW catchment management DLWC 1:250,000 Units committee Boundaries Victorian Public Land Coverage of public land as defined by DNRE 1:500,000 the Victorian Land Conservation Council National Public and NSW tenure layer AUSLIG 1:250,000 Aboriginal Lands NSW Local Aboriginal NSW Local Land Council Boundaries LIC 1:250,000 Land Council Boundaries NSW Regional Aboriginal NSW Regional Land Council LIC 1:250,000 Land Council Boundaries Boundaries State Forest Boundaries Boundaries of state forests AUSLIG 1:100,000 NSW State Forest Estate NSW State Forest Boundaries, Flora NSWSF 1:100,000 Reserves and Timber Reserves DLWC District Boundaries Administrative boundaries of the DLWC Various DLWC Areas subject to NPWS Areas where NPWS has voluntary NPWS 1:50,000 4 Voluntary Conservation conservation agreements with land Agreements owners (limited coverage) Custodian abbreviations are as follows: ANU Australian National University AUSLIG Australian Surveying and Land Information Group DAg NSW Department of Agriculture DLWC NSW Department of Land and Water Conservation DNRE Department of Natural Resources and Environment, Victoria DUAP NSW Department of Urban Affairs and Planning LIC NSW Land Information Centre MDBC Murray Darling Basin Commission NPWS NSW National Parks and Wildlife Service RBG NSW Royal Botanic Gardens, Sydney RAOU Royal Australian Ornithologist Union (Birds Australia) NSWSF NSW State Forests
57 The data obtained for this project is held under data licence agreements for the period of this project and is retained by the Spatial Systems Unit of NPWS’ Geographic Information System Division.
10.2.2 Discussion The detail of the data sets used for analysis were presented in the Methods - Database Development section of the report. However, it is relevant to discuss the findings of the data acquisition process, the quality of map based information and the gaps in current information.
Data Acquisition Process The review and consolidation of the large volume of data and its integration into GIS proved a major task and represented a significant investment in time and resources. It was expected that the data acquisition component of the project would take about 8 months to complete, however, this was expanded to 14 months.
The effort to obtain data was complicated because: S digital data were held by custodians in multiple locations. In NSW there is no single agency coordinating the supply of data. Even within a single agency such as DLWC, data were stored in regional or local offices or by individuals. This resulted in a trial and error approach to locating and obtaining data; S data were lost or misplaced due to poor data management within agencies. The staff turn over in the government agencies meant that current staff were not necessarily familiar with what data was available or its location; S locating the author of the original data, in order to seek permission for data use, was time consuming; S conversion of data into computer readable form was required. In particular, hard copy maps were digitised for use in the GIS; S some data required purchase, such as the information obtained from DNRE. This meant that serious consideration of the suitability and applicability of the data was required prior to purchase to ensure the efficient use of funds; S all agencies deal with data supply on a priority basis. In some instances data for the Riverina project was not considered a high priority by the custodian agency and therefore not processed promptly or at all; S negotiating the detail for some data licence agreements were not standardised because general interagency data agreements had not been finalised; and S political influences restricted the flow of data.
Whilst the process for data compilation and integration was technically straight forward it proved to be expensive in terms of the purchase of data, time and labor costs. The time necessary to undertake this project component was vastly underestimated during the project planning stage. Lessons learnt from this stage of the project include: S a realistic time frame for data acquisition is greater than previously anticipated. In a situation where the location and availability of data is unknown, one year at the least, should be allocated; S allocate sufficient time to audit and review data content and quality (consistency of information, scale, type of information etc.) prior to acquiring the data; S allocate sufficient funds to purchase data or undertake data survey;
58 S apply a cut off date after which no additional data is sought to avoid the temptation to continually ‘improve’ the data rather than process the information already available; S persistence is the key to data acquisition. It was important to follow-up correspondence with phone calls to monitor the progress of data collation, conversion etc.
Reliability and Limitations of Data A number of important issues arose during the course of the data audit which require consideration when using maps prepared by others. Consideration of these issues allow the user to identify limitations associated with the mapping and question the compatibility of that mapping for another purpose. These include: S understanding the original purpose for the preparation of the map so that the appropriateness of its use in a different context can be assessed; S understanding the methodology of data collection and mapping. It is important to understand whether the original data collection was scientifically and/or statistically valid (ie. adequate sampling, standard procedures etc.). It is important to know how the information was derived, for example interpretation of remotely sensed imagery or air-photo with or without extensive ground truthing field survey; S determining the completeness of the data coverage. Whether the mapping covers your area of interest; S understanding the extent of extrapolation and/or modeling used to derive the current data set. Again, it is important to know the derivation of the information and its scientific validity. If the data is from a model it will be important to understand the assumptions made in the model, and recognise that impact of a cumulative use of modelled information; S knowing the scale of the mapping. For example, it is possible to generalise information from a small map scale (more detailed) to a large map scale (less detailed) but the reverse can not be undertaken with any degree of accuracy; S knowing the currency of the map. Old data may be useful if the features are not likely to change rapidly with time, such as geology, but for those features which are subject to change such as land use or land tenure, the use of old data would be inappropriate; S recognising that differing data gathering methodologies, database grid sizes and any subsequent errors arising from map digitising and data conversion process can result in imperfect matching of one data set against another. In combining maps, discrepancies will arise which may impact on data analysis, such as anomalies in calculated areas for attributes.
In order to establish the suitability of the data, the user needs to have access to the information on the data specifications, called metadata. The onus is often on the user to piece together the metadata rather than the data custodian to ensure that metadata is made available to potential users. For this project, metadata was available for very few of the acquired data layers. Where possible, this information was obtained personally from the data provider or by reading published papers or reports to obtain an understanding of the data collection methodology. NPWS (Geographic Information System Division) holds the metadata for key data layers derived for this project.
59 Information Gaps A range of biological information existed for the Riverina Bioregion, but most of this information was captured to address highly specific issues dealing with particular biological species or communities (eg. Plains-Wanderer habitat), localities (eg. Murray River) or resources (eg. production forests). Consequently, individual data sets are often limited in geographic extent and are biased in their subject coverage. Between data sets are variation in the methodology and scale of data capture, format and quality.
There are few systematically surveyed or mapped GIS data available which provide a consistent coverage across the whole of the Bioregion. In addition, this information is often biased towards natural resources to promote agricultural production (such as hydrology), and therefore often fail to provide the broad based ecological knowledge required for conservation assessment.
The most obvious gap in current information relates to the quantity and quality of fauna data. Fauna data is available from the NSW NPWS Wildlife Atlas, but it is biased because it provides information on where species are known to occur, and not where species do not occur.
Within the Bioregion there are two threatened fauna species, the Plains-wanderer and Superb Parrot, which have been the subject of research. Although some information relating to these species exists in map form, it was not used in this project, due to issues of bias. The significance of these species is recognised and any recommendations for species recovery prepared should be implemented given the sites specific detail of the information collected.
The need for systematic fauna survey for the Riverina Bioregion is evident. Such a survey would enable predictive modeling of species distribution across the Bioregion. This information could then be incorporated into the comparative analysis approach to conservation assessment adopted for this project.
The other significant gap relates to the comprehensiveness of the Grassland mapping. Although current mapping shows the extent to which Grassland covers the Bioregion there is no qualitative information within that layer to indicate diversity of species or current condition of the Grassland coverage. For this reason effective comparison between Grassland sites can not be undertaken at this broad scale. To achieve this additional finer scale mapping is required to cover all Grassland areas.
Off reserve conservation areas such as fenced remnants have not yet been mapped. These measures are therefore not formally recognised as part of the protected area system nor accounted for in the analysis of protection status for lands within the Bioregion. Systematic mapping of these off-reserve protected areas should be an important component of future bioregional assessments.
Other noticeable gaps in the available information relate to data which would aid the prediction of threatening processes within the Bioregion such as the expansion of agricultural production particularly, irrigation areas for rice and cotton, areas affected by salinity, and trends in applications for vegetation clearing. Figure 5. Riverina Bioregion vegetation map
60 10.3 VEGETATION TYPES AND VEGETATION MAP
10.3.1 Outcomes The vegetation map prepared (Figure 5, best printed as A0) covers 99% of the Riverina Bioregion. 57,148 hectares was not mapped and is classified as ‘no data’, the bulk of which (56,511 hectares) is located in Victoria, near Swan Hill.
Ninety six native vegetation types were identified and mapped for the Riverina Bioregion (Figure 5). Table 8 shows the extent of coverage of each vegetation type across the Bioregion by state and province.
52% of the Bioregion contains native vegetation. The extent and distribution of native vegetation appears to be an artefact of land use and clearing.
An amalgamation of the vegetation types by dominant species is shown Figure 6 to provide a generalised overview of native vegetation coverage and distribution. The pattern of vegetation coverage varies noticeably from north to south. The northern half of the Bioregion is predominantly vegetated with Grassland, Bladder Saltbush, Cotton Bush/Dillon Bush and Lignum. The vegetation coverage for the southern half of the Riverina is highly fragmented. The largest remnants comprise Riverine Forest, Black Box Woodland, Callitris Woodland and Boree Woodland vegetation communities.
There are 27 vegetation types which occur singularly and/or are limited in extent and distribution across the Bioregion. These vegetation types are identified in Table 8 and Appendix 7. For this project these vegetation types are referred to as 'atypical' because they occur on the periphery of the Riverina and are associated with geomorphology types considered more representative of vegetation communities of an adjacent bioregion.
61
Table 8. The proportion (ha) of vegetation types within each of the provinces of the Riverina Bioregion. # indicates the atypical vegetation types.
Vegetation Types in the Total Extent of Victorian Lachlan Murrumbidgee Murray NSW (ha) Riverina Bioregion Vegetation Type Riverina Province Province Fans in Bioregion (ha) (ha) (ha) (ha) Province (ha) Riverine Forest 445837 91401 31999 136060 186377 354436 Riverine Forest / Black Box 53917 813 149 8133 44822 53104 Woodland Riverine Forest /Lignum 45590 0 37513 1063 7014 45590 Riverine Forest / Dillon Bush 1339 0 0 1339 0 1339 Riverine Forest / Callitris Mixed 852 0 0 0 852 852 Woodland Riverine Forest / Grey Box 501 0 0 0 501 501 Woodland Riverine Forest / Open Area 5156 151 0 0 5005 5005 Open Area / Riverine Forest / 290 0 0 0 290 290 Callitris Mixed Woodland Black Box Woodland 301928 17968 102993 138768 42199 283960 Black Box Woodland / Lignum 97729 0 75523 14168 8038 97729 Black Box Woodland / Old Man 10444 0 4210 6039 195 10444 Saltbush Black Box Woodland / Dillon 9429 0 5230 4199 0 9429 Bush Black Box Woodland / 8513 0 1397 7116 0 8513 (Casuarina) Intergrading Population Black Box Woodland / Callitris 25309 0 7966 16637 706 25309 Mixed Woodland Black Box Woodland / Grey 3406 0 0 0 3406 3406 Box Woodland Dune Crest Mallee # 803 0 58 0 745 803 Dune Crest Mallee / Linear 18 0 18 0 0 18 Dune Mallee / Open Area # Dune Crest Mallee / Belah- 934 0 934 0 0 934 Rosewood # Sandplain Mallee # 10095 0 9812 283 0 10095 Sandplain Mallee / Belah- 1293 0 0 1293 0 1293 Rosewood # Sandplain Mallee / Black 2293 0 2293 0 0 2293 Bluebush # Belah-Rosewood 33555 209 28475 4683 188 33346 Belah-Rosewood / Black 29419 0 29419 0 0 29419 Bluebush Belah-Rosewood / Callitris 13749 0 13215 534 0 13749 Mixed Woodland Belah-Rosewood / Acacia 11 1 10 0 0 10 melvillei Woodland Belah-Rosewood/Black 38411 0 975 37436 0 38411 Bluebush / Callitris Mixed Woodland Belah-Rosewood / Open Area # 987 0 987 0 0 987 Belah-Rosewood / Black Box 1054 0 300 511 243 1054 Woodland # Belah-Rosewood / Sandplain 18054 0 14893 0 3161 18054 Mallee / Callitris Mixed Woodland Belah-Rosewood / Pearl 629 0 629 0 0 629 Bluebush # Black Bluebush 204167 3 162544 41483 137 204164
63 Vegetation Types in the Total Extent of Victorian Lachlan Murrumbidgee Murray NSW (ha) Riverina Bioregion Vegetation Type Riverina Province Province Fans in Bioregion (ha) (ha) (ha) (ha) Province (ha) Black Bluebush / Black Box 2056 0 0 2056 0 2056 Woodland Black Bluebush / Pearl 36968 0 36968 0 0 36968 Bluebush Black Bluebush / Bladder 35083 1 35082 0 0 35082 Saltbush / Old Man Saltbush Black Bluebush / Callitris 825 0 825 0 0 825 Mixed Woodland # Black Bluebush / Acacia 747 0 0 747 0 747 melvillei Woodland # Black Bluebush / Old Man 47527 80 41049 6398 0 47447 Saltbush Black Bluebush / Old Man 1428 0 1428 0 0 1428 Saltbush / Dillon Bush Black Bluebush / Dillon Bush 16201 1 3864 12336 0 16200 Pearl Bluebush 9390 1 9389 0 0 9389 Pearl Bluebush / Black 1426 1 1425 0 0 1425 Bluebush / Old Man Saltbush Bladder Saltbush 586966 0 402509 183796 661 586966 Bladder Saltbush / Black 3303 0 3303 0 0 3303 Bluebush Bladder Saltbush / Slender 106349 0 78304 28045 0 106349 Glasswort Bladder Saltbush / Slender 1714 0 1714 0 0 1714 Glasswort / Old Man Saltbush Bladder Saltbush / Canegrass 36733 0 21134 15599 0 36733 Bladder Saltbush / Lignum 1908 0 1908 0 0 1908 Bladder Saltbush / Old Man 9002 0 7746 1256 0 9002 Saltbush Bladder Saltbush / Dillon Bush 32841 0 32841 0 0 32841 Canegrass 43246 2 35281 7765 198 43244 Canegrass / Lignum 13042 0 6569 6473 0 13042 Canegrass / Cotton Bush 18409 0 9994 8415 0 18409 Canegrass / Dillon Bush 5461 0 5461 0 0 5461 Callitris Mixed Woodland 86246 51 12187 66244 7764 86195 Callitris Mixed Woodland / 4899 0 0 4699 200 4899 Acacia melvillei Woodland Callitris Mixed Woodland / 24624 0 428 24196 0 24624 (Casuarina) Intergrading Population Callitris Mixed Woodland / 1388 0 0 0 1388 1388 Open Area Callitris Woodland on Prior 28895 0 0 28895 0 28895 Streams Acacia melvillei Woodland # 527 0 527 0 0 527 Lignum 365199 1728 248406 106772 8293 363471 Lignum / Black Bluebush 720 0 720 0 0 720 Lignum / Open Area 7526 0 7526 0 0 7526 Old Man Saltbush 22883 1 16170 6712 0 22882 Old Man Saltbush / Dillon Bush 1569 0 1560 9 0 1569 Cotton Bush 434149 1 48263 344222 41663 434148 Cotton Bush / Bladder Saltbush 35458 0 1576 30093 3789 35458 Cotton Bush / Callitris 3749 0 0 3749 0 3749 Cotton Bush / Dillon Bush 228444 0 170288 58156 0 228444 Dillon Bush 67116 0 23419 36708 6989 67116
64 Vegetation Types in the Total Extent of Victorian Lachlan Murrumbidgee Murray NSW (ha) Riverina Bioregion Vegetation Type Riverina Province Province Fans in Bioregion (ha) (ha) (ha) (ha) Province (ha) Dillon Bush / Lignum 3089 0 0 3089 0 3089 Dillon Bush / Cleared and-or 7734 0 7734 0 0 7734 Cropped Dillon Bush / Open Area 37861 0 37861 0 0 37861 Dillon Bush /Open Area 2990 1 2989 0 0 2989 /Lignum Great Cumbung Swamp 4445 0 4445 0 0 4445 Grey Box Woodland 24433 11575 0 432 12426 12858 Grey Box Woodland / Callitris 5141 0 0 2153 2988 5141 Mixed Woodland Grey Box-Blakely's Red Gum- 2108 0 0 0 2108 2108 Callitris # Boree Woodland 106718 0 10179 91504 5035 106718 Boree Woodland / (Casuarina) 594 0 594 0 0 594 Intergrading Population Open Area / Boree Woodland 1534 0 1534 0 0 1534 Grassland 774409 1 0 773451 957 774408 White-top Grassland / Callitris 299 0 0 299 0 299 Mixed Woodland White-top Grassland / Open 583 0 0 583 0 583 Areas (Casuarina) Intergrading 2955 0 2813 142 0 2955 Population Dwyer's Red Gum-Callitris-Grey 173 0 0 0 173 173 Box # Bull Mallee # 1494 1494 0 0 0 0 Blakely's Hill Gum # 732 732 0 0 0 0 Broad-leaved Peppermint # 188 188 0 0 0 0 Yellow Gum # 232 232 0 0 0 0 Red Stringybark # 460 460 0 0 0 0 Red Box # 125 125 0 0 0 0 Blue Mallee # 52 52 0 0 0 0 Narrow-leaved Peppermint # 23 23 0 0 0 0 Red Ironbark # 1916 1916 0 0 0 0 Long Leaf Box # 8817 8817 0 0 0 0 Broom Honey Myrtle # 490 490 0 0 0 0 Softwood Plantation VIC 185 185 0 0 0 0 Bare Areas / Degraded 422 0 422 0 0 422 Open Area 206705 1 183921 18750 4033 206704 Water 5611 94 674 2261 2582 5517 Cleared and-or Cropped 4092787 1960945 89921 745045 1296876 2131842 Area Native Vegetation (ha) 4,679,324 138,519 1,867,555 2,274,739 398,511 4,540,805 Total Mapped Area of 8,985,034 2,099,744 2,142,493 3,040,795 1,702,002 6,885,290 Riverina Bioregion (ha) % of Bioregion Comprising 52 Native Vegetation
65 10.3.2 Discussion The vegetation map produced for this project is the only compilation map that covers the entire Riverina Bioregion. There are recognised limitations to the map that are associated with vegetation classification and map interpretation techniques. In summary, these limits are: S the vegetation type map provides reliable detail for woody vegetation; S the Victorian structural vegetation mapping did not contain a Grassland category. Grassland in Victoria was not included in analyses; S the Grassland mapping for NSW does not differentiate between those areas which predominantly comprise native species and those that comprise improved pasture species. Thus, the Grassland coverage particularly in the Murrumbidgee Province appears extensive, but the composition, diversity and condition of the Grassland is not quantified or qualified. What is presumed to be native Grassland may well be grossly overestimated. Native Grasslands are recognised as a nationally important vegetation community but accurate and detailed Grassland mapping for the Riverina is lacking and this is a significant gap in the regional information base. Some high conservation value sites have already been identified by Benson et. al. (1996), which can be used to provide additional detail to the coarse scale map; S the coarseness of vegetation mapping excludes vegetation remnants smaller than 1 hectare. This is likely to have concealed the presence of some remnants as well as rare or unique features located within extensive vegetation types. Likewise heterogeneity within vegetation types is not identified. This means that the diversity of habitat within a vegetation type will not be recognised; S that inconsistencies in vegetation classification methodology and variation in scale have produced irregular data joins at the map edges. The most notable effect is shown on the map, west of Coleambally at the join of two map sheets. The straight line edge depicts Boree Woodland (Acacia pendula) on the western map sheet and Grassland on the eastern map sheet. This variation in interpretation may result in an under or overestimation of the area of vegetation types, namely Boree Woodland and Grassland; S that Victorian mapping is limited in species detail; S lack of a condition score attributed to the vegetation types. The map suggests that the condition of vegetation across the Bioregion is similar, where in fact this is not true; S that information presented for the woody vegetation is more reliable than for grassland/shrubland.
The production of a region-wide vegetation map for the Riverina (available in digital form) is a significant outcome of the Project. The Riverina vegetation map provides a good indication of the extent and distribution of native vegetation across the Bioregion and can be used effectively at the 1:250,000 scale to show trends in vegetation. In particular, the map provides a regional perspective on vegetation which was previously lacking. This perspective should aid decisions with respect to vegetation management across the landscape and provide some understanding of options available within each province. This opportunity is especially important in the Riverina because of the high degree of fragmentation of vegetation which has already occurred in the south of the Bioregion.
66 Whilst this report explicitly documents the limitations of the map this should be considered as an advantage rather than a hindrance to its use because acknowledging and understanding the limits of the map can only enhance its practicality as a tool for regional planning.
Improvements to the Riverina Bioregion vegetation map could best be made by: S the completion of mapping for the Jerilderie, Narrandera, Cargelligo and Ivanhoe 1:250,000 map sheets. The mapping techniques used should be compatible with that previously undertaken by the Royal Botanic Gardens to ensure similar classification, interpretation and map sheet edge joining techniques are used; S access to floristic and structural detail for Victorian vegetation to improve the understanding of vegetation diversity within native vegetation remnants; S undertaking native grassland mapping across its extent in the Bioregion at a finer scale; S assessing the relative condition of native vegetation; and S validating, monitoring and mapping the changes in vegetation coverage with time.
10.4 STATUS OF RESERVATION WITHIN THE RIVERINA BIOREGION
10.4.1 Area of Riverina Bioregion within Dedicated Reserves The Riverina Bioregion covers an area of approximately 9 million hectares of which only 0.6% (56, 854 ha) is currently protected in reserves for which conservation is the primary management objective (Table 9). The largest conservation reserve in the Riverina is Willandra National Park in NSW.
On an Australia-wide basis the reservation status of the Riverina Bioregion is very poor (Thackway and Cresswell, 1995).
Table 10 shows that 1.5% of land in the Victorian component of the Riverina is reserved, while in NSW the Bioregion has only 0.3% by area reserved. Of the provinces, the Victorian Riverina has the highest reservation status and within NSW, the Lachlan Province has the highest reservation status.
Table 9. Status of dedicated reserves in the Riverina Bioregion. Dedicated Reserve Category Number of Total Area Percent of Reserves (ha) Bioregion (%) National Park (NSW) 1 19091 0.21 Nature Reserve (NSW) 4 2912 0.03 Flora Reserve (NSW) 7 2523 0.03 State Park (VIC) 3 10400 0.12 Reference Area (VIC) 5 258 0.00 Flora and Fauna Reserve (VIC) 3 1321 0.01 Flora Reserve (VIC) 8 986 0.01 Bushland Reserve (VIC) 126 2320 0.03 Wildlife Reserve (VIC) 31 17043 0.19 Total Dedicated Reserves 188 56,854 Total Area Riverina Bioregion 9,042,182 0.63 Source: NPWS Estate; Auslig 1990 for Flora Reserve (updated from SFNSW Deniliquin); Department of Conservation and Natural Resources 1991 - Public Landuse.
67 Table 10. The area of land in dedicated reserves for each province. State Province Total Area Reserved Percent (ha) Area (ha) Reserved (%) New South Wales 6,891,966 24,526 0.36 Lachlan 2,145,081 19,786 0.92 Murrumbidgee 3,043,775 2,217 0.07 Murray Fans 1,703,110 2,523 0.15 Victoria Victorian Riverina 2,150216 32,328 1.50 Riverina Bioregion 9,042,182 56,854 0.63 Source: NPWS Estate; Auslig 1990 for Flora Reserve (updated from SFNSW Deniliquin); Department of Conservation and Natural Resources 1991 - Public Landuse.
10.4.2 The Status of Vegetation Types within Dedicated Reserves 0.8% (38,581 ha) of the mapped naturally vegetated area of the Riverina (4,679,324 ha) is within the reserve system.
68% of the reserve system within the Riverina contains native vegetation. The vegetation types within reserves are shown in Table 11. The remaining 32% contain degraded land and this is largely within Willandra National Park in NSW.
The vegetation types within the reserve system are not representative of the diversity of vegetation types that exist in the Riverina Bioregion. On a presence/absence basis, only 26 of the 96 vegetation types derived for the Riverina are represented within reserves (refer to Table 11). This means, 73% of the remaining vegetation types are not sampled in the reserve system.
Of the 26 vegetation types represented within reserves 13 have less than 2% of their current extent reserved and only 4 vegetation types have greater than 10% of their current extent reserved (see Table 11). Interestingly, of these 4 vegetation types Bull Mallee, Red Box, Broom Honey Myrtle and Blakely's Hill Gum are considered atypical of the Riverina Bioregion.
In effect, those vegetation types which are reasonably well represented by areal extent within reserves do not typify the Riverina Bioregion. Thus, with respect to vegetation types within dedicated reserves, the heterogeneity of the Bioregion is not sampled (ie. the reserve system is not comprehensive) and there is a high bias towards a few vegetation types. Many of the reserves which have been established in the Bioregion are too small and as a result conservation efficiency is reduced. While protecting areas of any size can benefit conservation goals, research has shown that more species are lost for a smaller remnant (ie. small remnants support less species per hectare than do more sizeable areas of similar habitat). This problem is compounded by the fact that, if managed to optimise conservation goals, smaller reserves generally require more management resources per hectare.
With the exception of Bull Mallee, Broom Honey Myrtle and Blakely's Hill Gum all vegetation types within the Riverina Bioregion require increased protection status within a protected area system.
68 10.4.3 Discussion The poor reservation status of the Riverina Bioregion is a consequence of several factors: S the historical lack of systematic state and region wide conservation reserve planning; S the lack of political and public appeal of semi-arid ecosystems for other than agriculture; S the limited availability of Crown land for incorporation into the reserve system; and S limited opportunity to purchase land due to the high costs involved.
Even when considered within the bioregional context, the Riverina Bioregion is split by the NSW - Victoria border and due to political sovereignty has largely been treated as two distinct areas. Whilst the Land Conservation Council of Victoria in 1985 prepared a planning context for the Victorian Riverina, there was no similar undertaking for NSW. Apart from the Riverina Bioregion being a constituent of the Murray-Darling Basin, this project represents the first study to use the Riverina as one biogeographic planning unit. As a result, there has not previously been any attempt to systematically assess the conservation status and consider regional conservation priorities for the Riverina.
Due to the lack of charisma of the arid and semi arid ecosystems such as the saltbush communities, there has been little public interest or concern raised and therefore no political imperative to protect these communities. However, with government commitment to establish a comprehensive, adequate and representative protected area system this is one factor which may be redressed.
The poor reservation status of the Riverina Bioregion is going to be difficult to rectify because there is a very limited availability of Crown land which the Government can convert to reserves, as has been the case for the bulk of NSW reserves. The predominance of freehold and leasehold land in the Riverina Bioregion means that the establishment of future conservation reserves requires purchase. This represents an initial dollar cost for government. The high agricultural potential of lands in the Riverina also means that purchase is so expensive it is often considered prohibitive.
The high productivity of land also means that there is strong competition between land use for conservation versus consumptive use of the natural resources. Land being made available (ie. on offer to conservation agencies, or on the open market) may in fact be land that is no longer suitable for agriculture or productive. Thus, a reserve system which is comprehensive and representative of biodiversity may never be achieved in the Riverina.
The combination of the lack of systematic assessment, lack of available funding for land purchase, high productivity of the Bioregion and the fierce competition for resources means that few reserves are established and areas subject to agricultural production expand. Over time, this has reduced the quality of the natural environment and will increasingly continue to limit options for reservation of protected areas. The reserve system in the Riverina is unlikely to ever be fully representative of natural biodiversity of the region. For this reason community based biodiversity protection measures should be encouraged by government.
69 Table 11. Native vegetation types within conservation reserves by area (ha) and percentage (%). Vegetation Type Total area Nature National Flora Flora Flora Bushland State Park Wildlife Reference Total Area % of within Reserve Park (ha) Reserve Reserve Fauna Reserve (ha) Reserve Area (ha) in Reserves Vegetation Bioregion (ha) (NSW) (VIC) (ha) Reserve (ha) (ha) (ha) Type Reserved (ha) (ha) (ha) in Bioregion
Broom Honey Myrtle 490 260 260 53.06 Blakely's Hill Gum 732 144 13 48 205 28.00 Bull Mallee 1494 277 42 319 21.35 Red Box 125 14 14 11.20 Red Stringybark 460 44 44 9.57 Blue Mallee 52 2 1 3 5.77 Grey Box Woodland / Callitris Mixed 5141 251 251 4.88 Woodland Black Box Woodland / Lignum 97729 238 3539 3777 3.86 Cotton Bush 434149 12238 12238 2.82 Grey Box Woodland 24433 11 185 289 113 598 2.45 Riverine Forest 445837 28 1030 237 71 7206 1373 256 10201 2.29 Yellow Gum 232 5 5 2.15 Black Box Woodland 301928 1671 88 773 270 1508 1877 6187 2.05 Callitris Mixed Woodland / Open Area 1388 26 26 1.87 Lignum 365199 147 2457 753 3357 0.92 Riverine Forest/ Lignum 45590 402 402 0.88 Dillon Bush / Open Area 37861 303 303 0.80 Red Ironbark 1916 3 9 12 0.63 Long Leaf Box 8817 47 47 0.53 Canegrass 43246 123 123 0.28 Cotton Bush / Dillon Bush 228444 109 109 0.05 Callitris Mixed Woodland 86246 32 2 34 0.04 Black Bluebush 204167 53 53 0.03 Black Bluebush / Old Man Saltbush 47527 6 6 0.01 Canegrass/Cotton Bush 18409 1 1 0.01 Bladder Saltbush 586966 6 6 0 Total 2912 18749 1056 795 917 643 9127 4127 256 38581 Source: Tenure - Auslig (1990); NPWS Estate; Department of Conservation and Natural Resources (1991) - Public Landuse and Riverina Bioregion Vegetation layer derived for the Riverina Project NPWS (1998).
70 There already exist a number of vegetation management initiatives in place which act to protect vegetation outside of the dedicated reserve system. These include: S voluntary conservation agreements administered by the NPWS and voluntary property agreements available under the NSW Native Vegetation Conservation Act 1997. S the protection of roadside vegetation, advocated and managed by local shire councils. Roadside vegetation management guidelines have been prepared for Conargo, Deniliquin, Corowa and Wakool Shires (Mulham, 1994 a, b, c; Oxley, 1995). S property planning to protect and regenerate vegetation remnants.
10.5 CLEARING STATUS
10.5.1 Outcomes Clearing refers to lands which are cleared of native vegetation including cropped, under plantation, bare, degraded and open (ie. degraded areas containing introduced pastures). Figure 7 shows that about 47% of the Riverina Bioregion is either currently cleared of native vegetation or mapped as degraded. Table 12 illustrates that both the Victorian Riverina and Murray Fans Province Provinces are predominantly cleared.
Table 12. The proportion of native vegetation cleared in the Riverina Bioregion by state and province. State Province Total Area Cleared Percent (ha) (ha) Cleared (%) New South Wales 6,891,966 34 Lachlan 2,145,081 274,264 13 Murrumbidgee 3,043,775 763,795 25 Murray Fans 1,703,110 1,300,909 76 Victoria Victorian Riverina 2,150,216 1,961,131 91 Total Mapped area of 8,985,034 4,300,099 48 Riverina Bioregion Derived from the Riverina Bioregion Vegetation Map, 1998 (note: 57,148 hectares of the Bioregion was not mapped).
10.5.2 Discussion As expected, clearing in the Riverina is associated with areas known to be suitable for large scale intensive cropping, namely the irrigation areas of the Victorian Riverina, Murray Fans and Murrumbidgee Provinces. Most of the clearing in the Riverina has occurred on floodplains, where the soils are fertile and access to water is good. This is illustrated from Table 13 which shows that areas identified as capable for agricultural production such as the Murray Fans and Murrumbidgee Provinces have already been cleared.
71 Table 13. The area of cleared land (not including degraded categories) within each land capability class for the Murray Fans and Murrumbidgee Provinces. Only 11% of the Lachlan Province are covered by the Rural Land Capability mapping as therefore this information is not presented. Province High Land Area Moderate Area Low Land Area Capability Cleared Land Cleared Capability Cleared (ha) (ha) Capability (ha) (ha) (ha) (ha) Murray Fans 933,702 900,299 513,761 324693 236,918 65,414 (96%) (63%) (28%) Murrumbidgee 445,151 370,285 2,068,881 301451 491,192 63,479 (83%) (15%) (13%)
Vegetation remaining in the Victorian Riverina and Murray Fans Provinces is now highly fragmented and restricted in its distribution. In contrast, the Murrumbidgee and Lachlan Provinces maintain a continuous native vegetation cover because there is less rainfall and access to water is more restricted. There has also been clearing restrictions placed on land in the Lachlan Province. These factors have restricted the capability of the land for permanent cultivation, but clearing has occurred through a process of land degradation such as through overgrazing.
Limits to the use of these results There are two main limitations of the mapping used to derive these clearing figures: S the clearing of native vegetation is continual and often parallels the development of new agricultural technology and procedures. It is therefore likely that the amount of clearing has actually increased since the vegetation maps were produced. S the mapping only shows where complete clearing has occurred rather than identifying where there has been a gradual degradation of vegetation communities. These figures therefore do not quantify the impact of vegetation degradation (eg. thinning, grazing), only the total removal of native vegetation. This may account for discrepancies between clearing figures quoted elsewhere (for example, NSWEPA, 1997).
Nevertheless, these figures can be powerful indicators of change in the Bioregion which may also reflect the state of biodiversity within the Bioregion.
72
10.6 VEGETATION RETENTION TARGETS
10.6.1 Outcomes The vegetation retention targets derived for each vegetation type, together with the area of vegetation required to satisfy those targets are shown in Table 14. The limited extent of vegetation remaining in the Bioregion and the fragmented nature of these remnants meant that many of the vegetation types were assigned a high retention target. Of the 96 vegetation types identified in this project, 52 were assigned a 90% target, 11 assigned a 50% target, 16 assigned a 15% target and 17 were excluded from the analysis (0 target).
Fifteen of the 27 atypical vegetation types were assigned a retention target of 90% because they are not extensive or are known to be poorly protected within adjacent bioregions. Vegetation types assigned a nil target included 12 atypical vegetation types, crops, cleared land, open water and Dillon Bush, because it represented a disclimax community.
Grassland was allocated a seemingly low 15% retention target. This target was allocated because Grassland is a vegetation type which is mapped as 'extensive' within the Bioregion. Without better detail regarding the composition and condition of the Grassland communities a higher retention target could not be justified.
To achieve the stated conservation goal 52% of the naturally vegetated area of the Riverina requires protection. This equates to 27% of the Bioregion.
10.6.2 Discussion Vegetation retention targets were used to explicitly define the conservation goal. For a fragmented landscape such as the Riverina, a sliding retention target scale (% - 0, 15, 50, 90) was applied rather than a single target percentage for all vegetation types. This was to account for natural and human induced rarity of vegetation types within the Bioregion.
The retention targets were consistent with the Murray CMC vegetation management categories (1996) and the targets selected were also consistent with the advice received from the Murray CMC after their review of the targets.
The significance of remaining native vegetation in the Riverina and the restricted opportunities available to protect vegetation diversity can not be understated. This is demonstrated by the 52% of the naturally vegetated area of the Riverina which is required to meet the conservation goal.
If the conservation goal is considered reasonable then the conservation effort required to protect 52% of the remaining vegetated component of the Riverina will be substantial. Although substantial in area this could be achieved by not clearing in conjunction with some level of management. Thus, halting degradation for 52% of the remaining vegetated area of the Riverina. Otherwise, the conservation goal will need to be re-evaluated.
74 Table 14. Vegetation type the current areal extent, retention target and the area required to satisfy retention targets. 4 refers to the vegetation type retention targets consistent with the Murray CMC management status categories (August 1996). Vegetation Types in the Riverina Atypical Extent of % of Retention Area within Consistent Bioregion Vegetation Vegetation Bioregion Target Bioregion with Murray Types Type within represented (%) required to CMC Bioregion by Satisfy (ha) Vegetation Retention Type Target (ha) Riverine Forest 445837 4.96 15 66875.55 4 Riverine Forest / Black Box 53917 0.60 50 26958.5 Woodland Riverine Forest /Lignum 45590 0.51 50 22795 4 Riverine Forest / Dillon Bush 1339 0.01 15 200.85 4 Riverine Forest / Callitris Mixed 852 0.01 90 766.8 4 Woodland Riverine Forest / Grey Box 501 0.01 90 450.9 4 Woodland Riverine Forest / Open Area 5156 0.06 15 773.4 4 Open Area / Riverine Forest / 290 0.00 90 261 4 Callitris Mixed Woodland Black Box Woodland 301928 3.36 90 271735.2 4 Black Box Woodland / Lignum 97729 1.09 90 87956.1 4 Black Box Woodland / Old Man 10444 0.12 90 9399.6 4 Saltbush Black Box Woodland / Dillon 9429 0.10 15 1414.35 4 Bush Black Box Woodland / 8513 0.09 90 7661.7 4 (Casuarina) Intergrading Population Black Box Woodland / Callitris 25309 0.28 90 22778.1 4 Mixed Woodland Black Box Woodland / Grey Box 3406 0.04 90 3065.4 4 Woodland Dune Crest Mallee Exclude 803 0.01 0 0 4 Dune Crest Mallee / Linear Dune Exclude 18 0.00 0 0 Mallee / Open Area Dune Crest Mallee / Belah- Include 934 0.01 90 840.6 4 Rosewood Sandplain Mallee Include 10095 0.11 90 9085.5 4 Sandplain Mallee / Belah- Include 1293 0.01 90 1163.7 4 Rosewood Sandplain Mallee / Black Include 2293 0.03 90 2063.7 4 Bluebush Belah-Rosewood 33555 0.37 90 30199.5 4 Belah-Rosewood / Black 29419 0.33 90 26477.1 4 Bluebush Belah-Rosewood / Callitris Mixed Include 13749 0.15 90 12374.1 4 Woodland Belah-Rosewood / Acacia Include 11 0.00 90 9.9 4 melvillei Woodland Belah-Rosewood/Black Bluebush 38411 0.43 90 34569.9 4 / Callitris Mixed Woodland Belah-Rosewood / Open Area Include 987 0.01 50 493.5 4 Belah-Rosewood / Black Box Include 1054 0.01 90 948.6 4 Woodland Belah-Rosewood / Sandplain 18054 0.20 90 16248.6 4 Mallee / Callitris Mixed Woodland Belah-Rosewood / Pearl Bluebush Include 629 0.01 90 566.1 Black Bluebush 204167 2.27 90 183750.3
75 Vegetation Types in the Riverina Atypical Extent of % of Retention Area within Consistent Bioregion Vegetation Vegetation Bioregion Target Bioregion with Murray Types Type within represented (%) required to CMC Bioregion by Satisfy (ha) Vegetation Retention Type Target (ha) Black Bluebush / Black Box 2056 0.02 90 1850.4 4 Woodland Black Bluebush / Pearl Bluebush 36968 0.41 50 18484 4 Black Bluebush / Bladder 35083 0.39 90 31574.7 4 Saltbush / Old Man Saltbush Black Bluebush / Callitris Mixed Include 825 0.01 90 742.5 4 Woodland Black Bluebush / Acacia melvillei Include 747 0.01 90 672.3 4 Woodland Black Bluebush / Old Man 47527 0.53 90 42774.3 4 Saltbush Black Bluebush / Old Man 1428 0.02 90 1285.2 4 Saltbush / Dillon Bush Black Bluebush / Dillon Bush 16201 0.18 15 2430.15 4 Pearl Bluebush 9390 0.10 90 8451 4 Pearl Bluebush / Black Bluebush / 1426 0.02 90 1283.4 4 Old Man Saltbush Bladder Saltbush 586966 6.53 90 528269.4 4 Bladder Saltbush / Black 3303 0.04 50 1651.5 4 Bluebush Bladder Saltbush / Slender 106349 1.18 50 53174.5 4 Glasswort Bladder Saltbush / Slender 1714 0.02 50 857 4 Glasswort / Old Man Saltbush Bladder Saltbush / Canegrass 36733 0.41 50 18366.5 4 Bladder Saltbush / Lignum 1908 0.02 50 954 4 Bladder Saltbush / Old Man 9002 0.10 90 8101.8 4 Saltbush Bladder Saltbush / Dillon Bush 32841 0.37 15 4926.15 4 Canegrass 43246 0.48 15 6486.9 4 Canegrass / Lignum 13042 0.15 15 1956.3 4 Canegrass / Cotton Bush 18409 0.20 15 2761.35 4 Canegrass / Dillon Bush 5461 0.06 15 819.15 4 Callitris Mixed Woodland 86246 0.96 90 77621.4 4 Callitris Mixed Woodland / 4899 0.05 90 4409.1 4 Acacia melvillei Woodland Callitris Mixed Woodland / 24624 0.27 90 22161.6 4 (Casuarina) Intergrading Population Callitris Mixed Woodland / Open 1388 0.02 90 1249.2 4 Area Callitris Woodland on Prior 28895 0.32 90 26005.5 4 Streams Acacia melvillei Woodland Include 527 0.01 90 474.3 4 Lignum 365199 4.06 90 328679.1 4 Lignum / Black Bluebush 720 0.01 90 648 4 Lignum / Open Area 7526 0.08 90 6773.4 4 Old Man Saltbush 22883 0.25 90 20594.7 4 Old Man Saltbush / Dillon Bush 1569 0.02 90 1412.1 4 Cotton Bush 434149 4.83 15 65122.35 4 Cotton Bush / Bladder Saltbush 35458 0.39 15 5318.7 4 Cotton Bush / Callitris 3749 0.04 15 562.35 4 Cotton Bush / Dillon Bush 228444 2.54 15 34266.6 4 Dillon Bush 67116 0.75 0 0 4 Dillon Bush / Lignum 3089 0.03 0 0 4 Dillon Bush / Cleared and-or 7734 0.09 0 0 Cropped
76 Vegetation Types in the Riverina Atypical Extent of % of Retention Area within Consistent Bioregion Vegetation Vegetation Bioregion Target Bioregion with Murray Types Type within represented (%) required to CMC Bioregion by Satisfy (ha) Vegetation Retention Type Target (ha) Dillon Bush / Open Area 37861 0.42 0 0 Dillon Bush /Open Area /Lignum 2990 0.03 0 0 Great Cumbung Swamp 4445 0.05 90 4000.5 Grey Box Woodland 24433 0.27 90 21989.7 4 Grey Box Woodland / Callitris 5141 0.06 90 4626.9 4 Mixed Woodland Grey Box-Blakely's Red Gum- Include 2108 0.02 90 1897.2 4 Callitris Boree Woodland 106718 1.19 90 96046.2 4 Boree Woodland / (Casuarina) 594 0.01 90 534.6 4 Intergrading Population Open Area / Boree Woodland 1534 0.02 50 767 4 Grassland 774409 8.62 15 116161.4 4 White-top Grassland / Callitris 299 0.00 90 269.1 4 Mixed Woodland White-top Grassland / Open Areas 583 0.01 15 87.45 4 (Casuarina) Intergrading 2955 0.03 50 1477.5 4 Population Dwyer's Red Gum-Callitris-Grey Include 173 0.00 90 155.7 4 Box Bull Mallee Exclude 1494 0.02 0 0 Blakely's Hill Gum Exclude 732 0.01 0 0 Broad-leaved Peppermint Exclude 188 0.00 0 0 Yellow Gum Exclude 232 0.00 0 0 Red Stringybark Exclude 460 0.01 0 0 Red Box Exclude 125 0.00 0 0 Blue Mallee Exclude 52 0.00 0 0 Narrow-leaved Peppermint Exclude 23 0.00 0 0 Red Ironbark Exclude 1916 0.02 0 0 Long Leaf Box Include 8817 0.10 90 7935.3 Broom Honey Myrtle Exclude 490 0.01 0 0 Softwood Plantation VIC 185 0.00 0 0 Bare Areas / Degraded 422 0.00 0 0 Open Area 206705 2.30 0 0 Water 5611 0.06 0 0 Cleared and-or cropped 4092787 45.55 0 0 Total Mapped Area 8,985,034 100.00 2,431,003 Total Area of Riverina 9042182 Bioregion
77 10.7 IRREPLACEABILITY ANALYSIS The result of the irreplaceability analysis is shown in Figure 8. The Figure depicts the relative importance of each of the 3942 grid cells in the Bioregion for achieving the defined conservation goal (ie. maintenance of vegetation diversity) as expressed by the conservation targets for each vegetation type. It is evident that about half of the total area of the Bioregion did not contribute to analysis because it was cleared of native vegetation and consequently was not assigned a retention target.
The analysis identifies 87 grid cells which are totally irreplaceable given the mix of vegetation types they contain. This means that some occurrences of a vegetation type might confer total irreplaceability; other occurrences of the same type may not. If the constituent vegetation types in the totally irreplaceable cells are lost (ie. destroyed) one or more of the conservation targets will become unachievable and consequently the conservation goal for the Bioregion will not be satisfied. Thus, the conservation of totally irreplaceable grid cells, or their driving constituent vegetation types, is critical to achieving the set retention targets and broader conservation goals.
The vegetation types which significantly contribute to the 87 irreplaceable grid cells are presented in Table 15. 2.4% of the whole Bioregion is represented by totally irreplaceable grid cells (ie. defined by their component vegetation types). This equates to 4.7% of the vegetated extent of the Bioregion.
Figure 8 also shows the ranking of irreplaceability across the Bioregion. The grid cells assigned a low irreplaceability value (Ir5) have the most replacement sites in the Bioregion and those assigned a totally irreplaceable value have the least. This means, if the vegetation within one Ir5 grid cell is destroyed it is easily replaced by another because the conservation goal can easily be met by a number of sites. To illustrate this concept: S the Great Cumbung Swamp vegetation type (refer to Figure 5) was assigned a 90% retention target. It is geographically restricted, limited extent (4445 ha) and found only in one locality within the Bioregion. If this vegetation type is lost from this location, then the vegetation type will be lost from the Bioregion. For this reason, it was calculated as totally irreplaceable; and S the extensive Grassland of the Murrumbidgee Province is mainly valued at Ir4 - Ir5 because there are many grid cells within the Bioregion containing Grassland which might contribute to satisfying a 15% target. However, if better detailed mapping was available the percentage target is likely to be higher and the irreplaceability value would correspondingly increase. It is expected that better mapping will show that native grasslands worthy of conservation action are more restricted than now shown. More detailed mapping would result in a subdivision of the Grasslands (as by Benson et al. 1996) and each Grassland type would have its own retention target. The occurrences of some types might confer very high irreplaceability on the cells that contain them, while other types may not.
While a low irreplaceability rating suggests there is an opportunity for further agricultural development, it must be recognized that the loss of vegetation from any grid cell will increase, to some extent, the irreplaceability rating of the other cells. If clearing or other forms of habitat destruction continue unabated, all remaining occurrences will
78 inevitably be reassessed as totally irreplaceable.
Table 15. The 87 grid cells considered as totally irreplaceable. The Table indicates the unique grid cell identification number; percentage of the cell which contributes to targets; the main vegetation types found within the cell which influenced its selection as a high priority. Grid Percent Vegetation Type & Percentage Contribution Cell Contribution Number (%) 72 84.36 Belah-Rosewood/Callitris - 11.4%: A. melvillei - 12% 73 79.44 A. melvillei - 99% ; Belah-Rosewood/Callitris - 7.44% 102 100 Belah-Rosewood/Callitris -12% 134 79.08 Sandplain Mallee - 11.24% 170 67.04 Pearl Bluebush - 12.22% 171 79.72 Pearl Bluebush - 19.32% 196 90.6 Lignum/Open Area - 18.14% 229 50 Lignum/Open Area - 12.42% 231 40.48 Lignum/Open Area - 1.87% 259 34.1 Belah-Rosewood/ Open Area - 165.55% 460 30.4 Boree Woodland / Casuarina Integrading Population - 35.58% 461 28.16 Boree Woodland / Casuarina Integrading Population - 75.66% 495 100 Belah-Rosewood/Sandplain Mallee/ Callitris Mixed Woodland - 15.37% 553 73.9 Casuarina Intergrading Population - 108.9% 594 99.164 Belah-Rosewood/Pearl Bluebush - 103.69%; Pearl Bluebush - 15.10% 611 95.72 Lignum / Open Area - 18.10%; Canegrass/Lignum - 1058% 699 71.08 Bladder Saltbush/Slender Glasswort/Old Man Saltbush - 184.36%; Pearl Bluebush - 5.45 777 43.48 Black Bluebush/ Old Man Saltbush/Dillon Bush - 21.16% 781 100 Dune Crest Mallee/Belah-Rosewood - 57.7%; Belah-Rosewood/Callitris Mix Woodland - 11.9% 791 100 Lignum/Black Bluebush - 31.94%; Canegrass/Lignum - 19.53% 792 100 Lignum/Black Bluebush - 75.62%; Canegrass/Lignum - 8.89% 820 76.84 Black Bluebush/Old Man Saltbush/Dillon Bush - 88.94%; Black Bluebush / Pearl BlueBush - 4.06% 824 100 Dune Crest Mallee/Belah Rosewood - 57.7%; Belah-Rosewood/ Callitris Mix Woodland - 11.9% 836 89.56 Bladder Saltbush / Lignum - 127.36% 899 73.28 Black Box Woodland / Casuarina Intergrading Population 23.91% 946 62.24 Black Box Woodland / Casuarina Intergrading Population 12.43% 947 73.44 Black Box Woodland / Casuarina Intergrading Population 12.65% 1006 100 Bladder Saltbush / Old Man Saltbush - 20.02% 1010 93.6 Sandplain Mallee / Black Bluebush - 12.99%; Old Man Saltbush/Dillon Bush - 7.65 1012 97 Old Man Saltbush/Dillon Bush - 16.15% 1015 80.48 Black Bluebush/Callitris Mix Woodland - 97.64%; Black Bluebush/Dillon Bush - 10.45% 1061 74.32 Sandplain Mallee / Black Bluebush - 66.14% 1067 100 Great Cumbung Swamp - 23.62 1068 100 Great Cumbung Swamp - 44.39% 1109 94 Old Man Saltbush/Dillon Bush 29.67 1120 100 Great Cumbung Swamp - 30.55% 1162 44.28 Old Man Saltbush/Dillon Bush 55.02% 1217 77.92 Bladder Saltbush/ Old Man Saltbush - 14.69% 1219 66.2 Pearl Bluebush/Black Bluebush/Old Man Saltbush - 44.96% 1278 33.72 Pearl Bluebush/Black Bluebush/Old Man Saltbush - 38.34% 1279 58.08 Pearl Bluebush/Black Bluebush/Old Man Saltbush - 21.51% 1282 15.08 Sandplain Mallee/Black Bluebush 18.27% 1316 49.74 White Top Grassland/ Open Area - 190.39% 1336 51.88 Belah-Rosewood/ A. melvillei Woodland - 122.22% 1768 100 Black Bluebush/ A. melvillei Woodland - 65.77% 1769 100 Black Bluebush/ A. melvillei Woodland - 45.39% 1825 90.6 Black Bluebush/Black Box Woodland - 37.78% 1826 100 Black Bluebush/Black Box Woodland - 53.07%
79 Grid Percent Vegetation Type & Percentage Contribution Cell Contribution Number (%) 1836 100 Callitris Mix Woodland /A. melvillei Woodland - 19.07% 1837 100 Callitris Mix Woodland /A. melvillei Woodland - 27.76% 1838 100 Callitris Mix Woodland /A. melvillei Woodland - 15.58% 1839 90.52 Callitris Mix Woodland /A. melvillei Woodland - 23.70% 1883 100 Black Bluebush/Black Box Woodland - 11.57%; Black Bluebush/Dillon Bush - 41.64% 2058 33.16 Belah-Rosewood/Black Box Woodland - 46.17% 2059 25.76 Belah-Rosewood/Black Box Woodland - 33.31% 2063 97.72 Sandplain Mallee/Belah Rosewood - 40.13%; Black Box Woodland/Dillon Bush - 18.74% 2064 100 Sandplain Mallee/Belah Rosewood - 28.01%; Black Box Woodland/Dillon Bush - 2.26% 2068 100 Black Box Woodland/Old Man Saltbush - 11.14% 2069 100 Black Box Woodland/Old Man Saltbush - 16.00% 2070 97.04 Black Box Woodland/Old Man Saltbush - 8.26%; Sandplain Mallee/Belah Rosewood - 30.68% 2080 100 White Top Grassland/Callitris Mix Woodland - 61.71% 2138 100 White Top Grassland/Callitris Mix Woodland - 49.44% 2380 91.8 Grey Box Woodland/ Callitris Mix Woodland - 20.10 - (contains Lake Urana Nature Reserve) 2452 32.32 Black Box Woodland/ Grey Box Woodland - 26.33% 2453 23.92 Black Box Woodland/ Grey Box Woodland - 17.32% 2511 20.04 Black Box Woodland/ Grey Box Woodland - 16.34% 2512 14.44 Black Box Woodland/ Grey Box Woodland - 11.78% 2565 17.6 Black Box Woodland/ Grey Box Woodland - 14.35% 2585 25.2 Grey Box Woodland/Callitris Mix Woodland - 13.62% 2591 31.76 Grey Box Woodland/Callitris Mix Woodland - 12.84% 2825 34.72 Grey Box Woodland/Callitris Mix Woodland - 16.53% 2876 46.32 Grey Box Woodland/Callitris Mix Woodland - 14.57%; Riverine Forest/Grey Box Woodland - 25.28% 2893 17.4 Grey Box - Blakey's Red Gum- Callitris - 22.93% 2927 93.04 Riverine Forest/Callitris Mix Woodland - 60.51% -(contains Millewa State Forest) 2928 57.44 Riverine Forest/Callitris Mix Woodland - 32.34%; Riverine Forest/Grey Box Woodland - 24.40% - (contains Millewa State Forest) 2929 36.04 Riverine Forest/Grey Box Woodland - 51.90% - (contains Millewa State Forest) 2944 3.04 E. dwyeri/Callitris/Grey Box - 11.56% 2979 97.76 Open Area/Riverine Forest/Callitris Mix Woodland - 67.82%; Callitris Mix Woodland/Open Area - 18.81% - (contains Millewa State Forest) 2980 91.88 Riverine Forest/Callitris Mix Woodland - 18.26%; Open Area/Riverine Forest/Callitris Mix Woodland - 43.30; Callitris Mix Woodland/Open Area - 15.45% - (contains Millewa State Forest) 2997 10.68 Grey Box - Blakey's Red Gum- Callitris - 14.07% 3076 87.88 Callitris Mix Woodland/Open Area - 12.97% - (contains Perncoota State Forest) 3101 0.72 E. dwyeri/Callitris/Grey Box -11.56% - (contains Boomanoomana State Forest) 3102 7.96 E. dwyeri/Callitris/Grey Box -84.14% 3129 81.96 Callitris Mix Woodland/Open Area - 29.94% - (contains Perncoota State Forest) 3826 48.36 Long Leaf Box - 15.20% 3925 40.92 Long Leaf Box - 12.89% 3926 36.92 Long Leaf Box - 11.63%
80
10.7.1 Discussion The Rank of Irreplaceability across the Bioregion The irreplaceability analysis was based on one attribute, vegetation, and was in effect an analysis of vegetation type rarity. However, unlike a rarity analysis irreplaceability is target dependent and is sensitive to differences in extent of vegetation types between cells in a way that recognises the distribution of sizes of occurrences across the study region (S. Ferrier, R.L. Pressey and T.W. Barrett, submitted)
Nevertheless, as expected, the totally irreplaceable sites largely contained those vegetation types with a low abundance, restricted distribution and consequently high retention target (90%). This is readily demonstrated by the location of several totally irreplaceable grid cells on the periphery of the Bioregion, which contain vegetation types such as Belah-Rosewood and Long Leaf Box; and within the Bioregion such as Black Box Woodland.
The occurrence of the higher irreplaceability ranked (totally irreplaceable, Ir1, Ir2) grid cells in the Lachlan Province and to lesser extent in the Murrumbidgee Province is due to the increase in diversity of vegetation types, and therefore reflects a clustering of retention targets which need to be satisfied, compared to what is found in the Murray Fans and Victorian Riverina Provinces. For the vegetation types represented in these grid cells, fewer options exist across the Bioregion to allow the conservation goal to be satisfied.
The grid cells containing vegetation types such as Grasslands, Cotton Bush and Riverine Forest which are mapped as extensive across the Bioregion, were generally calculated to have a lower irreplaceability value. A lower irreplaceability value does not mean that the constituent vegetation types have less conservation value than the cells identified as highly irreplaceable, what it does mean is that the relatively extensive coverage of the vegetation types provides for a greater number of options (ie. locations) to chose from when satisfying the conservation goal. In a conservation planning context, areas identified as having lower irreplaceability provide decision makers with flexibility and opportunity in site selection. In these cases, social and economic factors can be taken into account when deciding on which particular site to protect. Whereas for sites identified as totally or highly irreplaceable this flexibility does not exist, if the conservation goal is to be satisfied.
The difference in the vegetation mapping between NSW and Victoria, namely the lack of floristic detail in the Victorian vegetation mapping has limited the perceived contribution that the Victorian section of the Bioregion makes to achieving the conservation goal. Figure 8 reveals that Victoria in comparison to NSW has few totally irreplaceable sites and contributes little overall to meeting retention targets. The totally irreplaceable sites reflect the location of Long Leaf Box which is restricted to one location in the Riverina Bioregion. The remainder of Victoria is predominantly ranked as making a low contribution (Ir5) to the conservation goal. This is likely to be due to the fact that Riverine Forest occurs with other vegetation types within NSW for which the cells are more highly replaceable (eg. Grey Box Woodland, Callitris Mixed Woodland). This means that by selecting the highly irreplaceable cells the 15% target
82 of Riverine Forest may well be met.
The usefulness of selection unit The selection unit is one of the building blocks of the irreplaceability analysis because it subdivides the landscape and defines the basic unit of comparison across the Bioregion. Selection units may influence the way in which targets are satisfied, the most important factors are size and shape. For this project, a 2500 ha cell grid configuration was used because at the time, it was the most manageable size and shape in terms of computer capacity and processing time. Given the scale of the mapping (1:250,000) the selection unit size for this analysis did demonstrate the landscape patterns of irreplaceability quite clearly across the Bioregion.
One of the issues associated with the size of the selection unit was that where vegetation remnants were smaller than 2500 ha, the boundaries of the fragments were masked (ie. not apparent). In the case where the grid cell comprises part of a highly restricted vegetation type with a 90% retention target, the whole grid cell is detected as totally irreplaceable. The irreplaceability map (Figure 8) may give the impression that the whole grid cell is significant for conservation, whereas it may not be.
The diversity of woody vegetation considered typical of the Riverina Bioregion was sampled to some extent within the 87 totally irreplaceable grid cells. This is generally because the large selection unit captures a greater proportion of peripheral vegetation types relative to the targeted type/s, than might otherwise have been the case. To capture a retention requirement of 4,409 ha for Callitris Mixed Woodland/Acacia melvillei Woodland four grid cells are required and these total an area of 10,000 ha. An additional 5,591 ha of non targeted vegetation is contained within these cells.
The use of a large selection unit size (2500 ha), relative to vegetation remnant size or perhaps more importantly relative to the size of a patch of a high conservation value vegetation type and the degree of fragmentation meant that the conservation principle of efficiency (ie. maximising target representation in the least area possible) for the analysis failed to some extent. The over representation of retention targets could be investigated by trialing a range of selection unit sizes (eg., grid squares of 400 ha, 900 ha and 1600 ha). Grid cell size should be such so as to maximise the proportional representation of the cell, by area, by the target vegetation types; yet tempered with the practicalities of scale and consideration for land management units so as to minimise the inclusion in the cell of vegetation types which do little to contribute to the irreplaceability rating of the respective cell. Another possibility to be explored is the use of a selection unit based on the boundaries of vegetation remnants, though some consideration will need to be given to what would be the adequate size of an area required to ensure viability and persistence of biodiversity. The opportunity to trial the range of selection units is becoming possible with current developments in computer hardware capacity to calculate larger data sets within a practicable time frame.
While testing is still required with respect to selection units, the grid cells used in the analysis for this project are adequate for real-world planning because it focuses peoples attention on the vegetation within them. If some form of conservation action is then applied to only part of the cell, the targets for the protected vegetation types can then be
83 revised (but not those of the unprotected types) and a new map of irreplaceability produced, with the protected areas ‘locked in’.
Conservation Planning Software The conservation software is designed to be used as a planning tool by planners allowing them to review the implications of their decisions on-screen. The mapped result of irreplaceability only indicates one particular outcome, at one point in time. While the results of the irreplaceability analysis as depicted in Figure 8 are valid, the map itself is limited to indicating general areas for conservation investigation. The computer system holds the capacity to identify site specific attribute data but this information can not be transferred to a hard copy map.
The irreplaceability map produced for this project shows where the areas of high conservation value lie in the Bioregion, and therefore where conservation effort could be directed. It is important however, to recall that the irreplaceability assessment is a function of the environmental attribute used (vegetation), conservation goal (achieve the vegetation retention targets) and the selection unit (rectangular grid square). A change in any of these factors would alter the irreplaceability results. The irreplaceability results will also change as parts of the landscape are placed under adequate conservation management.
Likewise, it is important to recognise that while Figure 8 shows the location of the totally irreplaceable sites by grid cell, there is not a delineation of the precise area requiring conservation. To achieve the goal of vegetation retention in the Bioregion, the effort should be directed towards those 87 totally irreplaceable sites. In the first instance, this should involve site validation to confirm presence/absence of expected vegetation types, assessment of site condition and site viability. On the basis of this validation sites can be selected or rejected for conservation action and the type of conservation action/management required.
Whilst the strength of the conservation planning software lies in its ability to efficiently analyse many environmental attributes against conservation targets, the straight forward assessment undertaken for the Riverina Bioregion (ie. the use of a single attribute) and the expected outcome instills confidence in the logic and mathematical capability of the software. Refer to S. Ferrier, R.L. Pressey and T.W. Barrett (submitted) for validation of the statistical approach for predicting the irreplaceability of areas.
Some of the main conservation planning software issues which arose during the course of the project were that: S there was limited technical support for the software. Though this is currently changing with the C-Plan user’s site on the internet. S learning to use the software was based on a trial and error process. This has subsequently been rectified with the preparation of a C-Plan user manual, but learning to use the program efficiently will require a serious investment in time. S a series of technical difficulties arose with the installation and operation of the software. This was largely expected because C-Plan was in a process of refinement and ongoing development. Since this time the software has been trialed and used extensively, but will require modification as new issues arise.
84 S during the course of the project the technical development of C-Plan with the ERMS geographic information system ceased and programming effort was channelled into ArcView GIS. Thus some of the capabilities now possible with C-Plan were not available for this project. S to ensure the software is used to its fullest capability, experience and a good understanding of the analytical logic and programming process is required. Few people currently have the degree of knowledge and experience needed.
10.8 VULNERABILITY ASSESSMENT
10.8.1 Outcomes The vulnerability layer predicts the likelihood of an area being cleared, for agricultural production, based on geomorphic type and its relationship with past clearing, and on its rural land capability (ie. where that data was available). In this context, of the remaining vegetation within the Bioregion 50.3% has been classed as highly vulnerable to clearing, 45.5% as moderately vulnerable to clearing and only 3.9% as having a low vulnerability to clearing (the remaining 0.3% refers to water bodies which were excluded from the clearing analysis).
Figure 9 shows that much of the southern half of the Riverina Bioregion is identified as highly vulnerable while the northern half of the Bioregion is largely within the moderately vulnerable catgory.
While Figure 9 shows the Victorian Riverina and Murray Fans Provinces to have the greater proportion of highly vulnerable lands with regard to clearing, much of these lands have already been cleared (Figure 9a). It was expected the remaining vegetation remnants would be highly vulnerable to clearing because of the past agricultural focus on cropping and flood irrigation agriculture. This is demonstrated particularly in the Victorian Riverina. The intensive land use in these Provinces has been due to the combination of highly fertile soils alluvial soils, the proximity and availability of water for irrigation and the development of agricultural infrastructure to support the intensity of production.
The patches of moderately vulnerable areas within these two provinces tends to reflect the location of Riverine Forest / Black box communities which are currently under Crown management as state forest or are lands of limited suitability for cropping due to flooding.
In fact around 75% of all lands classified as highly vulnerable in the Bioregion have already been cleared. The Murrumbidgee Province retains the greatest area of vegetated lands under the highly vulnerable classification. These areas tend to be associated with irrigation areas (eg. Colleambally). The small highly vulnerable pockets along the northern extremity of the Bioregion are being expressed due to their proximity to the neighbouring Bioregion and the inclusion of geomorphic types more typically associated with the Murray Darling Depression Bioregion.
Grazing has been the major land use within the Murrumbidgee and Lachlan Provinces and therefore native vegetation still predominates, although with varying degrees of
85 degradation. Therefore, vegetation within these Provinces are considered to be of moderate vulnerability to clearing.
The least vulnerable area to clearing within the Bioregion occurs in the Lachlan Province on the depression plain geomorphology containing Black Bluebush and Bladder Saltbush vegetation. The restriction of this geomorphology type to the Lachlan Province means that the extrapolation of clearing trends from elsewhere could not be used to indicate a vulnerability category. On the basis of that virtually nil clearing has occurred in this area a low vulnerability ranking was assigned.
The general trend of this data suggests that the remaining vegetation within the Bioregion is at threat from continued clearing. The degree of threat appears to be aligned with soil fertility, climatic conditions, proximity to water sources for irrigation and availability of agricultural infrastructure. Hence, a southward trend of increasing vulnerability might be expected as the suitability of the land for intensive agriculture increases.
10.8.2 Discussion Vulnerability of the natural environment to detrimental impacts can be thought of as falling in two major categories. Firstly, vulnerability to direct impacts which can be largely arrested through the cessation of certain land management practices (eg. native vegetation clearing). Secondly, vulnerability to secondary impacts which can flow on from the direct action or impact. These impacts are not necessarily any less threatening than direct impact but the abatement of these impacts generally requires the application of management resources (eg. control of feral pests, weeds and remnant viability). In order to make the most efficient use of conservation resources, all other things being equal, and where a choice is available, it can be argued that conservation action should be initially directed towards the protection of lands which are for the most part subject to direct threats rather than secondary threats.
There are many threatening processes currently operating within the Bioregion which affect change in land use and thereby the viability of native vegetation in the Riverina. Such threatening processes include the expansion of cropping due to the engineering of new salt tolerant crop varieties, the ability to physically alter landscapes to better suit irrigation agriculture and use of groundwater supplies, together with the continuing effects due to past agricultural practices like rising salinity. However, due to the lack of reliable data an analysis of these factors was beyond the scope of this project but when these processes are described with appropriate quantitative data a more precise predictive model of vulnerability can be constructed.
Clearing is one of the few threats for which adequate data exists to develop a reasonably consistent vulnerability layer. The vulnerability layer for this project was therefore based solely on clearing as the threatening process rather than an amalgamation of recognised current or predicted future threatening processes. Importantly, a combination of the relative extent of historic clearing of various geomorphic types and the extent of clearing expected based on rural land capability mapping, provides a regional overview of the areas where further vegetation clearing might be likely. On this basis areas with a higher vulnerability appear to be attractive for some of the more
86 intrusive and ecologically destructive land uses and therefore need to be afforded higher priority for conservation management.
It is often the case that only fragments of natural vegetation remain in highly used landscapes, such as for the southern part of the Riverina. For efficient use of conservation resources the longer term viability (ie. as dictated by its size, shape, the ecological needs of its constituent species, etc.) of these remnants needs to be considered. The need to protect some of these remnants must be carefully considered given the intensive management required. The protection of these small areas in large numbers quickly becomes impracticable to resource.
Nevertheless, the fact remains, some high priority vegetation types may now only exist as small remnants within an otherwise heavily human modified, hostile environment (ie. subject to the impacts of modified hydrological and fire regimes, feral predators and competitors, weed invasion competing for growing space and further modifying the habitat and through limiting the size of resident populations reduce the gene pool of some species to levels which are unsustainable). These situations must be dealt with on a case by case basis and with an understanding of the full range of conservation management options available.
87
10.9 CONSERVATION MANAGEMENT PRIORITY AREAS
10.9.1 Outcomes The approach used for conservation assessment for this project is based on the relationship between the conservation value of an area (described as its relative irreplaceability) and its vulnerability to threatening processes (in this case native vegetation clearing). The combination of these determines the conservation management priority areas.
The distribution of conservation management priorities across the Bioregion is depicted in Figure 10. The higher the ranking of a site with regard to both values, the higher the conservation management priority. Thus, the map indicates the relative priorities within the Bioregion according to the likelihood of an area being cleared and the degree to which alternative sites are available to meet conservation targets for the protection of any particular vegetation type. It shows the spectrum of conservation management priorities within the Bioregion ranging from areas which are totally irreplaceable and highly vulnerable to those which have low irreplaceability and have a low vulnerability.
The sites with higher irreplaceability and high vulnerability are high conservation management priorities (refer to Figure 11). What this means is that the woody vegetation types contained within the highly irreplaceable grid cells have limited opportunities within the Bioregion for protection and that the trends show they are being preferentially cleared. Thus urgency for conservation action is required.
What the graph shows in Figure 10 is the area of native vegetation within each of the conservation management priority classes. That is, a graphical representation of the map but excluding the area of non-native vegetation.
Figures 10 and 11 suggest that with respect to the data and the method used, the Riverina has relatively few very high priority areas for which conservation should be initially directed. However, this is to some degree (ie. with respect to vulnerability) a relative measure. The Figure 10 graph indicates that of the naturally vegetated 52% of the Bioregion, 1.1% lies within the highest conservation management priority (ie. totally irreplaceable / high vulnerability) category.
About 0.1% of the naturally vegetated area falls within the lowest conservation management priority category (low irreplaceable / low vulnerability). The greatest percentage (60%) of vegetated lands lie within the more moderate areas of priority (moderate - low irreplaceability / moderate vulnerability). This is where the real opportunity for conservation decisions lie. In these areas there is a degree of flexibility about where conservation activities are initially directed and when action is undertaken. In this category conservation planners can consider competing land use interests within a landscape context.
90
It is important to note, however, that over time continued clearing of native vegetation in these moderate priority areas will increase the priority for the remaining cells, as the extent of each vegetation type across the Bioregion is reduced.
There are several factors which have most influenced the distribution of priorities as shown in Figure 11. These are: S scale. The coarse scale used for this assessment is valid for a bioregional assessment however, the shape and size of the priority areas identified in Figures 10 and 11 are based on the grid cells used for irreplaceability and the polygons derived from the vulnerability map. Due to the grid cell shape and the nature of the irreplaceability analysis the whole area identified as high priority in Figures 10 may not be naturally vegetated. Thus on-ground validation is critical. S edge effects. The decision to include a number of vegetation types (eg. Long Leaf Box) which may be more representative of neighbouring Bioregions, or more extensive outside the Bioregion such as Belah-Rosewood means that high priority areas for these peripheral types are being identified along the Bioregion boundary. This is inevitable because there is a scale issue associated with how the bioregions were initially defined and mapped compared to the current level of data and scale of mapping being utilized in the present project It is also expected that biological composition of vegetation types will vary with environmental gradients, disturbance history, and sheer geographic distance, it is therefore valid to include target occurrences of types that are more typical or widespread elsewhere and is based on the assumption that occurrences in the Bioregion are sufficiently different from those outside. Importantly, there is also a need for replication of types within and across bioregions as insurance against catastrophic events. S fragmentation. The broadscale clearing and landscape modification (and to some degree the techniques used for vegetation mapping) has resulted in the mapping of a high degree of fragmentation of native vegetation. This is represented in Figures 10 and 11 as a scattering of priority areas rather than clumping. In addition, some of the smaller fragments are so small that they are not easily recognised on the map.
This analysis is useful for indicating the relative conservation priorities for vegetation types and providing a context for finer site assessment. At this point in time, the conservation goal set can actually be met through strategies for vegetation retention. Revegetation of buffer zones surrounding important isolated remnants would also be useful in boosting their viability. However, there is no focus here on the rehabilitation or reconstruction of vegetation communities.
10.9.2 Discussion It is pertinent at this point to recall that the outcomes of this assessment are based on a number of assumptions and that these assumptions may not suit the requirements or expectations of all stakeholders in the Riverina. In particular, the conservation management priorities are dependent on the conservation goal (the vegetation retention targets) which is based on 1:250,000 scale vegetation mapping. For this reason, the priority areas identified are applicable generally to woody vegetation and do not adequately address the Grassland communities. What is important to acknowledge however is the validity and usefulness of the methodology upon which this assessment was founded and the ability of C-Plan to accommodate refinement in the data.
93 As noted, the process of assessing priorities has been: S quantitative because there is no mapped information which allows interpretation of the quality or condition of the areas identified; and S at the broad scale which means that the priority areas identified from this study provide a guide or direction for where a finer level of assessment can be targeted in the first instance.
The conservation management priorities identified provide a regional picture for conservation in the Riverina rather than final boundaries for site / property management. The data presented provides a starting point and some direction and guidance for the development of regional strategies for conservation, particularly vegetation management in the Riverina.
To use this database as a tool for vegetation conservation management: S on ground validation is required to ensure that the vegetation types expected to occur as mapped were correctly identified and still exist, assess the condition and conservation viability of the area prior to investing scarce conservation resources, determine the most appropriate actions/ programs for protection such as fencing, restrictions on clearing, feral animal and weed control etc., then identify the most suitable options for achieving these actions and programs (eg. reservation, voluntary conservation agreements, community programs etc.); S conservation scenarios need to be upgraded with information about new clearing; and S region wide layers should be updated and newly available data obtained.
Conservation assessment and planning is a dynamic process and the results of this study including the vegetation retention targets, the defining and mapping of irreplaceability, vulnerability and hence priority will alter with time and on-ground action such as protection or clearing. In undertaking the analysis it became evident that there was a need to include a wider range of variables (such as grasslands, species, cultural sites, predictive threat models) in the analysis to truly reflect conservation priorities in the Riverina. In the real world however, as this project demonstrates, these data are not always available.
An advantage of the approach used for this project is that, once the framework for assessment is established and the database developed, C-Plan can be used to test planning scenarios to aid with the decision making process. The ability to revise the mapping to reflect on-ground changes or to alter the conservation targets or to consciously choose to exclude sites from the analysis prior to recalculation provides the flexibility required to make decisions as current and transparent as possible.
94 11. TOWARDS CONSERVATION PLANNING - GENERAL DISCUSSION The Riverina Project involved: 1. Technical analyses of biophysical data, involving S an audit of existing data (no new raw data was collected); S acquisition of data and the construction of a project database; and S analyses of suitable data in order to: S provide new quantitative biophysical information about the Bioregion; and S identify indicative areas of conservation significance using C-Plan, a computer-based decision support system; 2. Community and interagency participation;
This discussion will comment on what worked and what didn't and some of the lessons learnt. It is most appropriate to structure this discussion into two components of the work, the technical and the community. The technical component involved the data audit, acquisition, compilation and analyses where the community component involved information exchange with the catchment management committees and several of the Local Aboriginal Land Councils.
The discussion that follows summarises these aspects. More detailed discussion of some of the points raised below can be found in the results section of the report. We have also included discussion of issues relating to general project management which are considered critical to the outcomes of the project and are applicable elsewhere for similar undertakings. The final section of the discussion covers general issues relating to overall project aims and objectives.
11.1 TECHNICAL COMPONENT
11.1.1 Data Audit and Database Construction This project sought to utilise techniques developed over the past 10 years in regional conservation planning that rely on data in digital format for use in computer based analyses. Data stored in digital format has many advantages in terms of its storage, retrieval, and accessibility. However, it is worth remembering that computer-based techniques are still being developed and this introduces problems of data accessibility, usability, reliability and applicability.
In this respect, the three primary observations from this project were: a) the volume of useful biophysical data over the study area in any format, digital or otherwise, is extremely low; b) collection and formatting of existing data is extremely labour intensive and time consuming; and c) the risks of misuse of data and inaccurate conclusions from its use are high because the quality, suitability and reliability of data available within the region are poorly documented. A skilled opporator is required to ensure a meaningful and accurate interpretation of the analysis is achieved.
95 Each of these general observations is discussed below.
The volume of useful data available for the Bioregion is extremely low While the technological capacity to effectively store, access, analyse and present information through computer-based systems has developed rapidly in recent years, the collection process for primary data which is an essential component of computer-based systematic analyses has failed to keep pace.
Few region-wide biophysical data sets are available for even coarse-level systematic assessments such as at the ecosystem level. The lack of a consistent regional vegetation coverage for the Riverina demonstrates this point. To deal with this fundamental problem a region-wide vegetation layer was ‘constructed’ by simplifying and amalgamating several existing vegetation maps, and combining this with geomorphology, to report on environments across the Bioregion.
Regional information at the species level is virtually non-existent. In the absence of information on individual species, vegetation and geomorphology were used as indicators, or ‘surrogates’ for primary biological information such as, the occurrence of species. Having said this however, it is important to realise that in the absence of primary data across the region, there is no systematic means, apart from using expert opinion, for identifying the adequacy or otherwise of the surrogates. What is assumed is that each environment will support a unique assemblage of species.
Models of the geography of species distributions in the Riverina Bioregion are not reliable without this primary information. Mapped information on the distribution of species within the Bioregion can only arise from future biodiversity surveys.
These comments apply equally to the location and distribution of Aboriginal sites.
Although the desired quantity and quality of information to undertake this asssessment was not available, the precautionary principle was applied such that the assessment was performed on best existing and available data, in full acknowledgement of the constraints and limitations of analysis.
However, people should be aware of the law of diminishing returns with respect to collecting and refining data, because there will be a point where additional information will not add value to the assessment relative to the resources required to obtain the data. It should also be noted that further refinement of the information is only likely to increase conservation management priority outcomes.
Collection and formatting of existing data is extremely labour intensive and time consuming The time required for this activity is often dramatically underestimated. The reasons for this include the problems associated with multiplicity of storage locations, cost, copyright, competing priorities of the user and data custodian, resistance to data sharing, or poor data or non-existent licence standards and protocols.
Obtaining data from Victoria was considerably easier than for NSW because the
96 Victorian data was held in the one location. In NSW, data sets are held by individual agencies, organisations and researchers requiring considerable time and effort to obtain. In fact, perseverance was proven to be one of the critical elements for successfully obtaining many data sets.
There is a strong tendency to collect interesting but extraneous data. The lesson learned here is that the only data that should be explored is that which contributes to answering the questions posed. This tendency could be avoided and the process of collection and conversion could be streamlined with access to detailed metadata.
In planning a project, additional time should be allocated to allow for unexpected data issues and firm cut-off times should be adopted for when to stop data collection and start analyses.
The collection of data relating to Aboriginal heritage had its own issues. In particular, the generally poor understanding and knowledge of current Aboriginal cultural needs and expectations in the conservation planning arena required a greater investment of time and effort than the project could accommodate. Moreover, the Aboriginal custodians were reluctant to supply new information to Government. This situation was not helped given the different ancestry of the NPWS Aboriginal sites officer available to assist in the discussions. The lesson learnt was that careful planning is required when dealing with Aboriginal communities to allow sufficient time for business to be conducted in a manner which is agreeable to the Aboriginal people.
The risks of misuse of data and inaccurate conclusions from its use are high because the quality, suitability and reliability of data available within the region is poorly documented Many current data sets explored for this project did not have accompanying metadata to provide the required technical information on the data. Naturally, this type of information is critical in determining the applicability of the data for use in analyses. Without it, serious questions can arise about the validity of the results of any analyses.
Consideration must also be given to the nature of the data, how the various data layers being used relate to each other, given the scales and purposes for which they were mapped (eg. peripheral areas of the Bioregion determined as being ‘highly irreplaceable’, may be very important or they may just be a consequence of the scale at which the Bioregion was mapped or by the fact that in many situations the bioregional boundary is a compromise. Either way lands which may be more characteristic of the neighbouring bioregion are included and are as a consequence seen in the analysis as highly irriplaceable).
11.1.2 Communicating Results This report documents the results, and in particular its strengths, limits and assumptions, in a complete and rigorous manner. As part of this process, the report has also sought to minimise technical jargon or to explain it. In doing so there was an attempt (within the limits of resources and contractual obligations) to make the work as useful as possible to end-users by making the justifiable limits to its use explicit and to make the work reasonably accessible to all potential users, including non-science based decision
97 makers.
Similarly it is important that outside of the formal report, the results are and will be communicated to processes such as native vegetation planning under the NSW Native Vegetation Conservation Act, 1998 with full detail on the real strengths of the data. However, in doing so we have exposed the perceived usefulness of the data to a few dangers: S criticism motivated by institutional rivalry for projects such as this and or political agendas which mitigate against the use of the best available information; S suggestions that for science to be ‘good’ it requires maximum use of technical language; S use of the documented limits to criticise the work (ie. complaining about what the project fails to tell us, rather than making use of what it can tell us); S a further problem arises where the decision makers are community members unused to using data within a framework of limits. While this situation exists in nearly all aspects of planning, the information is not always explicitly documented or in others the absence of information has resulted in no planning being undertaken. The responsibilities placed with landholders or committees in recent years has heightened the need for projects such as this to fully document project strengths and the weaknesses. This has not always been the case and therefore there is a chance that landholders and other planners will be deterred from using information at all because there are some limits.
It can not be emphasised enough that the results of the analysis as mapped in this report have a use by date. That is, the mapping used for analysis will be further refined and resource utilisation and management of the landscape will invariably change. As these changes occur the pattern of irreplaceability and probably also vulnerability will both change. The conservation planning tool requires regular iterative use to keep the planner in touch with the dynamics of the Bioregion and its environment.
11.2 METHODOLOGY The development of the Riverina database is the most significant project output because it provides an accessible, formatted storehouse of data from which analyses can be undertaken, and a foundation on which further data layers can be built.
It is important to realise that the analyses undertaken and reported on by this project were very specific to the questions asked. The analyses of suitable data involved some straightforward statistical reporting on biophysical information about the Bioregion and the identification of indicative areas of conservation significance.
The strengths of the methodology include: S that the bioregional basis of the project enabled analyses to be founded on more biologically meaningful regions than is traditionally the case for regional analyses. The Riverina and Cobar Peneplain Bioregions (project currently being finalised) are the only IBRA bioregions in NSW to date, where this has been attempted; S the methodology is explicit; S the computer-based system allows for large volumes of data to be stored and accessed;
98 S the computer-based system allows for the sorting of data and the running of analyses to be undertaken rapidly; S the computer-based GIS format for data makes the digital raw data potentially widely accessible to many users. This contrasts markedly with traditional hard copy formats (ie. where production and distribution costs can be problematic); S the methodology is repeatable allowing for the selection of indicative high conservation value areas to be re-run when additional data becomes available; and S the decision support system, C-Plan, is flexible and dynamic, allowing for adjustments in objectives to be made and for the operator to iteratively work through the selection process.
11.2.1 C-Plan Despite the early developmental stages of C-Plan it undoubtedly represents an extremely valuable tool for conservation planners which will be enhanced with time. However, at this point in its development and at this point in our biophysical knowledge of the Riverina Bioregion there is uncertainty in solely relying on these systems. Some of the issues generating this uncertainty include: S recognition that the outputs from such an analysis can only be as valid as the data inputs; S information not yet in GIS digital formats being largely excluded. Increasingly information will be transferred to digital format and new data collection will automatically be stored in digital format. Until this time a combination of expert and map based information will need to be utilsed; S because of the region-wide approach adopted, information not yet having region- wide or near-region-wide coverage, including detailed local data, is excluded from regional analyses; Moreover, at the present time available region-wide data sets are invariably ‘coarse’ in their resolution. They are useful for broad scale conservation planning and provide conservation planners with indicative guidance on likely areas of high conservation value. This alone will not produce definitive identifications of individual land parcels of high conservation value. It will need to be used in conjunction with much finer-scale data and on-ground survey before any credible determination of conservation value of any area can be made. S the quantitative approach and presentation quality of the computer-based technologies used can produce a facade of credibility which can hide serious inadequacies in data, methodology, software, etc.; It is imperative that data be of an adequate standard before such systems are relied on. Operators of such systems need to understand the limitations of the data and of the software before C-Plan results can be interpreted adequately and confidently implemented. techniques used rely on complex software systems and high capacity hardware. The skills and experience in the application of C-Plan and the interpretation of the results are such that they can not be rapidly and equally adopted by everyone. This project has demonstrated that considerable time is required for team members to
99 develop the skills and understanding of the operation and limitations of the computer and data systems before they can comfortably generate and interpret results that can be considered reliable. Where the technology and methodology is relatively new, for example, such as in the case of the conservation planning software (C-Plan), time and resources need to be allocated to allow for the development of the necessary computer operating skills. For this project staff located in Sydney were heavily reliant on assistance from the C-Plan programmers located in Armidale, to overcome technical difficulties. Readily accessible technical support is therefore essential when using these systems. Managers and decision makers need to understand that a high level of skill, experience and technical support is required by the users of such systems to ensure that the analyses and results are credible. Consideration of the above issues leads to the conclusion that the computer-based technique used for this project is not the definitive process for real world conservation planning. Rather, C-Plan is a highly desirable new tool to be mastered, further developed and applied increasingly to conservation planning in conjunction with an ongoing reliance on detailed systematic regional and local surveys, expert knowledge, advice and hard copy reports, databases and maps (see Figure 12 ).
Figure 12. Conservation planners are reliant on three forms of decision support systems.
DECISION SUPPORT SYSTEMS
EXPERT ELECTRONIC HARD COPY KNOWLEDGE DECISION DATA SUPPORT SYSTEMS - reports UTILISING GIS - maps - databases
- inventories
DECISION-MAKING
100 Finally, due to the coarse resolution of mapped information for the Riverina it is not surprising that the messages resulting from analyses (ie. that much of the Bioregion has been cleared, very little of the Bioregion is protected within reserves, vegetation remaining is very important) are already known to experts with a good regional knowledge of the Riverina. Though a criticism of this project may be that it generated information that was already known either through expert knowledge, previous surveys or intelligent observation and deduction, the strength of the analyses lies in that: S some of these coarse-scale expert judgments have been quantified for the first time; S conservation status information has now been quantified; S the results are freely accessible; S the raw data from which analyses were undertaken is now in an accessible format for all potential users to scrutinise and undertake analyses for themselves; and S the results form a basis for monitoring the progress in conservation.
11.3 COMMUNITY AWARENESS
The Riverina Project provided very limited opportunity for community involvement because of its technical basis (ie.the project provides a basis for planning decision making based on what is fact, as currently understood, in terms of data coverages which apply with some degree of consistency across the Bioregion. The options, provided by the tool, for conservation across the landscape can now be addressed with consideration to any number of variables and might at this time include community consultation). The community awareness component of the project primarily focused on informing the community via the Catchment Management Committees of the project's aims and objectives. Community members however, can offer on-ground knowledge on attributes such as vegetation and species, that could contribute to the development of the conservation goal. This participation would make the conservation goal more relevant, socially acceptable and possibly more achievable. One lesson learnt with respect to dealing with rural communities and in particular the Aboriginal community is that a level of familiarity and trust needs to be established before information and knowledge is shared. Unfortunately this is an aspect which tends to involve time, a commodity which is highly precious in project planning and minimised in order to restrict budget costs and increase the chances for project sponsorship. The attempt to gather information from the Aboriginal community on sites or issues of conservation importance revealed several issues which need to be considered in regional planning projects. These were: S ancestry should be considered during the employment of Aboriginal staff. This is an important consideration to ensure that interaction between the officer and the community is well established and without conflict; S each Aboriginal community may assign a different community value to an Aboriginal site type (eg. archaeological, spiritual). Broad generalisations regarding sites of
101 Aboriginal significance are therefore unacceptable. S Aboriginal communities do not appear to support the process of setting conservation priorities, consequently the use of C-Plan which is based on conservation targets may not be suitable for all situations.
11.4 PROJECT MANAGEMENT AND STAFFING
Regional conservation assessments involve careful planning, methodical approaches, exploration of options, voluminous and often laborious data collection, complicated analyses, reassessments of methods, testing of techniques etc. Such long-term and labour-intensive undertakings require perseverance and permanent personnel dedicated to the task. Observations from this project lead to a number of conclusions. 1. Full-time permanently employed staff need to be involved in regional conservation planning exercises to ensure that: S regional conservation planning skills are developed by permanent staff which in turn enhances the level of expertise within the agency; S permanent staff acquire ownership of the project and accrue regional conservation perspectives and knowledge which can be shared and applied widely within the agency; and S project interruption is minimised contrasting with the regular turn over which can be expected with temporary staff. 2. Community participation in such projects requires substantial time and effort. Realistic planning is needed to anticipate the time needed for these activities. Even low levels of community consultation may generate considerable media-interest which can be extremely time demanding. Realistically effective community consultation and participation requires full time community relations support for the life of the project. 3. Project administration requirements are easy to underestimate. Realistic planning is needed to anticipate the time needed for administering the various aspects of the project. This involves recognising the very powerful role of good clerical project support. 4. As already noted, the development of conservation assessment methodology based on GIS and computer decision support systems means time should be made available for team members to develop the operation skills and understanding of the limitations of the computer and data systems either prior to or during the project. Expert GIS and programming staff also need to be readily available to assist with problem solving; A diverse array of skills are needed of a project team undertaking integrated regional conservation assessments of this kind such as project management (resources, negotiation, community relations, etc.); computer programming; geographic information systems (data auditing, data licence negotiations and acquisitions, data conversion, database management, manipulation and interpretation); community and media relations and presentation skills sufficient to address both Aboriginal and non Aboriginal members of the community; knowledge of ecological principles; report
102 writing, etc. Not surprisingly one or two people alone are unlikely to hold the range and level of skills to effectively undertake such a multifaceted project. There is a need to share responsibilities throughout a team of people with a diverse and complementary skills and capacities and again to have good organisational support. 5. The ability to gain the trust of those from which the project team will depend on for assistance is another skill considered essential. Convincing stakeholders that the sharing of data will on balance be beneficial to all players is sometimes a challenge, as there is occasionally reluctance by some data-holders to share their data; and 6. Strong institutional leadership is required to support regional projects. This is because analyses of conservation value will ultimately be undertaken for various tenured lands covered by a number of jurisdictions that may form the basis of land use and land management decisions resulting in opportunities for disagreement, misunderstanding and controversy. Senior level understanding, direction and support are periodically needed by project staff in such situations.
103 12. CONCLUSIONS AND FUTURE WORK The Riverina Project used the best regional data currently available to form the basis for an analysis of the current status of the protection of biodiversity in the Bioregion and to apply to a systematic approach to conservation assessment to determine conservation priorities.
The main constraint of this project was associated with data - the lack of primary biological data, the inconsistency and quality of data and the inaccessibility of some of the existing data sets. Consequently, the conservation priority analysis was based on the attributes of vegetation and geomorphology which were mapped at a coarse scale. The use of coarse data has resulted in some constraints and limitations to the assessment and every attempt has been made in this report to expose these so that readers are aware of the issues involved. Understanding these limitations has lead to a knowledge of where the data or assessment should be strengthened and has resulted in some ideas for future directions in the Riverina.
Whilst a finer level of data was preferred, the precautionary principle dictates that the process of assessment and decision making should not be delayed by incomplete knowledge. The use of coarse level surrogate data for analysis is a real world reality and while a degree of detail may be masked by the coarse level data, the overall direction provided is a benefit to planning. In fact, refinement to the data is likely to increase the number of conservation management priorities areas as the detail of natural and cultural values becomes more evident.
This project used a methodology, in conjunction with a number of well documented assumptions, which was systematic, explicit and repeatable. In general, the methodology worked well, though a degree of flexibility in project aims and methods was required to account for the lack of mapped information. This again links back to understanding what data sets are available, their consistency, quality and hence suitability for use. Overall, the general methods adopted for this project could be applied in other Bioregions though the outcomes would be totally dependent on access to data.
With respect to C-Plan the project encountered numerous technical difficulties. This was primarily because the software was still in the early days of development and ‘bugs’ were being ironed out by the programmers. Resolution of these difficulties required a process of trial and error and whilst computer programming support was available, time delays were inevitable. Most of these technical difficulties have been resolved with further development of the software and its use with the Arcview GIS. However, the skills and experience in the application of this software and the interpretation of the results are such that they cannot be rapidly and equally adopted by everyone.
The strength of this methodology lies in the establishment of a database which provides the foundation for conservation assessment and planning and the interactive and flexible nature of C-Plan. Both of these strengths are difficult to express in a written report. C- Plan is a decision support tool which allows for the evaluation of multiple data sets and
104 scenario exploration through user input. The outputs of which will be totally dependent upon the inputs. This project presents one scenario. This scenario is based on a number of factors dictated to some extent by the availability of data, computer hardware and software constraints, and time, but otherwise largely determined by the author including: S Riverina vegetation and geomorphology maps, S IBRA Riverina boundary, S conservation goal, S vegetation retention targets, S grid based selection unit of 5 by 5 km, and S numerous assumptions relating to data and conservation planning principles. By altering any or all of these factors the results of the analysis will change. This is the flexibility of the system which provides for scenario testing.
Whilst this project presents only one scenario, the results presented will guide NPWS, other conservation organisations and community groups to prioritise areas for further detailed investigation. In particular, the results have identified serious gaps in knowledge and data within the Bioregion. The database will aid NPWS in initial analysis of the conservation value and priority of lands offered for purchase, provide direction for NPWS community conservation programs and enable a level of input into regional planning namely for native vegetation management.
12.1 FUTURE DIRECTIONS In seeking to build on this foundation for conservation planning developed through the Riverina Project, the following actions are recommended.
1. Addressing information deficiencies. Short Term S in general, ensuring that the currency and quality of the data sets are maintained. S an immediate step which can be taken includes completing a more comprehensive vegetation map for the eastern and northern parts of the Bioregion. This should be undertaken consistent with the mapping already completed by the Royal Botanic Gardens. S initiate and complete detailed grassland mapping within the Murrumbidgee and Lachlan Provinces so that composition and condition of the grassland communities can be taken into account during the assessment process. S enhance the vulnerability data sets by predicting the occurrence and extent of other threatening processes operating in the Bioregion such as salinisation, expanding irrigation cropping via the extraction of groundwater. Longer Term S systematic biodiversity surveys should be undertaken so that there is less bias in species data sets and so these data can be incorporated into future analysis. Vegetation mapping does not adequately reflect fauna distribution or habitat use. S liaison with Aboriginal communities should continue so that areas of importance to Aboriginal people are recognised as a legitimate component of the conservation planning process.
105 1. Addressing the Project Results Short Term S the priority areas identified require further field survey and validation to evaluate their condition, degree of fragmentation, viability S subject to validation consider what conservation protection mechanism, if any, would be most applicable.
Longer Term S to re-run the analysis using the completed vegetation mapping including grassland details and modification following site validation. S incorporate predictive information on the key threatening processes other than clearing to enhance the validity of the vulnerability mapping. S for use in regional planning the vegetation retention targets would need to be reviewed taking into account the practicality of the targets with respect to integrating biodiversity conservation with economic and social goals.
106 13. REFERENCES Andrews, J. and Flemons, P (1997) Murray Darling Basin Project M305. Methodology for mapping structural vegetation. Occasional Paper 29. NSW NPWS. Australian Nature Conservation Agency, (1996) A Directory of Important Wetlands in Australia. Second edition. ANCA, Australia. Baker-Gabb, D. (1998) Native Grasslands and the Plains Wanderer. Wingspan. Vol. 8 (1). Barrett, T. (unpublished) Documentation for C-Plan: Draft Users Manual. NPWS. Beadle, N. C. W. (1948) The vegetation and pastures of western New South Wales, with special reference to soil erosion. Thomas Henry Tennant, Government Printer. Sydney. Benson, J. (1989) Establishing priorities for the conservation of rare or threatened plants and plant associations in New South Wales. In, Hicks, M. & Eiser, P.; Proceedings of a National Conference on the Conservation of Threatened Species and their Habitats, p.17 - 82. I.U.C.N. Australian Committee Occasional Papers 2. Benson, J. S., Ashby, E. M. and Porteners, M. F. (1996) The native grasslands of the Southern Riverina, New South Wales. Unpublished report to Australian Nature Conservation Agency. Royal Botanic Gardens. Sydney. Brickhill, J. (1985) Review of Nature Conservation Programs. Paper No. 13. Vegetation - by Geographic Regions. “Southern Riverina”. Internal NSW National Parks and Wildlife Service Document. Brickhill, J. (1989) Abundance of Raptors in the Riverina, 1978 - 1987. Australian Raptor Studies. Proceedings 10th Anniversary Conference Australiasian Raptor Association Canberra, September 21 - 22, 1989. Ed. P. Olsen, RAOU. Briggs, J. D. and Leigh, J. H. (1995) Rare or Threatened Australian Plants. Centre for Plant Biodiversity Research. CSIRO. Bowen, P. F. and Pressey, R. L. (1993) Localities and habitats of plants with restricted distributions in the Western Division of New South Wales. NSW National Parks and Wildlife Service Occasional Paper No. 15. Butler, B. E., Blackburn, G., Bowler, J. M., Lawrence, C. R., Newell, J. W. and Pels, S. (1973) A geomorphic map of the Riverine Plain of south-eastern Australia. Australian University Press, Canberra. Cohn, J. S. (1995) The vegetation of Nombinnie and Round Hill Nature Reserves, central-western New South Wales. Cunninghamia Vol. 4(1), p. 81 - 101 Commonwealth of Australia (1992) National Strategy for Ecologically Sustainable Development. Commonwealth of Australia (1996) The National Strategy for the Conservation of Australia’s Biological Diversity. Commonwealth of Australia (1996) The National Forest Policy Statement. A new focus for Australia’s forests.
107 Dale, A. (1997) Principles for negotiating conservation on indigenous land. In Conservation Outside Nature Reserves. Ed. by P. Hale and D. Lamb, Centre for Conservation Biology, The University of Queensland. p. 74-79. Dalton, K. L. (1988) A review of the information relevant to the saltbush plain rangelands of western New South Wales. Technical Report No. 9. Soil Conservation Service of NSW. Deiz, S. and Foreman, P. (1996) The Management of Natural Grasslands on the Riverine Plain of South-Eastern Australia. Australian Nature Conservation Agency, NRSCP Project Number N405. Unpublished report. Department of Natural Resources and the Environment Victoria. (1996) Meta data SVEG100 Layer Description . R. Frisina Natural Resources Systems, Melbourne, Victoria. Department of Natural Resources and the Environment Victoria. (1996) National Parks Service Annual Report 1996/1997. Department of Natural Resources and the Environment, Victoria. Donovan, P. (1997) A History of the Millewa Group of River Red Gum Forests State Forest of New South Wales, West Pennant Hills. Emery, K. A. (undated) Rural Land Capability Mapping. Soil Conservation of New South Wales. Environmental Protection Agency (1997) New South Wales State of the Environment. Evans, R., Brown, C. and Kellet, J. (1990) “Geology and Groundwater”. In The Murray. Ed. N. Mackay, Murray Darling Basin Commission. Ferrier, S. F. (1988) Environmental resource mapping system (ERMS): users manual for version 1.2. National Parks and Wildlife Service, Sydney. Ferrier, S. F., Pressey, R. L. and Barrett, T. W. (submitted, 1999) A new predictor of the irreplaceability of areas for achieving a conservation goal, its application to real world planning, and a research agenda for further refinement. Biological Conservation. Garnett, S. (1992) Threatened and Extinct Birds of Australia. RAOU Report No 82, RAOU and ANPWS, Canberra. Hope, J. (1995) Aboriginal Burial Conservation in the Murray-Darling Basin. Historic Environment. Vol. 11(2&3), p. 57 - 60. Humphries, L., Van Der Lely, A., Muirhead, W., and Hoey, D. (1994) The development of on-farm restrictions to minimise recharge from rice in New South Wales. Australian Journal of Soil and Water Conservation. Vol. 7 (2) p. 11-20. IUCN (1994) Commission for National Parks and Protected Areas. JANIS (1996) Proposed Nationally Agreed Criteria for the Establishment of a Comprehensive, Adequate and Representative Reserve System for Forests in Australia. A Report by the Joint ANZECC / MCFFA National Forest Policy Statement Implementation Sub-Committee, Canberra.
108 Jones, A. (1993) Sandhill degradation on the Riverine Plain. Soil Conservation Service of NSW. Department of Conservation and Land Management. Deniliquin. King, S. (1983) Review of Policies, Priorities and Programmes for Nature Conservation in New South Wales. Paper No. 27 Vegetation by Communities / Habitats Grasslands. New South Wales National Parks and Wildlife. Kingsford, R. T., Thomas, R. F. and Wong, P. S. (1996) Significant wetlands for waterbirds in the Murray-Darling Basin. Murray-Darling Basin Commission. Land Conservation Council, Victoria. (1985) Murray Valley Area, Final Recommendations. Melbourne, May 1985. Leigh, J. H. and Noble, J. C. (1972) Riverine Plain of New South Wales. Its Pastoral and Irrigation Development. CSIRO, Canberra, Australia. Leigh, J. H. and Mulham, W. E. (1977) Vascular Plants of the Riverine Plain of New South Wales with Notes on Distribution and Pastoral Use. Telopea Vol. 1 No. 4. Mackay, N. (1990) Understanding the Murray. The Murray. Ed. N. Mackay, Murray Darling Basin Commission. Margules and Partners Pty Ltd, P. And J. Smith Ecological Consultants and Department of Conservation Forests and Lands Victoria (1990) River Murray Riparian Vegetation Study. (Murray Darling Basin Commission). McGuigan, A. (1986) Aboriginal Reserves in NSW: A Land Rights Research Aid. Occasional Paper (No. 4). New South Wales Ministry of Aboriginal Affairs, Sydney. Miller, (1996) Balancing the scales: Guidelines for increasing biodiversity’s chances through bioregional management. World Resources Institute, Washington DC. Moore, C. W. E. (1953) The Vegetation of the South-Eastern Riverina, New South Wales (1. The Climax Communities). Australian Journal of Botany, Vol. 1(3), p. 485 - 547. Morgan, G. and Terrey, J.(1992) Nature Conservation in Western NSW. National Parks Association. NSW Department of Lands. (1987) Aboriginal New South Wales. Central Mapping Authority, Bathurst. NSW National Parks and Wildlife Service (1996) Annual Report 1996/1997. NSW National Parks and Wildlife Service, Sydney. NSW National Parks and Wildlife Service (1999) NSW Biodiversity Strategy. NSW National Parks and Wildlife Service, (undated) C-PLAN Conservation Planning Software User Manua, For Version 2. (1998). Pardoe, C. (1988) The cemetery as symbol. The distribution of Aboriginal burial grounds in southeastern Australia. Archaeology in Oceania 23: 1 - 16. Porteners, M. F. (1993) The natural vegetation of the Hay Plain: Booligal-Hay and Deniliquin-Bendigo 1:250 000 maps. Cunninghamia Vol. 3(1), p.1 - 87.
109 Porteners, M. F., Ashby, E. M. and Benson, J.S. (1997) Natural vegetation of Pooncarie 1:250 000 map. Cunninghamia Vol. 5(1) p.139 - 230. Pressey, R. L. and Logan, V. S. (1995) Reserve coverage and requirements in relation to partitioning and generalization of land classes: analysis for western New South Wales. Conservation Biology Vol. 9 (6) p.1506-1517. Pressey, R.L. and Logan, V.S. (1998) Size of selection units for future reserves and its influence on actual vs. targeted representation of features: a case study in western New South Wales. Biological Conservation 85 p. 305-319. Pressey, R.L. and Logan, V.S. (1997) Inside looking out: findings of research on reserve selection relevant to “off reserve” nature conservation. In Conservation Outside Nature Reserves. p.407-418. Eds P. Hale and D. Lamb. Surrey Beatty and Sons, Sydney. Pressey, R. L., Ferrier, S., Hutchinson, C. D., Sivertsen, D. P. and Manion, G. (1995) Planning for negotiation: using an interactive geographic information system to explore alternative protected area networks. In Saunders, D. A. et al. (eds), Nature Conservation: The Role of Networks, p. 23 - 33. Surrey Beatty & Sons, Sydney. Pressey, R. L., Humphries, C.J., Margules, C.R., Vane-Wright, R.I. and Williams, P.H. (1993) Beyond opportunism: key principles for systematic reserve selection. Trends in Ecology and Evolution. 8, 124-128. Pressey, R. L., Johnson, I. R., and Wilson, P. D. (1994) Shades of irreplaceability: towards a measure of the contribution of sites to a reservation goal. Biodiversity and Conservation Vol. 3, 242-262. Rhodes, D. W. (1990) Hay District Technical Manual. Chapter 4. Soil Conservation Service of NSW. Roberts, J. and Brickhill, J. (1992) The fate of Wetlands on the Mirrool Creek Floodplain - a microcosm for south-western New South Wales. Paper accompanying a poster at the Murray-Darling Basin Floodplain Wetlands Management Workshop. Robinson, D. (1994) ARI Technical Report Series No. 133 Department of Conservation and Natural Resources, Melbourne. Robinson, D. and Traill, B. J. (1996) Conserving Woodland Birds in the Wheat and Sheep Belts of Southern Australia. RAOU Conservation Statement No 10, Supplement to Wingspan Vol. 6 (2). Rutherford, I. (1990) Ancient river young nation. The Murray. Ed. N. Mackay, Murray Darling Basin Commission. Saintly, G. and Jacobs, S. (1990) Waterplants. The Murray. Ed. N. Mackay, Murray Darling Basin Commission. Scott, J. A. (1992) The natural vegetation of the Balranald - Swan Hill area. Cunninghamia Vol. 2(4). p.597 - 652. Semple, W. S. (1990) Hay District Technical Manual. Chapters 1, 2, 3, 6, & 7. Soil Conservation Service of NSW. Smith, P. and Smith, J. (1990) Floodplain Vegetation. The Murray. Ed. N. Mackay, Murray Darling Basin Commission.
110 Sturt, C. (1833) Two expeditions into the interior of southern Australia, during the years 1828, 1829, 1830 and 1831, with observations on the soil, climate and general resources of the colony of New South Wales. Smith, Elder and Company. London. Thackway, R. and Cresswell, I. D. (1995) An interim Biogeographic Regionalisation for Australia: a framework for establishing the national system of reserves, Version 4.0. Australian Nature Conservation Agency, Canberra. Webster, R. and Ahern, L. (1989) Management plan for the conservation of the Superb Parrot (Polytelis swainsonii) in New South Wales and Victoria. Westcott L. (1997) Yorta Yorta stake their claim. ATSIC News Summer 1997.
111 14. ADDITIONAL READING Barlow, B. A. (1985) A Revised Natural Regions map for Australia. Brunonia Vol. 8, p. 387 - 392 Beadle, N. C. W. (1981) Forty Years Ago. Cunninghamia Vol. 1(1). p.1 - 6 Bedward, M., Keith, D. A. and Pressey, R. L. (1992) Homogeneity analysis: assessing the utility of classifications and maps of natural resources. Australian Journal of Ecology, Vol. 17, p.133 - 139. Bedward, M., Pressey, R.L., and Keith, D.A. (1992) A new approach for selecting fully representative reserve networks: addressing efficiency, reserve design and land suitability with an iterative analysis. Biological Conservation, Vol. 62, p.115- 125. Belbin, L. (1995) A multivariate approach to the selection of biological reserves. Biodiversity and Conservation Vol. 4, p.951-963. Benson, J. (1991) The effect of 200 years of European settlement on the vegetation and flora of New South Wales. Cunninghamia Vol. 2(3), p.343-370. Brunson, M. W. (1995) The Changing Role of Wilderness in Ecosystem Management. International Journal of Wilderness Vol. 1, p.12 - 16. Bull, A. l.; Thackway, R. and Cresswell, I. D. (1993) Assessing conservation of the major Murray-Darling Basin ecosystems. Phase 3: Towards a conservation strategy for the conservation of ecosystems and endangered and vulnerable species. Report no 4. Draft Version. Environmental Resources Information Network. Australian Nature Conservation Agency. Burkey, T. V. (1989) Extinction in nature reserves: the effect of fragmentation and the importance of migration between reserve fragments. Oikos Vol. 55, p.75 - 81. Commonwealth of Australia (1995) National Forest Conservation Reserves: discussion paper. Appendix A4, Assessment and analytical methods, p. 41 - 48. Commonwealth of Australia (1997) Natural Heritage Trust. A better environment for Australia in the 21st Century. National Partnership Arrangements 1997/98. DPIE and Environment Australia. Creaser, P. M. and Knight, A. T. (1996) Bioregional Conservation Strategy for the Cobar Peneplain; Stage I. Unpublished report, NSW National Parks and Wildlife Service. Crosthwaite, J. (1997) Economic Benefits of Native Grassland on Farms. Environment Australia - Biodiversity group. Grassland Ecology program project Number GEP 017. Crozier, R. H. (1992) Genetic diversity and the agony of choice. Biological Conservation Vol. 61, p.11 - 15. Curtis, A. and De Lacy, T. (1996) Landcare in Australia: Does it Make a Difference? Journal of Environmental Management Vol. 46, p. 119 - 137. Department of Conservation And Environment, Victoria. (1992) Barmah State Park and Barmah State Forest Management Plan. Benalla Region National Parks and
112 Public Land. Evans, W. R. and Kellet, J. R. (1989) The hydrogeology of the Murray Basin, south- eastern Australia. BMR Journal of Australian Geology and Geophysics Vol. 11, p. 147-166. Faith, D. P. (1994) Genetic diversity and taxonomic priorities for conservation. Biological Conservation Vol. 68, p.69 - 74. Forestry Commission of NSW. (1982) Plan for Steam Plains Management Area. Unpublished Report. Forestry Commission of NSW, Sydney. Frith, H. J. (1974) Wildlife in The Murray Waters Man, Nature and a River System. Proceedings of a Symposium, Ed. by Frith, H. J. and Sawer, G. Angus and Robertson Sydney. Hall, B. and Burgin, S. (1996) Potential problems associated with GIS for land resource assessment. Australian Journal of Soil and Water Conservation. Vol. 9(1), p. 4-9 Higgs, A. J. and Usher, M. B. (1980) Should nature reserves be large or small? Nature, Vol. 285, p.568 - 569. Janzen, D. H. (1983) No park is an island: increase in interference from outside as park size decreases. Oikos Vol. 41, p.402 - 410. Järvinen, O. (1982) Conservation of endangered plant populations: single large or several small reserves? Oikos Vol. 38, p.301 - 307. Keith, D. A. (1995) Involving ecologists and local communities in survey, planning and action for conservation in a rural landscape: an example from the Bega Valley, New South Wales. In Saunders, D. A. et al (eds), Nature Conservation: The Role of Networks, p. 385 - 400. Surrey Beatty & Sons, Sydney. Kirkpatrick, J. B. (1983) An iterative method for establishing priorities for the selection of nature reserves: an example from Tasmania. Biological Conservation. Vol. 25, p.127 - 134. Knight, A. T. (1996) Selection Unit Size: A Perspective for the Identification of Candidate Conservation Areas in the Cobar Peneplain Biogeographic Region. Unpublished report. NSW National Parks and Wildlife Service. Leslie, D. and Harris, K. (1996) Water Management Plan for the Millewa forests. A plan endorsed by the Murray-Darling Basin Commission as a River Management Plan. State Forests of NSW, Deniliquin and Department of Land and Water conservation, Deniliquin. Lomolino, M. V. (1994) An evaluation of alternative strategies for building networks of nature reserves. Biological Conservation Vol. 69, p.243 - 249. Margules, C. R. (1987) Single large or several small reserves? In Saunders, D. A. et al (eds), Nature Conservation: The Role of Remnants of Native Vegetation. Surrey Beatty & Sons, Sydney. Margules, C. R. (1989) Introduction to some Australian developments in conservation evaluation. Biological Conservation Vol. 50, p.1 - 9. Margules, C. R. and Stein, J. L. (1989) Patterns in the distribution of species and the
113 selection of nature reserves: an example from Eucalyptus forests in south-eastern New South Wales. Biological Conservation Vol. 50, p.219 - 238. Margules, C. R. and Usher, M. B. (1981) Criteria used in assessing wildlife conservation potential: a review. Biological Conservation Vol. 21, p.79 - 109. Margules, C. R., Nicholls, A. O. and Pressey, R. L. (1988) Selecting networks of reserves to maximise biological diversity. Biological Conservation, Vol. 43, p.63 - 76. Morton, S. R. (1990) The impact of European settlement on the vertebrate animals of arid Australia: a conceptual model. Proceedings of the Ecological Society of Australia Vol. 16, p.201 - 213. Morton, S. R., Stafford-Smith, D. M., Friedel, M. H., Griffin, G. F. and Pickup, G. (1995) The stewardship of arid Australia: ecology and landscape management. Journal of Environmental Management, Vol. 43, p.195 - 217. National Parks Association of NSW ( ? ) Forests of Western New South Wales. Nicholls, A. O., and Margules, C. R. (1993) An upgraded reserve selection algorithm. Biological Conservation, Vol. 64, p.65 - 169. Nicholson, D. (1997) Managing Cypress Pine on Your Property. State Forests of New South Wales, Western Division. NSW Department of Planning (1994) River Murray. Murray Regional Environmental Plan No. 2 - Riverine Land. Parmenter, M. (1996) Lowbidgee Land and Water Management Plan Agricultural Zone. District Summary. Department of Land and Water Conservation - Hay. An NRMS ICM Funded Project. Parson, A. (1991) Riparian Tree Communities in the Murray-Darling Basin, NSW. Annotated Bibliography. NPWS Pressey, R. L. (1986) Wetlands of the River Murray below Lake Hume. River Murray Commission Environmental Report 86/1. Pressey, R. L. (1987) The Mulga Lands of New South Wales: Background Information and trial reserve selection method. Report prepared for the NSW National Parks and Wildlife Service. Pressey, R. L. (1995) Review of regions for interim assessment. Preliminary notes for discussion by the Interim Assessment Technical Working Group. Pressey, R. L. and Bedward, M. (1991) Mapping the environment at different scales: Benefits and costs for nature conservation. In Margules, C. R. and Austin, M. P. (eds), Nature Conservation: Cost effective biological surveys and data analysis. CSIRO, Melbourne. Pressey, R. L., Bedward, M., and Nicholls, A. O. (1989) Reserve selection in Mallee lands. In, Noble, J. C. et al (eds), The Mallee Lands: A Conservation Perspective. Proceedings of the National Mallee Conference, Adelaide, 1989. p. 167 - 178. Pressey, R. L., Bell, F. C., Barker, J., Rundle, A. S., and Belcher, C. A. (1984) Biophysical features of the Lachlan-Murrumbidgee confluence, south-western New South Wales. NSW National Parks and Wildlife Service.
114 Purdie, R. W., Blick, R. and Bolton, M. P.(1986) Selection of a conservation reserve network in the Mulga biogeographic region of south-western Queensland, Australia. Biological Conservation Vol. 38, p.369 - 384. Saidlier, R. A., Pressey, R. L. and Whish, G. L. (1995) Reptiles and amphibians of particular conservation concern in the Western Division of New South Wales: distributions, habitats and threats. NSW National Parks and Wildlife Service Occasional Paper No. 21. Saunders, D. A., Hobbs, R. J. and Margules, C. R. (1991) Biological consequences of ecosystem fragmentation: a review. Conservation Biology Vol. 5(1), p.18 - 32. Sinden, J. A. and King, D. A. (1996) Conservation information: a market incentive to promote environmental quality. Biodiversity and Conservation Vol. 5, p. 943- 950. Smith, T. L. and Rutherford, J. (1966) Water and Land. Two case studies in irrigation. Australian University Press, Canberra. Smith, P. J., Smith, J. E., Pressey, R. L. and Whish, G. L. (1995) Birds of particular conservation concern in the Western Division of New South Wales: distributions, habitats and threats. NSW National Parks and Wildlife Service Occasional Paper No. 20. Stafford-Smith, D. M. and Morton, S. R. (1990) A framework for the ecology of arid Australia. Journal of Arid Environments Vol. 18, p.255 - 278. Thackway, R. (1996) The national reserve system - towards a representative system of ecologically based reserves, Chapter 16, in The 1996 Commission for National Parks and Protected Areas Regional Conference: Australia and Pacific Regions. ANCA and NPWS, Sydney. Thornton, S. A. and Briggs, S. V. (1994) A survey of hydrological changes to wetlands of the Murrumbidgee River. Wetlands (Australia) Vol. 13, p.1 - 13 ~ associated GIS. Underhill, L. G. (1994) Optimal and suboptimal reserve selection algorithms. Biological Conservation Vol. 70, p.85 - 87. Vane-Wright, R. I., Humphries, C. J. and Williams, P. H. (1991) What to protect - systematics and the agony of choice. Biological Conservation Vol. 55, p.235 - 254. Weatherly, M. (1993) Save what you can when you can: a reply to Bob Pressey. National Parks Journal, Vol. 37(1), p.10 - 11. Western Riverina Grassland Committee. (1996) Best Management Practice for Retained Grasslands of the Western Riverina. Wilson, A.D., Oxley, R.E. and Bratby, W.J. (1997) A grazing management strategy for Buckingbong State Forest. Department of Land and Water Conservation and State Forests of New South Wales.
115 15. APPENDICIES
15.1 APPENDIX 1 - COMMUNITY AWARENESS PACKAGE (1996, 1997) A. RIVERINA BIOREGIONAL ASSESSMENT The development of a conservation framework for the Riverina Bioregion Sandra Whight Project Officer, Land Assessment Unit (02) 9585 6964; fax (02) 9585 6495 October 1996
Project Background S IBRA Bioregions - Developed under a cooperative national scheme to provide a broad framework to develop a National Reserve System for Australia. Bioregions are mainly based on biophysical features (landform, rainfall, geology). S National Reserve System Cooperative Program (NRSCP)- is a national initiative to develop a comprehensive, adequate and representative reserve system for all of Australia. Australian Nature Conservation Agency (now Environment Australia) has been given money to fund state projects for planning on a bioregional basis. The aim of the of the NRSCP is to ‘develop and implement projects in cooperation with State and Territory nature conservation agencies to support the identification, establishment and consistent management across the nation of a comprehensive, adequate and representative system of terrestrial conservation reserves’
Riverina Bioregion S The Riverina Bioregion lies in Southern NSW and Northern Victoria. It consists mainly of the alluvial fans of the Lachlan, Murrumbidgee, Murray and Goulburn Rivers. The area has been extensively used for agriculture and forestry, resulting in a fragmented natural landscape. This has impacted on the distribution of flora and fauna. S There are only five reserves within the NSW portion of the region, making it one of the most poorly represented areas in the state. The five areas represented are biased towards lands that are not suitable for agriculture or forestry. The ecosystems present in the region are very fragmented and are vulnerable to clearing and increasing soil salinity.
Project Scope S The nature of this project is to develop a conservation framework for the Riverina Bioregion (both natural and cultural heritage). It has been funded by ANCA under the NRSCP. The funding covers the employment of a project officer for eighteen months, and a technical officer for nine months. This funding has been guaranteed for the first twelve months, however the remainder of the funding is subject to the sale of Telstra. S The Riverina project was developed in the wake of the Cobar Peneplain project which was already being funded by ANCA. S The project scope includes:
116 a literature review liaising with the aboriginal community for their input of suitable aboriginal heritage data liaise with the local community for their input and awareness liaise with other government agencies (both NSW and Victoria) develop methodologies for constructing a framework based on similar work elsewhere establish a GIS database of environmental attribute data with fine filter attributes for the bioregion
Project Objectives Based on the scope for this project, the main objectives are to: S Develop a methodology to design conservation frameworks for bioregional planning that incorporates a range of conservation options S Validate the results obtained from the methodology by ground truthing S Develop a conservation framework for the bioregion that can be used as a planning tool by land use authorities and the community.
Project methodology S the project is GIS based, funding only covers salaries at this stage, so we will only be able to use information which is already available. S a variety of different data layers will be collected, the majority of them will be biophysical. These include: fauna data forest fauna surveys NPWS fauna surveys Royal Australian Ornithological Union bird surveys geomorphology land capability land features (roads, rivers, towns) land systems land tenure (agricultural land, forests, Service estate, defence land etc.) land use rainfall soil salinity (predicted and irrigation salinity) topography vegetation forestry type maps grassland mapping (Royal Botanic Gardens and Victorian) riparian vegetation maps Royal Botanic Gardens S using Environmental Resource Management System (the National Parks and Wildlife Service Geographic Information System) all the relevant digital information will be overlayed. From this new layers can be derived that will assess the vulnerability of the landscape S this vulnerability layer will be developed into a conservation framework that will cover the entire bioregion.
117
Community Involvement S community involvement includes an awareness strategy, you know information is being collated and can have access to it (subject to data license agreements) S the community may have specific areas they would like to highlight in the framework S there may be specific issues that the community may wish to have addressed as part of this project, and we will endeavour to do so if it can be managed in the time available, and if it is suitable given the current scope of the project
How the results will be used S the project will produce a report and a series of maps of the bioregion. Copies will be available from NPWS offices or by request. S it may be possible to access the digital information at NPWS district offices also S each year the NPWS is offered a number of properties to buy to add to the NPWS estate. As our budget is quite tight, land offers have to be prioritised into those that are considered containing the highest natural heritage values. With a bioregional conservation framework in place, land offers can quickly be assessed S the Service will most likely use the tool to assist with planning, how other groups use the information is up to them!
Summary Project background. The Riverina Bioregion lies in Southern NSW and Northern Victoria. It consists mainly of the alluvial fans of the Lachlan, Murrumbidgee and Murray Rivers. The area has been extensively used for agriculture and forestry, resulting in a fragmented natural landscape. This has impacted on the distribution of flora and fauna.
There are only five reserves within the region, making it one of the most poorly represented areas in the state. The five areas represented are biased towards lands that are not as suitable for farming or forests. The ecosystems present in the region are very fragmented and under increasing threat from further clearing and increasing soil salinity in the area.
Project details Therefore, under a National Scheme to address conservation needs through out Australia, the Riverina was identified as an area where ecosystem degradation requires urgent attention. To address the problem, a Project has been funded by ANCA to assess the entire Bioregion and identify those ecosystems that are most under threat. The primary objective is to develop a conservation framework for the Bioregion, that incorporates a range of conservation options including reservation. Other options will include voluntary conservation agreements, wildlife refuges, modification of current land management practices.
The project is GIS based, and requires a variety of different data layers. These include: geomorphology, soils, vegetation, rainfall, slope, fauna and flora, land use, currently protected areas and location of areas of historic and cultural significance. After a framework is established, ground truthing will follow. The different data layers will be overlaid, and areas most under threat will be identified.
118 Project Management. The project is being coordinated by the National Parks and Wildlife Service. The Project Officer is: Sandra Whight Land Assessment Unit PO Box 1967 Hurstville NSW 2220 Phone: (02) 9585 6964 Fax: (02) 9585 6495
Although the project is being coordinated by NPWS, there is a strong emphasis in the scope of the project to consult with other Government Departments, Local Councils, Aboriginal groups and local Landcare organisations. This will also include Victorian interest groups.
Project Benefits The framework that will be developed as part of this project will be dynamic, and easily adapted to new information and changes in land use. The framework will be available for use by other authorities and local interest groups, and will be a useful tool to identify management needs in the area. It will benefit the community through the development of a comprehensive database of land type, use and condition for the region.
119 B. CATCHMENT MANAGEMENT COMMITTEE UPDATE AUGUST 1997 Background This information follows on from the previous package of information presented to the Committee in October 1996 by either Sandra Whight or Ross McDonnell. The current project officer is Lisa Metcalfe.
Recap on the Riverina Project The NSW National Parks & Wildlife Service (NPWS) and Environment Australia are funding a project titled ‘Bioregional Conservation Strategy for the Riverina.’ It is primarily a natural heritage conservation planning project which aims: S to test methodology to be used for broad scale conservation planning; S to identify those areas in the Riverina believed to have conservation value; S to develop a framework which can guide the Government and the community for conservation action in the Riverina Bioregion. The project is being undertaken by the NPWS and is due to be completed by December 1997, a total project duration of 18 months.
The Boundary of the Riverina The Riverina Bioregion is located in south-west NSW and central-north Victoria. The Bioregion extends from Narrandera in the east to Balranald in the west, and from Bendigo in the south to Ivanhoe in the north. It consists mainly of the alluvial fans of the Lachlan, Murrumbidgee and Murray Rivers, and incorporates all of the Hay Plain. The Bioregion covers an area of 90,534 km2, with approximately 77% occurring in NSW. 96% of land is under freehold or leasehold title and the remainder is Crown land, state forest estate, water supply reserve, national parks estate.
Project Scope The project is a computer based project which is focused at the broad regional scale and is dependent upon the availability and applicability of information that currently exists. The information to be used for this project has mainly been obtained from government agencies, universities with some information being made available from those undertaking specific projects in the region.
S The information is entered into a geographic information system database. This data can then be ‘overlayed’ to show where in the landscape each feature exists. From the database the ‘conservation software’ developed by NPWS, and currently used by government for the eastern NSW forest assessment process, is the tool to be used to aid the identification of areas of conservation value. This assessment will be based on the use of vegetation types as a surrogate for biodiversity. The factors taken into consideration in the assessment will be: S the proportion of each vegetation type in ‘protected’ tenure (conservation reserve, state forest, under voluntary conservation agreements or other reserve), S the extent of modification to the vegetation (decline since European development and current disturbance regime, for example fire, grazing by feral animals and stock, clearing), S the proportion of each vegetation type which should be retained in the landscape to maintain a representative sample.
120 The NPWS will primarily use this information to provide strategic direction, internally, to where conservation action may be required and to ensure that State funds made available for conservation such as voluntary conservation agreements are efficiently used. Each year the NPWS receives many offers from land holders for the sale of land. This database will be used as a ‘sieve’ which will allow officers to make some relatively quick and effective value judgments on the conservation value of the property offered. It is expected that other agencies and groups may use the information to focus on key areas for projects such as for rehabilitation or future Commonwealth Natural Heritage Trust project proposals requiring a regional perspective.
This project is not being undertaken to target individuals to alter either land use or resource allocation but to provide some broad planning guidance at the regional level to increase the efficiency of conservation action being undertaken in the region, with those groups willing to participate.
What information do we have? Natural heritage information Natural heritage information gathered for the Riverina bioregion includes; geomorphology, vegetation, land capability, tenure and locations of threatened flora and fauna species. This information has been collated from a variety of sources such as the Department of Land and Water Conservation, NSW National Parks and Wildlife Service, Royal Botanic Gardens, Australian National University and the Victorian Department of Natural Resources and Environment. This information forms the basis for conservation planning in the bioregion.
Cultural Heritage Information Cultural heritage information identifying the location of recorded Aboriginal sites is available from the NPWS. Additional documentation of places of significance to Aboriginal communities is also being pursued with Local Aboriginal Land Councils to identify areas and sites that are not already recorded.
Project Progress Status A stage 1 report has been forwarded to Environment Australia for consideration and acceptance, as a condition of the project contract. A response is expected towards the end of August.
Once the report has been accepted by Environment Australia, access to the report is expected to be made available via the NPWS Griffith District office. It must be noted that this is the stage 1 report and the results from this process deal primarily with the testing of the appropriateness and compatibility of the data with the computer software to be used.
Data Collection About 80% of the project time has concentrated on developing an inventory of information that can be used in the project. This process has been very time consuming because: S data at a scale consistent across the entire bioregion (that includes Victoria) is required. As a result, the scale of the information such as for vegetation, is very
121 broad and does not necessarily reflect the detail that can be obtained at the catchment level and less so at the local level. This broad scale level is however, appropriate for planning on a bioregional basis. S the author and/or custodian of the data had to be located and permission obtained or a data licence negotiated for data use. S the information had to either be converted from hard copy maps to digital format or converted from one digital format into another. S problem solving in relation to inconsistencies or inaccuracies in original data was required.
Recently information from Victoria has been received and this has been incorporated into the database. The database is now as complete as it can be for this particular project. Analysis will be carried out in the full knowledge that additional information exists, but that time does not permit information to be incorporated into the database. Planning is a dynamic process and the results of this project will be considered in this context.
Other Actions The remaining 20% of the project time has centred on: S undertaking preliminary analysis of the data with the software S preparing the Stage 1 report, and S following up on issues raised by interested parties within and outside of the project steering committee.
Results To date, there has been little in the way of results to forward to the Catchment Management Committee but it expected that now the database is complete, time will be allocated to undertaking analysis of the data.
Opportunity for input from the Catchment Management Committee The primary layer of information forming the basis of the conservation strategy is a uniform vegetation layer compiled from Royal Botanic Gardens mapping from 1992, 1993, 1997 and an extrapolation of this mapping to cover the entire NSW section of the bioregion. The Victorian vegetation data will be imported and modified, where necessary to ensure compatibility and complementarity with the NSW datalayer. The vegetation maps used and techniques used to define the NSW vegetation are outlined in appendix 2 of the Stage 1 report which has been forwarded to the CMC Coordinator for forwarding to the CMC Chair. Comments on the use of this vegetation layer as the basis for the conservation strategy would be greatly appreciated.
In order to test the software some ‘best guess’ assessments were made on the main vegetation communities in the Riverina bioregion regarding their conservation status (land within national parks, state forests, land covered by conservation agreements etc.) and the degree to which the vegetation community is threatened with extinction (clearing, irrigation, salinity etc.). The assessment was undertaken on a broad basis and used published literature and unpublished reports. Comments are also welcomed on the assessment of these vegetation communities as per appendix 4 of Stage 1 report.
122 There exists an opportunity for input of local information into this assessment of vegetation, as outlined in the above appendixes. The type of information useful and welcomed includes: S comment on the vegetation types identified (appendix 2) S comment on their perceived level of threat at the bioregional scale (appendix 4) S where rehabilitation projects are being undertaken, the vegetation communities and their condition. For example the property “Zara” and the rehabilitation of the sandhill vegetation. S general information about the spread of salinity and the communities being affected. S change in agricultural practices across the bioregion. S areas considered to be important for conservation at the catchment level.
It must be noted that information provided would be best considered on a catchment by catchment basis because the information will need to be translated into the bioregional level.
123 15.2 APPENDIX 2 - CONSERVATION STATUS OF VEGETATION
Summary of the conservation status and threatening processes affecting the vegetation in the Riverina Bioregion.
Vegetation types were derived from vegetation mapping at the 1:250 000 scale by Scott (1992) Balranald - Swan Hill, Porteners (1993) Booligal-Hay , Porteners et. al. (1997) Pooncarie and Victorian Structural Vegetation mapping SVEG100 DRNE (1991).
The Riverina Bioregion is an area where vegetation is highly modified through the effects of clearing, logging, grazing and changing water regimes (Benson, 1991). Many authors indicate the high level of modification to the structure and floristic composition of the vegetation and the expansion of opportunistic native and exotic species at the expense of the original climax communities (Beadle, 1948; Moore, 1953; Leigh & Mulham, 1977; Brickhill, 1985a and 1985b; Semple, 1990; Benson, 1991; Margules & Partners et al., 1990; Scott, 1992; Porteners, 1993.)
Eighty percent of the Riverina Bioregion is in the NSW Central Division, where six known plant species are extinct, two are endangered, 21 are vulnerable and 12 are rare (Benson, 1991). Roadsides, railway siding, travelling stock reserves and cemeteries are all very important areas for remaining native vegetation in the Riverina. As an example of how limited the options for retention of existing native vegetation are on public land within the Riverina; Conargo, Corowa, Deniliquin and Warkool Shires have had road side vegetation reports written. These reports (Mulham, 1994 a,b,c; Oxley, 1995) identify areas along roadsides that have high conservation value and indicate best management practice for the protection and enhancement of remaining vegetation on public land.
Following is a summary of the 30 major vegetation communities identifying their range within the Bioregion, threats that will effect their long term survival and their conservation status within the Bioregion. This information is interpreted to assign each vegetation type with a retention target. Each retention category reflects the percentage of the vegetation type which should be retained if it is to persist in the landscape.
A sliding scale of retention values is used to indicate the relative level of conservation significance in the Riverina Bioregion based on the above information.
Retention Target Description 90% Vegetation types that have been largely removed and are faced with ongoing threatening processes require high retention conservation targets. A 90% target is assigned to compensate for their much reduced extent.
50% Those vegetation types that are widely distributed but still subject to threatening processes.
124 15% Native vegetation types still extensive and not greatly threatened or existing in areas where management is compatible with persistence in the landscape.
0% Non native vegetation types or vegetation types extensively modified by past activities and considered unworthy of protection.
Riverine Forest Eucalyptus camaldulensis River Red Gum (Eucalyptus camaldulensis) forests occurs on the Murray, Murrumbidgee and Lachlan floodplains and rivers. Brickhill (1985a) states that the broadest belts and the best stands of River Red Gum in Australia are within state forests. Dense stands of River Red Gum are found in Barmah, Millewa, Perricoota, and Koondrook State Forests and are managed by the government for timber production and conservation (Leslie & Harris, 1996, Porteners, 1993 and Scott, 1992). As a result of logging, Leigh & Mulham (1977) suggest that no stands of trees are in their original condition.
River Red Gum is partially cleared from its original extent (MNCWG, 1996) and is still used as a commercial timber resource (Wilson, 1995; DCF&L Victoria, 1990). Decline in the “health” and quality of River Red Gum stands has been recorded by Margules & Partners et al., 1990; Somerville, 1988 and Allen, 1979. River Red Gum regeneration is poor where grazing is intense.
Specht et al. (1995) indicates that the conservation of River Red Gum within dedicated reserves is poor. About 400 ha occurs within the 437 hectares of Goonawarra Nature Reserve on Lachlan River; 81 ha is protected in Narrandera Nature Reserve on the Murrumbidgee River at the eastern edge of the plain (Brickhill, 1985a); Barmah State Park in Victoria conserves around 8500 ha.
Barmah & Millewa forests are internationally recognised as excellent wetland habitat (Finlayson & Moser, 1991). River Red Gum forests have high tourist, recreational (LCC, 1985; DCF&L Victoria, 1990) and significant cultural heritage values (Donovan, 1997).
Although River Red Gum is poorly represented in dedicated conservation reserves it is found extensively within the Bioregion and is being managed sustainably within a state forest context.
The retention target is set at 15%.
Black Box Woodland Eucalyptus largiflorens Leigh & Mulham (1977) describe Black Box (Eucalyptus largiflorens) as associated with the Lachlan River, east of Tocumwal and occurring on the Murray between the Murray and Edward Rivers west of Echuca. They suggest that for Black Box only a “very small proportion of the area remains in near-pristine climax condition.” Within NSW, Black Box occurs with Grey Box (Eucalyptus microcarpa) at the southern and eastern part of the Bioregion and can occur with Yellow Box (Eucalyptus melliodora)
125 (Porteners, 1993). In the Barmah forest at least one third of the flora recorded in the entire forest area is associated with the box woodlands indicating their greater diversity relative to River Red Gum forest (DCF&L Victoria, 1990).
Threats to Black Box include dieback in heavily irrigated areas. Margules & Partners et al. (1990) reported trees in poor condition over most of its distribution along the Murray River and that soil salinisation, extraction of timber for fences and lack of regeneration due to grazing pressure contribute to the degradation of this vegetation type. Semple (1990) indicates much of the original extent of this vegetation type has been cleared.
Brickhill (1985a) states that due to a change in grazing regimes the grassy understorey is being modified. He also suggests that the regeneration of Black Box is adversely affected by both river regulation and grazing. Scott (1992) indicates Black Box has been extensively cleared from the floodplains surrounding Swan Hill.
Willandra National Park has a fringing boundary of Black Box equal to about 500 ha; Goonawarra Nature Reserve (437 ha) comprises about 50 ha of Black Box and Yanga Nature Reserve (1173 ha) comprises about 800 ha (Brickhill 1985b). Along the periphery Barmah State Park small areas (a total of 1508 ha) of Black Box is found within areas zoned as priority protection of natural and cultural values. A further 2650 ha is conserved within Victorian Flora and Fauna Reserves (DCF&L Victoria, 1990).
The Murray Darling Basin Commission’s Ministerial Council (1987) recognised Black Box as a poorly conserved vegetation community in NSW. Murray Nature Conservation Working Group (1996) state that Black Box is significantly cleared from its original extent and recommends riparian vegetation should be retained wherever it occurs. Specht et al. (1995) indicate Black Box is moderately to poorly conserved Australia wide while Benson (1991) classifies Box Woodlands as very poorly conserved and most vulnerable or endangered in agricultural lands.
The retention target is set at 90% for this project.
Mallee E. socialis and E. dumosa This mallee vegetation type is a combination of Pointed Mallee (E. socialis) and Congoo (E. dumosa) with E. gracilis and E. leptophylla. Mallee is associated with the geomorphology categories of dunefields, indistinct plains and source bordering dunes. Dune-Crest Mallee and Sandplain Mallee have been distinguished as separate vegetation types in this Bioregion.
Most of the Mallee is cleared from its original extent in the east of the Bioregion with few old Mallee stands remaining (Porteners, 1993). The threats to Mallee include clearing, thinning, chaining and burning and soil erosion due to rabbits (Porteners, 1993). Scott (1992) indicates that salinisation problems would be reduced in the future if native vegetation was retained particularly Mallee vegetation.
Mallee is not adequately conserved in the Riverina as Table 1 below indicates. The table is modified from Brickhill (1985b) and shows those national parks and nature reserves
126 in New South Wales which contain Mallee. None occur in the Riverina Bioregion. Benson (1991) states that, Mallee associations in the Riverina are highly vulnerable to clearing and not protected in existing reserves.
The retention rate is set at 90%.
Table 1. The location and area of mallee conserved in NSW national parks and nature reserves from Brickhill (1985b) Location in Name of the Reserve relation to the Area in ha % of the Mallee Type Riverina Bioregion Reserve Mallee Cliffs West 1 700 3 E. incrassata E. socialis Mallee Cliffs West 15 000 25 E. socialis E. dumosa Mungo West 2 800 20 E. socialis E. dumosa Yathong North 50 000 50 E. socialis E. dumosa E. gracilis Roundhill & Nombinnie North 115 793 80 E. socialis E. dumosa E. gracilis Charcoal Tank East 43 50 E. viridis Quanda North 500 70 E. viridis Buddigower East 110 80 E. viridis Coolbaggie East 360 25 E. socialis E. dumosa Pulletop East 135 95 E. socialis E. dumosa Tollingo North East approx. 80 E. socialis E. dumosa Gubbatta East 153 95 E. socialis E. dumosa Loughnan East 370 97 E. socialis E. dumosa Woggoon North East 3 500 85 E. socialis E. dumosa
Belah-Rosewood Casuarina cristata Alectryon olefolius supsp. canescens Belah (Casuarina cristata) and Rosewood (Alectryon olefolius supsp. canescens) occurs most densely along the Ivanhoe-Balranald Road in the north west and east of Mossgiel. The vegetation type usually occurs as clumps of Belah then Rosewood separated by low chenopod shrubland. Also isolated trees and small groves can occur within mixed Callitris dominated woodlands (Porteners, 1993).
Threats noted in Porteners (1993) are clearing, scalding and erosion is often severe due to rabbit infestation. This vegetation type is often thinned and heavily grazed and it appears to survive by suckering. Where grazing occurs by stock and rabbits few suckers survive.
Leigh & Mulham (1977) state that Belah-Rosewood protrudes into the Riverine Plain and is regarded as atypical. Belah-Rosewood does not appear to be conserved in dedicated conservation reserves within the Riverina. Creaser and Knight (1997) have suggested that vegetation types that are atypical may be important, as they represent ecotonal changes between bioregions and there may be a need to protect these vegetation types at the limit of their range.
Belah-Rosewood is vulnerable to existing threats inside and outside the Bioregion. It is not well conserved in the Riverina Bioregion or in adjacent bioregions. Areas of Belah- Rosewood are mapped as isolated stands well within the Riverina Bioregion and will be considered as disjunct populations.
The retention rate for these isolated and small remnants is set at 90%.
127 Black Bluebush Maireana pyramidata Black Bluebush (Maireana pyramidata) is common in the north west of the bioregion where it occurs on soils highly susceptible to wind erosion (Porteners, 1993).
Threats include soil erosion due to rabbits and grazing. In the Western Division of NSW clearing is not permitted under Cultivation Permits from Western Lands Commissioner (Semple, 1990). It is also retained as a valuable source of drought forage.
Black Bluebush is not conserved on the Hay Plain or in the Riverina Bioregion. Brickhill (1985a) states that it is restricted to small areas in the western part of the plain and depleted by grazing. Benson (1991) indicates that Black Bluebush is very poorly conserved in NSW.
The retention rate for Black Bluebush is 90%
Bladder Saltbush Atriplex vesicaria Bladder Saltbush (Atriplex vesicaria) is the dominant vegetation community of the Riverina Bioregion (Porteners, 1993).
Excessive grazing led to a rapid decline in the original extent of Bladder Saltbush (Beadle, 1948; Knowles & Condon, 1951). Dieback events are still occurring. Small remnant patches exist around Deniliquin. Bladder Saltbush once occupied 1.1 million hectares, but by the end of 1983 only 0.5 million hectares remained (Clift et al. 1987). Bladder Saltbush is seriously threatened by moderated to heavy grazing and wide spread dieback. Fire is also a cause for decline in Bladder Saltbush. Leigh & Mulham (1977) state Bladder Saltbush “was the most widespread alliance but today no stands remain with their original structure.”
Benson (1991) and Specht et al. (1995) indicate that Bladder Saltbush is very poorly conserved. Some associations with Bladder Saltbush are endangered or vulnerable. Brickhill (1985a) states that Bladder Saltbush is not well conserved in the Willandra Lakes National Park (about 500 ha conserved) even though the reserve is in the centre of Bladder Saltbush distribution. Once a common and widespread association on the plains it now only occupies a small fragment of its former distribution. The Murray Nature Conservation Working Group (1996) note that extensive areas Bladder Saltbush have been degraded to annual grasslands and recommend management aimed at conserving susceptible perennial species.
The retention rate for Bladder Saltbush and Bladder Saltbush with Old Man Saltbush is 90%. The retention target for other Bladder Saltbush associations is 50%.
Slender Glasswort Sclerostegia tenuis Slender Glasswort and Round-leaf Pigface is closely aligned to Atriplex vesicaria and tends to become dominant in more saline situations (Porteners, 1993).
Slender Glasswort is not conserved in the Riverina Bioregion. Extensive areas of the this vegetation type are mapped. Threats include grazing, trampling by stock and some
128 dieback (Cunningham, 1981).
Slender Glasswort retention target is set at 50%
Callitris Mixed Woodland Callitris glaucophylla White Cypress Pine (Callitris glaucophylla) occurs on raised sandy areas, low linear dunes, sandhills, ridges and footslopes of rocky outcrops. Murray Pine may replace White Cypress on sandhills and ridges adjacent to Murray River in the Deniliquin / Bendigo area (Porteners, 1993). This vegetation community may be scattered or in monospecific groves. The understorey species are often severely grazed (Scott, 1992 and Porteners, 1993).
White Cypress occurs in Booroorban, Steam Plains, Puckawidgee, Edgar, Wahgunyah , Tholobin Boona, Kulki and other small State Forests in the Berrigan and Corowa Districts. Good stands of White Cypress with Old Man Saltbush occur on the property known as “Steam Plain”.
Threats include rabbit infestation, soil erosion and scalding due to lack of stabilising vegetation cover, thinning and selective logging of trees and lack of regeneration due to grazing by stock (Porteners, 1993). Clearing for irrigation and development has occurred in the south whilst the remaining mature trees are being lost to senescence and wind throw. Within River Red Gum forests the dunes with Murray Cypress Pine have largely been cleared. This vegetation type is particularly vulnerable, as it exists in even aged, often old stands with little or no regeneration due to the lack of appropriate germination conditions and predation of seedlings by rabbits.
Small sites of White Cypress Pine are conserved in NSW State Forest Flora Reserves and enclosures. Approximately 34 ha of White Cypress Pine is conserved in Barmah State Park, Victoria and a small area is conserved on “Waterloo Station” a property subject to a voluntary conservation agreement. Brickhill (1985a) records the existence of a Yellow Box White Cypress Pine association which has largely been eliminated by agricultural development. Leigh & Mulham (1977) state that a “very small proportion of the area remains in near-pristine climax condition” while Scott (1992) suggests that much of the White Cypress Pine remaining is found as isolated individual trees or roadside patches. White Cypress Pine is not well conserved in the Riverina and is also considered inadequately conserved elsewhere (Specht et al., 1995).
The retention target for Callitris Mixed Woodland is set at 90%.
Acacia melvillei Woodland Acacia melvillei is located south and north of Balranald (Scott, 1992) and in the far north of the Booligal area (Porteners, 1993). Many significant stands occur around Ivanhoe, and it forms local communities with Callitris and in the Belah-Rosewood country (Porteners, 1993).
Threats include scalding as a result of over grazing, rabbit infestation, and many areas are cleared of woody understorey shrubs. This vegetation type is small in extent or forms localised stands in Callitris and Belah-Rosewood. Firewood collection around
129 Ivanhoe has been noted as a threat by Semple & Eldridge (1989).
Acacia melvillei Woodland is not conserved in Riverina Bioregion and is considered inadequately conserved elsewhere (Benson, 1991). Acacia melvillei Woodland is distributed in small, isolated patches throughout the Bioregion.
Due to the fragmented nature of its distribution and lack of conservation within and outside the Bioregion the retention rate is set at 90%.
Lignum Muelenbeckia florulenta Lignum (Muelenbeckia florulenta) and Nitre Goosefoot (Chenopodium nitrariaceum) occurs adjacent to major rivers and creeks in low lying swampy areas and is common adjacent to the Murrumbidgee River west of Hay (Porteners, 1993). Lignum can withstand infrequent but prolonged flooding (Semple, 1990).
Threats include clearing for irrigation, grazing and cropping of lake beds (Porteners, 1993). Porteners (1993) also states that Lignum swamps are used for cattle grazing and much of it has been burned or cleared to promote herb and grass growth. Scott (1992) indicates that the Lowbidgee District has the best stands of Lignum and 40 % of this has been cleared for cropping or grazing. Lignum has also been cleared extensively in the Deniliquin region.
Lignum is important wetland and wildlife habitat, particularly for water birds. A small amount Lignum is conserved in Goonawarra Nature Reserve south west of Booligal on the Lachlan River, Willandra National Park (about 2400 ha) and a further 750 ha in Victorian Wildlife Reserves. Benson (1991) indicates Lignum is very poorly conserved.
As a result of the high level of threat associated with Lignum a retention target of 90% has been set.
Old Man Saltbush Atriplex nummularia Old Man Saltbush (Atriplex nummularia) has a patchy distribution. It was once a dominant understorey to Boree (Acacia pendula) (Beadle, 1948; Moore, 1953) but has almost completely disappeared in this region (Porteners, 1993).
Threats include clearing and poor regeneration due to grazing by rabbits, goats, stock and kangaroos. Old Man Saltbush is greatly reduced in its original extent by grazing (Beadle, 1948; Moore, 1953), the detrimental effects of which have been well documented (Cunningham, 1981). Brickhill (1985a) indicates that little is known botanically about the original association between Acacia pendula and A. nummularia. This association no longer exists in the Bioregion but was once the second most widespread alliance on the riverine plain (Leigh and Mulham, 1977).
Benson (1991) and Specht et al., (1995) indicate that Old Man Saltbush is very poorly conserved within its range and that some associations are endangered or vulnerable. Old Man Saltbush is present in Yanga Nature Reserve.
Due to the documented decline in the original extent of Old Man Saltbush and the on
130 going threats a retention target of 90% has been set.
Cottonbush Maireana aphylla Cottonbush is wide spread and has proliferated in areas that were once dominated by Atriplex vesicaria (Bladder Saltbush). Cottonbush is considered a disclimax or degraded community (Moore, 1953; Porteners, 1993).
The literature does not document any particular threats but as pressure increases for development, clearing could become a threat. About 12250 ha of Cottonbush is conserved in Willandra National Park (20 000 ha) where the Grassland and Cottonbush association is a result of former heavy grazing.
The Cottonbush and Bladder Saltbush alliance has been greatly reduced throughout the Riverina as a result of dieback caused by overgrazing (Leigh and Mulham, 1977). Brickhill (1985a) describes a Bladder Saltbush and Cottonbush alliance occurring in low lying areas on heavy soils, although extensively grazed this alliance still remains in relatively large areas and in good condition. Specht et al. (1995) suggests that over its entire range Cottonbush is poorly conserved.
As Cottonbush is considered a disclimax community and is conserved over part of its range in the Riverina a retention target of 15% has been set.
Dillon Bush Nitraria billardierei Dillon Bush occurs in dense continuous stands in areas of high grazing pressure adjacent to Riverine and Box Woodlands. This vegetation type occupies in disturbed areas and areas that were once dominated by Bladder Saltbush or Old Man Saltbush (Porteners, 1993).
Little information is available about the threats or conservation status of this vegetation type. Approximately 300 ha of Dillon Bush occurs in Willandra Lakes National Park. Leigh and Mulham (1977) indicate Dillon Bush attains its maximum size in degraded saltbush communities. It would appear this vegetation type has proliferated as a result of disturbance and is not of conservation value except in identifying areas where Bladder Saltbush and Old Man Saltbush may be re-established.
The retention target for Dillon Bush is 0%.
Great Cumbung Swamp Typha (Typha spp.) and Phragmites (Phragmites australia) occurs in semi-permanent water with River Red Gum and Black Box fringing the marshes (Porteners, 1993). At the Lachlan / Murrumbidgee confluence this area encompasses other wetland communities and includes areas of River Red Gum and Black Box. This vegetation type is associated with marshes and lakes on the main floodplain of the Murrumbidgee and extensive channelled Lignum (Pressey, 1988).
Distinct zonation of the main species in the Cumbung Swamp is noted by Porteners (1993), with Typha dominating the semi-permanent water and with Phragmites occurring from 0.3 m above the upper limit of Typha.
131 Threats include water and river regulation, reduced flow resulting in reduction in range of the community, some weed infestation and grazing and trampling by cattle.
Typha and Phragmites are not conserved in this area. King (1983) indicates that Phragmites is conserved in the Macquarie Mashes Nature Reserve, Myall Lakes National Park and Tuckean Nature Reserve but is poorly conserved in the Western Division of NSW and is not conserved in the Riverina. Benson (1991) suggests conservation is poor and Specht et al. (1995) indicate that Barmah State Park has good stands of Typha and Phragmites but overall the vegetation type is poorly conserved in the Riverina.
As Cumbung Swamp is reduced in extent and threatened by ongoing changes in the water regime a retention target of 90% has been set.
Grey Box Woodland Eucalyptus microcarpa Grey Box (Eucalyptus microcarpa) occurs south of the Hay Plains with Bull Oak and Yellow Box. White Cypress Pine (Callitris glaucophylla) occurs as a local community within Grey Box Woodlands. Porteners (1993) indicates that Grey Box is restricted to the far south of Deniliquin extending down to the Murray River with the north western limit as the Edward-Warkool River System. Grey Box replaces Black Box on higher ground. Moore (1953) defines two associations; Grey Box alone and Grey Box with White Cypress Pine. Grey Box is found in the Counties of Urana, Mitchell and Bourke while Grey Box and White Cypress Pine is found only on deep sandy soils like at “Bublebundie Sandhills,” south west of Darlington Point.
Leigh & Mulham (1977) state “a very small proportion of the area remains in near- pristine climax condition.” Moore (1953) also notes that Grey Box is limited by soil type and landuse and is threatened by development. Much of the original Grey Box has been cleared for cultivation and pasture improvement (Cunningham et. al., 1981). Around Deniliquin Grey Box has been extensively cleared and thinned for grazing and cropping.
The main threat to Grey Box is clearing for development and irrigation. There is little or no regeneration occurring at present in existing Grey Box and Yellow Box remnants (Mulham, 1996a-b-c). Remnants are prone to weed and rabbit infestation and are at risk of an increase in the water table in irrigation districts. Grazing pressure has resulted in the removal of the diverse shrub layer associated with Grey Box (Beadle, 1948) and that understorey grasses have been replaced by other species because of changes in grazing regimes (Brickhill, 1985a).
Grey Box is not well conserved in the Riverina Bioregion with Barmah State Park and Millewa State Forest Flora containing some Grey Box (Specht et al., 1995).
Due to the significant decline in the original extent of Grey Box and the ongoing threatening processes occurring in the Bioregion the retention target is set at 90%.
132 Grey Box, Blakely’s Red Gum and Pine Eucalyptus microcarpa, E. blakelyi & Callitris glaucophylla A single very small remnant of this vegetation type has been mapped on the Berrigan 1:100 000 map sheet. This remnant occurs in the Wahgunyah State Forest and on the property to the north of the State Forest. It is on sandy soil and contains Grey Box, Yellow Box, Blakely’s Red Gum and Pine. This is essentially a pine forest with the eucalypt species occurring at varying densities. It may be more appropriate for this remnant to be considered as part of the Callitris Mixed Woodland vegetation type. There are also similarities between this vegetation type and the Grey Box Woodlands.
As this vegetation type exists as an isolated remnant within the Riverina bioregion it is reasonable to suggest that this vegetation type requires consideration in a conservation strategy.
Grey Box, Blakely’s Red Gum and Pine is not conserved in the Bioregion.
Due to its limited extent, lack of conservation in the Riverina and adjacent bioregions and isolation from other examples of this type a retention target of 90% has been set.
Boree Woodland Acacia pendula Acacia pendula occurs mainly in the east of the Bioregion. The Hay Plains depicts the western limit of its range (Porteners, 1993).
Acacia pendula has been widely cleared or thinned and extensive areas are degraded. Moderate scalding and rabbit infestation occurs, weeds are common and few areas have shrubby understoreys. Regeneration is poor because of low fruit set, low levels of germination and seedlings are extremely palatable to grazers (Beadle, 1981). Porteners (1993) describes the remaining vegetation as remnants with a very open structure. Moore (1953) attributes the disappearance of Boree to heavy sheep grazing and a severe drought between 1875 and 1877. He considers that all stands are modified and no examples of the original structure exist. Danthonia caespitosa is believed to be a disclimax community that now occurs in place of Acacia pendula.
Boree is not represented in any reserves in south west New South Wales (Brickhill, 1985a). Brickhill (1985a) suggests that little is known botanically of the original association of Boree and Old Man Saltbush. Leigh & Mulham (1977) indicate that Boree “was the second most widespread of the woodland alliances but today no stands remain with their original structure” but small areas with chenopod and grassy understorey still occur.
Boree has no conservation status as it is not represented in any conservation reserve (Specht et al., 1995) and Benson (1991) supports the view that Boree and all Acacia shrublands and woodlands are poorly conserved.
As Boree is greatly reduced from its original extent and is in continued decline due to threatening process the retention target is set at 90%.
133 Prior Stream Remnant Woodland Callitris glaucophylla (White Cypress Pine) Hakea leucoptera (Needle-wood) H. tephrosma (Hooked Needlewood) occurs south and west of Griffith on prior streams. Prior Stream Remnant Woodland is very remnant in its nature and is often reduced to several scattered trees or a small grove along the relic prior stream lines (Porteners, 1993). Good stands of pine occur in the Millewa group of River Red Gum Forests and 5 ha of pine has been fenced on a sand ridge in Gulpa Island State Forest.
This vegetation type is largely cleared and subject to severe scalding and erosion due to rabbit infestation. There is little regeneration due to grazing by stock and rabbits.
Prior Stream Remnant Woodland is not conserved in the Bioregion but the property of “Zara” has been fenced through a co-operative venture including the Southern Riverina Field Naturalist Club, Greening Australia, Windouran Shire and Deniliquin / Moulamein Rural Land Protection Boards; News Limited FS Falkiner and Droughtcare/Landcare (Landcarer, 1997). The fenced remnant contains a good example of Callitris remnant woodland and with some Atriplex nummularia.
Due to the remnant nature of this vegetation type and the on going threats it faces a retention rate of 90% has been set.
Dwyers Red Gum, Pine and Grey Box Woodlands Eucalyptus dwyeri, Callitris glaucophylla & E. microcarpa.
Dwyers Red Gum / Tumbled Down Red Gum (E. dealbata) with Pine (Callitris glaucophylla) and Grey Box (Eucalyptus microcarpa) occurs on the shallow soils of the rocky outcrop of Mount Boomanoomana. This particular remnant is geographically isolated from other examples of this vegetation type. The geomorphology of Mount Boomanoomana is palaeozoic granites and sediments and these geomorphology types have been largely excluded from consideration within the Riverina as it is considered atypical of the Bioregion. However, as it is located within the IBRA bioregion it is being considered as a relevant vegetation type.
No threats are documented for this vegetation type but, its location on rocky outcrops would reduce the threat of clearing.
This vegetation type is not conserved in the bioregion.
As this Dwyers Red Gum, Pine and Grey Box Woodland occupies a very small area and is potentially threatened by grazing and lack of regeneration a retention target of 90% is set.
Grasslands For the Riverina five grassland communities have been defined by Benson et. al. (1996). The communities listed in table 2 below, are not mapped separately for this project.
134 Table 2. Grassland communities for the Riverina. From Benson et. al. (1996). Community Main Grass Species Distribution 1a Stipa nodosa, Chloris truncata and Danthonia caespitosa Jerilderie area 1b Stipa nodosa and Chloris truncata Deniliquin area 2 Thyridolepis mitchelliana, Themeda australis and Dantonia eriantha West of Lake Urana 3 Stipa aristiglumis and Homopholis proluta Eastern Riverina 4 Enteropogon ramosus, Stipa nodosa and Danthonia spp. Hay area 5 Agrostis avenacea and Danthonia duttoniana Scattered
The above communities are not represented in conservation reserves and are mostly under freehold management. Community 2 contains Kangaroo Grass (Themeda australis ) and Yam Daisy (Microseris lanceolata) which appears to be depleted through out the region.
Sixteen sites of botanical significance were identified form Benson’s work and are considered a suitable starting point for regional assessments of Grassland sites of significance. Benson et. al. (1996) suggest that sites identified by Chappell & Luke (1994) and Appleby et. al. (1991) containing Swainsona plagiotropis should be included in these sites of significance.
Danthonia caespitosa and Danthonia eriantha are short lived perennial and annual grasses which are moderately to extensively grazed with many areas degraded to annual grasslands. Danthonia will seed and recruit regularly, but may be eliminated by heavy and continuous grazing. King (1983) describes that this is a disclimax community with unknown conservation status in the Southern Riverina. Porteners (1993) goes on to suggest that the Grasslands were originally Acacia pendula, Atriplex nummularia or A. Vesicaria.
Although grass species inhabit different soils and may exist in a variety of associations, the most current and available consistent layer for grasslands is a general classification from the most natural grassland system to a degraded / improved pasture system. This grassland information really defines the limits of the grassland community rather than representing the specific associations of different species of grasses.
Threats to Grasslands include gross mechanical disturbance cultivation and improved pasture, irrigation, inappropriate grazing regimes (Foreman, 1994) and also weed invasion, increasing salinisation, infrequent fire, indiscriminate use of herbicides, and urban expansion particularly around Jerilderie (Benson et. al., 1996).
Grasslands are the most poorly conserved communities in Australia (Department of Conservation and Environment 1992, in Foreman, 1994). Table 3, modified from King (1983) summarises the conservation status and conservation priority of grasses in New South Wales. Thirteen out of sixteen grass species of high to medium conservation priority occur in the Riverina.
135 Table 3. The conservation priority and status in NSW for selected grasses that occur in the Riverina Bioregion. Modified from King (1983). Conservation Species Common Name Conservation Status Priority High Stipa aristiglumis Plains Grass poor not conserved Medium Stipa scabra ssp falcata Speargrass poor Kosciusko National Park Medium Themeda australis Kangaroo Grass coastal good, western poor Medium Aristida species Wiregrass unknown Medium Diplachne fusca A brown Beetle Grass unknown Medium Eragrostis australiasica Canegrass unknown Medium Eragrostis dielsii Mallee Lovegrass unknown Medium Eragrostis setifloia Neverfail unknown Medium Leptochloa digitata Umbrella Grass unknown Medium Cynodon dactylon Couch unknown Medium Pseudoraphis spinescens Spiny Mudgrass unknown Medium to low Pharagmites australis Common Reed see Great Cumbung Swamp Medium to low Triodia scariosa ssp scariosa Porcupine Grass moderate Mungo National Park Medium to low Enneapogon avenaceus Bottle Washers unknown probably poor Medium to low Danthonia caespitosa Ringed Wallaby Grass unknown Medium to low Danthonia eriantha Wallaby Grass unknown
Vegetation types occurring only in the Victorian section of the Bioregion.
Bull Mallee Eucalyptus behriana Disjunct populations of Bull Mallee occur in central south NSW and central west Victoria. The NSW population is located outside the Riverina Bioregion but a small proportion of the Victorian population occurs in the south western section of the Bioregion and occurs on Palaeozoic sediments. This geomorphology class is atypical of the Bioregion. Approximately 280 ha of Bull Mallee are represented in Victorian Flora Reserves in the Riverina.
As this vegetation type is atypical of the Bioregion and not disjunct from adjacent populations the retention rate is set at 15%.
Blakely’s Hill Gum Eucalyptus blakelyi Blakely’s Hill Gum is most commonly associated with the Southern and Northern Tablelands of NSW and in three disjunct populations in Victoria. Its range is largely outside the Bioregion. Within the Bioregion it occurs on palaeozoic granites which is a geomorphology class atypical of the Riverina. This vegetation type is extensively cleared in NSW (MNCWG, 1996) however, approximately 150 ha of Blakely’s Hill Gum is conserved in a Flora and Fauna Reserve in Victoria.
As this vegetation type is atypical of the Bioregion and not disjunct from adjacent populations the retention rate is set at 15%.
Broad-leaved Peppermint Eucalyptus dives Broad-leaved Peppermint is widespread in the Central and Southern Tablelands and the Central and Eastern parts of Victoria. Its range is largely outside of the Bioregion and within the Bioregion occurs on palaeozoic sediments a geomorphology class largely excluded from the Riverina Bioregion. This vegetation type is not represented in a dedicated reserve within the Bioregion.
136 As this vegetation type is atypical of the Bioregion and not disjunct from adjacent populations the retention rate is set at 15%.
Yellow Gum Eucalyptus leucoxylon Yellow gum is widely distributed on plains and nearby ranges of coastal South Australia. Disjunct populations occur close to the Murray in north central Victoria. Its range is largely outside of the Bioregion and within the Bioregion occurs on palaeozoic sediments a geomorphology class largely excluded from the Riverina. A population of Yellow Gum has been located recently on private property in NSW and an area of approximately 5 ha is represented in a Victorian Flora Reserve.
As this vegetation type is atypical of the Bioregion and not disjunct from adjacent populations the retention rate is set at 15%.
Red Stringybark Eucalyptus macrorhynca Red Stringy Bark is distributed on the lower ranges and tablelands of NSW and Victoria and as such is an atypical vegetation type for the Riverina Bioregion. Its range is largely outside the Bioregion and within the Bioregion it occurs on palaeozoic sediments and granites. These geomorphology classes are largely excluded from consideration in the Riverina. Approximately 45 ha of Red Stringybark is conserved in a Victorian State Park.
As this vegetation type is atypical of the Bioregion and not disjunct from adjacent populations the retention rate is set at 15%.
Red Box Eucalyptus polyanthemos Red Box is widespread on the central and southern tablelands of NSW and in central and eastern Victoria. Its range is largely outside of the Bioregion and within the Bioregion occurs on palaeozoic sediments a geomorphology class largely excluded from consideration in the Riverina. In NSW Red Box is cleared from about 50% of its original extent and is poorly conserved (MNCWG, 1996). 12 ha of this vegetation type occurs in a Victorian Wildlife Reserve in the Riverina Bioregion.
As this vegetation type is atypical of the Bioregion and not disjunct from adjacent populations the retention rate is set at 15%.
Blue Mallee Eucalyptus polybracta Blue Mallee has a restricted distribution in two disjunct occurrences. One near Wyalong in western NSW and the other in the Bendigo area of northern Victoria. These two populations are outside of the Bioregion. The 52 hectares of Blue Mallee that occurs within the Bioregion are on palaeozoic sediments a geomorphology class largely excluded from consideration in the Riverina. A tiny amount of Blue Mallee approximately 2 ha occurs is conserved in a Victorian Wildlife Reserve.
As this vegetation type is atypical of the Bioregion and not disjunct from adjacent populations the retention rate is set at 15%.
137 Narrow-leaved Peppermint Eucalyptus radiata Narrow-leaved Peppermint is located in the tablelands of NSW and Victoria. Its range is largely outside the Bioregion. Within the Bioregion it occurs on palaeozoic sediments, a geomorphology class largely excluded from consideration as part of the Riverina. This vegetation type is not represented in a dedicated reserve within the Bioregion.
As this vegetation type is atypical of the Bioregion and not disjunct from adjacent populations the retention rate is set at 15%.
Red Ironbark Eucalyptus sideroxylon Red Ironbark is widespread in central and southern Victoria. Its range is largely outside the Bioregion and within the Bioregion occurs on palaeozoic sediments a geomorphology class largely excluded from the Riverina. This vegetation type is not represented in a dedicated reserve within the Bioregion.
As this vegetation type is atypical of the Bioregion and not disjunct from adjacent populations the retention rate is set at 15%.
Long-leaved Box Eucalyptus goniocalyx Long-leaved Box is distributed in the NSW tablelands and in Victoria west towards the South Australian border. This Box occurs in the Bioregion on plains and plains with depressions as well as palaeozoic sediments. This vegetation type is not represented in reserves within the Bioregion.
As this vegetation type is atypical of the Bioregion and not disjunct from adjacent populations the retention rate is set at 15%.
Broom Honey-Myrtle Melaleuca uncinata Broom honey-myrtle occurs in the north west of Victoria and its range is largely outside of the Bioregion. It occurs on palaeozoic sediments a geomorphology class largely excluded from the Riverina Bioregion. 260 ha of Broom Honey Myrtle is conserved in the Riverina Bioregion.
As this vegetation type is atypical of the Bioregion and not disjunct from adjacent populations the retention rate is set at 15%.
References: Allen, B.(1979) Red gum county - the forest of the floodplains. Forest and Timber 15(3):2-4. Appleby, M.L. McDougall, K.L. & Barlow, T.J. (1991) Conservation research statement for Swainsona plagiotropis F. Muell. (Red Swainson-pea) NSW National Parks and Wildlife Service, Western Region: Broken Hill. Beadle, N.C.W. (1948) - The Vegetation and Pastures of Western New South Wales, with special reference to Soil Erosion. Thomas Henry Tennant, Government Printer. Sydney Benson, J. (1991) The native grasslands of the Southern Riverina, New South Wales. Report to Australian Nature Conservation Agency. June 1996.
138 Benson, J.S., Ashby, E.A. and Porteners, M.F. (1996) The effect of 200 years of European settlement on the vegetation and flora of New South Wales. Cunninghamia Vol. 2(3) Brickhill, J. (1985a) Review of Nature Conservation Programmes. Paper No. 13 Vegetation by geographic range “Southern Riverina”. NSW National Parks and Wildlife, Griffith District. Brickhill, J. (1985b) Review of Nature Conservation Programmes. Paper No. 21 Vegetation by communities/habitats Mallee. NSW National Parks and Wildlife, Griffith District. Chappell, A.C. & Luke, D.O. (1994) A community based action plan for the protection of Swainsona plagiotropis in the Jerilderie and Urana districts of NSW (Australian Nature Conservation Agency, Endangered Species Program, Project No. 305) Land Use Services Bendigo. Clift, D.K. Semple, W.S. and Prior, J.C (1987) A survey of Bladder Saltbush die back on the Riverine Plain of south-eastern Australia from the late 1970’s to 1983. Australian Rangelands Journal. 9(1):31-39 Creaser, P. M. and Knight, A. T. (1996) - Bioregional Conservation Strategy for the Cobar Peneplain; Stage I. Unpublished report, NSW National Parks and Wildlife Service. Cunningham, G.M. Mulham, W.E. Milthorpe, P.L. and Leigh, J.H. (1981) Plants of Western New South Wales. Soil Conservation Service of New South Wales. Department of Conservation, Forests & Lands Victoria (DCF&L), (1990) Proposed Barmah Management Plan Barmah State Park and Barmah State Forest. Benalla Region Department of Conservation, Forests and Lands, Victoria Donovan, P. (1997) A History of the Millewa Group of River Red Gum Forests. Prepared for State Forests of New South Wales. Foreman P. (1994) A recovery plan for Swainsona plagiotropis in the Jerilderie and Urana districts of NSW. Land Use Services, Bendigo, Victoria. Unpublished report to Australian Nature Conservation Agency. Finlayson, M. And Moser, M. (Eds) (1991) Wetlands. International Waterfowl and Wetlands Research Bureau (Facts on File Oxford, New York) King, S. (1983) Review of policies, priorities and programmes for nature conservation in New South Wales. Paper No. 27 Vegetation by communities/habitats Grasslands. NSW National Parks and Wildlife, Resource Office. Knowles, G.H. and Condon, R.W. (1951) The perennial saltbush Atriplex vesicaria Heward. Journal of Soil Conservation of New South Wales 7: 123-131 Landcarer (1997) The Murray Basin Landcarer Winter 1997, Ed Michael Elvins Holbrook. Land Conservation Council (LCC), Victoria (1985) Final Recommendations Murray Valley Area May 1985. Leigh, J.H. and Mulham, W.E. (1977) - Vascular plants of the Riverine Plain of New South Wales with notes on distribution and pastoral use. Telopea Vol. 1(4), p.225 - 293. Leslie, D. and Harris, K. (1996) Water management Plan for the Millewa State Forests. State Forests of New South Wales and Department of Land and Water Conservation.
139 Deniliquin. Margules and Partners Pty Ltd, P. And J. Smith Ecological Consultants and Department of Conservation Forests and Lands Victoria (1990) River Murray riparian vegetation study. (Murray Darling Basin Commission) Moore, C.W.E. (1953) - The Vegetation of the South - Eastern Riverina, New South Wales (1. The Climax Communities). Australian Journal of Botany, Vol. 1(3), p.485 - 547. Mulham, W.E. (1994a) Roadside Vegetation Survey and Management Guidelines, Deniliquin Municipality. Central Murray Roadside Vegetation Management Group Mulham, W.E. (1994b) Roadside Vegetation Survey and Management Guidelines, Corowa Shire. Central Murray Roadside Vegetation Management Group Mulham, W.E. (1994c) Roadside Vegetation Survey and Management Guidelines, Wakool Shire. Central Murray Roadside Vegetation Management Group Murray - Darling Basin Ministerial Council (1987) Murray - Darling Environmental Resources Study (Murray Darling Basin Ministerial Council: Canberra) Murray Nature Conservation Working Group (MNCWG) (1996) Discussion Paper: Vegetation in the Murray Catchment. Murray Catchment Management Committee Oxley, R. (1995) Roadside Management Plan, Conargo Shire. Department of Land and Water Conservation Porteners, M.F. (1993) - The natural vegetation of the Hay Plain: Booligal - Hay and Deniliquin - Bendigo 1:250 000 maps. Cunninghamia Vol. 3(1), p.1 - 87 Porteners, M.F., Ashby, E.M. and Benson, J.S. (1997) - Natural vegetation of Pooncarie 1:250 000 map. Cunninghamia Vol. 5(1), p.139 - 230 Pressey, R.L. (1988) Wetlands of western NSW: characteristics, conservation and management. National Parks Journal 32(3) 23-30 Semple, W. S. (1990) - The physical and vegetation resources of the aeolian landscapes of far south - western NSW. Technical Report No 14. Soil Conservation Service of NSW Semple, W. S. and Eldridge, D.J. (1989) Hay District Technical Manual. Chapters 1, 2, 3, 6, & 7. Soil Conservation Service of NSW Scott, J. A. (1992) - The natural vegetation of the Balranald - Swan Hill area. Cunninghamia Vol. 2(4). p.597 - 652. Somerville, J. (1988) Conservation of River Red Gums in New South Wales. National Parks Journal 32(3): 31 - 33 Specht, R.L., Specht, A., Whelan, B. and Hegarty, E.E. (1995) Conservation atlas of plant communities in Australia. Southern Cross University Press. Wilson, N. (1995) The Flooded Gum Trees: Land use and management of River Red Gums in New South Wales. Report to the Nature Conservation Council of NSW.
140 15.3 APPENDIX 3 - DERIVING NSW RIVERINA VEGETATION TYPES BY MERGING THE ROYAL BOTANIC GARDENS MAPPED VEGETATION CATEGORIES
Vegetation Description (from published Category Constituent Categories Equivalent Equivalent mapping) Extension Victorian Categories Categories Riverine Forest 1 1,1sc 1 River Red Gum Riverine Forest/Black Box Woodland 1/2 1/2,2/1,2/1sc,1sc/2sc,1/2sc 1/2 Riverine Forest/Lignum 1/18 1/18,18/1sc Riverine Forest/Dillon Bush 1/22 1/22 Riverine Forest/Callitris Mixed Woodland 1/16sc 1/16sc
Riverine Forest/Grey Box Woodland 1/24sc 1/24sc Riverine Forest/Open Area 1/OA 1/OA,OA/1sc,1sc/OA Open Area/Riverine Forest/Callitris Mixed OA/1sc/16sc OA/1sc/16sc Woodland Black Box Woodland 2 2,2sc 2 Black Box Black Box Woodland/Lignum 2/18 18/2 2/18,18/2sc,18/2,2/18sc,2sc/ 18sc Black Box Woodland/Old Man Saltbush 2/19 2/19,19/2sc,19/2,2sc/19sc Black Box Woodland/Dillon Bush 22/2sc 22/2sc,2sc/22 Black Box Woodland/(Casuarina) Intergrading 2/28 2/28,28/2 Population Black Box Woodland/Sandplain Mallee 2/3d 2/3d Black Box Woodland/Callitris Mixed 2/16sc Woodland 2/16sc,16/2,16/2sc,2sc/16sc, 16sc/2 Black Box Woodland/Grey Box Woodland 2/24sc 2/24sc
Dune Crest Mallee 3b 3b,3bsc,3b/3c,3c/3b,3c Dune Crest Mallee/Linear Dune Mallee/Open 3b/3c/OA Area 3b/3c/OA,3c/3b/OA,OA/3bsc ,OA/3c Dune Crest Mallee/Belah-Rosewood 3b/4 3b/4,4/3b,3b/4sc Sandplain Mallee 3d 3d,3dsc Sandplain Mallee/Belah-Rosewood 3d/4 3d/4,3d/4sc,4/3d,4/3dsc,4sc/ 3dsc Sandplain Mallee/Black Bluebush 3d/8 3d/8 Belah-Rosewood 4 4,4sc 4 Belah-Rosewood/Black Bluebush 4/8 4/8,8/4,8/4sc,4sc/8 Belah-Rosewood/Callitris Mixed Woodland 4/16 4/16,16sc/4sc,4/16sc,4sc/16s c Belah-Rosewood/Acacia Melvillei Woodland 4/17 4/17
Belah-Rosewood/Lunette Shrubland 4/30 4/30 Belah-Rosewood/Black Bluebush/Callitris 4/8/16 4/8/16,8/4sc/16sc Mixed Woodland Belah-Rosewood/Open Area 4/OA 4/OA,OA/4,OA/4sc,4sc/OA Belah-Rosewood/Black Box Woodland 4sc/2 4sc/2 Belah-Rosewood/Sandplain Mallee/Callitris 4sc/3dsc/16sc 4sc/3dsc/16sc Mixed Woodland Belah-Rosewood/Pearl Bluebush 4sc/8p 4sc/8p Black Bluebush 8 8,8sc,8 Black Bluebush/Black Box Woodland 8/2 8/2 Black Bluebush/Pearl Bluebush 8/9 8/9,9/8,8/8p
141 Vegetation Description (from published Category Constituent Categories Equivalent Equivalent mapping) Extension Victorian Categories Categories Black Bluebush/Bladder Saltbush/Old Man 8/11/19 8/11/19,11/8/19,8/19/11 Saltbush Black Bluebush/Callitris Mixed Woodland 8/16 8/16
Black Bluebush/Acacia Melvillei Woodland 8/17 8/17
Black Bluebush/Old Man Saltbush 8/19 8/19,8/19sc,19/8sc,19/8 Black Bluebush/Old Man Saltbush/Dillon 8/19/22 8/19/22 Bush Black Bluebush/Dillon Bush 8/22 8/22,22/8,22(8) Pearl Bluebush 9 9,8p Pearl Bluebush/Black Bluebush/Old Man 9/8/19 9/8/19 Saltbush Bladder Saltbush 11 11,11sc, Bladder Saltbush/Black Bluebush 11/8 11/8,11/8sc, Bladder Saltbush/Sclerostegia tenuis 11/12 11/12,12sc/11s, Bladder Saltbush/Sclerostegia tenuis/Old Man 11/12/19 11/12/19 Saltbush Bladder Saltbush/Canegrass 11/13 11/13,11sc/13,13/11,13/11sc Bladder Saltbush/Lignum 11/18 11/18 Bladder Saltbush/Old Man Saltbush 11/19 11/19,19/11 Bladder Saltbush/Dillon Bush 11/22 11/22,11sc/22,22/11sc Canegrass 13 13,13sc 13 Canegrass/Lignum 13/18 13/18,18/13,18/13sc Canegrass/Cotton Bush 13/21 13/21,21/13 Canegrass/Dillon Bush 13/22 13/22,22/13 Callitris Mixed Woodland 16 16,16sc 16 Callitris glaucophylla Callitris Mixed Woodland/Acacia Melvillei 16/17 16/17 Woodland Callitris Mixed Woodland/(Casuarina) 16sc/28sc 16sc/28sc,28sc/16sc,28/16 Intergrading Population Callitris Mixed Woodland/Open Area 16sc/OA 16sc/OA,OA/16sc Callitris Woodland on Prior Streams 16/27 16/27 Acacia Melvillei Woodland 17 17 Lignum 18 18,18sc 18 Lignum Lignum/Black Bluebush 18/8sc 18/8sc Lignum/Open Area 18/OA 18/OA,OA/18sc Old Man Saltbush 19 19,19sc Old Man Saltbush/Dillon Bush 19/22 19/22 Cotton Bush 21 21 21 Cotton Bush/Bladder Saltbush 21/11 21/11,21/11sc 21/11 Cotton Bush/Callitris 21/16sc 21/16sc,21sc/16sc Cotton Bush/Dillon Bush 21/22 21/22,22/21 21/22 Dillon Bush 22 22 Dillon Bush/Lignum 22/18 22/18 Dillon Bush/Cleared and-or cropped 22/C 22/C Dillon Bush/Open Area 22/OA 22/OA,OA/22,OA/22sc Dillon Bush/Open Area/Lignum 22/OA/18sc 22/OA/18sc Great Cumbung Swamp 23 23 Grey Box Woodland 24 24,24sc 24 Grey Box Grey Box Woodland/Callitris Mixed 24sc/16sc 24sc/16sc 24/16 Woodland Grey Box-Blakelys Red Gum-Callitris 24a 24a 24a E. blakleyi Hill Gum Boree Woodland 25 25,25sc 25
142 Vegetation Description (from published Category Constituent Categories Equivalent Equivalent mapping) Extension Victorian Categories Categories Boree Woodland/(Casuarina) Intergrading 25/28 25/28,28/25 Population Open Area/Boree Woodland OA/25sc OA/25sc White-top Grassland 26 26 Grassland White-top Grassland/Callitris Mixed 26/16sc 26/16sc Woodland White-top Grassland/Open Areas 26/OA 26/OA Prior Stream Remnant Woodland 27 27,27sc (Casuarina) Intergrading Population 28 28,28sc Eucalyptus dwyeri-Callitris glaucophylla-Grey 29a 29a 29a Box (E. behriana) Bull Mallee Bull Mallee. No equivalent in NSW mapping (E. dives) Broad-leaved Peppermint Broad-leaved No equivalent in NSW Peppermint mapping (E. luecoxylon) Yellow Gum Yellow Gum No equivalent in NSW mapping (E. macrorhyncha) Red Stringybark Red Stringybark, No equivalent in NSW mapping (E. polyanthemos) Red Box Red Box, No equivalent in NSW mapping (E. radiata) Narrow-leaved Peppermint Narrow-leaved No equivalent in NSW Peppermint, mapping (E. tricarpa) Red Ironbark Red Ironbark No equivalent in NSW mapping (E.goniocalyx) Long Leaf Box Long Leaf Box, No equivalent in NSW mapping (Melaleuca uncinata)Broom Honey Myrtle Broom Honey No equivalent in NSW Myrtle mapping Poplar spp. Plantation No equivalent in NSW mapping Softwood plantation Softwood No equivalent in NSW Plantation mapping Bare Areas/Degraded BA BA BA Open Area OA OA Cleared and-or cropped C C,C(x),"C(x,y)",C(x/y) C Non Forest Water Water Water,Lake Water Outside Outside Outside Unclassified
143 15.4 APPENDIX 4 - MERGING THE VICTORIAN STRUCTURAL VEGETATION CATEGORIES WITH NSW VEGETATION TYPES
Species name Area (ha) Height (m) Vegetation Form Density % Information from GIS overlay Equivalent category in NSW cover Acacia stenophylla 58 0-10 Woodland open 20-50 58 ha near Gulpa SF on Riverine Forest and cleared cropped keep Acacia stenophylla no equivalent in NSW. understory Black Box 1 15-20 N/A N/A only 1 ha Black Box Black Box 311 20-30 Open Forest 15-28m 50-80 Black Box Black Box 10885 10m-15m Woodland open 20-50 Black Box in western Victoria Black Box understory Black Box 12463 10m-15m Open Forest 15-28m 50-80 Mapped as RBG Riverine Forest near Gun Bower SF Black Box Callitris glaucophylla 1 20-30 Open Forest 15-28m 50-80 1 ha only as in RBG Callitris on Millewa dune Callitris Mixed Woodland Callitris glaucophylla 199 10m-15m Woodland open 20-50 Correlates very well with RBG dune Callitris mixed woodland this Callitris Mixed Woodland understory category also occurs south of the Riverina Bioregion Chenopodium nitrariaceum 4 0-10 Scrub open 0-20 4ha on NSW side of Murray RBG = cleared or cropped None (E. behriana) Bull Mallee 1494 0-10 Scrub open 20-50 Small intrusion into south west marginal to Bioregion . On Bull Mallee no equivalent in NSW. Paleozoic sediments and Tertiary sand and gravel. (E. blakleyi) Hill Gum 19 15-20 Open Forest 15-28m 50-80 Very marginal to Bioregion located in the east on Alluvial / Coluvial Blakely's Hill Gum, no equivalent in NSW. Slope Apron atypical of the Bioregion. (E. blakleyi) Hill Gum 713 10m-15m Woodland open 20-50 Very marginal to Bioregion located in the east and south on Alluvial Blakely's Hill Gum no equivalent in NSW. understory Coluvial Slope Apron and Paleozoic sediments atypical of the Bioregion. (E. dives) Broad-leaved 188 20-30 Open Forest 15-28m 50-80 Very marginal to Bioregion located in the east and south on Broad-leaved Peppermint no equivalent in Peppermint Paleozoic sediments atypical of the Bioregion. NSW. (E. luecoxylon) Yellow Gum 232 20-30 Open Forest 15-28m 50-80 Very marginal to Bioregion located in the west and south on Yellow Gum, no equivalent in NSW. Paleozoic sediments atypical of the Bioregion. (E. macrorhyncha) Red 57 10m-15m Woodland open 20-50 Very marginal to Bioregion located in the east and south on Red Stringybark, no equivalent in NSW. Stringybark understory Paleozoic granites atypical of the Bioregion. (E. macrorhyncha) Red 403 10m-15m Woodland open 20-50 Very marginal to Bioregion located in the east on Paleozoic Red Stringybark, no equivalent in NSW. Stringybark understory sediments atypical of the Bioregion. (E. polyanthemos) Red Box 125 10m-15m Woodland open 20-50 Very marginal to Bioregion located in the west and south on Red Box, no equivalent in NSW. understory Paleozoic sediments atypical of the Bioregion. (E. polyanthemos) Red Box 52 10m-15m Woodland open 20-50 Very marginal to Bioregion located in the west on Paleozoic Red Box, no equivalent in NSW. understory sediments atypical of the Bioregion. (E. radiata) Narrow-leaved 23 30-40 Open Forest 15-28m 50-80 Very marginal to Bioregion located in the east on Paleozoic Narrow-leaved Peppermint, no equivalent in Peppermint sediments atypical of the Bioregion. NSW. (E. tricarpa) Red Ironbark 1 20-30 Open Forest 15-28m 50-80 Small area all on Paleozoic sediments atypical of Bioregion. Red Ironbark, no equivalent in NSW.
144 Species name Area (ha) Height (m) Vegetation Form Density % Information from GIS overlay Equivalent category in NSW cover (E. tricarpa) Red Ironbark 100 10m-15m Woodland open 20-50 Small area all on Paleozoic sediments atypical of Bioregion. Red Ironbark no equivalent in NSW. understory (E. tricarpa) Red Ironbark 1815 15-20 Open Forest 15-28m 50-80 Small area all on Paleozoic sediments atypical of Bioregion. Red Ironbark no equivalent in NSW. (E.goniocalyx) Long Leaf 2 N/A N/A N/A Very marginal to Bioregion in the east on Paleozoic granites, Long Leaf Box no equivalent in NSW. Box atypical of the Bioregion. (E.goniocalyx) Long Leaf 2515 10m-15m Woodland open 20-50 Small remnants in far south east on Paleozoic granites and Long Leaf Box as no equivalent in NSW. Box understory sediments, atypical of the Bioregion. Some vegetation on Plains and Plains with depressions could have been more extensive previously. (E.goniocalyx) Long Leaf 6300 15-20 Open Forest 15-28m 50-80 Small remnants in far south east on Paleozoic granites, atypical of Long Leaf Box as no equivalent in NSW. Box the Bioregion. Grey Box 1 N/A Open Forest 15-28m N/A I ha only matches with RBG Grey Box Woodland Grey Box Grey Box 1442 20-30 Woodland open 20-50 Grey Box in far south central portion of the Bioregion Grey Box understory Grey Box 13605 20-30 Open Forest 15-28m 50-80 Some very small remnants in the SW and SE of the Bioregion. Grey Box Lignum 1 N/A N/A N/A Only 1 ha Lignum Lignum 1259 0-10 Scrub open 0-20 Lignum mapped in Victoria. Lignum (Melaleuca uncinata) Broom 490 0-10 Scrub open 20-50 Very small intrusion into SW marginal to Bioregion. On Paleozoic Broom Honey Myrtle as no equivalent in Honey Myrtle sediments atypical of the Bioregion. NSW. Non Forest 1 N/A N/A 50-80 N/A Clear/Cropped Non Forest 3 1/10/15 Open Forest 15-28m 50-80 N/A Clear/Cropped Non Forest 10 0-10 Scrub open 20-50 N/A Clear/Cropped Non Forest 16 15-20 Open Forest 15-28m 50-80 N/A Clear/Cropped Non Forest 25 N/A Open Forest 15-28m 50-80 N/A Clear/Cropped Non Forest 44 N/A N/A N/A N/A Clear/Cropped Non Forest 113 20-30 Woodland open 20-50 N/A Clear/Cropped understory Non Forest 11544 N/A N/A N/A N/A Clear/Cropped Non Forest 17651 N/A N/A 20-50 N/A Clear/Cropped Non Forest 2369944 N/A N/A N/A Cleared or not mapped in Victoria Clear/Cropped Poplar spp. 187 N/A Plantation Softwood N/A Place in cleared or cropped category no plantation category in RBG Plantation, no equivalent in NSW. River Red Gum 2 10m-15m Woodland open 20-50 Correlates well with Riverine Forest Riverine Forest understory River Red Gum 2 N/A Open Forest 15-28m N/A Correlates well with Riverine Forest Riverine Forest River Red Gum 5 N/A N/A N/A Only 5 ha good match Riverine Forest Riverine Forest River Red Gum 6 N/A N/A 50-80 Correlates well with Riverine Forest Riverine Forest River Red Gum 6 N/A Woodland open N/A Correlates well with Riverine Forest Riverine Forest understory River Red Gum 21 10m-15m Woodland open 20-50 Small area in far south of Bioregion Riverine Forest understory
145 Species name Area (ha) Height (m) Vegetation Form Density % Information from GIS overlay Equivalent category in NSW cover River Red Gum 200 20-30 N/A N/A Excellent correlation with Riverine Forest Riverine Forest River Red Gum 840 15-20 Open Forest 15-28m 50-80 Correlates well with Riverine Forest Riverine Forest River Red Gum 4403 30-40 Open Forest 28-40m 50-80 Correlates well with Riverine Forest Riverine Forest River Red Gum 12842 20-30 Woodland open 20-50 Excellent correlation with Riverine Forest Riverine Forest understory River Red Gum 143614 20-30 Open Forest 15-28m 50-80 Excellent correlation with Riverine Forest not picking up a small Riverine Forest section of Royaly Botanic Gardens mapped Callitris Woodland. Softwood plantation 103 N/A N/A N/A Place in cleared or cropped category no plantation category in RBG Softwood Plantation, no equivalent in NSW. Unclassified 5963311 N/A N/A N/A Unclassified category covers unmapped area Outside
146 15.5 APPENDIX 5 - LAND COUNCIL INFORMATION PACKAGE
SCOPE OF THE PROJECT
The aim of this component of the Riverina project is to document places of significance to Aboriginal communities which is not restricted to cultural sites but can include places of economic importance. For example, places that are valued for their potential to provide food or medicines or for use in ceremonies. We also hope to document land management issues that may be associated with these sites and areas.
AIMS OF ABORIGINAL LAND COUNCIL LIAISON 1. Record the information from Aboriginal people about; * Archaeological sites * places of cultural, ceremonial or spiritual significance * areas important for supply of resources such as food or medicines. 2. Enter this information in the Aboriginal Sites Register and make it available to the L.A.L.C and community. 3. Incorporate the above information into the conservation planning framework for the Riverina. 4. Identify threats or causes of degradation to these locations. 5. Identify sites which may require particular management for maintenance and protection. 6. Identify landuse issues important to Aboriginal communities. 7. Confirm or verify information about sites currently recorded in the Aboriginal Sites Register. 8. Consider specific Aboriginal landuse issues in the broader conservation planning context
METHOD Sites identified by the community then recorded on Aboriginal Sites Register cards will be entered into the Aboriginal Sites Register. This will mean the information for that sites the location, site type and who recorded the site, is made available to clients of N.P.W.S. (for example; L.A.L.C.s, consultant archaeologists preparing development applications).
Sites that are placed on the Register help to alert land managers to the presence of sites. Although all Aboriginal sites are protected if they are recorded on the register there is greater potential for protective mechanisms to be initiated if development of an area occurs.
Each L.A.L.C. wishing to participate will be visited. The L.A.L.C. will be provided with maps showing existing site records. Each Council will be encouraged to identify sites or broad areas of interest that they would like to have recorded.
Land management issues associated with the currently recorded or new sites will be
147 documented. This may include identification of activities which degrade or damage sites or recognition of sites which may require protection,
With the approval and consent of the people who provide the information, the information will be transferred from maps and notes and included in the N.P.W.S. Aboriginal Sites Register.
The information will be used in the conservation framework for the Riverina bioregion, with a focus on the relationship between sites of cultural and natural heritage significance and the land management issues that affect both in this region.
Recommendations for further development of this information and identification of sites that require protection will be included in the bioregional planning report.
Communities will be provided with new maps identifying the new and old sites in the N.P.W.S. Aboriginal Sites Register.
On completion of the project all data will be submitted to the Cultural Heritage Services Division for storage. The C.H.S. Division will ensure that access to this information will only be possible for legitimate and appropriate purposes.
CONFIDENTIALITY It is also possible to place further restrictions on access to sensitive or confidential information (for example personal stories). In such cases it will be necessary for the community or individual to clearly identify to the N.P.W.S. what the restrictions are. The N.P.W.S. will then protect the information as required.
148 15.6 APPENDIX 6 - ENDANGERED SPECIES RECORDED FOR THE RIVERINA BIOREGION
Legal status under the NSW Threatened Species Conservation Act 1995 Amphibians & Reptiles Scientific Name Common Name NSW Legal Last Date Victorian National Status Sighted Threatened Legal Status Species Tiliqua occipitalis Western Blue-tongued Vulnerable 15/08/83 Lizard Litoria raniformis (Frog) Endangered 2/12/93
Avifauna Scientific Name Common Name Legal Status Last Date Victorian National Sighted Threatened Legal Status Species Leipoa ocellata Malleefowl Endangered 31/12/93 4 Vulnerable Pedionomus torquatus Plains-wanderer Endangered 7/12/96 4 Vulnerable Phaethon rubricauda Red-tailed Tropicbird Vulnerable 6/12/79 Limosa limosa Black-tailed Godwit Vulnerable 16/10/93 Calidris tenuirostris Great Knot Vulnerable 28/11/91 Rostratula benghalensis Painted Snipe Vulnerable 8/02/92 Burhinus grallarius Bush Stone-curlew Endangered 7/10/95 4 Ardeotis australis Australian Bustard Endangered 1/09/94 4 Grus rubicunda Brolga Vulnerable 13/03/96 Botaurus poiciloptilus Australasian Bittern Vulnerable 8/11/95 Anseranas semipalmata Magpie Goose Vulnerable 24/04/93 Anseranas semipal Freckled Duck Vulnerable 19/08/95 Oxyura australis Blue-billed Duck Vulnerable 10/12/93 Lophoictinia isura Square-tailed Kite Vulnerable 3/01/90 Hamirostra melanosternon Black-breasted Buzzard Vulnerable 31/08/85 Falco hypoleucos Grey Falcon Vulnerable 1/03/96 4 Pandion haliaetus Osprey Vulnerable 8/07/85 Tyto novaehollandiae Masked Owl Vulnerable 6/09/84 4 Vulnerable Tyto tenebricosa Sooty Owl Vulnerable 6/05/91 4 Calyptorhynchus lathami Glossy Black-Cockatoo Vulnerable 22/07/95 4 Endangered Cacatua leadbeateri Major Mitchell's Cockatoo Vulnerable 30/12/95 4 Polytelis swainsonii Superb Parrot Vulnerable 14/12/96 4 Vulnerable Polytelis anthopeplus Regent Parrot Endangered 11/06/94 4 Vulnerable Neophema pulchella Turquoise Parrot Vulnerable 25/11/96 4 Lathamus discolor Swift Parrot Vulnerable 8/06/92 4 Vulnerable Pachycephala rufogularis Red-lored Whistler Endangered 5/10/87 4 Vulnerable Pachycephala inornata Gilbert's Whistler Vulnerable 14/12/96 Cinclosoma castanotus Chestnut Quail-thrush Vulnerable 30/01/94 Drymodes brunneopygia Southern Scrub-robin Vulnerable 18/09/93 Pyrrholaemus brunneus Redthroat Vulnerable 18/09/91 Hylacola cauta Shy Heathwren Vulnerable 16/10/94 Amytornis striatus Striated Grasswren Vulnerable 06/01/1880 Grantiella picta Painted Honeyeater Vulnerable 30/11/96 4 Certhionyx variegatus Pied Honeyeater Vulnerable 20/11/82
149 Avifauna Scientific Name Common Name Legal Status Last Date Victorian National Sighted Threatened Legal Status Species Xanthomyza phrygia Regent Honeyeater Endangered 30/11/93 4 Endangered Procelsterna cerulea Grey Ternlet Vulnerable 2/07/81
Mammals Scientific Name Common Name Legal Status Last Date Victorian National Sighted Threatened Legal Status Species Dasyurus maculatus Spotted-tailed Quoll Vulnerable 10/09/92 4 Endangered Phascogale tapoatafa Brush-tailed Phascogale Vulnerable 11/06/89 4 Antechinomys laniger Kultarr Endangered 1/01/1883 Sminthopsis macroura Stripe-faced Dunnart Vulnerable 1/04/88 Macrotis lagotis Bilby Extinct 1/01/32 Petaurus norfolcensis Squirrel Glider Vulnerable 31/12/92 4 Phascolarctos cinereus Koala Vulnerable 4/12/94 Lasiorhinus krefftii Northern Hairy-nosed Extinct 30/12/1884 Endangered Wombat Bettongia penicillata Brush-tailed Bettong Extinct 12/12/1857 4 Aepyprymnus rufescens Rufous Bettong Vulnerable 12/12/1857 Lagorchestes leporides Eastern Hare-wallaby Extinct 12/12/1890 4 Extinct Onychogalea fraenata Bridled Nail-tail Wallaby Extinct 12/12/1857 4 Endangered Petrogale penicillata Brush-tailed Rock-wallaby Vulnerable 6/05/91 4 Vulnerable Nyctophilus timoriensis Greater Long-eared Bat Vulnerable 31/12/88 Chalinolobus picatus Little Pied Bat Vulnerable 5/01/95 Myotis adversus Large-footed Myotis Vulnerable 11/08/79 Conilurus albipes White-footed Tree-rat Extinct 1/01/39 Extinct
150 15.7 APPENDIX 7 - VEGETATION TYPES ATYPICAL OF THE RIVERINA BIOREGION AND THEIR DISTRIBUTION WITHIN AND OUTSIDE OF THE RIVERINA BIOREGION
Vegetation Types Area % Extent Distribution Geomorphology Type Atypical of the Riverina (ha) of Bioregion Vegetation Type Dune Crest Mallee 803 0.01% Extensive areas to the west of the Dunefield Bioregion Dune Crest Mallee / Linear 18 0.00% Extensive areas to the west of the Dunefield Dune Mallee / Open Area Bioregion Dune Crest Mallee / Belah- 934 0.01% Not extensive outside the Bioregion. A Source bordering dunes Rosewood population 25 km inside the bioregional boundary Sandplain Mallee 10095 0.11% Not extensive outside the Bioregion Source bordering dunes localised areas in the west Sandplain Mallee / Belah- 1293 0.01% Not extensive outside the Bioregion Source bordering dunes Rosewood localised areas in the west Sandplain Mallee / Black 2293 0.03% Not extensive outside the Bioregion Source bordering dunes Bluebush localised areas in the west Belah-Rosewood / Acacia 11 0.00% Small areas mapped, distribution Plains with scalds melvillei Woodland throughout Bioregion Belah-Rosewood / Callitris 13749 0.43% Small areas mapped but distribution is Plains with scalds Mixed Woodland throughout the Bioregion Belah-Rosewood / Open 987 0.01% Small areas mapped but distribution is Plains with scalds Area throughout the Bioregion Belah-Rosewood / Black 1054 0.01% Small areas mapped but distribution is Plains with scalds Box Woodland throughout the Bioregion Belah-Rosewood / Pearl 629 0.01% Small areas mapped but distribution is Plains with scalds Bluebush throughout the Bioregion Black Bluebush/Acacia 747 0.01% Small areas mapped but distribution is Plains with scalds and melvillei Woodland throughout the Bioregion depressions Black Bluebush / Callitris 825 0.01% Small areas mapped but distribution is Plains with scalds and Mixed Woodland throughout the Bioregion depressions Acacia melvillei Woodland 527 0.01% Disjunct populations within the Plains with depressions Bioregion Grey Box-Blakely's Red 2108 0.02% Small area mapped 30 km from the Plains and plains with Gum-Callitris eastern boundary of the Bioregion depressions Dwyer's Red Gum- 173 0.00% No information about distribution Paleozoic granites and Callitris-Grey Box outside the Bioregion, isolated sediments remnants in the eastern portion of the Bioregion Bull Mallee 1494 0.02% Very small area just inside the Paleozoic sediments and small Bioregion, fragmented in the South areas on plains western slopes Bioregion Blakely's Hill Gum 732 0.01% Not extensive outside the Bioregion Paleozoic granites Broad-leaved Peppermint 188 0.00% Very small area just inside the Paleozoic granites Bioregion, fragmented in the South western slopes Bioregion Yellow Gum 232 0.00% Very small area just inside the Paleozoic granites Bioregion, fragmented in the Victorian Midlands Bioregion Red Stringybark 460 0.01% Very small area just inside the Paleozoic granites Bioregion, fragmented in the Victorian Midlands Bioregion
151 Vegetation Types Area % Extent Distribution Geomorphology Type Atypical of the Riverina (ha) of Bioregion Vegetation Type Red Box 125 0.00% Very small area just inside the Paleozoic granites Bioregion, fragmented in the Victorian Midlands Bioregion Blue Mallee 52 0.00% Very small area just inside the Paleozoic granites Bioregion, fragmented in the Victorian Midlands Bioregion Narrow-leaved Peppermint 23 0.00% Extensive in the South Western Slopes Paleozoic granites Red Ironbark 1916 0.02% Extensive but fragmented in the south Paleozoic granites and small west (Victorian Midlands) and south areas of plains with east (South Western slopes) of the depressions Bioregion Long Leaf Box 8817 0.10% Small isolated areas 30 km into the Paleozoic granites, plains and Bioregion. Could have been more plains with depressions extensive. Fragmented in adjacent Bioregion Broom Honey Myrtle 490 0.01% Extensive to the south of the Bioregion, Paleozoic granites but fragmented
152