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In this section you will find detailed information, including national overviews and state and regional level assessments, from the 2000-2002 National Land and Water Resources Audit theme assessments.
Australian Terrestrial Biodiversity Assessment 2002
Paul Sattler and Colin Creighton
National Land and Water Resources Audit, 2002
ISBN 0 642 3713
10. Regional biodiversity management
Summary
Fourteen case study regions, stratified across the six landscape stress classes and Australia's major agroecological regions, provide the basis of an analysis of the breadth and depth of biodiversity conservation issues and management responses required across Australia. The case studies comprehensively and systematically identify biodiversity issues and priority actions for conservation. These studies provide direction for determining cost-effective conservation priorities and the development of landscape management strategies.
Regional biodiversity management.
Photo: QEPA
In all case studies, a mix of reserve consolidation, threatened species and ecosystem recovery and integrated natural resource management measures are identified as essential to achieve effective biodiversity conservation. In many case studies, the wide range of planning activities leads to conflicting messages to the community. Integrated bioregional and multi-institutional planning as part of a whole-of-Government approach is imperative.
All 14 case studies identified that a significant increase of funding was necessary to achieve effective biodiversity conservation outcomes. Of the 14, seven estimated the level of expenditure required to achieve a significant practical effect for biodiversity conservation. The range of increase was between 1.5 to 23.6 times current expenditure. This varies with needs of bioregions. For example, for Tiwi Coburg bioregion, current expenditure is $225,000 and an estimated increase of $52,500 would deliver substantial biodiversity benefits. In comparison, for Northern Kimberley 1 subregion, current expenditure is $250,000 and the required increase is $5,650,000 to achieve significant conservation outcomes. A similiar proportional increase is also indicated for the Isaac-Comet subregion where a different suite of threatening processes exist. Acquisition of reserves is identified as a priority in a number of case studies where significant threats to the remaining key natural areas exist.
The case studies show that the investment required to deliver biodiversity conservation in predominantly natural bioregions is minimal compared to that required in the highly modified bioregions. Most of Australia's natural bioregions are in the rangelands and tropical woodlands. Therefore, a coordinated Australia-wide approach to biodiversity conservation for these bioregions is an investment priority.
In the more disturbed case study areas, there are many planning activities, which are often focused on a single issue. Yet in many of these regions the overall condition of biodiversity continues to decline. Either there are limited resources and commitment to go beyond the planning phase to implementation or we lack the knowledge to solve the problem (eg. salinity) in an affordable way. In these regions, strategic selection and funding of management activities may deliver higher returns than further planning activities. Planning under the Natural Heritage Trust extension and the National Action Plan for Salinity and Water Quality will need to be carefully coordinated so as to build on existing work and to focus on achieving well-defined outcomes.
The case studies demonstrate that increased attention by government to provide a policy environment and market drivers for biodiversity conservation on private lands is likely to yield substantial benefits for biodiversity conservation. Associated with an increased emphasis and encouragement of off-reserve conservation, the need for brokers is identified in some case studies to promote and coordinate activities on private lands to meet joint government and community targets for increased biodiversity conservation. Elsewhere it is indicated that little capacity exists to promote conservation without significant incentives.
The relationship between the case study subregions and other subregions was tested to demonstrate where similar biodiversity conservation measures may be required and where subregions are irreplaceable in terms of their species and the need to implement biodiversity conservation actions. The full text for each case study is available on the Atlas. The case studies should be referred to in regional planning where similar land use or landscape health scenarios exist. They provide a rich array of the detailed approaches taken to biodiversity conservation planning for different parts of Australia.
The Case Studies
To ensure that the Biodiversity Assessment was grounded in regional needs and identified the breadth of biodiversity issues and conservation responses, 14 case studies were undertaken. The case study subregions, and in some cases, entire bioregions, were stratified across the six landscape stress classes identified in the Landscape Health Assessment (NLWRA 2001a) and Australia's broad agro-ecological regions (Figure 10.1 and Table 10.1). Stratifying the case studies across Australia's agroecological regions enables each to be related to different regional land use patterns.
These detailed case studies assist in quantifying the strategies and the resources required to achieve significant biodiversity outcomes from systematically assessing the needs of each subregion or bioregion. This approach accords with the bioregional planning activities of the States and Territories and the Environment Protection and Biodiversity Conservation Act, 1999, that has provisions to encourage bioregional planning.
All States and Territories requested that these case studies be an integral component of the Biodiversity Assessment to demonstrate the need for systematic analysis and the requirements to effectively implement bioregional conservation strategies.
The case studies illustrate the benefits of integrated bioregional planning compared with the difficulties of dealing with a myriad of thematic or species-based strategies that may be planned in isolation to overall bioregional priorities. They demonstrate the importance of assessing the mix of conservation actions required at the bioregion or subregion level and the need for such assessment to inform regional planning and natural resource management programs.
Information Collected on Case Study Regions
To ensure a focus on outcomes rather than process and inputs, only a broad guiding structure for case study planning was outlined:
Description—major characteristics of region (to help correlate to like subregions across Australia) and special values.
Condition/status and trend—of landscapes, ecosystems and species including threatened species and ecosystems, and other taxa of special biodiversity value.
Threatening processes—extent, rate, and land use changes.
Methods—a description of methods to demonstrate the diversity of approaches across different environments.
Management responses—detailing existing effort and the proposed effort required that would be practical and produce a significant conservation outcome. This analysis included pie diagrams based on:
- management priority amongst the three principal conservation strategies of reserve consolidation, species and ecosystem recovery and integrated natural resource management
- timeframe, up to 5 years
- existing conservation effort
- effort required to produce a significant conservation result.
Limiting factors—constraints and opportunities.
Future scenarios—for example, if action is not taken, what are the implications such as regional extinctions, increased extent of clearing, or increase in salinity affected landscapes.
| SUBREGION OR BIOREGION NAME | SUB-REGION CODE | AGRO-ECOLOGICAL REGION | LANDSCAPE STRESS CLASS | STATE OR TERRITORY |
|---|---|---|---|---|
| Mitchell (Northern Kimberley 1) | NK1 | North-west wet/dry tropics | 6 (lowest stress) | WA |
| Dieri (Simpson Strezelecki Dunefields 3) | SSD3 | Arid interior | 6 (lowest stress) | SA |
| Desert Uplands | DEU 1, 2 & 3 | Semi-arid tropical/ subtropical plains | 5 (second lowest stress) | QLD |
| Murrumbidgee (Riverina 2) | RIV2 | Temperate slopes and plains | 5 (second lowest stress) | NSW |
| Tiwi-Coburg | TIW 1 & 2 | Northern wet/dry tropics | 5 (second lowest stress) | NT |
| Kangaroo Island (Kanmantoo 1) | KAN1 | Wet temperate coasts | 4 (third lowest stress) | SA |
| Mitchell Grass Downs (partial), Barkly Tableland (partial) and Georgina Limestone (Mitchell Grass Downs 1, 2 & 3) | MGD 1, 2 & 3 | Semi-arid tropical/ subtropical plains | 3 (third highest stress) | NT |
| Isaac - Comet Downs (Brigalow Belt North 11) | BBN11 | Subtropical slopes and plains | 2 (second highest stress) | QLD |
| Avon Wheatbelt 2 | AW2 | Temperate slopes and plains | 1 (highest stress) | WA |
| Cumberland Plain (Sydney Basin 8) | SB8 | Wet temperate coasts | 1 (highest stress) | NSW |
| Victorian Volcanic Plain 1 | VVP1 | Wet temperate coasts | 1 (highest stress) | VIC |
| Murrumbateman (South Eastern Highlands 6) | SEH6 | Temperate highlands | 1 (highest stress) | NSW & ACT |
| Tasmanian Northern Midlands | TNM | Temperate highlands | 1 (highest stress) | TAS |
| Goldfields (Victorian Midlands 1) | VM1 | Temperate highlands and Temperate slopes and plains | 1 (highest stress) | VIC |
Major Issues Arising From the Case Studies
In all case studies, a mix of reservation, species and ecosystem recovery actions and integrated natural resource management measures were identified to achieve effective biodiversity conservation outcomes. Priority outcomes were determined from an analysis of biodiversity values, major threatening processes, management options available and major constraints. The difficulties in highlighting and addressing sometimes competing priorities reinforces the need for integrated bioregional planning that enables an examination of the impacts of threatening processes in like environments and to include the full range of conservation strategies.
All 14 case studies identified that a significant increase funding was necessary to achieve effective biodiversity conservation outcomes. Of the 14, seven estimated the level of expenditure required to achieve a significant practical effect for biodiversity conservation. The range of increase was between 1.5 to 23.6 times current expenditure. This varies with needs of bioregions. For example, for Tiwi Coburg bioregion, current expenditure is $225,000 and an estimated increase of $52,500 would deliver substantial biodiversity benefits.
In comparison, within the Tropical Savannas, for Northern Kimberley 1 subregion, the current expenditure is $250,000 and the required increase is $5,650,000. Similiarly, 21 times current expenditure is required within the Isaac-Comet subregion in the Brigalow Belt North bioregion to acquire key reserves, secure remaining vegetation on private lands and recover threatened species and ecosystems.
Acquisition of reserves is identified as a priority in a number of case studies where significant threats to the remaining key natural areas exist. However, for the extensively developed parts of Australia reserve consolidation options are rapidly disappearing or may no longer exist.
The case studies show that the investment required to deliver biodiversity conservation in predominantly natural bioregions is minimal compared to that required in the disturbed bioregions where recovery is unlikely owing to the extent of degradation or modification (eg salinity, urbanization) or may require planning horizons of at least 50 years. Most of Australia's natural bioregions are in the rangelands and tropical woodlands. Therefore, a coordinated Australia-wide approach to biodiversity conservation for these bioregions is imperative.
Major differences in terms of conservation options emerged owing to the extent of landscape modification. In particular, the huge difference in the cost of biodiversity recovery and landscape repair versus preventative action. In one instance, Tasmanian Northern Midlands, it was assessed that restoration of 30% vegetation cover could cost $98 million whilst elsewhere within the Isaac-Comet Downs, extensive clearing is still occurring in a region with less than 30% remnant vegetation. In such circumstances, the cost of financial incentives to end clearing would be relatively minor in comparison with future restoration costs.
Analysing Case Study Results
Associating Subregions by Biodiversity Values and Land Use Conditions
Case study subregions were compared with all other subregions using nine condition and trend variables. Whilst this approach has not been taken further to examine the relativity of each case study and to identify common issues across similar subregions, it demonstrates the potential usefulness of such analyses in planning national biodiversity conservation priorities.
Nine condition and trend variables were selected to demonstrate the approach. These variables were used to define axes in ordination space describing the range of states of all subregions with respect to these variables (Figure 10.2).
Note: Abreviations for case study regions are shown in Table 10.1.
The variables used to characterise land use condition for subregions were:
- river condition (NLWRA 2002b);
- human population density in 1997 (Australian Bureau of Statistics 2000);
- land cover change from 1990-1995 (Barson et al. 2000);
- intensity of pastoral use given by the proportion of a subregion more than 6 km from an artificial stock watering point;
- percent area of a subregion in a formal conservation reserve (this project);
- percent increase in the area of land to become salinised by 2050 (NLWRA 2001e);
- percent of area cleared of native vegetation (NLWRA 2001c);
- projected percent change in human population to 2020 (Australian Bureau of Statistics 2000); and
- rate of addition of fertilizer to subregions (NLWRA 2001b).
The case studies demonstrate the cost-effectiveness of various management practices including improved fire regimes for relatively natural landscapes across northern Australia.
In the ordination depicted in Figure 10.2, Axis 1 describes the proportion of land cleared of native vegetation, the proportion that is within reach of domestic stock in the arid and semi-arid areas, and the likely increase in the proportion of area to become salinised. Large negative values on Axis 1 describes subregions that are either highly cleared and vulnerable to salinisation in the future (agricultural areas), or are highly developed for pastoralism (rangeland areas). Conversely large positive values of Axis 1 indicate regions that are relatively uncleared and lightly stocked. Axis 2 is a gradient of fertilizer inputs, river condition, and changing human population density (large negative values representing trends of greater biodiversity impact potential). Axis 1 correlates well with landscape stress class values (correlation coefficient R = 0.82) and with the proportion of the subregion cleared of native vegetation.
The case study regions are highlighted in the ordination space to indicate which non-case-study subregions are similar to the case study regions in terms of the landscape threat and change variables used in the ordination analysis. Subregions that were within a nominal distance of 0.8 units in the ordination space from the case study regions were considered to share a number of similar issues. Three examples of these associations are shown in Figure 10.3.
Hence, the solutions identified in the case study reports are also likely to be relevant to similar subregions.
Figure 10.3 shows that a number of subregions have similar landscape threat and change scores to the North Kimberley 1 case study. These include other parts of the Tropical Savannas, the arid parts of Western Australia and the Channel Country. In these regions, similar land uses, such as grazing, are affecting biodiversity. Other factors such as feral animals and changed fire regimes, not included in these analyses because of the lack of data, are also having a significant impact on irreplaceable elements of biodiversity including critical weight range mammals (see Chapter 6).
A number of subregions are similar in land use condition to the Avon Wheatbelt 2 case study: Southern Jarrah Forest, Goldfields and the Victorian Riverina in the south-eastern Murray-Darling Basin. This analysis reinforces the finding that for the intensively used agricultural parts of Australia, extensive effort in terms of landscape repair and restoration of ecological processes is required.
No other subregions are similar to the Sydney Basin 8 case study, where extensive urban and periurban development presents a unique set of biodiversity conservation challenges.
Note: Data used are assumed to be correct from the data suppliers.
Map Data Source: National Land and Water Resources Audit, Assessment of Terrestrial Biodiversity 2002 Database. ©Commonwealth of Australia 2002.
Using Irreplacability to Define Biodiversity Risk
As indicated elsewhere in this report, subregions defined often in terms of their endemic or relictual biodiversity values are of special concern for planning biodiversity conservation. Using the data sets made available through this study, an initial analysis of the relative importance and risk for subregions was undertaken. A biodiversity value index based in Irreplacability was graphed against Axis 1 of the land use condition ordination (Figure 10.4). The analysis ranks subregions on the basis of their significance for the complement of species they harbour.
Four risk categories are defined in Figure 10.4. Risk category 1 has subregions that:
- contain the sets of species that are least substitutable (i.e., if they are lost from these regions then they are likely to be permanently extinct);
- contain large numbers of species and therefore potentially large habitat diversity; and
- are the areas in which natural ecosystems and species are most threatened by anthropogenic sources of landscape change.
Subregions with risk code 1 typically occur in highly modified agricultural areas.
Risk category 2 is assigned to subregions that also have highest irreplacability scores but score on the positive end of Axis 1 of the land use condition ordination. Subregions with risk category 2 are typical of arid, semi-arid and tropical savanna rangelands that are used for pastoralism. While it is tempting to think that these subregions are in "good" condition and should not be of concern, there are many threatening processes occurring in these subregions that were not included in the ordination variables because of a lack of data (e.g., predation by introduced predators, invasion by exotic plants and animals, altered fire regimes). The irreplacability of the species in these subregions warrants substantial attention and efforts to reverse declining trends for species where they are apparent.
Risk categories 3 and 4 are applied to subregions that score lower for irreplacability. While these subregions may still contain endemic species whose entire population occurs within the subregion, they tend to harbour a larger proportion of species which also occur in other subregions.
Hence, the population is spread over a larger area and the probability of extinction could be reduced because of this range. Subregions with lower irreplacability indices should not be thought of as having no special biological values - it is likely that all subregions of Australia harbour some endemic species which could be lost if threatening processes are ignored and these relative rankings only relate to broad brush overviews. Subregions with risk category 3 are those of the slopes and plains west of the Great Dividing Range. Subregions with risk category 4 are those of inland Australia and tropical savannas.
These analyses show the similarity of case study subregions to other subregions and show the relative biodiversity value and risk to biodiversity for subregions. They facilitate the extrapolation of detailed information about each case study presented in the following section, to a broader range of subregions. They also inform us about which subregions have similar types of land use problems, and hence may share similar types of solutions and resourcing requirements.
Note: Subregions are shown as triangles and case study regions as filled circles. Abbreviations for case study regions are shown in Table 10.1.
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