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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
Case Study
Murrumbateman (South Eastern Highlands 6) Highest stress class
Tinderry Nature Reserve from the Monaro Highway
Photo: NSW NPWS
The Murrumbateman subregion is part of the South Eastern Highlands bioregion and traverses the Australian Capital Territory and New South Wales border. Land tenure is mainly private freehold land in New South Wales and leasehold in the Australian Capital Territory. The bioregion comprises grasslands and grassy woodlands, including some wetland and riparian communities. Much of the previous woodland area has been cleared and sown to improved pastures for grazing.
Land use is dominated by grazing, horticulture (grapes and olives), plantation forestry, and urban development. Only a relatively small area is formally reserved. Management for biodiversity conservation is largely in the hands of rural landowners and leaseholders.
Condition and trend
The natural temperate grasslands that are one of the dominant ecosystems in the Murrumbateman subregion is the most threatened ecosystem in Australia, having declined by 99.5% since European settlement. Similarly, the woodlands of the South Eastern Highlands bioregion are under threat from the combined factors of grazing, clearing, urban expansion and introduced plants.
The once widespread Yellow Box/Red Gum (Eucalyptus melliodora / E. blakelyi) grassy woodland community has been reduced in total area from 295,000 ha to 25,200 ha. A similar reduction has occurred with the native grassland (Themeda sp / Danthonia sp). The now highly fragmented distribution of these two communities mirrors the condition of all other native plant associations and communities. Fragmentation of the dominant vegetation communities has also resulted in the loss of connectivity of the communities across the landscape. Corridors between the larger areas of remnant native forest and woodlands, and west to east links are almost absent in the sheep-wheat area within New South Wales.
Associated with the decline of the formerly dominant grasslands and grassy woodlands is the reduction in abundance and distribution of many of the characteristic native plant and animal species. The latest figures for approvals for clearing native vegetation in NSW indicate that clearing continues in the subregion within New South Wales.
Threatening processes
The identified threats to biodiversity conservation have arisen primarily from rural land clearing and more recent rural residential development and urbanisation. Resulting impacts include:
- changed hydrology from farm dams and irrigation reducing water flow;
- predation by domestic cats on native fauna;
- grazing;
- salinity, particularly in the Yass River catchment;
- soil acidity in areas subject to pasture improvement and heavy application of artificial fertilisers; and
- reduction in groundwater and surface water quality following increased salinity and reduced surface run-off.
Management responses
Clearing of native vegetation should be immediately curtailed generally and specifically prohibited in those areas most greatly affected by past clearing, (eg the area of the sub-region in the sheep-wheat belt in New South Wales). There are few opportunities for acquisition of lands for the formal reserve system, and achievement of a comprehensive, adequate and representative reserve system is not likely to be achievable in the South Eastern Highlands bioregion. The emphasis for biodiversity conservation will be on off-reserve initiatives including establishing conservation management networks and conservation partnerships with landholders.
Action plans for the two major endangered ecological communities in the Murrumbateman subregion have been prepared for the ACT portion only. Recovery plans are in preparation for Box woodlands in NSW. The combined recovery programs will aim to assign conservation status at local and regional levels, and to identify opportunities for establishing conservation management networks.
There is considerable scope and capacity for landholder involvement and there is significant interest in doing so.
Several off-reserve initiatives in the ACT contribute to biodiversity conservation, including:
- urban open space (a statutory public land use zone under the ACT's territory plan);
- Memorandums of Understanding with Commonwealth Government agencies occupying land with threatened species or threatened ecological communities; and
- land management agreements covering leasehold rural land.
Limiting factors
A key requirement for achieving better biodiversity outcomes in the subregion is strategic coordination between government agencies, and between agencies and the private land owner communities. Provision of adequate resources is essential to support emerging cross-border cooperative programs for biodiversity conservation in the region.
Targeted rehabilitation and management programs are essential to support retention of existing areas with significant biodiversity values. The costs of revegetation can be prohibitively high. Using Yellow Box woodland as an example, it is estimated that some 7 to 8 million trees would have to be planted to raise the status of the Yellow Box woodland by about 1% from its current status of 4.5% extant occurrence. At about $2 per seedling planted, the costs would be a minimum of $14 to 16 million.
Future scenarios
Overall, the prognosis is for current levels of degradation and loss of biodiversity to continue unless there is considerable improvement in delivery of biodiversity conservation programs.
A coordinated program could be established within the context of conservation within the area of the region within the sheep-wheat belt. Such a program could include:
- activities to fully inform various decision making processes of the status and condition of biodiversity to NRM committees, Landcare, Local Government and other management groups and at the property level;
- curtail of broad scale clearing generally, and prohibit any further clearing in those areas most greatly affected by past clearing;
- increased investment in conservation initiatives for both reserve and off-reserve lands including tax and other financial incentives, covenants and other conservation agreements;
- support for programs that integrate conservation into land management plans and activities and provide management information across the landscape; and
- building upon existing cross-border cooperation for biodiversity conservation planning by ensuring appointment of a lead independent agency to broker and coordinate activities across all parties.
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