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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
Desert Uplands (1, 2 & 3) Second lowest stress class
Yellow jacket, Corymbia leichhardtii, woodland with Acacia complanata on sandy earths associated with sandstone ranges.
Photo: P. Sattler
The Desert Uplands bioregion is dominated by woodlands of Eucalyptus whitei, E. similis and Corymbia trachyphloia. The semi-arid climate varies between the northern and southern parts of the bioregion, reflecting its extensive latitudinal extent with corresponding changes in vegetation. The bioregion has 73 ecosystems with influences from the Brigalow Belt, Mulga Lands, Mitchell Grass Downs, Einasleigh Uplands and Gulf-Carpentaria Plains.
The Desert Uplands is an area of very low soil fertility; phosphorous is particularly lacking in most soil types except in the alluvial systems. Large scale cattle grazing enterprises are the dominant industry, principally on the alluvial systems.
The dominant feature of the bioregion is the internal drainage patterns resulting in Lakes Buchannan and Galilee. A number of Artesian and Mound spring systems occur, and endemic species including fish and flora and snails have been recorded in these systems.
Condition and trend
While large areas of the Desert Uplands still have tree canopies in place, the overall condition is fair and declining. The naturally restricted ecosystems are often grouped around lake margins and are usually in poorer condition.
The Desert Uplands has nineteen threatened species including the Red Goshawk, Julia Creek Dunnart, Eriocaulon carsonii and Edgbaston goby. Most of these species are declining in population numbers and range.
Data collated for 1999 indicate that 87% of the bioregion remains uncleared, with 1% (102,250 ha) cleared in two years since 1997.
Of 73 ecosystems, 44 are under threat. Nine of these are static, while 29 are declining and 6 are rapidly declining. Fifteen of the ecosystems are regarded as likely to completely lose biodiversity values within the next 10-20 years while a further 29 are likely to lose biodiversity values unless management responses occur.
Threatening processes
Broad scale tree clearing, overgrazing and fragmentation of alluvial systems are the main threatening processes for both ecosystems and species. The threat of feral animals and changed hydrological regimes are also key threatening processes for fauna. Tree clearing is mainly occurring in the higher fertility areas in the south and along the floodplains of the alluvial systems. In particular the clay soils associated with Lake Galilee have been affected.
Overgrazing occurs in many of the ecosystems. Alluvial systems, lake margins and river banks are particularly susceptible. Although a large percentage of the ecosystems remain uncleared, the vulnerable ecosystems are of particular biodiversity conservation interest due to their declining status.
Management responses
Due to the rapid decline in condition of this substantially intact bioregion, a range of conservation measures is urgently required. These measures encompass all three principal biodiversity conservation strategies including the consolidation of the national park estate, recovery of threatened species and ecosystems, and integrated natural resource management measures linked with structural adjustment of the pastoral industry.
Long-standing national park proposals exist for Lake Buchanan, the threatened Aramac and Doongmabulla artesian spring complexes and associated poorly conserved woodland and shrubland ecosystems. The Cape-Campaspe Plains subregion is unreserved.
Specific recovery actions are required for some critically endangered species such as the fish species of the Aramac Springs. This extensively vegetated part of the Great Dividing Range is also an essential link for migratory bird species.
The plight of the pastoral industry across this largely infertile region prompted a rural adjustment package to be put in place in recent years. This package has locally addressed a number of management issues.
At the broader scale of natural resource management, there is an opportunity for the community at large to consider the relative value and costs of pastoral production versus the extensive range of ecosystem services that this largely intact region provides. These values relate to biodiversity, maintenance of the Great Artesian Basin, control of greenhouse gas emissions and prevention of salinity and other forms of landscape degradation.
Structural adjustment that achieved the retirement of the most threatened and lowest capability lands to be managed for these multiple values would provide considerable benefits to society in the longer term. Australia-wide policy initiatives upon which to base such a long-term program are required. The resources required to achieve extensive structural adjustment are not reflected in Figure 10.7.
Limiting factors
Immediate opportunities include increased conservation covenants with property owners through the Desert Uplands Build Up Committee and negotiated protected area agreements.
Though a number of conservation agreements have been reached with devolved grant projects continuing incentives are required. Negotiation of key areas to consolidate the national park estate is constrained by the lack of resources for both acquisition and management.
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