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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
Tasmanian Northern Midlands Highest stress class
The threatened lowland Poa Tussock grassland ecosystem.
Photo: L. Gilfedder
Soils of the Northern Midlands are diverse and predominantly sandy, supporting extensive agriculture and forestry. More than 95% of the bioregion is in private ownership. Less than 30% of the area remains as native vegetation.
The bioregion has significant biodiversity conservation values, including:
- 10 plant species endemic to the bioregion (including 7 endemic orchids);
- two endemic freshwater mussels, and endemic freshwater snails and caddisflies;
- 32 nationally threatened taxa;
- more than 180 plant and animal species listed by the Tasmanian Threatened Species Protection Act 1995;
- 24 nationally threatened plant species which have a restricted distribution in Tasmania, most of their range within the bioregion with very high regional conservation significance; and
- 12 wetlands listed on the Directory of Important Wetlands in Australia, and 10 wetlands of regional significance.
The comprehensiveness, adequacy and representativeness of the reserve system are extremely low with most of the threatened ecosystems not protected in reserves. Less than 2% of the bioregion is protected (0.7% in reserves and 1% in nature refuges).
Condition and trend
The Northern Midlands was the second area in Australia to be settled and there has been a history of vegetation clearance and degradation. Less than 30% of the original vegetation remains—much of it in scattered small remnants in poor condition. There has been significant loss or degradation of wetlands and riparian vegetation is degraded and in decline.
Threatening processes
The past two decades have seen major changes in this landscape with serious and continuing problems of vegetation loss and degradation, soil erosion, degraded river systems, dryland salinity, rural tree decline, denuded north-facing slopes and weed invasion. There is widespread concern over the threat posed by weeds such as gorse (Ulex europaeus) and willows (Salix spp.).
Threatening processes for riparian zones are broad scale vegetation clearing, increasing fragmentation and loss of remnants, firewood collection, grazing, feral animals, weeds, salinity, changed hydrology (instream and off-stream dams), pollution, increased sediment loads and bank erosion, and simplification of riparian vegetation.
Land clearance is often associated with the conversion of native grasslands to crops such as opium poppies and potatoes. The region's upper catchments are subject to timber harvest operations, and commercial firewood harvesting is widespread. Some lowland forest ecosystems that have been identified as threatened continue to be cleared. The bioregion has some of the most severe dryland salinity in Tasmania, with over 60% of potentially affected land systems in Tasmania occurring in this bioregion, and in excess of 30,000 ha potentially at risk. One of these potentially affected land systems at Tunbridge in the south of the region contains 6 key wetlands and an important nature reserve.
A recent spate of credible fox sightings in the region signals a new and potentially devastating threat to biodiversity. The persistence of some threatened vertebrates in Tasmania has been attributed to the absence of foxes. Were this pest to become established in the Northern Midlands it might precipitate the extinction of species that are already in decline such as the Eastern Barred Bandicoot, Southern Brown Bandicoot, Tasmanian Bettong and Southern Bell Frog.
Management responses
Tasmania Together is a long term strategic plan that has been developed by the community through wide-ranging consultation. Tasmania Together has established indicators and targets in a number of areas relating to biodiversity and natural resource management. Reservation benchmarks for forest and non-forest vegetation are being established and targets to 2010-2020 for the percentage of land to be protected either by legislation, covenant or management agreements. In addition, the Tasmanian Government has developed a Tasmanian Natural Resource Management Strategy to guide the future management of natural resources across the State.
With less than 2% of the bioregion reserved in the protected area network and little public land in the area, the focus of conservation planning is off-reserve conservation initiatives. A total of 67,093 ha (56786 ha forest and 10307 ha non-forest) has been identified as rare, vulnerable or endangered ecosystems or as ecosystems with a high conservation priority.
The need for action to reverse the decline in the extent and condition of native vegetation in the region is urgent and is reflected in the formation of 54 community-based groups who are trying to reverse the trend. Over $2m has been spent in the past year alone on natural resource management issues.
A number of projects funded by the Natural Heritage Trust have achieved significant conservation outcomes and improved awareness of conservation issues:
- Midlands Bushweb—a devolved regional project, is implementing a Rate Rebate Scheme across 3 councils and an Environmental Levy scheme is being investigated as a possible means of funding rate rebates beyond the life of the Natural Heritage Trust.
- The Protected Areas on Private Land Program has covenanted a total of 181 ha on three properties, and the Private Forest Reserves Program has 1106 ha on nine properties and one management agreement covering 113 ha. Three purchases have also been made for a total of 775 ha.
- Land and Water Australia and Australian Wool Innovations are jointly funding a project to develop and promote the adoption of viable sheep grazing systems to provide for ecologically sustainable agriculture and protect biodiversity in the Northern Midlands bioregion of Tasmania. A key issue is the integration of biodiversity conservation into sustainable grazing systems.
Limiting factors
The lack of public land in the bioregion means there is little opportunity to add to the protected area system without a significant acquisition program. It could cost over $46m to establish a protected area system using a mix of acquisition, covenants and management agreements. Strategic revegetation to achieve 30% native vegetation cover on the lower slopes of the bioregion could cost over $98m and take 50 years or more to achieve. Complementary initiatives will require voluntary participation from landowners with incentives or stewardship schemes to facilitate voluntary participation.
Future scenarios
Severe degradation and loss of biodiversity will continue unless considerable resources are made available for recovery actions and reserve consolidation. Recent changes to legislation have led to vegetation clearance controls for forest vegetation. These need to be extended to non-forest ecosystems. Local government authorities will need to incorporate vegetation retention targets into their planning processes. Retiring land from production may be an option for some producers, and agricultural accreditation, particularly in the wool industry, may be a real incentive for biodiversity protection and improved environmental management.
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