At a glance
The Australian Heritage Commission's National Wilderness Inventory (Lesslie & Maslen 1995) describes wilderness as having two essential attributes-remoteness and naturalness. While wilderness means different things to different people, it is measurable (subject to available information), and changes can be reported over time. An on-line handbook of procedures, content and usage of the National Wilderness Inventory has been prepared by Environment Australia.
The National Wilderness Inventory is measured as a continuum from cleared land (rating of 0) through to the highest quality wilderness areas (20). The nationally agreed Reserve Criteria for a Comprehensive, Adequate and Representative Reserve System in Australia (JANIS 1997) defined high quality wilderness as areas larger than 8,000 ha having National Wilderness Inventory ratings of 12 or greater. This definition was used in the delineation of high quality wilderness areas under the Tasmanian Regional Forest Agreement process in 1997.
In principle, the scope of this SoE Report would cover changes in wilderness quality under 12 (particularly values from 9-12). This is justified because improvements in biophysical naturalness outside high quality wilderness may provide buffers for maintaining the values of higher quality wilderness areas. Such areas may still retain wild character that can also contribute to the visitor experience and the sense of place of Tasmanians. However, while some areas have the potential to be restored to high quality wilderness in the short-medium term, most areas at the lower end of the scale (below 12) are not normally considered as wilderness as they typically contain varying levels and types of disturbance.
Changes to land use and land cover influence biophysical naturalness and wilderness quality. An update of the National Wilderness Inventory has not been undertaken for Tasmania and consequently these changes cannot be reported. In the absence of this update, this SoE Report is limited to indicators that can only provide a guide to issues and trends.
This 'At a glance' section provides an overview of wilderness in Tasmania. More detailed information and references are available in the Wilderness Issue Report. Two indicators are presented in this report: Wilderness Extent and Quality and Terrestrial Protected Areas.
A recommendation is also provided on Wilderness.
- The Inquiry on the Progress with the Implementation of the Tasmanian Regional Forest Agreement 1997 (RPDC 2002) identified that 95% of Tasmania's 1.9 million ha of high quality wilderness was within formal and informal reserves. This is an increase of 9% or 176,700 ha in the area of high-quality wilderness reserved since 1996 (RPDC 2002). The remaining 5% of the high quality wilderness areas are mainly located in areas subject to multiple use forestry.
- Much of the State's highest quality wilderness is contained within the World Heritage Area, which is subject to management prescriptions to maintain wilderness values.
- The biophysical naturalness of many areas outside the higher wilderness values that are still significant as part of the wild character of Tasmania have also benefited from the creation of new reserves, particularly in the east and north-east of the State, through the Regional Forest Agreement.
- Further major road development impacts on the State's highest quality wilderness values are not anticipated due to the 'mature' state of Tasmania's road system. The last major impact on the wilderness from development of the State's road network occurred with the completion of the 'Western Explorer' Link Road in 1996.
- There has been an improvement in baseline mapping which could be applied in preparing any future updates of the wilderness inventory for Tasmania.
- Wilderness quality change is influenced by land use impacts. These impacts may include tracks, mining, agriculture, multiple use forestry, recreation, tourism, energy, industry and infrastructure impacts. The intensification of land use has impacted on biophysical naturalness and, over time, reduced the area of high quality wilderness in Tasmania. However, impacts on wilderness quality since the previous SoE Report are likely to have been confined largely to wilderness values of less than 12. Recreational impacts at finer scales on higher quality wilderness are also likely to have occurred.
- The past two decades has seen an increase in the number of walkers in Tasmania's Wilderness World Heritage Area. This increased 'traffic' has led to deterioration in the walking tracks throughout much of the region, and contributed to other usage-related problems such as crowding and unplanned track formation. The problems are made worse in Tasmania by the fragility of the landscape. The total number (960) and length (3,100 km) of tracks in Tasmania is known to exceed the State's capacity to manage them all to a consistent standard (Tourism Tasmania 1997).
- There are 1,057 km of tracks in the World Heritage Area. In the early 1990s (as reported in SoE 1997), it was estimated that 120 km were already heavily eroded to a depth of 25 cm or more. Local erosion in some areas is even deeper: over 1.5 m on peat soils. About 150 km of tracks were muddy and 85 km were braided. Monitoring data from throughout the World Heritage Area indicate that deterioration is continuing on unimproved tracks. Track conditions are generally worse and rates of change greater in the Southwest than in the Central Highlands.
- The Western Arthur Range, a rugged mountain range in Southwest Tasmania that includes some 45 km of tracks, 68 permanent monitoring sites and is visited by up to 600 walkers each year, provides a case study. On a section of the range with relatively high use (300-600 passes/year), an overall deepening and (despite considerable fluctuation) a net widening of the main track has occurred since 1994 (see figures). Depths and widths at some monitoring sites have been increasing by more than 1 cm and 4 cm per year, respectively.
- Assessing wilderness condition requires an understanding of the various impacts on wilderness quality at different scales. At Statewide scales, there are a range of land use and land cover influences on wilderness quality while, at finer scales, land management issues may be significant.
- The indicators presented in this report, from the available data, provide only a limited perspective of the issue of conditions and trends in Tasmanian wilderness. There is a need for periodic updates of the wilderness inventory, particularly of the disturbance data.
- Wilderness quality may improve in some areas where, for example, tracks are closed and grown over. Vegetation disturbance (the key measures for biophysical naturalness) may improve with time (regardless of tenure but subject to appropriate management action) and this can lead to an increase in the wilderness rating. Improvements in biophysical naturalness may have occurred in some areas as an indirect result of an increase in reserved areas following the RFA. However, in the absence of an update of the Wilderness Inventory for Tasmania, this cannot be verified.
- Some areas previously identified as containing high quality wilderness values may need to be reviewed due to uncertainty over the extent of disturbance and clearance. These areas would include the north-east of the State, Cape Barren Island, and around Woolnorth in the far north-west.
- Wilderness managers cannot accurately assess the effectiveness of management responses to increased bushwalker numbers, due to a lack of information and limited monitoring.
- Wind energy development presents particular challenges in managing impacts on wilderness values, owing to the high visibility of wind farms and the location of potential wind energy developments in the remoter areas of Tasmania's west coast. Environmental impact assessments for wind energy developments would be supported by an up-to-date wilderness inventory for Tasmania.