|
At a glance 
The issue Land cover refers to the physical state of the land surface and includes vegetation, soil, rock, water and man-made structures. It represents the cumulative consequence of human influence and ecological processes over many thousands of years. More recent land management decisions have extensively modified land cover. These decisions are influenced by market forces and land tenure classifications. Definitions of land tenure are also continually evolving as they are influenced by legislation and public values. Woody vegetation decrease maps have been used in the issue report to provide an indication of areas of land cover activity. The maps show those areas that have had comparative land cover stability and those that have undergone change. There is a close relationship between land tenure and land cover change. In addition, Landsat 7 data from 1999-02 were analysed and classified by the School of Geography and Environmental Studies at the University of Tasmania. Up to 30 land cover classes were identified. This information is presented in the background report showing the principal land cover maps for each of the bioregions.
This 'At a glance' section provides an overview of the issue of land tenure, land use and land cover in Tasmania. More detailed information and references are contained in the Land Tenure, Land Use and Land Cover Issue Report. Three indicators are provided within this report (see indicators). Recommendations relevant to this issue are presented: Strategic Land Resource Management; Productivity of Soils; and Information Needs for Land Management. Favourable news - Tasmania's diversity of landform and vegetation has itself conferred some protection against land cover change. Although very small in area compared to mainland Australia, Tasmania has a remarkably varied geology, a wide range of landforms, and the most mountainous terrain on the continent. The environment-particularly the diversity of soils, landscapes, vegetation and terrain-has influenced the regional pattern of land use and land cover. Large-scale clearing for agriculture has occurred mostly on the better soils and gentler slopes.
- Previously, there was a lack of benchmark information on the area of land under key land use categories and no standard classification of land use. However, this situation has improved with the release of a land use classification of Tasmania. Land use maps for Tasmania at 1:25,000 scale have been produced for the South-East, Northern Midlands and Northern Slopes bioregions, and at 1:100,000 scale for the rest of the State. Land use information can be used to better understand and develop responses to threatening processes, such as catchment salinity, and nutrient and sediment problems.
- Reservation in National Parks, Forest Reserves and other conservation areas allows 'natural' rates of change to occur and offers relative protection from land cover change and disturbance. The coverage of reserves in Tasmania is reviewed in more detail in the Reservation Issue Report.
Unfavourable news - Significant environmental pressures facing land in Tasmania are not confined to any one land tenure or use. All tenures have priority land management issues, including track degradation and peatland erosion in Conservation Areas and National Parks, soil loss and degradation in agricultural areas, urban growth into agricultural land and bushland, and management of State and private forests.
Uncertain news - There has been a general trend towards more intensive production of commodities providing higher yields and higher profits. This is achieved through intensification in the form of increased irrigation on agricultural land and plantation development in State and private forests. The increase in the area of land utilised for private forest plantations, particularly in the north-west of the State, indicates an increase in the intensity of use. Increasing land use intensity may have consequences for the environment through requirements for irrigation water and the clearance of native forest for plantation development. Changes from grazing of native grassland to other more intensive cropping would also have consequences.
- Keeping track of changes in land cover and land use relies on a variety of data sources and measures. Key information sources include TASVEG vegetation mapping, satellite data for change detection, building completions, ABS Agricultural Census data, and Forest Practices Board Annual Reports on Harvested Area. Land tenure is maintained by the State Government as a core dataset of the LIST.
- There is a general lack of capacity to detect change in vegetation cover in Tasmania.
|
