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At a glance 
The issue Housing clearly provides critical social infrastructure and benefits (see Social and Economic Conditions and Home Ownership Rates) and the housing industry is a major employer in the State. Planning for housing development to minimise the clearance of remnant native vegetation in and around Tasmania's urban centres and coastlines-through maximising use of existing cleared land for housing and existing housing stock-will be a key challenge for planning over the coming years. One of the most significant threats to natural diversity in Tasmania is the clearing of native vegetation and its replacement with another activity or land use. The more intensive forms of land clearance, which are generally irreversible, include plantation development, clearance of native vegetation for improved pasture and cropping, inundation, and urban growth. Land clearance in general in Tasmania is reviewed in the Land Clearance Issue Report. The Urban Growth Issue Report focuses on clearance related to housing and urban infrastructure. The actual impact of urban growth varies depending on the house area relative to lot size, subdivision scale and intensity relative to remaining bushland, the actions of builders and land owners in retaining native vegetation, and approaches to management of hazard reduction for bushfires. Topography and slope also influences the landscape impacts of urban development (see Scenic Landscape Condition Issue Report). Urbanisation places pressures on the natural biodiversity of an area. Urban sprawl into the bushland fringe causes the physical destruction of natural habitats, causes pollution (including nutrient enrichment), and introduces a range of animal and plant species, including predators such as cats and dogs. Such factors push back the boundary of the natural area, sometimes to the point where there is no longer enough area to support some elements of the biota. The coastal zone in Tasmania has been particularly affected by urban development. Many wetlands have been drained and saltmarshes destroyed either directly by development, or indirectly through the alterations and contamination caused by run-off from such areas. Ribbon development along the shore, in particular, has seriously disrupted many ecologically important sea-to-land transitions which are essential for many species, including penguins, intertidal molluscs and crustaceans. While urbanisation has not resulted in the extent of clearance that some other broad-scale land use activities have, Tasmania's larger urban areas are concentrated in areas containing vegetation types which have been substantially cleared, including: grasslands and grassy woodlands, coastal heathland, dry forests and wetlands. The classification of land cover for Greater Hobart and Launceston (see Land Use and Land Cover for Hobart and Launceston) gives an indication of the area of urban development which has occurred. According to the classification of land cover derived from satellite data in 2001, urban and suburban land cover occupies 7.9% of Greater Hobart and 9% of Launceston. 'Modified' land cover classes that can be identified from Landsat data represent 33.5% of Greater Hobart and 45% of Launceston (ABS statistical boundaries). This 'At a glance' section provides an overview of the urban growth issue. More detailed information is available in the Urban Growth Issue Report. This Issue Report includes three indicators: Land Use and Land Cover for Hobart and Launceston, Native Vegetation Clearing, and Population Distribution. A recommendation is provided for the Biodiversity Chapter on Native Vegetation. Recommendations from the Settlements Chapter are also relevant, including: Settlement Patterns and Processes; Sustainable Housing; and Sustainable Development in Bushfire Prone Areas. Favourable news- 'Natural' land cover classes account for 61.9% of Greater Hobart and 49.6% of Launceston (ABS statistical boundaries) based on Landsat land cover classification. The difference between Hobart and Launceston is due, in part, to the greater significance of agriculture, pasture and forestry activity around Launceston. Mt Wellington Park and the Meehan Range in Greater Hobart also occupy a larger area of the Greater Hobart statistical division, contributing to the higher overall proportion of 'natural' land cover.
- There are undoubtedly many examples of dwellings in Tasmania that have a minimal footprint on the local bushland and where owners have adopted a stewardship ethic in maintaining their local environment. Covenants are used by some land owners and programs such as Land for Wildlife, Private Forests Reserve Program, and the Protected Areas on Private Land provide assistance in protecting conservation values. These programs are actively protecting some areas of remnant native vegetation near urban areas. At the same time, increasing land and property values in Tasmania makes it more difficult to fund purchases of land for conservation in proximity to urban centres.
Unfavourable news- Housing completions have potentially affected 805 ha of priority forest vegetation in Hobart and 291 ha of priority forest vegetation in Launceston in the period 1992-2002. This provides a guide only to the potential impacts on priority forest vegetation through urban growth, as the proportion of a land parcel cleared of native vegetation for any housing completion is unknown and will vary depending on the lot size and the attitudes of builders and owners.
- Inefficient land use, among its consequences, will also result in less land being potentially available for conservation and protection of habitat. With Greater Hobart containing a number of threatened species and priority vegetation communities identified by the Regional Forest Agreement, efficient land use is also a biodiversity priority.
- In Hobart, priority forest vegetation communities that have been potentially affected over the period 1992-2002 through housing completions include: Eucalyptus risdonii (up to 15 ha); Eucalyptus tenuiramis inland forest (up to 110 ha); Eucalyptus obliqua tall forest (up to 122 ha). Rare Eucalyptus risdonii trees were cleared in October 2002 for the development of residential blocks in the Clarence municipal area.
- In Launceston, priority forest vegetation communities that have been potentially affected over the period 1992-2002 through housing completions include: Eucalyptus ovata - E. viminalis shrubby forest (up to 14 ha); and, Eucalyptus amygdalina forest on dolerite (up to 161 ha).
Uncertain news- An assessment of urban growth in Greater Hobart and Launceston represents only part of the story. Development along Tasmania's coastlines, particularly the east and north coasts, is also significant. However, development trends and implications for remnant vegetation have not been assessed for these areas in the time available for this Report.
- The extent of the loss of urban bushland in the State is unknown. Defining what constitutes urban bushland also presents some challenges as urban development is now more extensively dispersed across the landscape. Local area assessments using historic aerial photographs to determine the loss of remnant vegetation between 1946 and the early 1990s have been made, which indicate the extent of the clearance problem. These were reported in the last SoE Report (SDAC 1997), but it was not possible to provide updates of these estimates for the current report. Some other broad measures of urban vegetation condition, clearance, and land cover have been included to provide an indication of the type of changes that have occurred.
- Housing completion data can be used as a measure of where residential development is occurring (see maps), although this does not accurately show the cleared area of land that has occurred on each property.
- Related to the presently limited capacity for vegetation change detection in Tasmania at regional and Statewide scales, is an uncertainty about the cumulative consequences of planning and land use decisions for threatened flora and fauna communities, and landscape values.
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