Biodiversity and Vegetation - Victoria

Proportion of native vegetation remaining in this IBRA region Victoria
Methods
Applications
Limitations
What major vegetation groups have been cleared in Victoria since European settlement?
Methods
Applications
Limitations
Link to cleared native vegetation information for Victoria's bioregions
What sources of information were used?
References
Partnerships
Further information

Victoria

Proportion of native vegetation remaining in Victoria

In Victoria, more than 60% or 14.6 million hectares of native vegetation has been cleared, making it proportionally the most cleared of all States. Most remaining native vegetation is on public land in state forests or protected areas and remote from historical development.

Clearing has been mainly for dryland agriculture, livestock grazing, irrigated agriculture and urban development. Remaining vegetation in these landscapes is fragmented and varies in condition. The bioregions most affected by clearing are the Murray Darling Depression, Riverina, Victorian Midlands, Victorian Volcanic Plain, Naracoorte Coastal Plain, South East Coastal Plain, South East Highlands and the South East Corner.

Vegetation types that had the largest areas cleared are the eucalypt woodlands, eucalypt tall open forests, eucalypt open forests and mallee woodlands and shrublands. The vegetation types most cleared relative to their pre-European extent are the tussock grasslands, eucalypt open woodlands, melaleuca forests and woodlands, acacia shrublands, low closed forests and closed shrublands, mallee woodlands and shrublands and eucalypt woodlands.

The Audit assessment of landscape health provides a summary on a subregional basis of the landscape stresses in Victoria including clearing, grazing, feral animals and weeds (NLWRA 2001c).

Table: Area (km²) of pre-European major vegetation groups and major vegetation groups (circa 1997) in Victoria
Major Vegetation Group	Pre-European Area (km²)	Circa 1997 Area (km²)	% remaining relative to pre-European area
Rainforest and vine thickets	445	407	91
Eucalyptus tall open forests	20,973	16,755	80
Eucalyptus open forest	23,099	15,018	65
Eucalyptus low open forest	357	180	51
Eucalyptus woodlands	78,302	25,051	32
Acacia forest and woodlands	825	400	48
Callitris forest and woodlands	584	429	73
Casuarina forest and woodlands	46	46	100
Melaleuca forest and woodlands	182	45	25
Other forests and woodlands	2,583	2,186	85
Eucalyptus open woodlands	23,936	1,185	5
Mallee woodlands and shrublands	37,861	10,843	29
Low closed forest and closed shrublands	2,957	818	28
Acacia shrublands	39	14	35
Other Shrublands	5,829	3,450	59
Heath	1,859	1,801	97
Tussock grasslands	19,175	614	3
Other grasslands, herblands, sedgelands and rushlands	2,397	1,059	44
Chenopod shrub, samphire shrub and forblands	3,103	2,038	66
Mangroves, tidal mudflat, samphire and bare areas, claypan, sand, rock, salt lakes, lagoons, lakes	2,397	2,257	94

Methods

This analysis is based on a comparison of the present extent of major vegetation groups (circa 1997) and pre-European mapping.

Applications

Analysis at the Australia-wide, State and Territory and regional scales provides information on which to base broad assessments of change in extent and type of vegetation. This is a key input to assessing:

the representativeness or otherwise of Australia's nature conservation estate and for related interpretations (e.g. setting priorities for retention of native vegetation types);
opportunities for catchment rehabilitation, whether the issue is catchment hydrology or dryland salinity control;
the types of vegetation suitable for rehabilitation, restoration and/or revegetation activities in an area; and
priorities for protection of biodiversity in landscapes under stress.

Limitations

Pre-European vegetation and present native vegetation for many States and Territories do not match in mapping method or scale. Development of pre-European vegetation maps in cleared areas of Australia is usually dependent upon coarse or generalised data on landforms and soils sometimes at 1:250 000 or even 1:1 000 000 scale. Reconstructing the natural complexity of vegetation patterns from such broad interpretations is difficult. Earlier vegetation mapping for areas now cleared may similarly be coarse in scale and/or generalised, with little data from systematic field sampling to support the derivation of mapping units and the allocation of individual patches of native vegetation to mapping units.

Pre-European data is more reliable where:

impacts of European land use is minimal;
there is good physical and floristic information (e.g. in Victoria) which can be used for detailed interpolation; and
the scale of the pre-European mapping and method is similar to that of the current extent mapping (e.g. in Queensland, Victoria, Northern Territory and Western Australia).

Data variability is greatest in New South Wales, the Australian Capital Territory and South Australia, where the pre-European data does not meet the requirements of the National Vegetation Information System. In Tasmania the pre-European data is not finalised. In these States it is assumed that the present vegetation mapped is an approximate representation of the pre-European vegetation. The Australia wide pre-European major vegetation groups data set is an interim product.

What major vegetation groups have been cleared in Victoria since European settlement?

Table: Major vegetation groups cleared in Victoria
Major Vegetation Group	Cleared Area (km²)	% cleared across VIC as total of clearing
Rainforest and vine thickets	38	0
Eucalyptus tall open forests	4,219	3
Eucalyptus open forest	8,082	5.7
Eucalyptus low open forest	176	.1
Eucalyptus woodlands	53,251	37.3
Acacia forest and woodlands	425	.3
Callitris forest and woodlands	155	.1
Melaleuca forest and woodlands	136	.1
Other forests and woodlands	398	.3
Eucalyptus open woodlands	22,751	16
Mallee woodlands and shrublands	27,018	18.9
Low closed forest and closed shrublands	2,140	1.5
Acacia shrublands	26	0
Other Shrublands	2,379	1.7
Heath	58	0
Tussock grasslands	18,561	13
Other grasslands, herblands, sedgelands and rushlands	1,338	.9
Chenopod shrub, samphire shrub and forblands	1,065	.7
Mangroves, tidal mudflat, samphire and bare areas, claypan, sand, rock, salt lakes, lagoons, lakes	140	.1

Note: The clearing referred to in table 2 does not include grazing, thinning or other activities. In particular, parts of the rangelands may be heavily disturbed.

Map: Cleared Major Vegetation Groups (circa 1997) in Victoria

Cleared Major Vegetaion Groups in Australia

Source:

Major vegetation groups V1.0 (1km), National Land and Water Resources Audit 2001. Data used are assumed to be correct from suppliers.

The summary maps provide information on Australia's native vegetation collated within the National Vegetation Information System (NVIS) at July 2001 and with additional mapped information. The NVIS will be updated as vegetation mapping becomes available.

The map is a compilation of data collected at different scales by different organisations. Major Vegetation Groups were compiled by Environment Australia based on data collated by the Bureau of Rural Sciences and provided by Environment ACT, Department of Urban Services; NSW National Parks and Wildlife Service; NSW Royal Botanic Gardens; NSW State Forests; NT Department of Infrastructure, Planning and Environment; Queensland Herbarium, Environmental Protection Agency; SA Department for Environment and Heritage; Tasmanian Department of Primary Industries, Water and Environment; Flora Section, Department of Natural Resources and Environment; Agriculture Western Australia; Western Australia Department of Conservation and Land Management and Geoscience Australia, National Mapping Division.

Methods

This analysis is based on the present extent of native vegetation and data on the type and area of these groups cleared in Australia from the pre-European mapping. All summary findings are based on the data sets compiled for the National Vegetation Information System and development of the major vegetation groups.

Applications

This analysis at the Australia-wide, State and Territory and regional scales provides information on which to base assessment of change in land cover and type of vegetation, a key input to vegetation management activities. Loss of particular vegetation types across regions impacts on biodiversity values and landscape function and this analysis highlights those major vegetation groups.

At the regional scale, the National Vegetation Information System compilation provides an excellent basis for regional planning groups to understand the changes in vegetation extent that have occurred and set their regional priorities for vegetation management in the context of this information. The assessment of major vegetation groups across Australia provides a broader context.

Limitations

As detailed previously, issues of attributes, scale and currency of available mapping limits the precision of this analysis. The broad nature of the major vegetation groups masks the distinct vegetation types and regional clearing patterns that would emerge at a finer scale of analysis.

Link to cleared native vegetation information for Victoria's bioregions

Map of cleared native vegetation information for Australia's bioregions

What sources of information were used?

View the guidelines for the interpretation of vegetation mapping products.

References

View the references used in the Australian Native Vegetation Assessment 2001.

Partnerships

Australian Native Vegetation Assessment 2001 was facilitated and coordinated by the National Land and Water Resources Audit and prepared in partnership with State, Territory and Commonwealth agencies: