Biodiversity & Vegetation - New South Wales

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

New South Wales

Proportion of native vegetation remaining in New South Wales

In New South Wales, 30%, or 23.4 million hectares, of native vegetation has been removed in the coastal lowlands and floodplains of northern New South Wales, the central coast from the Hunter to Illawarra and the south coast around Bega district. The alluvial plains, adjoining north-west slopes and New England Tableland of the Murray-Darling Basin have also been extensively cleared, as have the south-west slopes and southern highlands such as the Monaro Tableland. New South Wales has one of the largest areas of cleared land in Australia.

The main cause of decline and change to native vegetation since European settlement have been clearing for cropping and grazing by stock, grazing by feral animals, logging, weed invasion, mining, soil degradation through compaction, salinisation and acidification and pollution including nutrification of waterways (Benson 1999).

Major vegetation groups most affected are the eucalypt woodlands, tussock grasslands, acacia forests and woodlands, chenopod shrublands, eucalypt open forests, eucalypt tall open forests and rainforest and vine thickets.

Much of the New South Wales mapped data available for compilation in the National Vegetation Information System does not reflect the current extent of native vegetation. The data over-represents the amount of tree cover in the State as clearing has occurred since the mapping was undertaken. More recent extent figures summarised by subregion are presented in the Landscape Health report (NLWRA 2001c) and are available from New South Wales Department of Land and Water Conservation. Pre-European data is interim and area estimates from this comparison have been included for indicative purposes. Currently a program exists to map pre-European vegetation at a finer level of mapping across the State.

The Audit's assessment of landscape health provides a summary on a subregional basis of the landscape stresses in New South Wales 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 New South Wales
Major Vegetation Group	Pre-European Area (km²)	Circa 1997 Area (km²)	% remaining relative to pre-European area
Rainforest and vine thickets	4,836	2,218	46
Eucalyptus tall open forests	8,567	4,405	51
Eucalyptus open forest	138,576	90,979	66
Eucalyptus low open forest	10,894	10,883	100
Eucalyptus woodlands	207,980	68,306	33
Acacia forest and woodlands	26,099	21,184	81
Callitris forest and woodlands	23,724	22,132	93
Casuarina forest and woodlands	42,580	40,698	96
Melaleuca forest and woodlands	130	14	11
Other forests and woodlands	189	141	75
Eucalyptus open woodlands	31,247	31,245	100
Acacia open woodlands	138	138	100
Mallee woodlands and shrublands	36,746	33,889	92
Low closed forest and closed shrublands	3,761	3,725	99
Acacia shrublands	77,081	77,017	100
Other Shrublands	5,294	5,117	97
Heath	1,245	1,154	93
Tussock grasslands	40,790	19,318	47
Hummock grasslands	4	4	100
Other grasslands, herblands, sedgelands and rushlands	65,917	65,761	100
Chenopod shrub, samphire shrub and forblands	68,766	62,322	91
Mangroves, tidal mudflat, samphire and bare areas, claypan, sand, rock, salt lakes, lagoons, lakes	5,670	5,411	95

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 New South Wales since European settlement?

Table: Major vegetation groups cleared in New South Wales
Major Vegetation Group	Cleared Area (km²)	% cleared across NSW as total of clearing
Rainforest and vine thickets	2,618	1.1
Eucalyptus tall open forests	4,162	1.8
Eucalyptus open forest	47,598	20.3
Eucalyptus low open forest	12	0
Eucalyptus woodlands	139,675	59.6
Acacia forest and woodlands	4,915	2.1
Callitris forest and woodlands	1,592	.7
Casuarina forest and woodlands	1,882	.8
Melaleuca forest and woodlands	116	0
Other forests and woodlands	48	0
Eucalyptus open woodlands	2	0
Mallee woodlands and shrublands	2,857	1.2
Low closed forest and closed shrublands	36	0
Acacia shrublands	64	0
Other Shrublands	176	.1
Heath	90	0
Tussock grasslands	21,472	9.2
Other grasslands, herblands, sedgelands and rushlands	156	.1
Chenopod shrub, samphire shrub and forblands	6,444	2.7
Mangroves, tidal mudflat, samphire and bare areas, claypan, sand, rock, salt lakes, lagoons, lakes	259	.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 New South Wales

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 New South Wales'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: