Vegetation and biodiversity
The Central West covers a wide diversity of landforms and vegetation, with more than 550 vertebrate species recorded in the catchment, in 81 broad vegetation types, with 3183 species of plants.
At the time of European settlement, the catchment supported a complex mosaic of forests, temperate and semi-arid woodlands, wetlands, shrub lands, heaths and grasslands. Clearing and subsequent degradation have reduced this natural vegetation cover to a large number of small, isolated remnants on the less fertile and productive soils. For example, the Box and Ironbark woodlands which originally occupied large parts of the slopes and plains have been reduced by as much as 90%, and are now among the most significantly altered plant communities in NSW.
In many instances, the dominant species of those communities which have been heavily cleared are still relatively common in the landscape. However, remnants often occur as single trees or small groups of mature or senescent trees, typically with little, if any, of the original understorey structure and species diversity and no regeneration. In the case of native grasslands, remnant elements are generally scattered throughout the improved pastures, which dominate much of the region, as well as roadside remnants and travelling stock routes.
In recent years there has been a growing recognition within all levels of government and the wider community that native vegetation has an important part to play in achieving a range of conservation, land management and water quality objectives. Native vegetation is now recognised as important in helping control soil erosion and watertable levels and providing reservoirs of native fauna and flora. However, external pressures are jeopardising sustainability.
It is now widely recognised that successful management of native vegetation relies on a coordinated and strategic approach to managing the whole landscape - retention, restoration, enhancement and revegetation are the key.
The extent and importance of native vegetation
The CMA commissioned a vegetation mapping study of the catchment – “Reconstructed and Extant Distribution Native Vegetation in the Central West Catchment” - to show the extent and importance of native vegetation. The study identified 81 broad vegetation types in the catchment, shown in the form of a map detailing existing vegetation coverage, alongside a reconstructed “Pre-European Clearing” map.
Using this mapping project, it has been estimated that approximately 38% of the Central West catchment is currently vegetated to some extent and 62% has been cleared. There are an estimated 14 broad vegetation types with less than 1,000ha of their reconstructed extent remaining, 20 with less than 30% remaining, 31 with between 30% and 70% remaining and 10 with more than 70% of their reconstructed extent existing today. The remaining seven vegetation types don’t have enough data to estimate conservation status.
The representation of vegetation in conservation reserves was also identified, with 21 broad vegetation types not reserved at all in the catchment and only 12 types that have more than 15% of their extent area in conservation reserves. The vegetation maps give a conservative view of the level of clearing and vegetation degradation within native vegetation.
The “Reconstructed and Extant Distribution Native Vegetation in the Central West Catchment” maps are intended as a regional planning tool for the CMA, but are also a useful tool for contractors working with the CMA, educational institutions and some tertiary students. Click here for instructions on how to apply for a CD copy of the maps.
For up to date legislation related to native vegetation/ biodiversity management and actions please go to www.legislation.nsw.gov.au
Last Updated: 15-Aug-2012 11:58 AM