How the mapping took place

The mapping was carried out by the NPWS, and was funded jointly by the NPWS, the Urban Development Institute of Australia and Landcom. The project aimed to:

• map all remnant native vegetation within the study area greater than 0.5ha using repeatable, scientifically robust methods
• provide large scale (1:25,000) maps of all vegetation mapped during the project
• contribute to greater certainty and rigour in the environmental impact assessment process through consistent, region-wide mapping
• provide sufficient information to assist with an assessment of bushland conservation significance.

Interim maps were released in 2000, and final maps were then released in 2002. There were three stages in creating the vegetation data layer:

Stage 1: Floristic Surveys

Field surveys were carried out at over 400 sites between October 1998 and June 1999, with additional surveys for the production of the final map series. Survey sites were chosen where vegetation was intact and sites were as far away as possible from areas of weed infestation or soil disturbance.

In each quadrat all plant species and their cover/abundance were recorded along with other environmental variables including location, elevation, soils, slope, aspect and disturbance (erosion, weed invasion, logging and fire).

Stage 2: Modelling of Native Vegetation Communities

Field data collected was then run through a software package called PATN to define the vegetation communities. These communities were then modelled across the study area using another software package, ALBERO.

ALBERO utilises the relationships between field site data and environmental variables such as rainfall, slope, geology and aspect to predict the distribution of vegetation communities across the study area.

Stage 3: Aerial Photograph Interpretation

The interpretation of aerial photographs was used to delineate the current extent and condition of remnant vegetation within the study area. Aerial photographs at a scale of 1:16 000 flown between November 1997 and March 1998 were used for this process.

The photos were viewed through a stereoscope and remnants were classified into 6 condition classes according to remnant size, canopy cover, canopy species, understorey species and disturbance. The remnants identified by the aerial photograph interpretation and the modelled vegetation communities were then overlaid to produce the final vegetation layer.