The Georges River Biodiversity Study comprises four main components, the mapping of vegetation communities within the catchment, habitat modelling for priority fauna and flora species and a conservation assessment to identify areas of likely high biodiversity value. The area of extant native vegetation was estimated for the Cumberland Plain using aerial photograph interpretation (API). Aerial photographs flown between November 1997 and March 1998 were interpreted at a scale of 1:16000 using a stereoscope. Remnants were classified into 6 classes according to remnant size and the density of Eucalyptus tree cover. The floristic composition of the overstorey was estimated for Classes A, B and C. Class C polygons included remnants with a non-Eucalyptus tree stratum and remnants with no tree stratum (eg shrublands). Descriptions of the understorey were mainly qualitative (eg presence/absence of shrubs, weeds, mesic species or vines), but dominance by particular genera was noted where possible (eg Casuarina, Melaleuca, Olea). Class B polygons of area less than 5 ha were mapped as class TX (scattered trees). Areas of scattered trees where agricultural activities were evident (eg heavily grazed areas, mustering yards, cropped land) were mapped as TXR. Areas of scattered trees with building structures present were mapped as TXU. VIS_ID 4101