Floristic variability, distribution and an extension of range for the endangered Pittwater Spotted Gum Forest, Central Coast, New South Wales
- Multivariate analysis and non-metric multidimensional scaling have been used to compare the floristic composition of vegetation dominated by Spotted Gum, Corymbia maculata, and Grey Ironbark, Eucalyptus paniculata, from the Pittwater and Gosford local government areas, and elsewhere on the Central Coast of New South Wales. When placed within a regional context, vegetation from both local government areas is strongly related, and is sufficiently distinct (at 30% similarity) from other areas of Spotted Gum-Ironbark vegetation within the region to warrant their collective consideration as Pittwater Spotted Gum Forest (PSGF), an Endangered Ecological Community in New South Wales. Within Pittwater local government area, two forms of PSGF are present: a dryer, more widespread form present on ridges and slopes, and a moister form with strong littoral rainforest affinities confined to gullies. Gosford local government area supports only the dryer form. Extant and pre-1750 mapping of PSGF from both local government areas (excluding Ku-ring-gai Chase National Park) shows a total extant distribution of 227 ha, and since 1750 an estimated loss of 727 ha (76%) from the original 954 ha. PSGF is present in two secure conservation reserves: Ku-ring-gai Chase National Park (~40 ha, Thomas & Benson 1985) and Bouddi National Park (~30 ha, Bell 2009), totaling ~ 70 ha. Despite this, much of the extant distribution lies at the reserve-urban interface, and is subject to ongoing threats of regular low-intensity fire, unmitigated clearing and weed invasion.