The Native Vegetation of Yengo and Parr Reserves and Surrounds
This report describes the distribution and composition of the native vegetation of Yengo National Park, Parr State Conservation Area, Comleroy State Forest and adjoining private lands and inholdings. The project offers a revision of the vegetation classification and mapping studies completed by Sanders et al. (1988) and Bell et al. (1993). Since these previous efforts there has been a greater demand placed on vegetation maps to delineate the distribution of Endangered Ecological Communities (EECs) and threatened species habitats, as well as describe the condition of the vegetation within the reserve system to aid reserve management and regional conservation planning.
The completion of a new digital multi-attribute vegetation map for the study area is part of an incremental approach to achieving consistent flora and fauna information for all reserves in the Central Branch of the Parks and Wildlife Group under the Biodiversity Survey Priorities (BSP) program. In particular it is a step towards providing key natural resource data for management of the Blue Mountains World Heritage Area. In all, data from 124 new floristic sites was collected, providing a total of 441 sites across the reserves and adjoining lands. Over 1000 plant species are recognised from site data of which eighteen are listed as threatened under the NSW Threatened Species Conservation Act (TSC Act), 1995. Ten of these threatened species are also recognised nationally under the Commonwealth Environment Protection and Biodiversity Conservation Act, 1999. (EPBC Act). Maps describing the distribution of vegetation communities and disturbance patterns were generated by interpretation of recent 1:25 000 aerial photography and extensive field traverse.
The study area is situated within a large rainshadow zone between the coastal escarpment and the Blue Mountains-Wollemi ranges. Patterns in the local distribution of vegetation communities are heavily influenced by soil type and aspect. However within a broader regional and statewide context the vegetation composition relates more directly to the pervading dry and warm climate and infertile sandstone sediments that dominate the landscape.
The native vegetation communities present in the study area conform to several broad statewide vegetation classes described by Keith (2004) as follows:
- Sydney Hinterland Dry Sclerophyll Forests extend across the infertile sandstone plateaux. There are nine Map Units that fall into this class, offering a high diversity of shrubby forests and woodlands.
- Taller forests associated with sandstone gullies have only a low diversity and cover of mesic species and are very dry representations of the North Coast Wet Sclerophyll Forests. However it is in these forests that there are extensive stands of two rare eucalypts, the Hillgrove Gum (Eucalyptus michealiana) and a box eucalypt (E. hypostomatica).
- Small areas of depauperate Northern Warm Temperate Rainforests are found on sandstone in very deep gullies. Residual basalt peaks of Mount Yengo and Mount Wareng include small areas of Dry rainforest with Stinging Tree (Dendrocnide excelsa).
- Coastal Valley Grassy Woodlands are found on small areas of richer soils associated with residual shale caps, basalt flows and riverflats. These communities all are typified by the indicators of past and current disturbance associated with agricultural land use. Most stands exist in highly modified states and Map Units that fall within this vegetation class are mostly recognised as Endangered Ecological Communities (EECs) under the NSW TSC Act, 1995.
- Also in the riverflat environments there are examples of Coastal Floodplain Wetlands, Coastal Freshwater Wetlands Coastal Swamp Forests and Eastern Riverine Forests, all recognised as EECs under the NSW TSC Act, 1995.
- The study area encompasses the eastern half of the Mellong Plateau an area of unusual perched sand deposits. These support unique shrubby open woodlands and are recognised with their own statewide vegetation class, Sydney Sand Flats Dry Sclerophyll Forests.
- Small areas of Western Slopes Dry Sclerophyll Forests are present on the footslopes of the Hunter escarpment.
Page last updated: 27 February 2011