Ephemeral wetlands of the Pilliga Outwash, northwest NSW

Abstract

The floristic composition and vegetation partitioning of the ephemeral wetlands of the Pilliga Outwash within the Pilliga National Park and Pilliga State Conservation Area (30˚30'S, 149˚22'E) on the North Western Plains of New South Wales are described. SPOT5 imagery was used to map 340 wetlands across the Pilliga Out wash. A total of 240 plots within 31 wetlands explored composition and species richness in relation to water depth and wetland size. The predominant community described is the species-rich herb field of shallow basin wetlands, along with the structurally distinct but the less common sedge land/herb field of the deeper 'tank' wetlands and a single wetland with a floristically depauperate 'Diplachne fusca' wet grassland. A total of 131 taxa were recorded including three species listed under the NSW Threatened Species Conservation Act (1995): 'Eriocaulon australasicum', 'Lepidium monoplocoides' and 'Myriophyllum implicatum'. New records for an additional six taxa were recorded for the North Western Plains. 11% of taxa were exotic in origin.