Wetland biodiversity in coastal New South Wales: the Wallis Lake catchment as a case study

Abstract

The floristic composition and environmental relations of wetland vegetation in the Wallis Lake catchment (32° 09'S; 152° 20'E), area 1292 km², on the lower North Coast of NSW are described. The catchment supports wetlands listed as Endangered Ecological Communities (NSW 'Threatened Species Conservation Act 1995') and plant species of high conservation value. A methodology of air photo interpretation, site-based sampling (114 quadrats) and landscape differentiation was developed. A total of 393 vascular plant taxa were recorded (including 10% exotics). Wetland vegetation formations and subformations including mangrove forest, swamp sclerophyll forest, wet heathland, chenopod shrubland, tussock grassland, sedgeland and rushland are described using numerical classification. 31 plant species of national or regional conservation significance are identified. Four Endangered Ecological Communities are discussed - Coastal Saltmarsh, Swamp Oak Floodplain Forest, Swamp Sclerophyll Forest on Coastal Floodplains, and Freshwater Wetlands on Coastal Floodplains. A key recommendation is the completion of reliable wetland vegetation and soil landscape mapping for all land tenures in the catchment - to assess wetland condition and conservation significance, and representation in formal conservation reserve, thereby directing future priorities for the protection of wetland biodiversity on both public and private lands. The methodology developed can be applied to the survey and conservation of wetland biodiversity in other parts of coastal NSW.