Wetland monitoring in the Wheatbelt of south-west Western Australia: site descriptions, waterbird, aquatic invertebrate and groundwater data

Abstract

The Wheatbelt of south-west Western Australia contains a range of wetland types with varying salinity, including many naturally saline lakes and playas. The increase in salinity of most wetlands during the last 50 years as a result of land-clearing is a major threat to wetland biodiversity. As part of the State Salinity Strategy, a wetland monitoring program began in 1997 at 25 wetlands from locations throughout the wheatbelt. The aim of the monitoring program was to document trends in biodiversity at the 25 wetlands and relate these trends to physical conditons in the wetlands and patterns of surrounding landuse. This report summarizes existing information on the wetlands and provides, as baseline conditions, results of initial waterbird, aquatic invertebrate and groundwater monitoring. It documents the monitoring methods used and highlights the need for a long-term program. There was a strong negative relationship between aquatic invertebrate species richness and salinity. A negative relationship also existed for waterbird richness, although other factors determined numbers of species in many wetlands with salinity being a constraint on maximum potential waterbird richness rather than a determinant of the actual number of species. Further salinization is likely to change detrimentally both invertebrate and waterbird communities. Such changes are apparent in historical waterbird data from some wetlands.