Limnological studies of waterfowl habitat in south-western New South Wales. II. Aquatic macrophyte productivity

Abstract

Aquatic macrophyte productivity and soil organic matter were measured in two impermanent wetlands in south-western New South Wales. Macrophyte biomasses (≤463 g dry wt m^-2) were similar to or higher than those in submerged communities elsewhere. Macrophyte productivities in both wetlands were greatest in the year following reflooding. But even in that year, macrophyte productivity in Lake Merrimajeel (the only wetland for which data are available) was considerably less than soil organic reserves before reflooding. It is suggested that these soil organic reserves directly contribute to the relationship between wetland flooding and waterfowl breeding, while macrophytes contribute indirectly by providing detritus for invertebrates. It is recommended that wetlands managed for waterfowl breeding should periodically dry out and reflood.