The loss of biodiversity due to the removal of farm dams in peri-urban Western Sydney

Abstract

In Australia, in areas such as peri-urban Western Sydney, farm dams are numerous in the agricultural landscape. These constructed aquatic habitats are mostly built for the purposes of irrigation and/or watering livestock but they also inadvertently play a dual role as they are often important habitats for wetland biodiversity. Whilst legislation pertaining to farm dams is aimed predominantly at regulating water usage, there is very little recognition of their potential as a biodiversity conservation tool. The agricultural lands in peri-urban Western-Sydney are rapidly urbanising to accommodate the increasing human population of the expanding city of Sydney. Coincidently, the farm dams of the area are being removed. This study compared the biodiversity of birds, frogs and macroinvertebrates of farm dams of this area with urban wetlands in Western Sydney to determine the loss of fauna that occurred with the removal of these farm dams for urbanisation. The biodiversity of farm dams was also compared with natural wetlands of the area to determine how effective farm dams are at supporting wetland organisms. The study determined that there was a similar abundance and diversity of frogs and macroinvertebrates in natural wetlands and farm dams but farm dams supported different assemblages of species. This indicated that while farm dams are important for aquatic biodiversity they do not replace natural wetlands for some species. In urban wetlands, frogs and macroinvertebrates were negatively affected while birds increased in abundance and diversity in urban wetlands when compared to farm dams; however, this was in part due to the resilient species that thrive in urban environs. Farm dams and urban wetlands did not; however, support similar species assemblages. This study demonstrated that farm dams are important in maintaining biodiversity and despite not replacing natural wetlands for some species; they maintained a similar diversity and abundance of all fauna groups investigated although not all species. With urbanisation and the removal of farm dams some species that utilise farm dams may be lost exacerbating the loss that has already occurred with the loss of natural wetlands due to the development of agriculture.

Date of Award	2016
Original language	English