Changes in Phragmites australis in South-Eastern Australia: A habitat assessment

The status of common reed (Phragmites australis) in south-eastern Australia was assessed by considering its physical habitat. Phragmites habitats were categorized into three types-wetland, riverine and estuarine and all three showed negative change (loss, degradation) since European settlement. However, there were also instances of positive (new, re-establishment) changes. Integrating these negative and positive changes at the catchment scale for the Murrumbidgee River, suggest a re-distribution of Phragmites is occuring, and this may be true for other rivers managed for irrigation. Agriculture appears to be the principal cause of Phragmites australis losses in eastern Australia. There is no evidence to date of reed decline in Australia like that in parts of Europe, nor of expansion as in the coastal wetlands of the United States of America. The habitat approach used here was qualitative but this was necessary due to the lack of historical data on Phragmites and to the limited number of case studies. However, quantitative studies are needed, in order to understand how river health and aquatic biodiversity are being affected.