Processing of riparian and wetland plant litter in the River Murray, South Australia

Abstract

The breakdown of litter from eight common plants was investigated in Sunnyside Swamp, a wetland connected to the River Murray. Breakdown rates were related to the content of structural carbohydrate tissue in each species. Burial in wetland sediments inhibited the breakdown of relatively fast-decomposing species (e.g. Myriophyllum caput-medusae), but did not affect slow-decomposing species (e.g. Typha orientalis). Fungicide treatment proved to be an unreliable method to measure the contribution of physical abrasion to breakdown. The breakdown of redgum litter (Eucalyptus camaldulensis) did not differ between river and wetland sites (43% weight loss over 10 weeks), but willow litter (Salix babylonica) lost 15% less weight in the wetland than in the river over the same period. Data are fitted to double-exponential models describing weight loss in litter from each species over time.