I submitted my PhD thesis in 2010.This research was the first examination of the ecology of aquatic fungi in Australian wetlands. It included a review of literature in the fields of carbon cycling in wetland systems and plant litter decomposition by aquatic fungi. Several laboratory and field experiments used molecular methods to confirmed the presence of aquatic fungi in floodplain wetlands, compare fungal dynamics between newly fallen and floodplain aged Eucalyptus camaldulensis leaves, and examine differences in the biomass and community structure of fungi and Oomycetes and on a leaf substrate between floodplain wetlands and the adjacent river environment. Changes in fungal community structure were also examined in floodplain sediments undergoing drying. Finally, Fourier transform infra-red micro-spectroscopy was used to develop maps and images of partially decomposed leaf sections, showing changes in the chemical composition of E. camaldulensis leaves as they undergo decomposition by fungi in the aquatic environment. This work was done at the Australian synchrotron. This research demonstrated that fungi are important in the decomposition of plant detritus submerged in floodplain wetlands on Australian lowland rivers, consuming the more refractory carbon resources found in the leaf vascular tissue and contributing to humification. Fungal biomass also has the potential to contribute protein to wetland food chains. However, fungi are not important decomposers in wetland sediments. Since completing the thesis I have been working with Murray-Darling Freshwater Research Centre in Albury-Wodonga, Australia. This work reports on the effects of hypoxic blackwater on biota of a forested floodplain wetland on the Murray River, with a discussion of the function of blackwater in lowland river systems. Other woirk includes an interogation of 454 metagenomics data derived from floodplain soils to examine patterns in the taxonomic diversity and functional roles of soil fungi.