Full Title
The role of fungi in the carbon cycle of floodplain wetlands
Student
Janice Williams
Supervisors
Dr Roger Croome (La Trobe University); Dr Darren Baldwin (MDFRC); Dr Gavin Rees (MDFRC)
Funding Body
La Trobe University
Duration
This project is part-time, with a five year duration. Commenced October 2006.
Outcomes
PhD
Summary
The carbon cycle of aquatic systems incorporates biological, chemical and geological sinks and fluxes that provide profound insights into the characteristics of these ecosystems. Recent research has illucidated many aspects of carbon movement through streams and wetlands but the contribution of fungi to these systems has not yet been investigated.
Given the intrinsic economic, environmental and social values of the wetlands of the Murray River (particularly the Barmah-Millewa Forest), a complete understanding of the carbon cycle of these ecosystems is important. This is because knowledge of carbon dynamics in floodplain wetlands allows more reliable prediction of (1) the impacts of various flooding regimes on ecosystem function, (2) the onset of "blackwater" events, and (3) the impact of slugs of nutrients of pollutants. The activities of fungi may attenuate or exaggerate these effects, and are also of significance to invertebrate food chains and nutrient cycling.
The aims of this project are:
- To investigate the role of fungi in the decomposition of floodplain leaf litter and woody debris in wetlands associated with the Murray river (including the Barmah-Millewa Forest).
- To compare fungal communities in terrestrial, aquatic/aerobic and aquatic/anaerobic environments.
- To determine how wetland wet/dry regimes affect rates of fungal degradation of floodplain litter.
- To determine which chemical substrates (carbon sources) are being degraded by different fungal groups under the three above conditions and what the products of the degradation process are.
- To determine the impacts of fungal activity on carbon availability to other aquatic organisms.
This will be achieved through an experimenal program that will:
- Provide an indication of genetic diversity;
- Determine the major fungal taxonomic groups present;
- Determine fungal biomass and production;
- Quantify rates fungal activity;
- Calculate the decomposition rate of floodplain litter, under various conditions;
- Determine the rate of loss of major groups carbon compounds (cellulose, hemicellulose, phenolic compounds, water soluble compounds, ether and alcohol soluble compounds and proteins) from decomposing litter.
