Thesis abstract:

Climatic variables have long been considered key factors influencing litterfall and litter decomposition. Our recent research has demonstrated the additional effect of landscape-scale variation such that litterfall in an inland forest was seasonal, with a maximum in summer and early autumn but, in a coastal forest it varied considerably and was affected more by periodic weather events including storms and coastal winds. From this research, the question arises whether geographic location and bioclimatic conditions also interact to influence litter quality and rate of decomposition.

In addition, in eucalypt forests, litter accumulation and its rate of decomposition is often punctuated by fire events, leading to the modification of litter inputs from the overstorey, composition of the understorey vegetation, soil properties, and microbial activity. The degree of alteration of each component is dependent on fire regime, location, and environmental conditions. Fire often promotes the growth of understorey plants such as legume that are rich in nitrogen and herbaceous forbs and ferns which may accelerate the decomposition of overstorey litter. A projected increase in the frequency of bushfires means long unburnt forest area could become scarce and regenerating forests become more dominant across Australia. Investigation of the effects of post-fire understorey species in nutrient cycling help us to understand the role of litter decomposition in fuel accumulation after bushfire.