Soil, fire and physiological processes causing deterioration of coastal eucalypt forests.

Substantial areas of coastal eucalypt forests are declining in health as evidenced by crown deterioration and dieback, and in the longer term, mortality. A range of factors have been implicated as either inciting or exacerbating this decline – nutrient enrichment as a result of reduced incidence of low intensity fires is one, others include insect outbreaks and the presence of Bell Miner bird colonies.

This PhD is investigating the proposal that these factors all contribute to forest decline, however the underlying problem is one of reduced incidence of fire which leads to nutrient enrichment and release of insect populations from nutrient controlled population limits.

Specific components of this research include: a study of litterfall in declining and healthy forest; soil nutrient pools and fluxes in healthy and declining forest; the development of a physiological measure of tree decline using foliar stress chemicals; estimation of recent fire regime from soil charcoal; and questioning whether human-altered fire regimes have affected soil nutrient cycling processes and lead to forest decline.