We suggest that treeline is unlikely to control the position of the Arctic front but that heating contrasts between tundra and forest could be important in generating local scale circulations that could feed back to maintain or extend treeline. In addition, I am involved in a Monash University based proposal to examine the impacts of fire in Australian tropical savanna lands. Such fires have a large impact on the atmosphere and many of these impacts on climate, biota and hydrology are not well understood. The role of fire as one of the primary natural carbon cycling mechanisms is a key issue in considering global climate change feedbacks. In particular, the partitioning of the carbon fluxes between the atmosphere and terrestrial ecosystems is important for predicting and managing atmospheric CO 2 concentrations.
Fire is likely to radically alter the surface energy and carbon balance of tropical savanna lands.
Fire scars will reduce surface albedo, increase the available energy for partitioning into the convective fluxes, and increase soil heat flux into the substrate. Fire results in a rapid loss of carbon to the atmosphere but some proportion of this carbon is likely to be assimilated in regrowth. In addition, the aerodynamic properties of the vegetation system would change, affecting the surface-atmosphere coupling. The project would aim to quantify the role of fire in landscape change and the feedbacks to hydrology and climate. In particular I am interested in quantifying the short and long term carbon balance and pools of these savannas and their vulnerability to climate change and variability, especially in terms of changes in fire frequency.