The contribution of direct moisture deposition from cloudsto the hydrologic budget of high catchments in southern Colombiaand possible impacts of forest removal.

South American deforestation, climate change and climatic predictions for the Choco biogeographic area based on the UK Hadley centre Atmospheric General Circulation Model (AGCM).

Supervisors : Dr. Mark Mulligan (KCL)

In addition to environmental change at the land surface as a result of development programmes, the Choco biogeographic region is likely to experience considerable climatic change as a result of global warming and deforestation in south America. This large scale impact may produce a series of regional climatic changes which may, in turn, impact on the distribution of ecosystems causing ecosystem change in endemic areas. Combined with land use change, these climatic impacts may have serious effects on Colombian biological resources.

The student will examine the climatic impacts of deforestation in South America using the advanced Hadley centre AGCM to predict the impact of Amazonian deforestation and global atmospheric CO₂ increase on the magnitude and distribution of rainfall, temperature, cloud distributions and other meteorological variables in the Choco biogeographic region. The results of the AGCM research will be downscaled to the Choco region and used to drive a large scale plant distribution and plant growth model. Firstly, the plant growth model will use measured climatic variables to model the distribution of plant functional types under present conditions. The model results will be validated with respect to existing maps of vegetation distribution in Pacific Coast and Andean slopes.

The validated growth model will then berun with GCM scenarios for climatic change, under various CO₂ emissions and Amazonian deforestation futures produced at the Hadley Centre and the change in ecosystem distribution examined with recourse to its possible impact on species loss and regional environmental change.

This studentship provides the largest scale examination of environmental change effects for the HERB project.

Recent Publications

Lean J, Rowntree PR (1993) A GCM Simulation Of The Impact Of Amazonian Deforestation On Climate Using An Improved Canopy Representation. Quarterly Journal Of The Royal Meteorological Society, 1993, Vol.119, No.511, pp.509-530

Mylne MF, Rowntree PR (1992) Modeling The Effects Of Albedo Change Associated With Tropical Deforestation. Climatic Change, 1992, Vol.21, No.3, pp.317-343

Mulligan, M. (1995) The Complexity of Vegetation Response to Climatic Variability and Climatic Change. Submitted to Advances in Hillslope Processes

Rowntree PR, Lean J (1991) Possible Climatic Impacts Of Tropical Deforestation - Comment. Climatic Change, 1991, Vol.19, No.1-2, pp.197-199.