Author(s)

O. van Dam

Abstract

Selective logging in the tropical rain forest of Guyana creates gaps in the canopy. The PCRaster model FORGAP was made to calculate the radiation energy, evapotranspiration and soil water dynamics of logging gaps. Model input data was gathered in experimental gaps that differ in size. Calibration was done with measured soil moisture in the experimental gaps. The model proves a good tool in identifying areas within a gap that receive more light, show larger evapo- transpiration rates or experience more moisture stress. The model can be used in scenario studies of the effects of gap size, shape and orientation to the sun on the microclimatic conditions and water availability that regulates forest regeneration. 1 Introduction One

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