Most land cleared of forest in Latin America's lowland tropics eventually ends up as pasture. This transformation of high biomass forests into relatively unproductive pasture is one of the most salient environmental transformations of the last 25 years. The incineration of large areas of forest in Amazonia currently generate 10 - 15% of the total carbon additions from biomass burning to the atmosphere (Dickinsen 1987) and banishes from biological history several species every day. Local impacts include siltation of smaller creeks and rivers, and sharp changes in microclimates as well as potential shifts in the hydrological regimes (Salati and Vose 1984).