Human beings are altering land cover at rates and scales that are unprecedented in human history (NRC 2002), rivaling glacial/interglacial transitions in magnitude (NAS 2000). Nowhere are human-mediated changes in land cover affecting global processes more than in the tropics. Understanding the causes and effects of regional land cover and land use change (LCLUC) is one of the grand challenges in the environmental sciences (NAS 2000). Further refinement in the estimates of tropical forest conversion will also be important for balancing the global carbon budget, and reconciling flux estimates from models (Houghton et al., 2000) and atmospheric measurements (Ciais et al., 1995a, 1995b).