Effect of Forest Fires on Hydrology and Biogeochemistry of Watersheds

Abstract

Forest fire generally includes both natural wildfire and human-induced fire (e.g., slash-and-burn agriculture and accidental fire). Areas burned by forest fire are relatively widespread across the world (Table 30.1), but vary substantially across continents. For example, burned areas account for about two thirds of the total area in Africa, yet only approximately 1% in North America (Roy et al. 2008). Wildfire occurrence is primarily related to drought intensity, whereas agricultural demands oftentimes drive human-induced fires, particularly slash-and-burn cultivation. Because the controlling factors of both fire types have increased recently, global burned areas have also increased. In the Amazon catchment alone, burned area has expanded to encompass more than ten times its pre-1980 area (Peres et al. 2006). These increases in forest fire frequency and intensity have enhanced its role in, and contribution to, total global deforestation (Roy et al. 2008).