Beyond pre-Columbian burning: the impact of firewood collection on forest fuel loads

Abstract

Government agencies in the United States (US) adopted a prescribed burning policy based in part on paleo-environmental evidence of pre-Columbian Native American burning regimes. However, biomass collection by Native Americans in the pre-Columbian era left little direct or indirect evidence of its magnitude or influence on fire regimes. In many developing countries, local peoples harvest biomass for shelter, tool production, cooking, and heating, and often manage forests communally. The objective of this study was to use modern proxy biomass collection estimates analogous to pre-Columbian era practices in the western US to estimate the potential impacts of regionwide firewood collection on fuel loads in the Sierra Nevada range of California. A minimum of 59% of the forested area of the Sierra Nevada range could have been completely stripped of surface fuel accumulation in the 100-hour (100 h) fuel moisture class (2.54–7.62 cm diameter) each year in the pre-Columbian era, but upper estimates suggest Native American fuelwood requirements may have exceeded the amount of 100-h surface fuels accumulated over the entire range each year. The collection and removal of the fuels from the surface fuel loads may have contributed to reduced fire severities over that era. Dead wood collection in Nepal and India was found to reduce the threat of forest fires. Including the effects of cultural practices on fuel loads may improve reconstructions of past fuel and fire regimes and may benefit modern management strategies.