Livestock Grazing Effects on Fuel Loads for Wildland Fire in Sagebrush Dominated Ecosystems

Abstract

Herbivory and fire are natural interacting forces that contribute to the maintenance of rangeland ecosystems. Wildfires are becoming larger and more frequent in the sagebrush dominated ecosystems of the Great Basin compared to conditions a few decades ago, potentially altering plant communities and habitat. This synthesis describes what is currently known about the cumulative impacts of historic livestock grazing patterns and short-term effects of livestock grazing on fire and fuels in sagebrush steppe ecosystems. Over years and decades grazing can alter fuel characteristics of ecosystems. On a yearly basis, grazing can reduce the amount and alter the continuity of fine fuels changing wildlife fire spread and intensity. However, how grazing-induced fuel alterations affect wildland fire depends on weather conditions and plant community characteristics. As weather conditions become extreme, the influence of grazing on fire behavior is limited especially in communities dominated by woody plants.