Grazing herbivores reduce herbaceous biomass and fire activity across African savannas

作者：Allison T. Karp, Sally E. Koerner, Gareth P. Hempson, Joel O. Abraham, T. Michael Anderson, William J. Bond, Deron E. Burkepile, Elizabeth N. Fillion, Jacob R. Goheen, Jennifer A. Guyton, Tyler R. Kartzinel, Duncan M. Kimuyu, Neha Mohanbabu, Todd M. Palmer, Lauren M. Porensky, Robert M. Pringle, Mark E. Ritchie, Melinda D. Smith, Dave I. Thompson, Truman P. Young, A. Carla Staver · 发表于：Ecology Letters · 年份：2024 · DOI：10.1111/ele.14450 · 被引用次数：27 · 研究领域：Rangeland Management and Livestock Ecology、Fire effects on ecosystems、Wildlife Ecology and Conservation

Abstract Fire and herbivory interact to alter ecosystems and carbon cycling. In savannas, herbivores can reduce fire activity by removing grass biomass, but the size of these effects and what regulates them remain uncertain. To examine grazing effects on fuels and fire regimes across African savannas, we combined data from herbivore exclosure experiments with remotely sensed data on fire activity and herbivore density. We show that, broadly across African savannas, grazing herbivores substantially reduce both herbaceous biomass and fire activity. The size of these effects was strongly associated with grazing herbivore densities, and surprisingly, was mostly consistent across different environments. A one‐zebra increase in herbivore biomass density (~100 kg/km 2 of metabolic biomass) resulted in a ~53 kg/ha reduction in standing herbaceous biomass and a ~0.43 percentage point reduction in burned area. Our results indicate that fire models can be improved by incorporating grazing effects on grass biomass.