Anthropogenic modifications to fire regimes in the wider Serengeti‐Mara ecosystem

Probert, J. R. et al. (2019) Anthropogenic modifications to fire regimes in the wider Serengeti‐Mara ecosystem. Global Change Biology, 25(10), pp. 3406-3423. (doi: 10.1111/gcb.14711) (PMID:31282085) (PMCID:PMC6852266)

Abstract

Fire is a key driver in savannah systems and widely used as a land management tool. Intensifying human land uses are leading to rapid changes in the fire regimes, with consequences for ecosystem functioning and composition. We undertake a novel analysis describing spatial patterns in the fire regime of the Serengeti‐Mara ecosystem, document multidecadal temporal changes and investigate the factors underlying these patterns. We used MODIS active fire and burned area products from 2001 to 2014 to identify individual fires; summarizing four characteristics for each detected fire: size, ignition date, time since last fire and radiative power. Using satellite imagery, we estimated the rate of change in the density of livestock bomas as a proxy for livestock density. We used these metrics to model drivers of variation in the four fire characteristics, as well as total number of fires and total area burned. Fires in the Serengeti‐Mara show high spatial variability—with number of fires and ignition date mirroring mean annual precipitation. The short‐term effect of rainfall decreases fire size and intensity but cumulative rainfall over several years leads to increased standing grass biomass and fuel loads, and, therefore, in larger and hotter fires. Our study reveals dramatic changes over time, with a reduction in total number of fires and total area burned, to the point where some areas now experience virtually no fire. We suggest that increasing livestock numbers are driving this decline, presumably by inhibiting fire spread. These temporal patterns are part of a global decline in total area burned, especially in savannahs, and we caution that ecosystem functioning may have been compromised. Land managers and policy formulators need to factor in rapid fire regime modifications to achieve management objectives and maintain the ecological function of savannah ecosystems.

• Item Type: Articles
• Additional Information: Natural Environment Research Council. Grant Number: JZG10015 Leverhulme Trust. Grant Number: IN-2014-022 Vetenskapsrådet Sida and Formas. Grant Number: 2016-06355
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Morrison, Dr Thomas and Hopcraft, Professor Grant
• Authors: Probert, J. R., Parr, C. L., Holdo, R. M., Anderson, T. M., Archibald, S., Courtney Mustaphi, C. J., Dobson, A. P., Donaldson, J. E., Hopcraft, G. C., Hempson, G. P., Morrison, T. A., and Beale, C. M.
• College/School: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Journal Name: Global Change Biology
• Publisher: Wiley
• ISSN: 1354-1013
• ISSN (Online): 1365-2486
• Published Online: 08 July 2019
• Copyright Holders: Copyright © 2019 The Authors
• First Published: First published in Global Change Biology 25(10):3406-3423
• Publisher Policy: Reproduced under a Creative Commons License