Fire shapes the structure and function of savanna ecosystems by determining the balance between grasses and woody plants, the composition of plant communities, and the availability of habitat for animals. Research by William J. Bond University of Cape Town demonstrates that differences in fire frequency and intensity can favor either grass-dominated or tree-dominated states, making fire regime management a primary driver of savanna biodiversity. Local species have evolved under particular regimes, so altering those regimes shifts competitive relationships and community assemblages.
Fire regime components and ecological mechanisms
Key components of a fire regime—frequency, seasonality, intensity, and spatial pattern—affect nutrient cycling, seedling recruitment, and habitat heterogeneity. David M. J. S. Bowman University of Tasmania explains that early-season, low-intensity fires tend to maintain grasslands and promote a mosaic of successional stages, while late-season, high-intensity fires can cause tree mortality and reduce understory diversity. Fire interacts with grazing, rainfall and soil fertility; where grazing pressure is high, fire effects on vegetation structure and species composition are often amplified.
Management practices and biodiversity outcomes
Different management approaches produce contrasting outcomes. Prescribed burning applied at low intensity and patchily across the landscape generally supports higher species richness by creating a diversity of microhabitats and successional stages. Conversely, long-term fire suppression promotes woody thickening and can reduce grassland-specialist species, while repeated intense burning can reduce seed banks and favor opportunistic or fire-tolerant species. Evidence from savannas studied by Robert J. Scholes Council for Scientific and Industrial Research shows that landscape-level patchiness created by varied burning practices sustains both herbaceous and woody taxa more effectively than uniform regimes.
Human and cultural practices matter: Indigenous and local communities in Australia and parts of Africa use mosaic burning for hunting, forage quality and cultural reasons; these practices often align with biodiversity-supporting regimes. Territorial and climatic contexts also influence outcomes—savannas in seasonally dry Africa behave differently from those in floodplain or montane settings, so management must be place-specific. The consequences extend beyond species composition to ecosystem services: altered fire regimes affect carbon storage, erosion risk and livelihoods. Adaptive, evidence-based fire management that respects local knowledge and ecological research provides the best path to maintaining savanna biodiversity.