The Ecological Role of Fire

Abstract

AbstractFire is the great consumer of Africa’s vegetation cover, most markedly since the Late Miocene (10 Million years ago) due to the cooling and drying, and increased seasonality, of the climate. Dry winters presented ideal conditions for extensive fires, opening forests and expanding grassy savannas and their fire adapted trees and C4 grasses. This Chapter describes the complex geophysical and biological process and feedback mechanisms that govern different fire regimes and fire types, collectively termed pyromes. Fire regimes differ widely across Angola, with frequent, cool, small fires being typical of the miombo mesic savannas, rare, intense and large fires typical of arid savannas. Frequent, intense, large fires are typical of the extensive peneplains of the Lundas and Cuando Cubango. Responses of plants and animals to fires differ between biomes. Pyrophobic forest trees are fire-intolerant, but pyrophilic savanna trees have evolved many adaptive traits, such as thick bark, ligno-tubers, epicormic buds and self-pruning. The responses of humans to fire have evolved over millennia, being used as a tool in agriculture and hunting, but increasingly, with a frequency that is detrimental to ecosystem resilience and human wellbeing.