concept

Fire regime

The characteristic pattern of burning in an ecosystem: the frequency, intensity, seasonality, severity and extent of its fires taken together. The essential point is that a regime is a property of the system over time, not of an event - "one big fire" says nothing about a regime, while "severe crown fire every 60-150 years" does. The regime is what selects which species can persist: forests that burn lightly at the surface every few years favour thick-barked trees, while those that burn rarely and violently in the canopy favour species that store seed in the crown. Shifting a regime in either direction, toward more fire or toward total suppression, changes which species live there.