An integrative model of human-influenced fire regimes and landscape dynamics

Fire regimes depend on climate, vegetation structure and human influences. Climate determines the water content in fuel and, in the longer term, the amount of biomass. Humans alter fire regimes through increased ignition frequency and by hindering the spread of fire through fire suppression and fuel fragmentation. Here, we present FIRE LADY (FIre REgime and LAndscape DYnamics), a spatially explicit fire regime model that takes into account daily weather data, topography, vegetation growth, fire behaviour, fire suppression and land use changes. In this model, vegetation growth depends on water availability, and stem diameter and stand density are the fundamental parameters. Fire behaviour is modelled using the Rothermel equations and taking into account both crown fire and spotting. Human influences on fire regime, such as ignition frequency, fire suppression and land use changes, are explicitly modelled. The model was calibrated for three regions in NE Spain and reproduces fire regimes, changes in land cover distribution and tree biomass with promising accuracy. The explicit modelling of human influences makes the model a useful and unique tool for assessing the impacts of climate change and informing local fire regime management strategies.