Biodiversity, resilience and the control of ecological-economic systems: the case of fire-driven rangelands

This paper advances a model to assess how grazing pressure in rangelands may lead to change in the ecological state of the range with a particular focus on fire-dependent semi-arid rangelands. The impact of management decisions on fire-dependent grasslands, such as active fire suppression policies or the incidental fire suppression effect caused by allocating higher stock densities, serve to reduce the build-up of fuel loads, inhibit fire and its regulating effect on shrub growth. The loss or disruption of periodic fire in such systems induces a loss of resilience and a shift to a state with lowered grazing potential.

The model considers whether the impact of fire on rangelands and the choice of grazing strategy can be accommodated in models of optimal choice developed for more stable cases. The model parameters are not based on a particular rangeland.