The effect of forest fire on vegetation

© 2009 by Taylor & Francis Group, LLC. Fire events are common disturbances in many ecosystems. The role of fire in ecosystems is encompassed in the concept of ‘fire regime’, which includes both temporal and spatial aspects as well as the physical characteristics of the fire. Vegetation recovery mechanisms determine ecosystem resilience, or the capacity to return to pre-fire conditions. In general, ecosystems submitted to frequent fires tend to be more resilient. The new environment produced by fire often determines successional trajectories. Thus, species that were not dominant in the pre-fire conditions will eventually be replaced by shadetolerant species. However, this successional scheme is not universal. In some forests, such as fire-prone Mediterranean forests, direct regeneration occurs resulting in post-fire communities that are similar to pre-fire communities. This case supports the fire regime-resilience coupled model. However, under certain conditions, this coupling is disrupted and results in decreased resilience to fire. For example, new climatic conditions, change in the species pool (planted species or invasive species moving into an area), or policies modifying fire regimes, may result in vegetation dynamics that move toward new communities.