HOW WILDFIRES AFFECT SOIL PROPERTIES. A BRIEF REVIEW

Wildfires may produce several changes in the short-and longterm in the landscape and in the soil system. The magnitude of these changes induced by fire in the components of ecosystems (water, soil, vegetation and fauna) depends on fire properties (fire intensity and severity) and environmental factors (vegetation, soil, geomorphology, etc.). The most important impacts on soils in the short-term are the reduction of vegetation cover (which increases soil erosion risk), the deposition of ash after combustion of biomass, the induction of enhancement of water repellency and changes in the structure and soil components. Combustion of biomass and soil organic matter also results in the release of gases and other pollutants into the atmosphere. Similarly, the changes induced by fire on the biological soil components (vegetation, animals and soil microorganisms) may occur rapidly and produce a large-scale response. The long-term effects of fire on soils and water may well persist for relatively short periods (hours, days or months), long (years or tens of years), or be permanent depending on the severity of fire and fire regime. Some of these effects are a consequence of the relationship between fire, soil, hydrology and nutrient cycling.