Strategies to prevent forest fires and techniques to reverse degradation processes in burned areas

Ferreira, António José Dinis; Alegre, Sérgio Prats; Coelho, Celeste Oliveira Alves; Shakesby, Rick A.; Páscoa, Fernando M.; Ferreira, Carla Sofia Santos; Keizer, Jan Jacob; Ritsema, Coen


Forest fires are probably the more deleterious event in forest and range areas in the Mediterranean nowadays. Despite the significant area burned every year, little has been done to develop strategies and techniques for soil and water conservation in burned areas, despite the major impacts on soil erosion and hydrological processes. The main problem is the fast speed at which soil and water degradation occur right after the fire, in response to the first autumn rainfall events. This limits the opportunities to mitigate the deleterious impacts. This paper presents several ex-ante strategies and techniques, such as the forest planning, prescribed fire and preventive forestry, and several ex-post techniques, such as mulching, seeding, hillslope barriers, creating infiltration opportunities, channel treatments and ecosystem restoration. To be effective and implementable, techniques must be in place as soon as possible, if possible before the first rainfall events, since a significant exportation of ash and soil losses occur after the first rainfall events from burned systems. The ex-post techniques can mitigate the degradation processes, but due to the fast implementation and to the associated costs, should be implemented in key points within the burned area, driven by the knowledge on how hydrological and erosion processes work in burned areas. The objective is to attain the most cost-effective strategies and techniques that might include the integration of several techniques at various scales, to reduce the output of water, sediments and nutrients, and therefore the degradation of local ecosystems.