Prescribed fire experiences on crop residue removal for biomass exploitations and cost-benefits analysis, in mediterranean ecosystems

Abstract

The progressive increase in the use of prescribed fires, as a fire management technique for the prevention and reduction of the impact of forest fires, demands the development of new approaches. The generation of interesting utilities of this technique is not only related to the control of fuel load, but also to the creation and maintenance of operational scenarios. Biomass harvesting possibilities to rural development have led to a high woody biomass accumulation increasing potential wildfire severity. Mechanical thinning and prescribed burning practices could be jointly used to prevent large fires. The aim of this study was to assess burning treatment effectiveness in a medium-term planning (12 years) following mechanical thinning from biomass harvesting. An econometric model was designed to predict prescribed fires costs to reduce slash fuels, and as a consequence, the maximum efficiency or cost-benefit, mainly in strategic management or critical focal points. Prescribed fires reduced available fuel in all fuel categories, mainly in fine dead fuel category. A cost-benefit analysis to mitigate fire behavior was carried out using different burning severities. An efficiency burning management could reduce between 19.94% and 40.63% of the total costs in a medium-term planning (12 years). The most significant variables are related to fire severity (flame residence time) and stand characteristics, mainly canopy base height and remnant canopy cover. These variables allow us to predict costs per unit area based on different management alternatives. Managers can use this information to design technical prescription to achieve the targets while decomposed litter retention maintaining the soil properties and biodiversity under economic point of view. Understanding the most effective “burn window” should help better plan prescribed burning, in term of fire behavior, fuel consumption and the total budget that is necessary to reach the forest fires prevention and impact reduction in the forest landscapes in a medium-term planning.