Post-fire regeneration of P. pinaster Ait. in Sierra de Guadarrama (Central Spain): modelling of initial density and survival

Abstract

Natural regeneration of Pinus pinater after wildfire is quite irregular and depends on several unwellknown factors. The objective of this research work is to analyze said process in the forest fire which took place in summer 1999, affecting a total surface of 450 ha, in the Monte Abantos (Sierra de Guadarrama), located in the region of Madrid (Central Spain). This study was carried out in 50 permanent plots, 3 × 3 m size, over the following four years after the fire, collecting data about density, height, slenderness and mortality of the P. pinaster natural regeneration. The final results show that there are a large number of factors which affect seedlings emergency and mortality. A linear pattern that reveals the importance of germination layer physical properties (litter, outcrops and erosion), physiography and interspecific competition, has been obtained. According with the logistical pattern generated, interspecific competition is the most important factor to determine seedlings survival, although physiography, potential forest productivity, basal area, and erosion are also determinant.