Effects of fire on forest communities and sclerophyllous scrubs in Central Chile as a basis for the formulation of restoration guidelines

Abstract

The effects of fire on forest and Mediterranean scrubs in four regions of Chile were studied. The main objective was to determine different levels of damage in watersheds with forest and native sclerophyllous scrubs belonging to the most valuable plant formations in Central Chile. The methodology consisted of the characterization of sampling areas that were qualitatively and quantitatively compared with the characterization of forests and shrublands without recent affectations of fires. Four regions of Chile were evaluated, where fires are concentrated in areas with sclerophyllous native vegetation. In each region, two sampling areas were selected to study the effects of fire. Three classifications were made based on structure, species composition, and response to fire. These were: deciduous scrub consisting of A. caven (tree), R. moschata (bush), and A. barbata (herbs); sclerophyllous evergreen scrub consisting of L. caustic-C. alba-and a mixed scrub of P. boldus (tree)-R. trinervia (scrub) and A. barbata. A dendrogram was produced on the relative abundances and the Bray & Curtis Similarity Index of the species. In addition, the results indicated an initial stage of damage to the soil structure, erosion processes, and water transport due to hydrophobicity at different levels of fire intensity, but recovery was observed a few weeks after the fire. Recovery was more apparent in the soil structure and cover of the scrub vegetation and later the tree species. These results provide useful background for the preparation of restoration, reforestation programs, and actions for the conservation of plant species vulnerable to the impact of wildfires.