EFFECTS OF MEDITERRANEAN SHRUB COVER ON WATER EROSION (VALENCIA, SPAIN)

Mediterranean forest areas are ecosystems on fragile equilibrium and u nder the pressure of a range of degradative processes that increase th e risk of desertification. Soil erosion is one of the most serious pro cesses of degradation in these areas. To diminish its effects differen t approaches have been traditionally used most of them based on mecani c structures (bench terraces, ditches, etc.). Biological approaches li ke the planting of shrubs for soil protection have been scarcely studi ed. Because of this lack of information and experience, the influence of typical forest Mediterranean shrub vegetation on soil erosion proce sses and its comparison with two foraging species (Medicago arborea L. and Psoralea bituminosa L.) is the objective of this study. It has be en observed that natural vegetation gives always the best protection, reducing comparatively a 74.96% of soil loss. However the tested speci es, mainly Medicago arborea, show good protection rates reducing a 37. 60% of sediment production.