In Mediterranean mountainous environments, the removal of natural vegetation for developing agriculture increased the surface areas prone to erosion in the past centuries. In Southern PrePyrenees, the process was inverted during the middle of the 20th century. This work aims to assess how land use changes after widespread land abandonment affect soil redistribution. For this purpose, 137 Cs was used in a 23 km 2 catchment that was mostly cultivated at the beginning of the past century. After land abandonment, 16.5% of croplands persisted but afforestation and natural revegetation occupy 83.5% of the catchment area.
137Cs massic activity and related soil properties-stoniness, grain size, and organic matter contents-were analysed in 98 bulk core samples. Physiographic characteristics-slope, altitude, and solar radiation-at the sampling points were determined by using Geographic Information Systems. Soil erosion and deposition rates were derived from . These results outline the impact of land use changes on soil redistribution in fragile mountain agroecosystems.
KEYWORDS
137Cs measurements, catchment scale, erosion and deposition rates, land use changes, soil and physiographic properties