Vegetation and soil erosion under a semi-arid Mediterranean climate: a case study from Murcia (Spain)

The objectives of the present work are to analyse some relationships between soil and vegetation parameters for Mediterranean matorral in the El Ardal experimental field site in Murcia (Spain), the response of this system in terms of erosion and runoff, and the pedological and vegetation effects of some disturbing factors such as agricultural use and grazing. The El Ardal experimental field, which is provided with automatic weather stations, erosion plots and other devices have been used over a period of two years to study the evolution of factors such as erosion, runoff, vegetation cover, biomass, litter production, soil moisture, water retention capacity and aggregate stability. The results obtained show that in general the pedological and vegetation properties are far from those expected in semi-arid Mediterranean environments. Runoff and sediment losses in the erosion plots are low as a result of the efficient control of the same by the matorral at the scale of the hillslope. The abandoned field shows a good capacity to recover its pedological and vegetation characteristics after disturbances such as agricultural use. Finally, grazing does not seem to seriously affect the dynamics of the matorral, which shows values of primary production close to those found in other Mediterranean scrublands, although there are other indirect effects on pedological and vegetation characteristics due to livestock trampling.