Influence of scrubs on runoff and sediment loss in soils of Mediterranean climate

Scrubland communities are the most common plant communities in eroded areas with Mediterranean climate. These protect the soil in different ways including the interception of raindrops (which lowers their erosive capacity) and the provision of organic carbon (necessary for the formation of organomineral aggregates). Vegetation were analysed and rainfall simulations performed in 29 natural plots in areas of significant erosion in the Madrid (Spain) region. The results show that plant cover is the main factor reducing surface runoff and the movement of sediments. Vegetation structure is also important, with pluri-stratified communities offering more protection against water erosion than mono-stratified communities. The plant growth forms were also found to be influential. Nanophanerophytes as Rosmarinus officinalis were the most efficient of those studied. Biodiversity did not seem to be important in soil protection in the studied area.