Use of vegetation to combat desertification and land degradation: Recommendations and guidelines for spatial strategies in Mediterranean lands

A strategy for use of vegetation to control soil erosion has been developed that is spatially targeted at hotspots and flow pathways in the landscape. It is based on the premise that most of the soil erosion in semi-arid areas is by water erosion along specific flow lines. Soil is removed from fields and transported downslope and into channels if the connectivity of flow and sediment pathways is high, causing offsite problems as well as loss of agricultural productivity. Vegetation can reduce that connectivity by decreasing erosion and increasing sedimentation. The research combines mapping and analysis of the connectivity pathways and erosion hotspots with analysis of the most effective indigenous plants to control erosion and suited to the particular landscape position and environment. The crucial innovative element is the combination of physical process understanding with plant ecology, and its spatial application. The scheme has been developed by research in the driest part of the European Mediterranean region, in SE Spain, and examples of application strategies are illustrated. It is particularly suited to upland rain-fed agricultural areas on soft rocks, which are highly vulnerable to land degradation. Recommendations are provided on locations for planting or encouraging vegetation growth and on suitable species. The spatially targeted strategies apply vegetation to the critical locations to intervene in the pathways and this minimal intervention approach still allows cultivation of fields. The methods proposed can form the basis for sustainable catchment management to combat soil erosion and desertification. (c) 2012 Elsevier B.V. All rights reserved.