Land degradation in the Mediterranean Basin: Linking bio-physical and economic factors into an ecological perspective

Land degradation is a global problem which involves different ecological factors. Originally limited to the most arid regions of the world, desertification risk has rapidly increased in temperate regions. In Mediterranean Europe, high human pressure, climatic changes and intensive economic development combine to produce land consumption. Soil degradation and erosion, as well as salinization and fire risk, are all considered key factors in desertification processes. The aims of this paper are to review recent findings in term of land degradation phenomena and vulnerability assessment, especially focusing on ecological, demographic and economic aspects of the problem. For many years the term land degradation has been strictly associated with bio-geo-physical conditions (e.g. climate, aridity, soil characteristics, slope, vegetation cover, soil erosion) but in very complex ecosystems such as the Mediterranean region the study of the interaction of physical patterns with population characteristics is necessary to better delineate vulnerable areas. We describe a simplified model in which ecological variables may significantly accelerate land degradation and thus provoke desertification phenomena. Indicators suitable for assessing such processes in the Mediterranean basin were analysed mainly based on the experience of defining vulnerable areas in Italy. Finally, we delineate new findings to be achieved in the context of human impact on environment as an original contribution to the study of land degradation.