During the last decades Mediterranean systems are being affected by important land use changes which are transforming the entire landscape. Traditional irrigated lands have constituted one of the most characteristic agro-landscapes in the Mediterranean and have played a relevant socio-economic, ecological and environmental role. However, these valuable agro-landscapes are progressively decaying due to recent socio-economic changes which, at the same time, are promoting new irrigated lands outside the river valleys. These new irrigated lands have a major effect on land, water resources, landscape and the biodiversity value of extensive tracts of the Mediterranean area. At the same time, Mediterranean drylands are quickly disappearing due to land abandonment. In addition, Mediterranean areas are suffering a quick urbanisation process affecting both natural and agricultural areas. These trends may be considered as a reduction of the most characteristically rural Mediterranean landscape to favour ecologically extreme landscapes: on one side the natural areas and on the other side the new irrigated lands and urban areas. It is necessary, therefore, to understand the factors driving the land use changes in the Mediterranean, to analyse their ecological effects and to explore the potential implications of several policies regarding land use and natural resources.To this aim, we have analysed the land use changes and their socio-economic and environmental context in three study cases in Southeastern Spain, an arid Mediterranean area where the four above-mentioned land use changes are taking place. These study cases are the traditional irrigated land of Murcia, the agricultural system of Mazarron-Aguilas and the land use changes in the Mar Menor watershed. The ancient Murcia irrigated lands constitutes a paradigmatic example of the loss of this valuable agro-landscape and its highly fertile soils due to the urbanisation process and spread of infrastructures. The Mazarron-Aguilas new irrigated lands may be considered as representative of the most intensive agricultural systems in the Mediterranean area, which are quickly spreading at the expense of drylands and natural areas. The Mar Menor watershed have suffered important agricultural and urban-tourist land use changes affecting the hydrological and nutrient dynamics and the biological communities of the coastal lagoon and associated wetlands. An integrated approach has been applied combining GIS, Remote Sensing, spatial and environmental modelling and dynamic system models to analyse the sustainability of these three case studies, the spatial and temporal patterns of land use, the main socio-economic and environmental driving factors and their ecological implications.
