A comparison of microclimate and environmental modification produced by hedgerows and dehesa in the Mediterranean region: a study in the Guadarrama region, Spain

Two common forms of traditional land use systems in Mediterranean landscapes are dehesa and hedged fields. Both are agroforestry systems in which domestic stock are pastured: amongst parklike trees in dehesa, and in enclosures surrounded by stone walls and woody vegetation in hedged fields. The latter are now tending to be replaced by dehesa due to labour costs. Here, we investigate the boundary layer microclimate and environmental characteristics of these two land uses in order to evaluate the respective differences in relation to climate modification, soil organic carbon, and soil water content. Fraxinus angustifolia-dominated sites were investigated in the Guadarrama mountains, Spain, in high summer with simultaneous sampling under trees in both dehesa and hedgerows and in adjacent open fields. Whilst temperature profiles were similar in both systems, hedgerows had higher soil water content, lower wind speeds, and higher total soil organic carbon compared to dehesa, and moreover these trends also applied to open fields of the respective systems. We conclude that not only do hedged fields have advantages over dehesa for shelter and production, but that the climatic modifications of hedged field systems potentially modify boundary layer climates on a broader scale than both individual fields and dehesa. Thus, the conservation of hedged field systems provides natural capital and broad environmental gains.