Mediterranean

Abstract

Mediterranean-type ecosystems occur in areas characterized by winter rainfall and summer drought. Five ecoregions possess a Mediterranean climate: the Mediterranean Basin, California, central Chile, southwestern Cape in South Africa, and southwestern Australia. The originality of Mediterranean ecosystems can be explained by complex interaction between historical biogeography patterns and unique ecological processes. Insights of paleoecology and phylogeography indicate the importance of paleogeographical and paleoclimatic events in shaping this massive and original Mediterranean biodiversity and ecosystem types. This article provides a comprehensive overview of the main Mediterranean-type ecosystems (shrublands, forests, and grasslands) and of their ecological characteristics, with a balanced view concerning ‘ecological convergences’ notably from the point of view of species traits and community structure. Methods of phylogenetic comparative biology have indeed recently demonstrated that similarity between traits of Mediterranean woody plants could be more due to phylogenetical inertia than to common adaptive strategies under Mediterranean climates. However, these climates induce severe and contrasted stresses to ecosystems and species, which have to cope with strong temporal variation in climate and resource availability. Natural and anthropogenic disturbances also play a determinant role in ecosystem dynamics, and fire and grazing constitute in several Mediterranean ecoregions a major selective force that shapes both the evolution of life-history traits and structure and function of these ecosystems.