Plant biodiversity in habitats of Community interest of Mediterranean large scale grazing systems

Large scale grazing systems are one of the best examples of adaptation of agro-pastoral activities and environmental limitation in the European marginal rural areas. They support high biodiversity levels and therefore they are recognized as an important part of European high nature values farmlands. They are also a source of agro-ecosystem services and they are linked with the history of the resident populations and for this reason many cultural landscapes are associated with them. Because of the socio-economical changes of the last decades, large scale grazing systems have been greatly reduced. Agro-pastoral activities intensification and abandonment are the main factors that threaten their conservation. With them could disappear an important part of biodiversity and a part of historical and cultural roots of humanity.Therefore, their conservation is included in the European rural development policies and nature preservation strategies.In this thesis I describe the studies that I have carried out in order to investigate different aspects of Mediterranean large scale grazing systems with the aim to contribute to the knowledge concerning the conservation status and biodiversity levels in habitats of Community interest linked with them. The surveys were made at different spatial scale in order to investigate the ecosystemic processes using a suitable level of detail.