Ecology, diversity and conservation of relict laurel—leaved mesophytic scrublands in mainland Portugal

Abstract

Phylogeographic studies have repeatedly identified the southern European peninsulas (Iberian, Italian and Balkanic) as major refuges for the flora during Pleistocene glacial events. Due to the succession of cold and warm periods, a large number of frost—sensitive species became extinct or confined to isolated positions in the southern peninsulas, where specific physical conditions working at a local scale enabled the persistence of those frost-sensitive, relict species. The global purpose of this paper is to address the ecology and diversity of relict laurel—leaved scrublands in mainland Portugal (Southwest Europe), where geographic segregation gave rise to a floristic diversification of community types. These biogeographically isolated scrublands configure seven distinct associations, which are recognisable from both classical and numerical phyto- sociological approaches. The conservation of relict laurel—leaved scrublands in the territory is also assessed in the framework of the EEC “Habitats” Directive.