Endemic sand dune vegetation of the northwest Iberian Peninsula: Diversity, dynamics, and significance for bioindication and monitoring of coastal landscapes

Coastal areas are sensitive systems suffering both natural and anthropic pressures. Specifically, coastal sand dune dynamics is related with observable modifications in plant communities, and this relationship is being pointed out in recent years as a monitoring tool in littoral areas. Plant community types, with a relatively stable floristic composition related to specific ecologic conditions (plant associations), provide a suitable tool for bioindication within monitoring processes and in the management of littoral areas. In this regard, recent bio-geologic studies performed in dune systems of Southwest Europe allowed the identification of a number of specific bioindicators for both mobile and interior dunes. In Northwest Iberian Peninsula, sand dune vegetation is distinguished by its transitional character between typical Atlantic and Mediterranean vegetation types, and its originality is still enhanced by the occurrence of narrow endemic species and by the fact that most vegetation types are endemic to the territory. The organisation of these community types within dune systems is strongly determined by specific dynamic processes mediated by both natural and anthropic disturbances, so they present a large potential for bioindication of coastal dynamics and conservation status. In this paper, the most significant ecologic, floristic and biogeographic characters of sand dune vegetation in Northwest Iberian Peninsula are discussed with the purpose of demonstrating the usefulness of well-defined vegetation types for bioindication within the context of both short- and long-term monitoring of coastal sand dune systems.