Using dune-restricted species to assess the degree of natural diversity of dune systems on Mediterranean tourist coasts

Abstract

Here we focus on an improved floristic understanding of the condition and impacts to coastal dunes along the Catalan coastline of Spain. We identified 21 native dune-restricted plant species that can serve as indicators of the ecological integrity of these coastal dunes, a habitat that has been impacted by both urbanization and tourism. To that end, we employed a new analysis approach that calculated the ratio of the diversity of the dune restricted species to the overall plant diversity of the site. Values of this analysis could range from 0 to 1, with 1 corresponding to the most ecologically intact habitats. Our analyses revealed that regardless of habitat size, sand dunes that lacked significant human activity and that were not adjacent to urbanization had more dune restricted plant species present and so had values closer to "1″. However, larger dune habitats retained a higher number of dune-restricted species despite their proximity to urbanization or levels of tourism, indicating that their larger size provided resilience to negative anthropogenic effects. By first identifying key, dune restricted plant species that should occupy this dune landscape we were able to then provide an independent, objective indicator of the impacts of human activity on this ecologically important habitat