Urban expansion depletes cultural ecosystem services: an insight into a Mediterranean coastline

In the Mediterranean sandy coasts, urban expansion mainly occurs to support seaside tourism, causing a drastic loss of natural coastal dune habitats and the associated ecosystem services. We investigated on a representative tract of the Mediterranean coast to which extent land conversion into urban areas affected natural dune ecosystems and the related recreational Ecosystem Service over 50 years. Using empirical data derived from 591 questionnaires of beach users, we quantified the recreational ecosystem service (ESR) provided by the main dune habitat types of the Adriatic coast (Beach with Pioneer annual Vegetation, Herbaceous Dune Vegetation and Mediterranean macchia). On the basis of detailed multi-temporal land cover maps (years 1954, 1986 and 2006), we quantified the conversion of natural dune habitats into urban areas over time, by means of transition matrices. By combining the results of the assessment of ESR with the transition matrices, we measured how the natural dune habitats' loss reduced the related ESR supply. Results show that although natural dune habitats have an important role as ESR suppliers, urban expansion eroded them with specific rates, causing a total percent loss of 12% in the ESR. Our work underlines the fragility of natural coastal dunes, which during the last decades have become a privileged destination for touristic and recreational activities and, thus, have been progressively replaced by urban areas, with an unwanted direct impact on their ESR supply. By combining multi-temporal mapping techniques with ecosystem services measurements, we enhanced our understanding of transformation processes on coastal dunes, offering as well new insights for dune management. According to our results, an effective dune management shall favor natural dune zonation, by welcoming sustainable sea-side recreational activities as the only acceptable form of coastal tourism.