Alien species and the impact on sand dunes along the NE adriatic coast

Abstract

This chapter presents the results of a multifaceted approach to determine how sand dune plant communities have been affected by invasion of alien species. We sampled Velika plaža beach in Montenegro (E Adriatic), which is an under-researched part of the Mediterranean. Velika plaža is the largest sandy beach with both still well-developed sand dunes and moist plant communities in this part of Adriatic coast. On the other hand, this beach is also a touristic hot spot and subject to intensive land use change. We gathered maps of past and present land use by using GIS and field mapping from 1950, 1979 and 2015. The species composition of plant communities was randomly sampled and information on phylogeny and plant functional traits was gathered from several databases. Five alien plant species occurred in the sand dune vegetation, with a significant effect of the presence of aliens on native species cover. Invaded plots, when the whole beach is considered, were functionally less diverse than uninvaded ones. Plant species functional traits change along the sea-inland gradient, particularly rosette type, woodiness and nitrogen fixation. Phylogenetic diversity due to the presence of alien species was highest in sand dune slacks, but the results of phylogeny are not consistent and should be used with caution. The results of a multifaceted approach enable further management and monitoring of sand dunes and prevent the conflict between nature conservationists and landscape planners that is foreseen with further development of beaches in this part of the Mediterranean.