The role of the expansion of native-invasive plant species in coastal dunes: The case of Retama monosperma in SW Spain

Invasion by allochthonous plant species are identified, at present, among the main conservation hazards to coastal dunes. Nevertheless, the role of the expansion, with invasive character, of native species in these ecosystems has received little attention in ecological studies. In recent decades, Retama monosperma, a late colonizing legume shrub found in coastal sandy areas, endemic to the SW of the Iberian Peninsula and NW Morocco, has displayed invasive behavior in coastal dunes in different parts of the world, including its natural area of distribution. Its rapid expansion and increase in coverage has significantly contributed to the dune stabilization process, sometimes involving notable changes in the environment, plant community and shaping local distribution of some associated fauna, thus modifying the functioning of the whole ecosystem. In this review we examine the role of the expansion of R. monosperma in SW Spain coastal dunes, causes and implications, in the context of the ecological theory of invasions, and comparing it with other case studies.