Effects of buildings on plant composition and diversity in a Mediterranean protected area

Abstract

In natural protected areas, buildings such as small villages, farms, shepherd's huts, camps, small hotels or visitor centres are common, usually at very low densities. Although buildings could play a role in modifying the biodiversity of natural protected areas, there has hardly been any attempt to describe the composition and characteristics of the vegetation associated with these buildings. Here, we analysed if there is specific vegetation associated with buildings in a set of six buildings within the Doñana National Park (SW Spain). We used Detrended Correspondence Analysis to identify trends of variation associated with buildings, and G-tests to examine if the species associated with buildings differed significantly in geographical distribution and functional characteristics from the species of the natural area. To compare species richness between the plots associated with the buildings and those associated with the natural area, sample-based rarefaction curves were created using incidence data. We found that buildings increased the richness of plant communities, mainly of species with a wide geographical distribution or which are adapted to heavy disturbance. This effect remained even 40 years after abandonment, which means that buildings act as a long-lasting refuge for ruderal and invasive plant species that remain around them, but not invading the surroundings unless there are disturbances. We conclude that the perturbation caused by isolated buildings seem to create localized plant diversity hotspots in the sands of the Doñana ecosystems that remain distinct from the surrounding natural area for decades.