Human trampling effects on Mediterranean coastal dune plants

Abstract

Coastal habitats are particularly vulnerable to recreational impacts because these environments are highly dynamic and continually change in response to biotic and abiotic factors. Sand dune communities are worldwide characterized by high levels of biodiversity, but are often affected by human-induced impacts as those caused by tourist trampling. To understand the effects of human frequentation, trampling, and other human-induced impacts, fencing experiments have been traditionally carried out on coastal dunes. Since in touristic areas dune systems are subjected to different intensities of human frequentations rather than to opening or fencing, in this study we explore the effects of accessibility on vascular plants cover. This study tests the hypothesis that human frequentation on beaches affects spatio-temporal variability of vascular plant abundance on dunes by comparing the plant assemblages of high and low accessible sites in North-East Sardinia (Italy). Our results show that accessibility plays a crucial role in conditioning the percentage of vegetation cover in Mediterranean dunes. In fact, not only we found a perennial vegetation cover that was significantly higher in the sites with low accessibility (and consequently low frequentation), but we also showed that at the sites with high accessibility there were significant differences in vegetation cover between times of sampling (cover was higher before than after summer): on the contrary, differences in perennial vegetation cover among times were not significant at the low frequentation sites. After summer, the difference among low and high frequentation sites in species composition and cover was . 90%. Multivariate analysis identified those species that play a pivotal role in differentiating the low and the high frequentation sites. Among them, Crucianella maritima and Sporobolus virginicus can be considered as differential species. Overall, our data show vegetation and plant species responses to human-induced impacts, and are therefore important to support conservation actions in Mediterranean coastal areas interested by mass tourism.

Seasonal Functional Partitioning of Carbohydrates and Proline among Plant Parts of the Sand Daffodil

“…P. maritimum (sea or sand daffodil, sea or sand lily) grows naturally along the coastline of the Mediterranean region and blossoms during the hot and dry summer, at a time when simultaneously flowering plant taxa are scarce [3]. The expansion of its beautiful flowers coincides with the period of excessive tourism in coastal areas of the Mediterranean region; therefore, excess of floral sampling, tourist trampling, alteration, and dune erosion have seriously threatened populations of P. maritimum [4][5][6][7][8], which are expected to be further affected by sea-level rise and human-induced impacts [9,10]. Additionally, attention from the international scientific community has been given to the use of P. maritimum as a commercial, ornamental plant [11,12].…”

Does the gathering of shellfish affect the behavior of gastropod scavengers on sandy beaches? A field experiment

“…The effect of trampling on shores has been extensively studied (e.g., Farris et al, 2013;Davenport and Davenport, 2006;Beauchamp and Gowing, 1982) and it is associated with economic activities such as tourism and commercial harvesting in coastal areas (Sarmento and Santos, 2012;Schlacher and Thompson, 2012;Veloso et al, 2008). It has been reported in literature that human trampling and shellfish harvesting, clearly have negative effects on the fauna of sandy beaches (e.g., Farris et al, 2013;Sheehan et al, 2010;Moffett et al, 1998) and this is considered to be a major cause of biodiversity loss in protected areas (Andersen, 1995).…”

“…It has been reported in literature that human trampling and shellfish harvesting, clearly have negative effects on the fauna of sandy beaches (e.g., Farris et al, 2013;Sheehan et al, 2010;Moffett et al, 1998) and this is considered to be a major cause of biodiversity loss in protected areas (Andersen, 1995).…”

Evidence for age-structured depensation effect in fragmented plant populations: The case of the Mediterranean endemic Anchusa sardoa (Boraginaceae)

“…As a model species we chose A. sardoa, a narrow endemic plant that grows in a limited area where the touristic impact is very high both in habitat loss and in human trampling (Farris et al, 2013). Genetic data showed that this species has low levels of genetic variation due to bottleneck events caused by loss of habitat and natural stochastic factors (Bacchetta et al, 2008;Coppi et al, 2008).…”