A methodological approach for assessing the effects of disturbance factors on the conservation status of Mediterranean coastal dune systems

Abstract

Questions How can the conservation status of Mediterranean coastal dunes be assessed? What is the effect of disturbance factors on it? Location Tyrrhenian coast of Central Italy. Methods Vegetation releves along 164 transects lying perpendicular to the shoreline along the Tyrrhenian coast of Central Italy were used to identify the presence of dune habitats by means of TWINSPAN classification and detrended correspondence analysis. Multiple correspondence analysis was used to analyse relationship between habitats and disturbance factors. The resulting Burt's table was used to build an index (habitat-disturbance, HDi) for analysing this relationship. Based on HDi values, a correspondence analysis (CA) between presence/absence of habitats and disturbances was performed. The overall plant species diversity of dunes was measured with NHDUNE, a modified version of the Shannon index. Multi-way ANOVA procedure was used to investigate effect of single disturbance factors and their interactive effect on NHDUNE. Results Classification and ordination procedures identified four sequential habitats moving from the shoreline to inland: annual vegetation on drift lines characterized by Cakile maritima; embryonic shifting dunes dominated by Elymus farctus; shifting dunes with Ammophila arenaria subsp. australis; back dune grasslands characterized by Ononis variegata. CA showed that disturbance factors influence dune habitats differently. In particular, the Cakile community had a negative relationship with beach tourism and mechanical cleaning; the Elymus community had a positive relationship with beach tourism and mechanical cleaning and a negative relationship with erosion and bathing establishments; the Ammophila community had a negative relationship with mechanical cleaning and bathing establishments and a positive relationship with dune cross-trampling; and the Ononis community had a negative relationship with bathing establishment. According to multi-way ANOVA, single disturbance factors can have different effects on plant species diversity as measured by NHDUNE. However, the overall effect is negative, with erosion as a single factor and the combination of mechanical cleaning and bathing establishments significantly lowering the plant diversity of coastal dune systems. Conclusions The proposed method allows a fast and replicable evaluation of the effects of disturbance factors on the conservation status of Mediterranean coastal dunes, providing the information necessary for development of conservation strategies focusing on a single habitat or on the overall dune system

Shrub Encroachment Effects on Habitat Heterogeneity and Beetle Diversity in a Mediterranean Coastal Dune System

“…Nevertheless, grazing and other disturbances such as trampling can increase abundance and species richness of annual plants, carabids and other insects (e.g. Attorre et al ., ; Damgaard et al ., ; Pedley et al ., ; Brunbjerg et al ., ). Furthermore, in this study, we support evidence that Mediterranean species and habitats have co‐evolved with anthropogenic disturbance (see Nocentini & Coll, , and references therein).…”

Biological Flora of the British Isles: Eryngium maritimum

“…In Italy, the frequency of E. maritimum decreased by nearly 80% in embryonic and yellow dunes, when these dune types were dominated by Carpobrotus acinaciformis (Attorre et al . ).…”

“…On the south-eastern coast of France, the non-native species Carpobrotus edulis forms dense mats that out-compete E. maritimum (Suehs, M edail & Affre 2003). In Italy, the frequency of E. maritimum decreased by nearly 80% in embryonic and yellow dunes, when these dune types were dominated by Carpobrotus acinaciformis (Attorre et al 2013).…”

Rare dune plant species in Samsun Province, Turkey

“…Almost all species in the main dune zone are rare because this zone has similar properties with primary dune zone. In this zone, plant communities tend to be permanent and less exposed to harsh conditions (Maun, 2009;Acosta et al, 2007Attorre et al, 2013), but it was exposed to the high disturbance regarding salt spray, dune movement, and tourism activities. So plant density and diversity gradually decreases.…”