Multiple drivers of plant diversity in coastal dunes: A Mediterranean experience

In light of the global biodiversity loss, syntheses of the available knowledge about drivers of biodiversity are becoming increasingly important. However, despite the high number of studies analyzing patterns of plant species diversity, few attempts have beenmade to synthesize findingswithin different ecosystems. In this work, the relative role of a wide set of predictors imputable to three conceptual-methodological domains (abiotic, humanmediated disturbance and landscape domain, hereafter AD, DD and LD)was simultaneously analyzed in 644 random plots distributed along the coastal dunes of Central Italy. Native species richness and focal species cover, both field-recorded, were used as response variables. Predictors pertaining to the three domains were derived from both field surveys and high-resolution remotely sensed imagery (LiDAR and orthophotos). To test how AD, DD and LD affect native species richness and focal species cover, a GLM and a linearmodelwere fitted respectively. The three domains were then ranked according to their relative importance. Although the role of the three domainswas always significant, they turned out to unequally contribute to the explanation of native species richness and focal species cover patterns. ForMediterranean coastal dune ecosystems, AD appears to be the key biodiversity driver, followed by DD and LD. Our results suggest that as long as human disturbance is limited, plant diversity will distribute according to species abiotic tolerances, regardless of habitat