Quantifying plant species diversity in coastal dunes: a piece of help from spatially constrained rarefaction

摘要: Since coastal dunes are one of the most vulnerable landscapes in Europe, their maintenance requires specific conservation and monitoring programmes. In this paper, dune systems two natural parks located central Italy were analyzed aiming at: (1) assessing diversity patterns all vascular species, endemic alien taxa plant communities along coast-to-inland gradient; (2) comparing these between sections characterized by different dynamical processes (accreting, stable erosive coasts); (3) testing differences induced methodological approach used to characterize patterns. Twenty-one transects randomly positioned perpendicular shoreline whole area (30 km length), full spectrum was sampled. Patterns assessed using spatially explicit methods, namely spatial constrained rarefaction (SCR), able avoid confounding effect autocorrelation. The results show that species richness varied significantly gradient with highest values at level mobile transition dunes. Species higher than those found accreting fact, sand dynamics (accumulation as well erosion) create periodic vegetation disturbances affecting composition variability succession. SCR methodology avoided overestimation when compared classical curves. Our findings pinpointed a highly structured mosaic which represent compositional heterogeneity. Local managers encouraged consider for planning adequate strategies.