Drivers of beta-diversity variation inBromus erectussemi-natural dry grasslands

摘要: Questions What are the main drivers of variation in beta-diversity for Bromus erectus semi-natural dry grasslands habitat 6210(*) at different scales? How should environmental variables and spatial patterns be taken into account to conserve maximum possible within habitat? Location Central Italy. Methods We used 195 vegetation releves distributed three nested extents: a single mountain, mountain chain southern Lazio. Multiple regression on distance matrices was performed using dissimilarity based on: (1) species abundances as response variables; (2) coordinates parameters (altitude, slope, percentage rock stone coverage, aspect, annual rainfall) explanatory variables. The two groups were separately partition variation, jointly assess relative contribution each individual variable. Those found significantly affect to: compare levels between set randomly selected stratified releves; analyse distribution across gradients. These analyses, together with curves describing relationships distances composition dissimilarities, inform management decisions habitat. Results Most variance explained by variables, whose share higher smallest intermediate extent than broadest extent. Community increased proportion differences altitude every Accordingly, all extents, selection or taking minimum included within-habitat beta-diversity, releves. relation aspect rainfall varied extents. Conclusions Our results demonstrate that grassland plans aimed conserving take among which proved critical factor Also, positively levels, scale-dependent patches when selecting conserved study area.