Do climate, resource availability, and grazing pressure filter floristic composition and functioning in Alpine pastures?

We studied the floristic composition in the pastures of the Southern Alps (Trento Province, Italy). One hundred and five plots in seven different pasture plant communities were sampled: (1) nitrophilous, (2) montane mesic, (3) subalpine mesic, (4) calcareous montane, (5) calcareous subalpine, (6) acid montane, and (7) acid subalpine pastures. Forward selection and variation partitioning were applied to identify the most important factors controlling the species composition and plant traits in the pastures. Aggregated weighted averages were calculated for each plot using the published values of average height, specific leaf area, and seed mass for each species. Explanatory variables were recorded for each site to reflect climate, soil properties, and grazing pressure. We hypothesised that species composition and functional variation in pastures of the Southern Alps are controlled by three main environmental filters: climate, resource availability, and grazing pressure. We found that var...