Variation of functional diversity of the herbaceous layer of beech woods along the Apennine ridge (Italy)

In 164 plots (20 x 20 m) we recorded: plant species cover-abundance values, altitude, aspect and slope angle. For each species, we evaluated some categorical traits (occurrence and type of storage organ and vegetative propagation, leaf phenology, type of pollen/spore transfer); then we calculated FD indices for each trait in each plot. Results highlighted that both biogeographical and elevation gradients affected the herbaceous layer species composition, mirroring some significant FD trends. Rao’s Q and FDis showed a positive trend along the biogeographical gradient for leaf phenology and pollination and a negative one for vegetative propagation (as well as FRic). About storage organs, FEve was negatively related to the biogeographical gradient, instead FDiv showed a positive trend. Significant relations were found also between elevation and FEve, Rao’s Q, FDis (decreasing with increase in altitude) concerning pollination. Rao’s Q and FDis of storage organs were negatively related, while FDiv was positively related, to elevation gradient.