Functional diversity of alpine plant communities: A case study of plant height

Functional diversity (functional richness, evenness, divergence) of plant height was studied for the four alpine communities (alpine lichen heaths, Festuca varia grasslands, Hedysarum-Geranium meadows, and alpine snowbed communities) in Teberda Reserve, the NW Caucasus. We tested the hypothesis that functional divergence is higher when plants are taller and communities are more productive. For each species we measured mean plant height, biomass, and calculated community-weighted mean height values (CWM). Plant abundance influenced strongly on the values of functional diversity indices. Contrary to our hypothesis, we showed that in the short, low productive alpine snowbeds functional evenness was significantly lower, but functional divergence higher than in the more tall and productive communities, e.g. Festuca varia grasslands. Above-ground production positively correlated with functional richness in the general analysis of all data, but this correlation is not detected within communities. Functional evenness was not related to community production. Unimodal relationship between functional divergence index and above-ground biomass was showed only for the Festuca varia grasslands (maximal divergence is observed on plots with the middle biomass).