FUNCTIONAL TRAITS VARIATION IN SNOWBED PLANTS ALONG A SNOW COVER GRADIENT AS A PREDICTION OF ADAPTATION TO CLIMATE WARMING

Snowbed habitats, i.e. topographical depressions or slopes covered by snow for most of the year and colonized by species adapted to short growing season, can be considered as model systems for research addressing the effects of climate change on alpine vegetation. Their particular environmental conditions allow the growth of plant species highly sensitive to warmer temperatures. Currently, great attention is given to functional traits as important carriers of ecological information for vascular plant species. Functional traits also vary within species, reflecting phenotypic adaptations to specific environmental conditions. The quantification of this phenotypic plasticity gives insight on how plants respond to environmental variation such as the reduction of the period of snow cover under climate warming. The aim of this study was to analyze the phenotypic plasticity of functional traits of key snowbed species (specialists and generalists) along a snow cover gradient. We considered leaf and seed traits. We investigated one siliceous and one calcareous snowbed, the first located at Gavia Pass (ca. 2700 m a.s.l., Lombardy region), the second located close to Forcella Travenanzes in the eastern Dolomites (ca. 2680 m a.s.l., Veneto region). In each snowbed, we randomly chose five to six plots in early and late snowmelt areas respectively. We identified five key species on the siliceous bedrock and six on the calcareous ones. For each key species in each snowmelt area we sampled the functional trait attributes of 20 individuals. For leaf nutrient content, the samples were pooled within each plot. We will report the effect of snow cover duration on specific leaf area (SLA), leaf dry matter content (LDMC), leaf phosphorus content (LPC), leaf nitrogen content (LNC) and seed mass of selected snowbed species. The findings on the adaptation potential of functional traits will be discussed against the background of predicted climate warming and consequent reduction of snow cover duration