Environmental Constraints Influence Clonal Traits of Herbaceous Plant Communities in an Alpine Massif

In this paper we assess the relationship between the frequency of clonal traits and environmental factors in plant communities facing abiotic constraints imposed by an alpine environment. The study was conducted in the Vanoise Massif,inner part of the French Alps, at 1,620 to 2,800 m a.s.l. We sampled 169 communities that encounter a broad set of environmental constraints, and that were distributed over the entire Massif. For all species, we documented clonal traits using data available in the literature (e.g., the CLOPLA database), completed by other sources and our own measurements. Four traits that have previously been shown to be correlated with abiotic stress and disturbances were considered: duration of clonal integration, clonal production, spreading rate, and bud-bank size. Clonal characteristics of plant communities (aggregated traits) along the two main environmental gradients (altitude and duration of snow cover) were assessed. The distribution of clonal traits was significantly but weakly correlated with environmental factors. The duration of clonal integration and bud-bank size increased with altitude, and clonal production decreased. The duration of clonal integration and the size of the bud bank were also higher in snow beds. Scree communities were characterized by a high spreading rate and a large bud bank. The duration of integration was unexpectedly shorter in disturbance-prone habitats, and spatial mobility was unexpectedly higher in one of the most stressed habitats.