Respective influence of habitat conditions and management regimes on prealpine calcareous grasslands.

摘要: The calcareous grasslands of the south-western French Alps have been poorly studied, although they provide suitable habitat for rare plant species and communities. separate combined effects on grassland communities conditions (lithology, soil moisture) management regimes (grazing intensity, cutting regime) were studied using constrained ordination techniques (canonical correspondence analysis with variance partitioning). Among explanatory variables considered, most important factor determining floristic composition was lithology, which explained 11.9% variability, followed by grazing intensity (6.0%). Additive lithology 23.9% variability. Species niche amplitude measured conditional variances samples along main axes, in order to define adequate conservation rarest short-lived narrow breadth both gradients.