Analyse éco-coenotique des prairies édifiées par Carex curvala All. des Carpates roumaines

Abstract This paper deals with the floristic variability and the ecological factors responsible for it in the Carex curvula alpine grasslands. For this purpose a non-hierarchical clustering method based on non-parametric density estimates and the detrended correspondence analysis (DCA) were employed. Most of the 150 releves are grouped in a central, well-defined cluster whereas the other 23 clusters are formed of one or two releves considered as outliers. Primula minima and Loiseleuria procumbens display a good correlation with DCA axis 1, suggesting a complex ecocline from pioneer communities to those featuring dwarf shrubs and high total cover. The DCA axis 2 overlaps on a weak nutrient richness gradient as it is best correlated with the cover of Cerastium alpinum and Potentina aurea subsp. chrysocraspeda. The minimum spanning tree reveals certain dynamic tendencies related with the co-dominance of Primula minima or the increase in dwarf shrub cover.