Effect of grazing on grasslands in the Western Romanian Carpathians depends on the bedrock type.

This study correlated the floristic composition of grassland communities with environmental variation in the Western Romanian Carpathians, focusing on the effect of grazing. Grasslands were sampled using 231 plots each 0.25 km2 in area. Vascular flora, altitude, aspect, slope, bedrock and grazing intensity were recorded for each plot. Data were processed using direct gradient analyses (CCA) and a generalized linear model. The results revealed three distinct communities associated with bedrock, landscape topography and grazing intensity. Grazing changes the floristic composition of grasslands on limestone more than on other types of bedrock. Specifically the floristic composition of the limestone-area plots subjected to low grazing pressure differ significantly from that of the plots of grassland on flysch and volcanic bedrock. When intensively grazed, the floristic composition of chalk grassland does not differ from that of the lightly grazed vegetation growing on flysch or volcanic bedrock. The reasons for this pattern and implications for management are discussed.