The Impact of Extensive Sheep Grazing on the Population and Individual Traits of Trollius altissimus Crantz

The montane glades in the Polish Carpathians were created centuries ago and have lasted mainly as a result of mowing and grazing. The observed abandonment of traditional methods of tillage in the last century led to adverse changes in vegetation cover, including a decrease in floristic diversity and the disappearance of many plant species and associations. One of a rare mountain taxa in Poland is the alpine globeflower Trollius altissimus Crantz. The investigations were carried out between June and September 2014 in the Hala Długa glade (Gorce Mts.) at two 36 m2 plots: extensively grazed (P1) and unmanaged (P2). Light intensity, abundance and density of individuals and ramet clusters were significantly greater in the extensively grazed plot, whereas height of plant canopy, length of basal leaf petioles, width of leaf lamina, number and length of generative stems, number of flowers and follicles achieved higher values in the unmanaged plot. The structure of developmental stages and number of basal leaves did not differ remarkably between the studied sites. Also, the soil properties in both plots were very similar. The studies show that extensive sheep grazing has a positive influence on Trollius altissimus. In the studied locality such management contributes to the gradual spreading of this species. However, too intensive pasturage might eliminate this species as it has never been observed in any of the permanently grazed patches in the vicinity.