The Influence of Surrounding Arable Fields on the Species Diversity and Composition of Isolated Mountain Mesic Grassland Patches

This study aimed to determine the impact of arable fields on the diversity and species composition of isolated meadow patches of the order Arrhenatheretalia . The study was conducted in the Sowie Mountains and the adjacent hills (SW Poland). The species composition of the vegetation was analyzed along transects designated from the edge up to 33 m into the meadow patches. The species composition varied significantly in zones directly affected by arable fields, proving their strong negative impact on the vegetation of the mesic grasslands examined. The highest values of the diversity index were recorded 9 m away from the edge, while the lowest values were found in the direct influence zone of arable fields—2 m from the edge. In the case of apophytes, synanthropic species of local origin, the lowest values were recorded within 1 m and the highest values were recorded within 9 m. A significant change in the percentage of graminoids and dicotyledonous herbs was found between 9 m and 33 m from the edge. The study found no significant differences in habitat parameters measured with ecological indicators. Species of the Artemisietea vulgaris class effectively penetrate deep into grassland patches and can visibly degrade their vegetation.