Vegetation response to long-term extensive sheep and goat grazing in dry grasslands

Abstract In this study, we examined the impact of the regularity of low-intensity grazing on vegetation dynamics of dry grasslands through 24 years monitoring of 127 permanent plots. The regularity of grazing in each permanent plot was defined as the ratio of the number of years in which grazing occurred to the number of years in which the plot was studied. From a nature conservation perspective, it was positive that regular grazing led to a reduction in woody plant cover. However, the cover of Red List (threatened) species significantly decreased with increasing grazing regularity. A negative correlation was found between monocotyledonous plant cover, especially grasses, and both the cover and number of Red List species. Although grazing regularity had no statistically significant influence on monocotyledonous plant cover, it was linked to reduced cover of dicotyledonous species. Additionally, no relationship was detected between the grazing regularity and cover of the target dry grassland Festuco-Brometea species or ruderal species. No direct relationships were identified between grazing regularity and overall vegetation conditions, as summarized by correlation coefficients for diversity, stability, and synchrony, but dry grassland community stability decreased with increasing synchrony, and synchrony was positively influenced by community diversity or species richness. At some sites, there was a very close positive correlation between community stability and total community cover and between diversity and M-Godron instability. Our findings show that while grazing regularity does not consistently dictate vegetation conditions, it significantly influences specific plant groups and interacts with community stability in complex ways. Low-intensity grazing appears to be an effective management strategy for dry grasslands, especially when combined with multi-year rest periods or occasional mowing, while continuous grazing generally suppresses dicotyledonous plants, including a number of threatened species.