The short-term impacts of cessation of grazing on plants and land snails in grasslands in the west of Ireland

The Burren in western Ireland is famous for its biodiversity. It is well accepted that the high biodiversity of the region is linked strongly to its agricultural traditions. However, there are significant changes happening in the landscape including a major expansion of hazel scrub into grazing land. This is due, at least in part, to changes which have occurred in farming in recent decades. To provide some evidence-based insight into this issue, this study investigated the effects that the complete cessation of grazing in Burren grasslands would have on biodiversity – with the focus on vascular plant and land snail communities. Large changes were recorded from within fenced grassland exclosures (with more mixed pictures emerging for scrub and woodland). A significant decrease was seen in both species richness and diversity for the plants in the grasslands, along with a significant increase in the amount of litter present. In the case of the snails, however, abundance increased significantly inside the fenced plots, while there was only a very small change in the controls. Shifts in community structure were also evident. It is likely that the molluscs benefitted from the higher vegetation and denser litter, providing them with food, shelter and moisture.