Burren National Park, west Ireland, contains globally-significant calcareous wetlands and exceptional floristic diversity for northwest Europe. It is an anthropic landscape that has been grazed at low intensity for several millenia. We studied wetlands in Burren National Park to explore relationships between flooding duration, biomass, and floristic diversity.  In spring 2008, we conducted an inventory of all major wetland basins in the park. At each wetland, we sampled vegetation composition, soils, presence of grazing, and hydrological data at 2 x 2 releve samples along centripetal transects from the edge to interior and conducted repeat photography to document seasonal flooding dynamics. Lab analyses determined soil pH, organic carbon loss-on-ignition, and vegetation biomass. We are currently analyzing patterns and correlates of floristic diversity in the park wetlands as well as preparing a classification and map of the wetland plant communities.

Results/Conclusions

Vascular plant species richness ranged from from 2-24 species / 4m² releve with a decrease in the mean and variance in richness with increasing biomass. Floristic distinctiveness increases with pH, from acid-soil generalists to marl-floor specialist species. Most very rich sites were  in areas where winter livestock grazing has maintained a low sward. Results suggest that conservative management of the national park will need to closely consider the trade offs between strict preservation and the maintenance of the indigenous grazing regime in this anthropic landscape.