Session

Wet grasslands are facing severe threats due to agriculture intensification and climate change related decreasing soil water contents. The UNESCO biosphere reserve concept seems to provide fitting solutions to secure the diversity of grasslands, aiming on connecting nature conservation and sustainable economic development. A further strategy is the implementation of agri-environmental schemes (AES) to promote sustainable land use. This study analysed the development of 92 sites belonging to the EU habitat types 6510 (Lowland hay meadows), 6410 (Molinia meadows) and 7230 (Alkaline fens) ten years after a first survey. To detect changes in habitat development we assessed the EU conservation status on site level and compared the results with the prior study. We further conducted vegetation surveys to get more detailed information on diversity measures and species composition. To test for effects of AES measures on the given variables we compared habitat development and plant diversity between sites with different agricultural management. On average, conservation status of the monitored grasslands declined by one rank within the last 10 years in the biosphere reserve. AES management weakened this deterioration although trends were still negative. Furthermore, no influence of AES management on plant diversity or number of threatened species per plot could be found. Conservation status development was worst on Alkaline fens which rely on the wettest and nutrient poorest soil conditions. Differences in habitat type development could be associated to nutrient and water demand of the different plant communities. Alkaline fens showed decreased moisture values on sites where a change in habitat type occurred, indicating negative effects of decreasing soil water contents. Molinia meadows showed higher nutrient levels on sites with a bad conservation status, indicating negative effects of increased nutrient contents. We conclude that AES measures in the current extent are not sufficient to halt habitat deterioration of wet grasslands. Especially Alkaline fens are under acute threat in the biosphere reserve and seem not to be addressed by AES management. To stop negative development additional measures such as an active involvement of farmers and habitat specific management are needed.