(BEGIN) Biodiversity of European Grasslands - the impact of Atmospheric Nitrogen Deposition .

Eutrophication is perhaps the most important threat to European biodiversity. A major source of nutrients to semi-natural ecosystems is atmospheric nitrogen deposition and experiments have suggested that these nutrients may reduce species richness.However, until very recently there was no clear evidence that widespread biodiversity reduction caused by regional air pollution was actually occurring. Stevens et al. (Science, 303, 1876) changed this perception. Described as a 'milestone in global change research', the study (i) showed a dramatic decline in species richness of UK acid grasslands in relation to nitrogen (N) deposition, (ii) linked empirical with experimental research to estimate the timescale of the observed change, and (iii) provided a predictive equation to estimate species richness of similar sites based on N deposition.The current proposal brings together an interdisciplinary team of leading ecologists, biogeochemists and atmospheric chemists to develop and extend this approach. They aim to determine whether N-deposition is seriously impacting species richness on a wider scale across European grasslands and to elucidate the mechanism responsible.We plan to use a multinational and multidisciplinary approach to address the ecological processes that drive biodiversity change in the systems.