Workshop on nitrogen deposition, critical loads and biodiversity: scientific synthesis and summary for policy makers

It is clear that nitrogen (N) deposition impacts on the biodiversity and ecosystem services provided by natural and semi-natural ecosystems have been experienced in Europe, North America and Asia over the last 50 years. Impacts are also estimated to increase in line with increasing rates of N deposition in coming decades across the globe, especially in Asia. To improve the assessment of impacts progress is required in the following key areas: the extent of monitoring networks and the measurement of dry and organic deposition; the modelling of N deposition in areas with complex topography; the assessment of impacts on fauna generally and impacts on flora in areas outside the relatively well studied temperate ecosystems; the application of critical load (CL) and level approaches outside of Europe; and the linkage between impacts on biodiversity and important ecosystem services. New indicators are required, in addition to N deposition and critical loads, to demonstrate the wider impacts and to help integrate the biodiversity, air pollution and climate change policy communities.