The Countryside Council for Wales has published a report of atmospheric nitrogen impacts on saltmarsh habitats. CCW Science Report 995 is a review of the relative contributions of atmospheric and aqueous sources to UK salt marshes. The report provides advice on which end of the current nitrogen critical load range (20 - 30kgN/ha/year) to apply to different areas of saltmarsh when assessing nitrogen deposition impacts.
Critical loads are used by the environment agencies, conservation agencies and others as benchmarks against which to assess the potential impacts of atmospheric deposition. Deposition of sulphur and nitrogen compounds can contribute towards acidification and both should be taken into account when assessing potential acidification impacts.
We have now published a new tool on APIS to calculate exceedance of the acidity critical load function and for comparing nitrogen and/or sulphur deposition from a source to the critical load function. The method has been agreed by the environment agencies and conservation agencies.
The UK’s leading web database on the impacts of air pollution on the natural environment, APIS, has been given a makeover – it’s now easier than ever to search for the information you want.
APIS is freely available and provides users with a one-stop-shop to evaluate the impact of air pollution on natural habitats. It is used by the UK’s air pollution regulators and local planning authorities to evaluate air pollution impacts as part of their consenting or permitting work.
The new, improved APIS also provides site specific data on nitrogen and acid deposition across the whole UK network of protected sites. Pollutant deposition and concentration data is available for all locations through a ‘search by location’ tool. Each Area/Site of Special Scientific Interest is now listed as well as the UK’s areas of European importance, which were previously available.
JNCC has recently published an analysis of national vegetation data sets in relation to nitrogen deposition. The study clearly demonstrated significant changes in the abundance of individual species and variables describing habitat structure and function as a result of N deposition. This, together with previous evidence from surveys and experiments, provides clear evidence of impacts of N.