Site nitrogen action plans (SNAPs) for native woodland sites in Wales

Carnell, E.J.; Pearson, C.; Rowe, E.; Jones, L.; Misselbrook, T.; Perring, M.; Dragosits, U.. 2021 Site nitrogen action plans (SNAPs) for native woodland sites in Wales. Edinburgh, UK Centre for Ecology & Hydrology, 49pp. (UKCEH Project no. 07622) (Unpublished)

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Report to Snowdonia National Park Authority. Air pollution by ammonia and other nitrogen (N) compounds causes damage to habitats and wildlife, especially to sensitive lower plant communities such as lichens and mosses. The SNAPs project investigated the sources of N pollution at five woodland sites in Wales, and assessed how pollution levels and their effects on the woodland could be mitigated. The main source of ammonia at the sites studied was low-intensity beef and sheep farming. While some ammonia disperses over large distances, large amounts of ammonia from a given source are deposited within a few hundred metres, so nearby sources are important. Action is needed to limit regional and international flows of air pollution, but considerable improvements could be made by reducing the emissions from nearby sources of ammonia. The most useful measures are covering slurry stores; hard standing at feeding stations; and injecting slurry into the soil rather than broadcasting onto the ground surface. Some conservation sites are very large, and if particularly sensitive areas can be identified within sites, this could help identify off-site mitigation measures, which can be applied to sources nearest the sensitive area. For woodlands, on-site measures have only limited potential for reducing the ecological impacts of nitrogen pollution. Nitrogen generally increases plant growth and litter production, causing more shading of the ground surface. These effects can be reduced in woodlands by increasing scrub clearance, or grazing. However, these measures may have other effects on the site, and remove very little nitrogen from the system, meaning that it continues to accumulate in the vegetation and soil. Ultimately, nitrogen-sensitive features within woodland sites can only be safeguarded if nitrogen emissions decrease both locally and regionally. This project is part of the Celtic Rainforest Wales project, which is financially supported by LIFE, a financial instrument of the European Community

Item Type: Publication - Report (Technical Report)
UKCEH and CEH Sections/Science Areas: Atmospheric Chemistry and Effects (Science Area 2017-)
Soils and Land Use (Science Area 2017-)
Funders/Sponsors: Snowdonia National Park Authority
NORA Subject Terms: Atmospheric Sciences
Date made live: 30 Oct 2023 16:53 +0 (UTC)

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