Skip Navigation

Forestry 1996 69(3):205-214; doi:10.1093/forestry/69.3.205
© 1996 by Institute of Chartered Foresters
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Search for citing articles in:
ISI Web of Science (16)
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by EMMETT, B. A.
Right arrow Articles by REYNOLDS, B.
Right arrow Search for Related Content
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Nitrogen critical loads for spruce plantations in Wales: is there too much nitrogen?

B. A. EMMETT and B. REYNOLDS

Bangor Research Unit, Institute of Terrestrial Ecology Bangor Orton Building, Deiniol Road, Bangor, Gwynedd, LL57 2UP, Wales

We have used the mass balance approach for calculating nitrogen critical loads (CL(N)) to avoid eutrophication for Sitka spruce plantation forestry in Wales. The various approaches for assigning values to the parameters in the mass balance equation are discussed with particular reference to the soil nitrogen immobilization value. A CL(N) value of 11 kgN ha–1 a–1 was calculated for an intensively studied site in Wales of Yield Class 14 on a freely draining acid soil. If this site is assumed to represent a typical spruce stand, application of the CL(N) value means that 97 per cent of the area of coniferous forest in Wales, which is predominantly Sitka spruce, is currently receiving nitrogen deposition in excess of the CL(N). The area of coniferous forest at risk is reduced to 72 per cent if the proposed empirical CL(N) for managed acidic coniferous forests to prevent ecological changes (10–20 kgN ha–1 a–1) is applied and to 45 per cent if the empirical CL(N) to prevent nitrogen saturation, nitrate leaching and depletion of soil base cations is applied (10–25kgN ha–1 a–1). Irrespective of the choice of CL(N) values, the implications of critical load exceedance need urgent investigation. Available information at present indicates that the main known consequence of chronic atmospheric nitrogen deposition to coniferous forest ecosystems is enhanced nitrate and associated aluminium leaching to freshwaters. There is insufficient information regarding the potential adverse effects of eutrophication of soils and waters and of impacts on tree health and production.

Received 1 March 1995.
Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer:
Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.