The impact of nitrogen on forest soils and feedbacks on tree growth

Authors
Citation
Ba. Emmett, The impact of nitrogen on forest soils and feedbacks on tree growth, WATER A S P, 116(1-2), 1999, pp. 65-74
Citations number
39
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Environment/Ecology
Journal title
WATER AIR AND SOIL POLLUTION
ISSN journal
0049-6979 → ACNP
Volume
116
Issue
1-2
Year of publication
1999
Pages
65 - 74
Database
ISI
SICI code
0049-6979(199911)116:1-2<65:TIONOF>2.0.ZU;2-E
Abstract
The effects of pollutant nitrogen on forest soils and the potential feedbac ks on tree growth are discussed using data from recent plot and catchment m anipulation studies. Results indicate that N applied to the soil affects bo th soil N transformations and base cation status in some forest soils. Whil st reductions in tree growth are infrequently reported, a greater understan ding of the effect of increased N deposition on soil N transformations, and associated changes in soil acidification and nutritional balance, is essen tial if sensitive stands are to identified. In particular, the factors cont rolling soil N accumulation rates and thus the onset of nitrate leaching ar e not clearly understood with increased nitrogen availability potentially i ncreasing nitrogen accumulation due to abiotic fixation and lignolytic enzy me suppression, whilst the onset of nitrification as the C/N ratio of fores t floor material declines, may reduce N retention efficiency. The switch fr om increased to decreased tree growth rate in response to N additions in so me experiments highlights the need for long-term studies as a necessary com ponent of future research.