Nitrogen deposition effects on carbon dioxide and methane emissions from temperate peatland soils

Citation
R. Aerts et H. De Caluwe, Nitrogen deposition effects on carbon dioxide and methane emissions from temperate peatland soils, OIKOS, 84(1), 1999, pp. 44-54
Citations number
71
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Environment/Ecology
Journal title
OIKOS
ISSN journal
0030-1299 → ACNP
Volume
84
Issue
1
Year of publication
1999
Pages
44 - 54
Database
ISI
SICI code
0030-1299(199901)84:1<44:NDEOCD>2.0.ZU;2-K
Abstract
Northern peatlands are important sources of carbon dioxide and methane emis sions to the atmosphere. Increased atmospheric N deposition may have a sign ificant impact on the emission of these greenhouse gases. We studied CO2 an d CH4 emissions from untreated temperate pc at soils from a eutrophic and a mesotrophic Fen in a high N deposition area (the Netherlands) and from a m esotrophic fen in a low N deposition area (north-cast Poland). In addition, we investigated the effects of N, P and glucose amendments on the emission s of CO2 and CH4 from these soils. Nitrogen availability (extractable NH4+) in untreated pent from the high N area was 2.5-7.5 times higher than in the low N area, whereas the pH was 0. 9-1.7 units lower. Using 6-week laboratory incubations of peat columns, we found that mean daily CO2 emission from untreated peat soils from the high N area was lower than that from the low N area. Both linear and multiple re gression analysis shelved that CO2 emission was positively related to soil pH (r(2) = 0.64). Additional N supply led to pn reduction and to lower CO2 emission, especially in the low N peat soils. Thus, increased atmospheric N deposition lends, probably as a result of soil acidification, to fewer CO2 emission. Although glucose amendments resulted in increased CO2 and CH4 em ission, we did not find evidence that this was caused by increased minerali zation of native pest. Mean daily CH4-C emission was about 1-2 orders of ma gnitude lower than mean daily CO2-C emission. In the untreated peat soils f rom the high N eutrophic site, methane emission was higher than in the high N mesotrophic site and in the low N mesotrophic site. Linear regression an alysis showed a positive relation between methane emission and soil fertili ty variables (r(2)=0.41-0.55), whereas a multiple regression model revealed that methane emission was determined by N-related soil chemistry variables (r(2) = 0.93). Increased nutrient supply initially resulted in higher meth ane emission from soils of both mesotrophic sites, but there was no effect on the high N eutrophic soil. These results show that increased atmospheric N deposition leads to increased methane emission from low-fertility pent s oils. However, the ultimate effect of atmospheric N deposition on trace gas emissions and thereby on global warming is determined by the balance betwe en the ratios of the change in CO2-C emission and CH4-C emission and the ra tio of their global warming potentials (1:21).