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Nitrogen deposition induced significant increase of N2O emissions in an dry alpine meadow on the central Qinghai–Tibetan Plateau.
- Source :
-
Agriculture, Ecosystems & Environment . Oct2018, Vol. 265, p45-53. 9p. - Publication Year :
- 2018
-
Abstract
- Atmospheric concentrations of nitrous oxide (N 2 O) have increased over the last 150 years due to human activities. Soils are important source of N 2 O where its production is largely regulated by biological processes. Nitrogen (N) deposition can alter the processes of autotrophic nitrification and denitrification, thus affecting the rate and direction of the soil N 2 O exchange with the atmosphere. It is obvious that atmospheric N deposition has influenced a dry alpine meadow in the Qinghai–Tibetan Plateau (QTP). Therefore, we investigated the effects of N deposition on the annual N 2 O emissions in an alpine meadow of the QTP. The N 2 O flux was measured for 2 years using static chambers and gas chromatography methods at four treatments (N0, background level; N7, add 7 kg N ha −1 yr −1 ; N20, add 20 kg N ha −1 yr −1 ; N40, add 40 kg N ha −1 yr −1 ). We found that high N deposition increased the N 2 O flux, not only in the growing season but also in winter and the spring thaw period. The average annual N 2 O fluxes at N0 and N40 plots were 3.1 and 6.1 μg m −2 h −1 , respectively. Compared with N0, the average annual N 2 O fluxes increased at N7, N20, and N40 plots by 13.7%, 47.6%, and 98.7%, respectively, the N 2 O fluxes in N40 plots increased by 113.6%, 41.6%, and 78.7% during the growing season, winter and spring thaw period, respectively. The emission of N 2 O during the growing season, winter and spring thaw period accounted for 63.2%, 29.9% and 6.9% of annual total emission of N 2 O, respectively. The N 2 O flux correlated significantly with air temperature, soil temperature, soil water content, total nitrogen, total organic carbon, and soil NH 4 + –N content in the alpine meadow. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 01678809
- Volume :
- 265
- Database :
- Academic Search Index
- Journal :
- Agriculture, Ecosystems & Environment
- Publication Type :
- Academic Journal
- Accession number :
- 131182700
- Full Text :
- https://doi.org/10.1016/j.agee.2018.05.031