| Autor: |
Zhao, Zhenzhen1, Dong, Shikui1 dsk03037@bnu.edu.cn, Jiang, Xiaoman1, Liu, Shiliang1, Ji, Hanzhong2, Li, Yu1, Han, Yuhui1, Sha, Wei1 |
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| Zdroj: |
Science of the Total Environment. Aug2017, Vol. 592, p565-572. 8p. |
| Abstrakt: |
Increases in nitrogen (N) deposition along with climate warming can change the dynamics of carbon and nitrogen in the soil, and alter greenhouse gases (GHGs) fluxes. To examine how N deposition and warming affect GHGs (CH 4 , CO 2 and N 2 O) fluxes in alpine grasslands, we conducted experiments in an alpine meadow (AM), alpine-steppe (AS), and alpine cultivated grassland (CG) on the Qinghai-Tibetan Plateau (QTP). We simulated N deposition by treating soil with ammonium nitrate (NH 4 NO 3 ) (8 kg N ha − 1 year − 1 ), a warming treatment using an open top chamber (OTC) was carried out, and a combined treatment of warming and N deposition (8 kg N ha − 1 year − 1 ) was conducted. The GHGs were collected during early, peak, and late plant growing seasons, i.e., May, August, and October of 2015, respectively, using a static chamber. We found, in general, neither N deposition nor warming solely altered CH 4 and N 2 O fluxes in the alpine grasslands. The N deposition under warming conditions reduced CO 2 emission significantly. The reduction of CO 2 emission was most significant in the alpine steppe. The effects of climatic warming and N deposition on the GHGs varied greatly across the grassland types and the growing seasons. The cultivated grasslands were much more unstable than the native grasslands in CH 4 uptake. In can be concluded the N deposition associated with human activities may buffer the CO 2 emission in the alpine grassland ecosystems in terms of climate changes on the QTP. [ABSTRACT FROM AUTHOR] |
| Databáze: |
GreenFILE |
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Full Text from ScienceDirect