title: A five-year study of the impact of nitrogen addition on methane uptake in alpine grassland.
abstract: It remains unclear how nitrogen (N) deposition affects soil methane (CH4) uptake in semiarid and arid zones. An in situ field experiment was conducted from 2010 to 2014 to systematically study the effect of various N application rates (0, 10, 30, and 90 kg N ha(-1) yr(-1)) on CH4 flux in alpine grassland in the Tianshan Mountains. No significant influence of N addition on CH4 uptake was found. Initially the CH4 uptake rate increased with increasing N application rate by up to 11.5% in 2011 and then there was gradual inhibition by 2014. However, the between-year variability in CH4 uptake was very highly significant with average uptake ranging from 52.9 to 106.6 μg C m(-2) h(-1) and the rate depended largely on seasonal variability in precipitation and temperature. CH4 uptake was positively correlated with soil temperature, air temperature and to a lesser extent with precipitation, and was negatively correlated with soil moisture and NO3(-)-N content. The results indicate that between-year variability in CH4 uptake was impacted by precipitation and temperature and was not sensitive to elevated N deposition in alpine grassland.
authors: State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China.|College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China.|University of the Chinese Academy of Sciences, Beijing 100039, China.
authors: Ping
authors: P
authors: Yue
authors: State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China.
authors: Kaihui
authors: K
authors: Li
authors: State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China.
authors: Yanming
authors: Y
authors: Gong
authors: State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China.
authors: Yukun
authors: Y
authors: Hu
authors: State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China.
authors: Anwar
authors: A
authors: Mohammat
authors: College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China.
authors: Peter
authors: P
authors: Christie
authors: College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China.
authors: Xuejun
authors: X
authors: Liu
mesh_terms: D065966:Absorption, Physicochemical; D002681:China; D065948:Grassland; D006802:Human Activities; D006801:Humans; D006813:Humidity; D008697:Methane / Q000032:analysis* / Q000493:pharmacokinetics; D009584:Nitrogen / Q000494:pharmacology*; D006109:Poaceae / Q000378:metabolism; D011446:Prospective Studies; D011891:Rain; D012621:Seasons; D012987:Soil / Q000737:chemistry*; D013696:Temperature
chemical_list: D012987:Soil; D009584:Nitrogen; D008697:Methane