Effects of increasing precipitation and nitrogen deposition on CH4 and N2O fluxes and ecosystem respiration in a degraded steppe in Inner Mongolia, China
Effects of increasing precipitation and nitrogen deposition on CH4 and N2O fluxes and ecosystem respiration in a degraded steppe in Inner Mongolia, China
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DOI：
10.1016/j.geoderma.2012.08.018
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发表时间：
2013-01-01
期刊：
影响因子：
6.1
通讯作者：
Lin, Shan
中科院分区：
文献类型：
--
作者：
Chen, Weiwei;Zheng, Xunhua;Lin, Shan
温带半干旱草原的大部分牧场由于过度放牧而退化。然而，对退化草原间温室气体交换的研究却很少。研究了内蒙古退化草原生长季甲烷（CH4）、氧化亚氮（N2O）和二氧化碳（CO2）作为生态系统呼吸的通量及其对模拟水分有效性和氮供应增加的响应。生态系统呼吸的时间变化(即。CO2通量主要受土壤温度和湿度的影响，而N2O排放主要受土壤湿度的影响。在生长季节，环境退化草原（即没有获得额外的水和氮供应）分别是CH4的汇（-1.41 +/- 0.04 kg C ha(-1)）和N2O的源（0.17 +/- 0.09 kg N ha(-1)）。水和氮供应的增加使N2O的排放显著增加65-94% (p
Most rangelands in temperate semiarid steppes have degraded due to over-grazing. However, the exchanges of greenhouse gases (GHG) between the degraded steppes have been poorly studied. In this study we investigated the fluxes of methane (CH4), nitrous oxide (N2O) and carbon dioxide (CO2) as ecosystem respiration during the growing season and their responses to simulated increases in water availability and nitrogen supply at a degraded steppe in Inner Mongolia, China. Temporal variation of ecosystem respiration (i.e.. CO2 flux) was dominated by the interaction of soil temperature and moisture, whereas N2O emissions were mainly dependent on soil moisture. The ambient degraded steppe (i.e., not receiving additional water and nitrogen supplies) was a sink of CH4 (-1.41 +/- 0.04 kg C ha(-1)) and a source of N2O (0.17 +/- 0.09 kg N ha(-1)) during the growing season, respectively. Increases in water and nitrogen supplies significantly stimulated N2O emissions by 65-94% (p