Low-level nitrogen deposition significantly inhibits methane uptake from an alpine meadow soil on the Qinghai-Tibetan Plateau
Low-level nitrogen deposition significantly inhibits methane uptake from an alpine meadow soil on the Qinghai-Tibetan Plateau
复制标题
低水平氮沉降显着抑制青藏高原高寒草甸土壤甲烷吸收
DOI：
10.1016/j.geoderma.2013.08.006
复制
发表时间：
2014-01-01
期刊：
影响因子：
6.1
通讯作者：
Li, Yingnian
中科院分区：
文献类型：
--
作者：
Fang, Huajun;Cheng, Shulan;Li, Yingnian
了解氮沉降对土壤甲烷（CH4）吸收的影响对更好地理解陆地生态系统碳(C)动态至关重要。采用静室技术和气相色谱法每周监测土壤CH4通量、土壤温度和土壤湿度。每月测定土壤无机氮库、土壤pH和地上生物量，探讨土壤CH4通量的关键控制因素。结果表明，施氮显著促进了植物生长，改变了土壤充水孔空间（WFPS），但短期内对土壤无机氮储量没有影响。与对照相比，低施氮量显著降低了季节CH4吸收量8.6%。土壤CH4通量主要由土壤WFPS决定，其次是无机氮有效性。施氮增加了土壤WFPS、pH和土壤NO3-储量的贡献。由于对甲烷营养细菌的生化抑制作用较小，氮添加引起的CH4摄取减少可能主要是由于物理扩散的减少。这些结果表明，土壤无机氮是土壤CH4吸收的调节因子，其对土壤CH4吸收的促进或抑制作用取决于陆地生态系统中氮的状况。(C) 2013 Elsevier B.V.版权所有
It is crucial to understand the effects of enhanced nitrogen (N) deposition on soil methane (CH4) uptake to develop a better comprehension of carbon (C) dynamics in terrestrial ecosystems. A two-year field study was conducted to assess the effects of various forms of N (NH4+ and N-3(-)) and associated N deposition rates (0, 10,20 and 40 kg N ha(-1) yr(-1)) on alpine meadow soil CH4 fluxes on the Qinghai-Tibetan Plateau, China. Soil CH4 fluxes, soil temperature, and soil moisture were monitored weekly using the static chamber technique and gas chromatography. Soil inorganic N pools, soil pH and aboveground biomass were measured monthly to examine the key controlling factors of soil CH4 flux. Our results showed that N addition significantly promoted plant growth and changed soil water-filled pore space (WFPS), but did not alter soil inorganic N storages over the short term. Low rates of N addition significantly decreased the seasonal amount of CH4 uptake by 8.6% compared with the control. Soil CH4 fluxes were mainly determined by soil WFPS, followed by inorganic N availability. N addition increased the contribution of soil WFPS, pH and soil NO3- storage. The observed reduction in CH4 uptake caused by N addition may be largely due to a decrease in physical diffusion, as the biochemical inhibition effects on methanotrophic bacteria are minor. These results suggest that soil inorganic N is a regulatory factor of soil CH4 uptake, and its promotion or inhibition to soil CH4 uptake depends on the N status in terrestrial ecosystems. (C) 2013 Elsevier B.V. All rights reserved.