Gao Y H, Ma G, Zeng X Y, Xu S Q, Wang D X
J Environ Biol. 2015 Jan;36(1):261-5.
An incubation experiment was conducted to examine the effects of nitrogen (N) application on microbial respiration in alpine meadow and alpine shrub soils from eastern of Qinghai-Tibetan Plateau. Four different levels of nitrogen fertilization were selected in this study: control (CK, 0 mg N g(-1)), low (LN, 0.04 mg N g(-1)), medium (MN, 0.16 mg N g(-1)), high (HN, 0.4 mg N g(-1)). The results showed that microbial respiration was higher in alpine shrub than in alpine meadow soil, regardless of the rate of N application. Total microbial respiration overthe course of incubation period decreased in both soils with HN and MN treatments relative to control, but no significant differences were observed in soils with LN treatments. There was significantly positive correlation between total microbial respiration and dissolved organic carbon concentration in both soils. The results indicated that DOC may be a useful indicator of microbial respiration rate in alpine soils and the increasing N inputs could drive a negative feedback to global warming effects of carbon dioxide emitted to the atmosphere in alpine soils.
开展了一项培养实验，以研究施氮对青藏高原东部高寒草甸和高寒灌丛土壤中微生物呼吸作用的影响。本研究选取了四种不同的施氮水平：对照（CK，0毫克氮/克）、低氮（LN，0.04毫克氮/克）、中氮（MN，0.16毫克氮/克）、高氮（HN，0.4毫克氮/克）。结果表明，无论施氮量如何，高寒灌丛土壤中的微生物呼吸作用均高于高寒草甸土壤。与对照相比，在培养期内，HN和MN处理的两种土壤中总微生物呼吸作用均下降，但LN处理的土壤中未观察到显著差异。两种土壤中总微生物呼吸作用与溶解有机碳浓度之间均存在显著正相关。结果表明，溶解有机碳可能是高寒土壤中微生物呼吸速率的一个有用指标，增加氮输入可能会对高寒土壤中排放到大气中的二氧化碳的全球变暖效应产生负反馈。
