文献类型：期刊文献

英文题名：Changes in precipitation regime lead to acceleration of the N cycle and dramatic N2O emission

作者：Zhang, Kerou[1,2,3] Li, Mingxu[4] Yan, Zhongqing[1,2,3] Li, Meng[1,2,3] Kang, Enze[1,2,3] Yan, Liang[1,2,3] Zhang, Xiaodong[1,2,3] Li, Yong[1,2,3] Wang, Jinzhi[1,2,3] Yang, Ao[1,2,3] Niu, Yuechuan[5] Kang, Xiaoming[1,2,3]

第一作者：Zhang, Kerou;张克柔

通信作者：Kang, XM[1]

机构：[1]Chinese Acad Forestry, Inst Wetland Res, Beijing 100091, Peoples R China;[2]Beijing Key Lab Wetland Serv & Restorat, Beijing 100091, Peoples R China;[3]Sichuan Zoige Wetland Ecosyst Res Stn, Zoige Cty 624500, Sichuan, Peoples R China;[4]Chinese Acad Sci, Inst Geog Sci & Nat Resources Res, Key Lab Ecosyst Network Observat & Modeling, Beijing 100101, Peoples R China;[5]Univ Chinese Acad Sci, Beijing 100049, Peoples R China

年份：2022

卷号：808

外文期刊名：SCIENCE OF THE TOTAL ENVIRONMENT

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000740226100015)】；

基金：This paper was supported by the National Natural Science Foundation of China (No. 42041005), the National Nonprofit Institute Research Grant (No. CAFYBB2019SY038), and the Second Tibetan Plateau Scientific Expedition and Research Program (STEP) Grant (No. 2019 QZKK0304).

语种：英文

外文关键词：Nitrous oxide; Precipitation regime; Field experiment; Extracellular enzyme activity; Functional genes

摘要：Alpine meadows on the Qinghai-Tibetan Plateau are sensitive to climate change. The precipitation regime in this region has undergone major changes, "repackaging" precipitation from more frequent, smaller events to less frequent, larger events. Nitrous oxide (N2O) is an important indicator of responses to global change in alpine meadow ecosystems. However, little information is available describing the mechanisms driving the response of N2O emissions to changes in the precipitation regime. In this study, a manipulative field experiment was conducted to investigate N2O flux, soil properties, enzyme activity, and gene abundance in response to severe and moderate changes in precipitation regime over two years. Severe changes in precipitation regime led to a 12.6-fold increase in N2O fluxes (0.0068 +/- 0.0018 mg m(-2) h(-1)) from Zoige alpine meadows relative to natural conditions (0.0005 +/- 0.0029 mg m(-2) h(-1)). In addition, severe changes in precipitation regime significantly suppressed the activities of leucine amino peptidase (LAP) and peroxidase (PEO), affected ecoenzymatic stoichiometry, and increased the abundances of gdhA, narI and nirK genes, which significantly promoted organic nitrogen (N) decomposition, denitrification, and anammox processes. The increase in abundance of these genes could be ascribed to changes in the abundance of several dominant bacterial taxa (i.e., Actinobacteria and Pmteobacteria) as a result of the altered precipitation regime. Decreases in nitrate and soil moisture caused by severe changes in precipitation may exacerbate N limitation and water deficit, lead to a suppression of soil enzyme activity, and change the structure of microorganism community. The N cycle of the alpine meadow ecosystem may accelerate by increasing the abundance of key N functional genes. This would, in turn, lead to increased N2O emission. This study provided insights into how precipitation regimes changes affect N cycling, and may also improve prediction of N2O fluxes in response to changes in precipitation regime.