土壤氧化亚氮通量对增温的响应及其微生物学机制：以水分条件不同的两种高寒草地为例

项目名称： 土壤氧化亚氮通量对增温的响应及其微生物学机制：以水分条件不同的两种高寒草地为例

项目编号： No.41501265

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 地质学

项目作者： 陈永亮

作者单位： 中国科学院植物研究所

项目金额： 20万元

中文摘要： 气候变暖导致的土壤氧化亚氮(N2O)释放可能在调节大气N2O浓度中扮演重要角色。然而，目前学术界对于调控土壤N2O通量的微生物机制的认识还相对薄弱。为此，本项目以两种水分条件完全不同的高寒草地生态系统为对象，基于国际上正在倡导的Coordinated Distributed Experiments(CDE)设计方案，采用完全一致的实验设计在高寒草原和高寒沼泽草甸中开展增温实验研究，考察增温对两种生态系统中土壤N2O通量、土壤硝化反硝化潜势和N循环功能微生物(氨氧化细菌，氨氧化古菌和反硝化细菌)丰度和群落结构的影响。同时，基于结构方程模型分析不同自变量(土壤理化性质、土壤硝化反硝化潜势、土壤N循环功能微生物丰度和群落结构)与土壤N2O通量之间的定量关系。本项目的实施有望阐明高寒生态系统土壤N2O通量对增温的响应及其微生物学机制，并为理解气候变暖背景下高寒生态系统土壤氮循环的变化提供科学基础。

中文关键词： 氧化亚氮；全球变化；氨氧化细菌；氨氧化古菌；反硝化细菌

英文摘要： Nitrous oxide (N2O) emissions induced by climate warming may play an important role in regulating atmospheric N2O concentrations. However, our understanding of underlying microbial mechanisms of soil N2O flux remains limited. In this project, we will focus on two types of alpine grasslands with completely different moisture conditions, carry out experimental warming studies in alpine steppe and alpine swamp meadow using the same experimental design based on the coordinated distributed experiments (CDE) design scheme, and try to examine the effects of warming on soil N2O flux, soil potential nitrification rates and denitrification rates, abundance and community structures of soil N cycling microorganisms (ammonia oxidizing bacteria, ammonia oxidizing archaea and denitrifying bacteria). Furthermore, we will use structural equation modeling (SEM) to analyze the quantitative relationships between soil N2O flux and independent variables such as soil properties, soil potential nitrification and denitrification rates, soil N-cycling microbial abundance and community structures. This project could enhance our knowledge about the responses of soil N2O flux to experimental warming and their underlying microbial mechanisms, and provide important scientific basis for understanding the dynamics of the soil N cycle in alpine grasslands under warming scenarios.

英文关键词： nitrous oxide;global change;ammonia oxidizing bacteria;ammonia oxidizing archaea;denitrifying bacteria