青藏高原高寒草甸温室气体排放对增温和降水改变的响应

项目名称： 青藏高原高寒草甸温室气体排放对增温和降水改变的响应

项目编号： No.31300415

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 生物科学

项目作者： 张振华

作者单位： 中国科学院西北高原生物研究所

项目金额： 26万元

中文摘要： 研究表明增温和降水的改变对草地生态系统碳、氮循环过程有着显著影响。青藏高原作为世界的第三极，被认为是气候变化的敏感区域。由于高寒草甸是青藏高原的主体，掌握增温和降水改变对青藏高原高寒草甸生态系统温室气体排放的影响机制，将有助于科学估算未来气候变化背景下青藏高原温室气体排放的贡献量。本研究依托海北高寒草甸生态系统定位站，以高寒草甸为研究对象，采用增温(对照，增温)和改变降水(减水50%，对照，增水50%)两因素完全随机区组实验设计，利用静态箱-气相色谱法，研究增温和降水改对高寒草甸生态系统生长季和非生长季尤其是冻融期温室气体排放规律的影响，量化温室气体的全年排放量；结合对土壤环境因子、团粒结构、微生物生物量、矿质氮以及植被净初级生产力等因素的研究，分析高寒草甸温室气体排放对水热条件改变的敏感性以及主要驱动因子，为准确估测未来气候变化背景下，高寒草地生态系统温室气提排放提供理论依据。

中文关键词： 增温；降水；温室气体；驱动因子；高寒草甸

英文摘要： Temperature increases and precipitation changes are both expected to alter grassland ecosystem processes, such as carbon and nitrogen biogeochemical cycles. The Qinghai-Tibetan Plateau, which is regarded as the third pole of the word, is believed to be particularly sensitive to global climate changes. Alpine meadow embodies the dominant grassland type of the Qinghai-Tibetan Plateau. Therefore, it is critical to understand the effects of warming and alter precipitation to greenhouse gases in an alpine meadow (especially in non-growing season), which will contribute to assess the contribution of the greenhouse gases emissions from alpine meadow ecosystems. A two-way factorial design (warming: control, warming; precipation(50% reduction of precipitation, control, 50% increase of precipitation) was used to assess how greenhouse gases emissions are affected by warming and precipitation changes and to quantify the annual emissions from an alpine meadow on the Qinghai-Tibetan Plateau. Furthermore, we also study the effects of warming and alter precipitation on soil temperature,soil moisture, soil aggregate structure, soil mineral nitrogen and plant net primary productivity, to explore the mainly control factors of the responses of greenhouse gases on temperature increase and precipitation changes. This study will contr

英文关键词： warming；precipitation；greenhouse gases；driving factors；alpine meadow