The effect of elevated atmospheric CO2 concentration on gross nitrogen dynamics, plant N-uptake and microbial community dynamics in a permanent grassland

大气二氧化碳浓度升高对永久草地总氮动态、植物氮吸收和微生物群落动态的影响

• 批准号: 215493639
• 负责人: Professor Dr. Christoph Müller
• 金额: --
• 依托单位: Institut für Pflanzenökologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2012
• 资助国家: 德国
• 起止时间: 2011-12-31 至 2015-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/215493639?language=en
• 关键词: effect; elevated; atmospheric; CO2; concentration

To predict ecosystem reactions to elevated atmospheric CO2 (eCO2) it is essential to understandthe interactions between plant carbon input, microbial community composition and activity and associated nutrient dynamics. Long-term observations (> 13 years) within the Giessen Free Air Carbon dioxide Enrichment (Giessen FACE) study on permanent grassland showed next to an enhanced biomass production an unexpected strong positive feedback effect on ecosystem respiration and nitrous oxide (N2O) production. The overall goal of this study is to understand the long-term effects of eCO2 and carbon input on microbial community composition and activity as well as the associated nitrogen dynamics, N2O production and plant N uptake in the Giessen FACE study on permanent grassland. A combination of 13CO2 pulse labelling with 15N tracing of 15NH4+ and 15NO3- will be carried out in situ. Different fractions of soil organic matter (recalcitrant, labile SOM) and the various mineral N pools in the soil (NH4+, NO3-, NO2-), gross N transformation rates, pool size dependent N2O and N2 emissions as well as N species dependent plant N uptake rates and the origin of the CO2 respiration will be quantified. Microbial analyses will include exploring changes in the composition of microbial communities involved in the turnover of NH4+, NO3-, N2O and N2, i.e. ammonia oxidizing, denitrifying, and microbial communities involved in dissimilatory nitrate reduction to ammonia (DNRA). Stable Isotope Probing (SIP) and mRNA based analyses will be employed to comparably evaluate the long-term effects of eCO2 on the structure and abundance of these communities, while transcripts of these genes will be used to target the fractions of the communities which actively contribute to N transformations.

为了预测生态系统对大气CO2浓度升高的反应，必须了解植物碳输入、微生物群落组成和活性以及相关营养动态之间的相互作用。在对永久性草地进行的吉森自由空气二氧化碳富集研究中进行的长期观察（> 13年）表明，除了增加生物量生产外，对生态系统呼吸和一氧化二氮（N2 O）生产也产生了意想不到的强烈正反馈效应。本研究的总体目标是了解长期的影响eCO 2和碳输入微生物群落组成和活性，以及相关的氮动态，N2 O的生产和植物N的吸收在吉森FACE研究永久性草地。将原位进行13 CO2脉冲标记与15 NH 4+和15 NO3-的15 N示踪相结合。土壤有机质的不同组分（柠檬酸盐，不稳定的SOM）和土壤中的各种矿物氮库（NH 4+，NO3-，NO2-），总氮转化率，池大小依赖的N2 O和N2排放量以及N物种依赖的植物氮吸收率和CO2呼吸的起源将被量化。微生物分析将包括探索参与NH 4+、NO3-、N2 O和N2周转的微生物群落组成的变化，即氨氧化、硝化和参与异化硝酸盐还原为氨（DNRA）的微生物群落。稳定同位素探测（SIP）和mRNA为基础的分析将被用来重新评估eCO 2对这些社区的结构和丰度的长期影响，而这些基因的转录本将被用来针对社区的积极贡献N转换的馏分。

项目成果

Dynamics of soil CO2 efflux under varying atmospheric CO2 concentrations reveal dominance of slow processes

• DOI: 10.1111/gcb.13713
• 发表时间: 2017-09
• 期刊: Global Change Biology
• 影响因子: 11.6
• 作者: Dohyoung Kim;R. Oren;James S. Clark;S. Palmroth;A. C. Oishi;H. McCarthy;C. Maier;K. Johnsen