EAPSI: The Temperature Sensitivity of Greenhouse-gas Producing Bacteria at High Latitudes

该奖项将进行的研究将确定产生温室气体甲烷的土壤细菌如何受到长期1-2°C温度升高的影响。该项目是与位于中国长春的东北研究所合作开展的，并将建立在与主持研究员宋长春博士合作的关于温度升高对湿地影响的日益增长的知识基础上。该研究所已经运行了近10年的开放式暖室，其内部温度为1-2°C（与未来几十年的气候变化预测相当）。通过研究这些腔室的影响，研究人员将确定长期温度升高如何影响产生和消耗甲烷的不同类型的细菌。高纬度湿地储存了大量可以释放到大气中的碳，预计未来几年高纬度地区的气温上升幅度将大于低纬度地区。然而，由于这些细菌的甲烷产生和消耗模式的变化，北部湿地的甲烷排放将如何受到气候变暖的影响，还存在一些不确定性。这个基于实地的实验是一个独特的机会，可以更好地了解气候变化对湿地温室气体排放的影响。高纬度湿地在高温下的甲烷产量在科学上是一个不确定的问题，但与全球碳循环有关。了解温室气体排放的通量和驱动因素是东北研究所的一个目标，该研究所维护着开放式顶室，并监测温室气体排放、土壤化学性质和植被参数。我的实验将利用实验变暖室，以及小组先前建立的采样和实验方案，来确定1-2°C变暖对夏季甲烷循环细菌活动的影响。为期8周的研究将包括：1)从中国科学院东北地理与农业生态研究所的开放式恒温箱中收集土壤样本；2)利用反转录定量聚合酶链反应（RT-qPCR）技术分析微生物生产和甲烷氧化相关功能基因的表达。研究结果将有助于预测对气候变化极其敏感的高纬度湿地未来的甲烷排放率。本研究还将进一步比较三江平原（寒冷富有机质）和密西西比河三角洲平原（温暖富有机质）湿地本地微生物群落对全球气候变化的响应。这项研究的结果将表明，在野外条件下，长期变暖如何影响产甲烷菌的活动。该奖项由美国国家科学基金会和中国科技部共同资助，隶属于东亚和太平洋暑期研究所项目，支持美国研究生的暑期研究。

The study to be conducted in this award will determine how soil bacteria that produce the greenhouse-gas methane are affected by a long-term 1-2°C increase in temperature. This project is a collaboration with the Northeast Institute in Changchun, China, and will build upon a growing knowledge base on the impacts of temperature increase on wetlands working with host researcher Dr. ChangChun Song. The Institute has operated open-top warming chambers, which warm the inside 1-2°C (comparable to what is forecasted for climate change over the coming decades), for almost 10 years. By studying the effects of these chambers, the researcher will determine how a long-term temperature increase impacts different types of bacteria that produce and consume methane. High-latitude wetlands store an enormous amount of carbon that could be released to the atmosphere, and high latitudes are predicted to experience a greater temperature increase than low latitudes in the coming years. However, there is some uncertainty on how methane emissions from northern wetlands will be impacted by a warmer climate due to changes in the methane-producing and methane-consuming patterns of these bacteria. This field-based experiment is a unique opportunity to better understand how greenhouse gas emissions from wetlands will be impacted by climate change.The quantity of methane production in high-latitude wetlands under elevated temperatures is a matter of scientific uncertainty, but relevant to the global carbon cycle. Understanding the fluxes and drivers of greenhouse gas emissions is a goal of the Northeast Institute, which maintains the open top chambers, and monitors greenhouse gas emissions, soil chemical properties, and vegetation parameters. My experiment will utilize the experimental warming chambers, as well as sampling and experimental protocols previously established by the group, to determine the impact of 1-2°C warming on methane-cycling bacterial activity during the summer. The 8-week study will include 1) collecting soil samples from open-top warming chambers operated by the Northeast Institute of Geography and Agroecology of the Chinese Academy of Sciences and 2) analysis of the expression of functional genes involved in microbial production and oxidation of methane using the reverse transcription quantitative polymerase chain reaction (RT-qPCR) technique. Results will help predict future rates of methane emission from high-latitude wetlands that are extremely sensitive to climate change. The data will also further a comparative study on responses of indigenous microbial community to global climate change in the Sanjiang Plain (cold and organic-rich) and Mississippi River Deltaic Plain (warm and organic-rich) wetlands. The results from this study will show how methanogen activity is affected by long term warming under field conditions. This award, under the East Asia and Pacific Summer Institutes program, supports summer research by a U.S. graduate student and is jointly funded by NSF and the Chinese Ministry of Science and Technology.