Antarctica as a Model System for Responses of Terrestrial Carbon Balance to Warming

本研究的主要目的是研究南极半岛土壤中碳转化过程和负责这种转化的微生物群落。该研究将检查不同暴露年龄的土壤之间的净生态系统碳平衡，这些土壤已经被退缩的冰川所暴露。这项研究将使用一种新技术来识别活跃与不活跃（可能是冷保存）的土壤微生物群落的个体成员，以便更好地了解南极环境中群落演替的基本过程，以及持续变暖是否会导致群落活跃部分的群落转移。该项目支持了几名研究生和本科生。研究结果将通过同行评议期刊上的出版物和研讨会/讲座传播给科学界，并通过向当地社区进行科学介绍和在小学进行讲座（包括Skype）传播给更广泛的社区。该研究将重点关注南极半岛西部的一个冰川消退系列，该系列提供了初级生产力的强大梯度，并为研究南极海洋环境特有的土壤碳动态提供了平台。实验将使用与对照区配对的开顶室，沿生产力梯度排列。碳通量（流入和流出）将在所有试验室中使用红外气体分析来确定。本研究还将在培养和实验中使用重水（富含18O的水）来鉴定活性和非活性土壤微生物成员。该项目的研究成果将促进植物和土壤微生物生态学、生态系统建模的研究，并促进对南极生态系统因变暖条件而可能发生的变化的理解。

The main goal of this study is to investigate carbon transformation processes and the microbial communities that are responsible for such transformations in soils of the Antarctic Peninsula. The study will examine net ecosystem carbon balance among soils with different exposer ages that have had been uncovered by retreating glaciers. The study will use a novel technique to identify individual members of the soil microbial community that are active versus those that are not active (perhaps cold-preserved) in order to better understand the fundamental processes of community succession in the Antarctic environment and whether continued warming could lead to community shifts in the active portion of the communities. Several graduate and undergraduate students are supported on this project. Findings of the research will be disseminated to the scientific community through publications in peer-reviewed journals and through seminars/lectures, and to the broader community through science presentations to the local community and through lectures in elementary schools (including Skype). The study will focus on a deglaciated sere on the western Antarctic Peninsula, which offers a strong gradient in primary productivity and a platform for investigating soil carbon dynamics specific to the Antarctic maritime setting. The experiment will use open-top chambers paired with control plots, arrayed along the productivity gradient. Carbon fluxes (incoming and outgoing) will be determined in all the plots using infrared gas analysis in experimental chambers. This study will also use heavy water (water enriched with 18O) to identify active versus inactive soil microbial members in incubations and experiments. Findings from this project will advance research in plant and soil microbial ecology, ecosystem modeling and advance understanding of the potential changes in the Antarctic ecosystem due to warming conditions.