PostDoctoral Research Fellowship

这个博士后研究奖学金的重点是在阿拉斯加高地草丛苔原生态系统碳平衡的土壤变暖和干燥的作用？不连续多年冻土带。PI假设，由于冻土带土壤碳储量暴露于更高的温度和更干燥的条件下，将发生更大的有机质降解和CO2通量增加到大气中。拟议的研究涉及土壤温度和地下水位深度的实验操作，在已经建立了变暖实验的实验区。除了检查干燥的额外影响，以及干燥和变暖的综合影响，对CO2通量的大小，PI将（1）测量呼吸CO2的碳-14签名，以确定？年龄？（2）调查深层与浅层土壤对CO2通量的贡献;（3）研究土壤分解增加对养分循环和植物生长的影响。成果将在会议上、在同行审查的出版物中以及通过公共外联讲座传播。PI将在赞助科学家指导本科生？的实验室，并与研究生和本科生在该领域的工作。

This postdoctoral research fellowship focuses on the role of both warming and drying of soils on ecosystem carbon balance in upland tussock tundra in Alaska?s discontinuous permafrost zone. The PI hypothesizes that as tundra soil carbon reserves are exposed to higher temperatures and drier conditions, greater organic matter degradation will occur and CO2 fluxes to the atmosphere will increase. The proposed research involves experimental manipulations of both soil temperature and water table depth, in experimental plots that already have been established for a warming experiment. In addition to examining the additional effect of drying, and the combined effect of drying and warming, on the magnitude of CO2 fluxes, the PI will (1) measure the carbon-14 signature of the respired CO2 to determine the ?age? of the organic matter that is being decomposed, (2) investigate the contribution of deep versus shallow soil layers to CO2 fluxes, and (3) examine consequences of increased soil decomposition on nutrient cycling and plant growth. Results will be disseminated at conferences, in peer-reviewed publications, and through public outreach lectures. The PI will mentor undergraduates in the sponsoring scientist?s laboratory, and work with both graduate and undergraduate students in the field.