PostDoctoral Research Fellowship

这个博士后研究项目的重点是研究土壤变暖和变干对阿拉斯加高地灌丛苔原生态系统碳平衡的作用。S不连续多年冻土带。PI假设，随着冻土带土壤碳储量暴露在更高的温度和更干燥的条件下，将发生更大的有机物降解，大气中的二氧化碳通量将增加。拟议的研究包括对土壤温度和地下水位深度的实验操作，在已经为变暖实验建立的实验地块上进行。除了研究干燥的附加影响，以及干燥和变暖的综合影响，对二氧化碳通量的大小，PI将(1)测量呼出的二氧化碳的碳-14特征，以确定年龄？(2)研究深层和浅层土壤对二氧化碳通量的贡献，以及(3)研究土壤分解加剧对养分循环和植物生长的影响。结果将在会议上、同行评议的出版物上以及通过公共宣传讲座传播。PI将在赞助科学家中指导本科生？并与该领域的研究生和本科生一起工作。

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.