SGER: Undergraduate Research in Biogeochemistry: Controls Over the Isotopic Composition of Nitrous Oxide

笑气更为人所知，一氧化二氮(N2O)也是一种极其重要的温室气体，导致全球变暖。森林生态系统发生森林火灾后，导致N2O产生的土壤氮素转化是极其动态的。这个项目将利用最近亚利桑那州弗拉格斯塔夫附近的一场野火来研究这些动态。两类不同的细菌在土壤中产生N2O。由于这些细菌对不同的环境条件很敏感，了解它们对N2O产生的相对贡献对于预测未来的N2O通量很重要。N2O中氮和氧的稳定同位素被认为是导致N2O产生的特定微生物过程的标志，但这一想法从未在现场得到明确验证。这项工作将让本科生参与研究，利用火灾后N2O产生的自然动力学来测试这些同位素“指纹”在多大程度上可靠地表明产生N2O的细菌群是从土壤进化而来的。

Better known as laughing gas, nitrous oxide (N2O) is also an extremely important greenhouse gas, contributing to global warming. Soil nitrogen transformations that lead to production of N2O are extremely dynamic after wildfire in forest ecosystems. This project will examine these dynamics using a recent wildfire near Flagstaff, Arizona. Two distinct groups of bacteria produce N2O in soils. Because these bacteria are sensitive to different environmental conditions, understanding their relative contributions to N2O production is important in predicting future N2O fluxes. Stable isotopes of nitrogen and oxygen in N2O have been proposed as signatures of the particular microbial processes responsible for N2O production, but this idea has never been explicitly tested in the field. This work will involve undergraduate students in research using the natural dynamics of N2O production after fire to test to what extent these isotopic 'fingerprints' reliably indicate the bacterial groups producing N2O evolved from soil.