DISSERTATION RESEARCH: Plant-microbe effects on soil carbon storage in a changing global environment

我们星球的环境正在发生变化。自工业革命以来，土地利用的变化、化肥的使用和化石燃料的燃烧使大气中的二氧化碳浓度增加了40%，氮素输入增加了12倍。植物和土壤可以减缓或加速这一全球变化，因为它们在吸收和循环碳和养分方面发挥了作用。这项研究阐述了植物-土壤系统中的一个关键因素如何影响碳的储存和释放。土壤中的真菌连接到植物的根上，将土壤中的养分转移到植物中，以换取植物的碳。然而，目前尚不清楚这些真菌是否会促进土壤中碳的净保留或释放。一方面，在CO2浓度升高的情况下，真菌可以保护土壤中的碳。土壤真菌也有可能产生相反的作用，加速碳的分解。这一博士论文改进资助项目将测试这些情景的准确性程度。实验将在明尼苏达州的雪松溪生态系统科学保护区进行，这位博士生在那里进行了她的主要论文研究。这项研究的结果，与学生正在进行的工作相结合，将揭示在不断变化的全球环境中，土壤真菌可能如何影响土壤总碳储量。这项研究不仅将增进对全球变化对碳循环影响的理解，还将提供独特的教育机会。这一奖项将通过稳定同位素分析方面的合作极大地加强博士生的研究生培训-稳定同位素分析是一种研究生态系统中碳流动的新工具-否则是不可能的。通过与在稳定同位素分析方面有丰富经验的Elise Pendall博士(西悉尼大学)合作开展拟议的工作，该学生将在参加美国国家科学基金会资助的犹他大学稳定同位素生物地球化学和生态学课程的基础上，培养强大的技能。发展在生态研究中使用稳定同位素的技能通常也可以增加她将为未来的合作带来的价值。此外，这位研究生将利用她在明尼苏达大学环境研究所Boreas环境领导力项目中的持续领导能力，为理科研究生探索新的职业发展机会，以讨论和练习与非学术受众分享他们的研究。

Our planet's environment is changing. Since the Industrial Revolution, land use change, fertilizer use, and fossil fuel combustion have increased atmospheric carbon dioxide concentrations by 40% and nitrogen inputs twelve fold. Plants and soils could either mitigate or accelerate this global change because of their role in taking up and cycling carbon and nutrients. This research addresses how one key player in plant-soil systems affects carbon storage and release. Fungi in soil connect to plant roots and transfer nutrients from the soil to the plant in exchange for carbon from the plant. However, it is unclear whether these fungi will facilitate net retention or release of carbon in the soil. On the one hand, fungi could protect carbon in soil under elevated CO2 concentrations. It is also possible that soil fungi have the opposite effect, and accelerate decomposition of carbon. This doctoral dissertation improvement grant project will test the extent to which each of these scenarios is accurate. Experiments will take place at Cedar Creek Ecosystem Science Reserve in Minnesota where the Ph.D. student has conducted her main dissertation research. Results from this research, combined with the student's ongoing work, will inform how total soil carbon storage might be affected by soil fungi in a changing global environment.This research will not only advance understanding of global change effects on C cycling but will also provide unique educational opportunities. This award will greatly enhance the Ph.D. student's graduate training through collaboration in stable isotope analysis - a novel tool for studying flow of C through ecosystems - which would not be possible otherwise. Through performing the proposed work in collaboration with Dr. Elise Pendall (University of Western Sydney), who has significant experience with stable isotope analysis, the student will develop a strong skill set, building off her participation in the NSF-funded Stable Isotope Biogeochemistry and Ecology course at the University of Utah. Developing skills in using stable isotopes in ecological research could also generally increase the value she would bring to future collaborations. Additionally, the graduate student will leverage her ongoing leadership with the Boreas Environmental Leadership Program at the University of Minnesota's Institute on the Environment to explore new professional development opportunities for graduate students in the sciences to discuss and practice sharing their research to non-academic audiences.