Molecular Biogeochemistry of Soil Organic Matter with Environmental Change

拟议的研究计划将使用一系列新的分子工具，提供有关土壤有机质(SOM)组成、生物地球化学和生态系统功能的详细信息。这些工具由我的研究小组首创，包括使用质谱学(MS)和核磁共振(核磁共振)光谱学的定向和非定向方法；可以说，这是现代科学中可用的两种最先进的结构技术。这些技术将与美国大学的研究人员合作，用于研究从几个长期田间实验中收集的土壤样本中的土壤有机质。该计划还将利用创新的实验室实验来研究土壤有机质的机制。土壤有机质占陆地碳储量的三分之二以上，但目前和预测的环境变化趋势导致了对土壤碳储量命运的不确定性。SOM生物地球化学循环通过支持土壤微生物呼吸和植物光合作用之间的复杂平衡来调节大气二氧化碳，从而在全球碳循环中发挥着不可或缺的作用。以前的研究假设土壤有机质的组成对水分、温度、大气二氧化碳水平和氮沉积的变化高度敏感，以及与局部环境条件有关的差异。例如，大气二氧化碳水平的增加、氮沉积的增加、土壤温度的升高和碎屑沉积的增加都被假设为改变了土壤的生物地球化学过程。然而，关于土壤有机质动态变化与长期环境变化的机制，我们的理解存在差距。因此，迫切需要开发和使用研究工具，能够在分子水平上检测土壤有机质生物地球化学的变化，从而提高对生态系统对环境变化的响应的理解。*拟议的研究计划将研究长期田间土壤有机质的分子生物地球化学，重点是土壤变暖、氮沉积和森林中植物碎屑输入的变化。这些信息将与来自合作大学的信息相结合，并将使分子能够从生态系统、自下而上地了解土壤有机质生物地球化学和生态系统对环境变化的反应。拟议的研究计划还将使用采用创新的MS和核磁共振技术的实验室研究来检查SOM保护机制。学员将通过使用用于监测环境中SOM的新工具的实践培训来发展高度期望的技能。总体而言，这项研究计划将确定环境变化对土壤碳循环的影响，并将形成新的政策和环境管理实践，以确保土壤资源的长期可持续性。

The proposed research program will employ an array of novel molecular tools that provide detailed information about soil organic matter (SOM) composition, biogeochemistry and ecosystem function. These tools, which have been pioneered by my research group, involve both targeted and non-targeted approaches using using mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopy; arguably two of the most advanced structural techniques available in modern science. These techniques will be used to study the SOM in soil samples collected from several long-term field experiments in collaboration with University researchers in the United States. This program will also examine SOM mechanisms using innovative lab-based experiments.******SOM constitutes more than two-thirds of terrestrial carbon stocks yet current and predicted trends with respect to environmental change have resulted in uncertainties about the fate of soil carbon reserves. SOM biogeochemical cycling plays an integral role within the global carbon cycle through the regulation of atmospheric carbon dioxide via the intricate balance between supporting soil microbial respiration and plant photosynthesis. Previous research has hypothesized that SOM composition is highly sensitive to changes in moisture, temperature, atmospheric CO2 levels, and nitrogen deposition, as well as differences related to localized environmental conditions. For example, increases in atmospheric CO2 levels, increased nitrogen deposition, increased soil temperatures and increases in detrital deposition have all been hypothesized to alter soil biogeochemical processes. However, there is a gap in our understanding with respect to the mechanisms of SOM dynamics with long-term environmental change. As such, there is a desperate need to develop and use research tools that can detect shifts in SOM biogeochemistry at the molecular-level that improve the understanding of ecosystem-level responses to environmental change. ******The proposed research program will study the molecular biogeochemistry of SOM from long-term field sites that focus on soil warming, nitrogen deposition, and shifts in plant detrital inputs in forests. This information will be coupled with that from collaborating Universities and will enable a molecule to ecosystem, bottom-up understanding of SOM biogeochemistry and ecosystem-level responses to environmental change. The proposed research program will also examine SOM protection mechanisms using laboratory studies that employ innovative MS and NMR techniques. Trainees will develop highly desired skills via hands-on training with novel tools used to monitor SOM in the environment. Overall, this research program will identify environmental change impacts on soil carbon cycling and will shape new policies and environmental management practices to ensure the long-term sustainability of soil resources.**