International: Using 13C NMR spectroscopy to study the influence of litter chemistry on soil organic matter formation in forests

森林是土壤有机质的重要储存库，在全球范围内具有重要的碳吸收作用；然而，今天和未来森林中发生的变化有可能扰乱这些生态系统的碳平衡。例如，温带森林中优势树种的特性正因气候、火灾制度以及虫害或病原体暴发的人为变化而改变。对于这些树种组成的变化将如何影响土壤有机质的动态，我们知之甚少。这一建议解决了有关土壤有机质形成和顽固性的基本问题和假设。结合正在进行的波兰普通花园土壤有机质特性的互补分析，该提案？碳-13核磁共振研究为研究凋落物化学多样性对土壤有机质来源和动态的影响提供了新的思路。更广泛的影响：这项工作结果的一个应用将是利用树种凋落物化学的变化来预测树种组成变化对森林土壤有机质动态的影响。准确估计森林碳预算对美国和国外的碳管理工作至关重要，包括碳信用交易和碳补偿销售。通过与Ingrid博士Kögel-Knabner（慕尼黑工业大学）一起进行这项研究，美国研究小组将在美国和欧洲机构之间建立新的关系，并使两种高度专业化的技术得以利用，包括物理土壤分选和碳-13核磁共振波谱。

AbstractOISE-0754731David Eissenstat, Penn StateForests are substantial reservoirs of soil organic matter and are globally significant in the absorption of Carbon; yet changes taking place in forests today and in the future threaten to perturb the Carbon balance of these ecosystems. For example, the identity of dominant tree species in temperate forests is being altered by human-driven changes in climate, fire regimes, and pest or pathogen outbreaks. Very little is known about how these alterations in tree species composition will impact the dynamics of soil organic matter. This proposal addresses fundamental questions and hypotheses regarding soil organic matter formation and recalcitrance. In combination with on-going, complementary analyses of soil organic matter properties at the Polish common garden, this proposal?s Carbon-13 nuclear magnetic resonance studies are well positioned to provide new insights regarding the impacts of chemical diversity of plant litter on soil organic matter sources and dynamics.Broader impacts: One application of the results of the work would be to use variation in litter chemistry among tree species to predict the impacts of shifts in tree species composition on soil organic matter dynamics in forests. Accurate estimates of forest Carbon budgets are critical to efforts in the U.S. and abroad to manage Carbon, including trading of Carbon credits and sales of Carbon offsets. By conducting this research with Dr. Ingrid Kögel-Knabner (Technical University of Munich), the U.S. research group will establish new relationships between U.S. and European institutions and enable the utilization of two highly specialized techniques, including physical soil fractionation and Carbon-13 nuclear magnetic resonance spectroscopy.