Collaborative Research: MSB: Microbial control of litter decay at the cellulose-lignin interface

这项工作的关键科学意义是在植物凋落物的长期降解和稳定过程中整合微生物群落和化学相互作用，因为目前还没有以全面的量化框架表示的这一知识的工作综合。植物凋落物分解是土壤肥力和碳(C)固持的主要控制因素。人们对了解土壤获得或失去碳的条件越来越感兴趣，部分原因是土壤含有比大气更多的碳，在全球变暖中可能起到缓和或加剧的作用。为了确定这些关系，需要对土壤固碳、植物凋落物化学和分解过程中微生物群落组成和活动之间相互作用的生化机制进行综合的田间、实验室和模拟研究。Moorhead和Sinsabaugh(2006)发展了一个将微生物动力学融入分解过程的新模型--Guild分解模型(GDM)，该模型提出了一系列关于分解过程中植物凋落物化学、C稳定和微生物群落组成和活性之间相互作用的机制的具体假设。这项拟议的研究将通过监测植物凋落物化学以及微生物群落组成和功能在分解过程中的变化，在有和没有添加氮的情况下模拟氮沉积，对这些假说进行实验评估。稳定碳同位素(13C)标记将进一步确定能够代谢植物凋落物特定化学成分的活性微生物的群落组成。这项研究将从机制上深入了解N沉积、CO2升高、植物群落组成变化和气候变化对植物凋落物分解和土壤C固存的影响。在托莱多大学创意教学中心(CCI)的帮助下，一个综合的教育和推广计划将补充这项研究。对于这个项目，CCI将开发一个树叶分解的在线互动模型(IMold)，为5-12年级提供关于分解的教育宣传。参观者将能够沿着时间线直观地看到垃圾作为一个整体或不同的单个垃圾化学成分的分解过程，以了解时间、垃圾类型和环境与事物腐烂的速度或速度的关系。教师和学生将能够在研究人员和其他学校的教室之间建立网络，使他们能够共享数据，提出问题，并就实验进行合作。将建立一个交流中心，以便研究人员和教室可以在类似博客的环境中分享想法和结果，并提出问题。此外，该项目还将为几名本科生和研究生提供培训。托莱多大学和肯特州立大学为科学界代表性不足的群体提供服务，他们将被招募到这个项目中。

The key scientific significance of this work is the integration of microbial community and chemical interactions during the long-term degradation and stabilization of plant litter because there has not yet been a working synthesis of this knowledge expressed in a comprehensive quantitative framework. Plant litter decomposition is the main control on soil fertility and carbon (C) sequestration. There is growing interest in understanding the conditions under which soils gain or lose C, in part, because soils contain more C than the atmosphere and could play either a moderating or exacerbating role in global warming. An integrated field, laboratory, and modeling study of the biochemical mechanisms driving interactions between soil C sequestration, plant litter chemistry, and microbial community composition and activity during decomposition is needed to define these relationships. Moorhead and Sinsabaugh (2006) developed a new model that incorporates microbial dynamics into the decomposition process, the Guild Decomposition Model (GDM), which has generated a series of specific hypotheses about the mechanisms controlling the interactions between plant litter chemistry, C stabilization and microbial community composition and activity during decomposition. The proposed research will evaluate these hypotheses experimentally by monitoring changes in plant litter chemistry and microbial community composition and function during decomposition, with and without added N to mimic N deposition. Stable C isotope (13C) labeling will further determine the community composition of active microorganisms capable of metabolizing specific chemical components of plant litter. This research will provide mechanistic insight into the impacts on plant litter decomposition and soil C sequestration from N deposition, elevated CO2, plant community composition shifts, and climate change. An integrated education and outreach program will complement this research, assisted by the University of Toledo's Center for Creative Instruction (CCI). For this project, the CCI will develop an online interactive Model Of Leaf Decomposition (iMold) to provide educational outreach about decomposition for grades 5-12. Visitors will be able to visualize the progress of the decomposition of litter as a whole, or different individual litter chemical constituents, along a time line to see how time, litter type, and environment relate to how quickly or slowly something decays. Teachers and students will be able to network between researchers and classrooms at other schools, enabling them to share data, ask questions, and collaborate on experiments. A communication center will be created so that the researchers and classrooms can share ideas and results, as well as ask questions in a blog-like environment. Additionally, this project will provide training for several undergraduate and graduate students. University of Toledo and Kent State University serve significant populations of underrepresented groups in science, and they will be recruited to this project.