EAPSI: The Effect of Elevated Nitrogen on Lignin Degrading Microbial Communities in Mt. Changbai Soil

本项目将调查中国的污染对植物凋落物分解的影响。植物凋落物由枯死的植物叶、木头和根组成。它的周转是维持土壤中有机碳的一个重要过程，主要由微生物推动。中国因工业污染而产生的前所未有的氮素水平，大幅提高了土壤氮素浓度。目前尚不清楚氮素升高将如何影响植物凋落物的分解和本地微生物群落。通过对长白山田间土壤进行氮素改良的实验室培养，研究人员可以监测植物凋落物组成和参与植物凋落物周转的微生物的变化。这项研究将与中国科学院应用生态研究所(CAS IAE)著名土壤地球化学专家张旭东博士合作进行。研究人员的目标是阐明氮含量升高对森林土壤生态系统的长期影响，因为森林土壤生态系统是重要的碳库。该项目将调查氮沉积增加对山上植物凋落物降解微生物群落的影响。长白森林土壤。本实验将直接测试稳定的土壤有机碳木质素与氮沉降之间的联系。从山上的一块田野上采集的新鲜土壤。将用木质素和不同浓度的硝酸铵对长白进行取样和修改。在培养过程中，将对所有土壤微观世界进行常规采样，以使用碱性氧化铜进行降解木质素分析。微观世界还将每周进行采样，通过下一代测序进行微生物群落结构和功能分析。利用生物信息学，将对样品进行比较，以确定不同氮添加水平下木质素微宇宙中不同丰富的物种。更好地了解氮和碳循环将带来更好的土壤碳管理实践。该奖项由东亚和太平洋夏季学院项目资助一名美国研究生的夏季研究，由美国国家科学基金会和中国科技部联合资助。

This project will investigate the effect of China's pollution on plant litter decomposition. Plant litter consists of dead plant foliage, wood, and roots. Its turnover is an essential process in maintaining organic carbon within soils and is facilitated largely by microorganisms. The unprecedented levels of nitrogen in China due to industrial pollution have drastically increased soil nitrogen concentration. It is unclear how the elevated nitrogen will effect plant litter decomposition and the native microbial communities. Creating laboratory incubations of Mt Changbai field site soil amended with nitrogen, researchers can monitor changes in the composition of plant litter and the microbes involved in plant litter turnover. This research will be conducted in collaboration Dr. Xudong Zhang, a noted expert in soil geochemistry, at the Chinese Academy of Science Institute of Applied Ecology (CAS IAE). Researchers aim to elucidate the long-term impact of elevated nitrogen on forest soil ecosystems because they are important reservoirs of carbon.The project will investigate the effect of elevated nitrogen deposition on the plant litter-degrading microbial community in Mt. Changbai forest soil. This experiment will directly test for the link between stable soil organic carbon lignin and nitrogen deposition. Fresh soil from a field site in the Mt. Changbai will be sampled and amended with lignin and varying concentrations of ammonium nitrate. During incubation, all soil microcosms will be routinely sampled for degraded lignin analysis using alkaline copper oxide. The microcosms will also be sampled weekly for microbial community structure and function analysis via next generation sequencing. Using bioinformatics, samples will be compared to determine differentially abundant species in lignin microcosms at the different levels of nitrogen addition. A better understanding of nitrogen and carbon cycling will lead to better management practices of soil carbon.This award under the East Asia and Pacific Summer Institutes program supports summer research by a U.S. graduate student and is jointly funded by NSF and the Chinese Ministry of Science and Technology.