Biotic Controls on Soil C Dynamics and N Cycling Under Elevated CO2

摘要提案编号：deb9708596研究者(S): MILCHUNAS机构：COLORADO STATE UNIVERSITY尽管在野外实验中广泛研究了大气CO2浓度增加对初级生产和其他地上生态系统过程的影响，但对地下CO2影响的实验研究通常尚未开展。本研究旨在探讨CO2浓度升高对科罗拉多草原土壤碳动态和氮循环的影响。地下响应的主要驱动因素被认为是二氧化碳引起的植物可溶性渗出物与组织组分之间C和N分配的变化，以及总C和N通量的变化。测量的重点是根分泌物，植物凋落物化学和凋落物分解，以及土壤动物，特别是线虫的变化。结果将使用Century模拟模型进行综合。这项研究是美国国家科学基金会环境地球化学和生物地球化学项目的一部分，得到了环境生物学、地球科学和大气科学部的支持。

ABSTRACT PROPOSAL # : DEB-9708596 INVESTIGATOR(S) : MILCHUNAS INSTITUTION: COLORADO STATE UNIVERSITY Although the effects of increasing atmospheric CO2 concentrations on primary production and other aboveground ecosystem processes are widely studied in field experiments, experimental studies of the effects of CO2 belowground have generally not been done. The aims of this research are to investigate the effects of elevated CO2 concentrations on soil C dynamics and N cycling in Colorado grasslands. The main driver of belowground responses is assumed to be CO2-induced changes in plant C an N allocation among soluble exudates versus tissue components, in addition to changes in total C and N fluxes. The focus of the measurements is on root exudates, plant litter chemistry and litter decomposition, and changes in soil fauna, particularly nematodes. Results will be synthesized using the Century simulation model. This research is part of the NSF Environmental Geochemistry and Biogeochemistry Program, with support from the Divisions of Environmental Biology, Earth Sciences, and Atmospheric Sciences.