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

摘要 提案编号：DEB-9708596 经销商：MILCHUNAS 机构：科罗拉多州立大学 虽然大气CO2浓度增加对初级生产和其他地上生态系统过程的影响在实地实验中得到广泛研究，但CO2地下影响的实验研究一般还没有进行。 本研究的目的是调查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力被认为是CO2诱导的变化，植物C和N分配之间的可溶性分泌物与组织成分，除了总C和N通量的变化。 测量的重点是根系分泌物，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。结果将使用世纪模拟模型进行综合。 这项研究是NSF环境地球化学和生物地球化学计划的一部分，得到了环境生物学，地球科学和大气科学部门的支持。

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.