Partitioning CO2 fluxes with isotopologue measurements and modeling to understand mechanisms of forest carbon sequestration

Davidson, Eric A.¹  Saleska, Scott²  Savage, Kathleen¹  Finzi, Adrien³  Moorcroft, Paul⁴  Wehr, Richard² 

[1] Woods Hole Research Center, Falmouth, MA (United States);Univ. of Arizona, Tucson, AZ (United States);Boston Univ., MA (United States);Harvard Univ., Cambridge, MA (United States)

关键词: Forest?? carbon?? partitioning?? eddy fluxes?? belowground allocation?? isotopes;   

DOI  :  10.2172/1238149
RP-ID  :  DOE-WHRC--07053
PID  :  OSTI ID: 1238149
Others  :  Other: 5084145421

学科分类：环境科学（综合）

美国|英语

来源: SciTech Connect

【 摘 要 】

1. Project Summary and Objectives This project combines automated in situ observations of the isotopologues of CO₂ with root observations, novel experimental manipulations of belowground processes, and isotope-enabled ecosystem modeling to investigate mechanisms of below- vs. aboveground carbon sequestration at the Harvard Forest Environmental Measurements Site (EMS). The proposed objectives, which have now been largely accomplished, include: A. Partitioning of net ecosystem CO₂ exchange (NEE) into photosynthesis and respiration using long-term continuous observations of the isotopic composition of NEE, and analysis of their dynamics ; B. Investigation of the influence of vegetation phenology on the timing and magnitude of carbon allocated belowground using measurements of root growth and indices of belowground autotrophic vs. heterotrophic respiration (via trenched plots and isotope measurements); C. Testing whether plant allocation of carbon belowground stimulates the microbial decomposition of soil organic matter, using in situ rhizosphere simulation experiments wherein realistic quantities of artificial isotopically-labeled exudates are released into the soil; and D. Synthesis and interpretation of the above data using the Ecosystem Demography Model 2 (ED2).