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

Saleska, Scott¹  Davidson, Eric²  Finzi, Adrien³  Wehr, Richard⁴  Moorcroft, Paul⁵ 

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

关键词: carbon cycle;    carbon allocation;    belowground processes;    microbial model;   

DOI  :  10.2172/1248334
RP-ID  :  DOE-BU--0006916
PID  :  OSTI ID: 1248334

学科分类：环境科学（综合）

美国|英语

来源: SciTech Connect

【 摘 要 】

This project combines automated in situ observations of the isotopologues of CO₂ with root observations, novel experimental manipulations of below ground processes, and isotope-enabled ecosystem modeling to investigate mechanisms of below- vs. above ground 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 below ground using measurements of root growth and indices of below ground autotrophic vs. heterotrophic respiration (via trenched plots andisotope measurements); (C) Testing whether plant allocation of carbon below ground 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).