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

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).
 [1] ;  [2] ;  [3] ;  [4] ;  [5]
  1. Univ. of Arizona, Tucson, AZ (United States). Dept. of Ecology and Evolutionary Biology
  2. Woods Hole Research Center, Falmouth, MA (United States)
  3. Boston Univ., MA (United States). Dept. of Biology
  4. Univ. of Arizona, Tucson, AZ (United States)
  5. Harvard Univ., Cambridge, MA (United States). Dept. of Organismic and Evolutionary Biology
Publication Date:
OSTI Identifier:
Report Number(s):
DOE Contract Number:
Resource Type:
Technical Report
Research Org:
Boston Univ., MA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23)
Country of Publication:
United States
54 ENVIRONMENTAL SCIENCES carbon cycle; carbon allocation; belowground processes; microbial model