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Harvard Forest Symposium Abstract 2017

  • Title: What Goes Up Must Come Down: Carbon Dynamics with Forest Regrowth After Clearing
  • Primary Author: Christopher Williams (Clark University)
  • Abstract:

    Ecological disturbances such as clear cutting of forests perturb ecosystem-atmosphere exchanges of water, carbon and water in profound ways but the magnitude of response and pace of recovery (if at all) are poorly documented. Forest responses often involve long-lived legacies with implications for a host of ecosystem services such as carbon sequestration, wildlife habitat, and climate regulation. This project reports on 7 years of carbon, water, and energy fluxes measured after the clearing of a plantation stand followed by natural stand regeneration. Initial net carbon release two years after clearing (-680 and -610 g C m-2 y-1) gave way to net carbon uptake four years after clearing (320 g C m-2 y-1) and rose to 1040 g C m-2 y-1 in the seventh year post-harvest. Gross ecosystem productivity (GEP) rose consistently over the seven years from 1200 to 2600 g C m-2 y-1, consistent with a steady rise in summertime, light-saturated GEP and canopy conductance, as well as a continued rise in annual evapotranspiration (460 mm y-1 to 770 mm y-1). Ecosystem respiration peaked two years post-clearing (1960 g C m-2 y-1), and then fell over next four years leveling toward 1550 g C m-2 y-1. Patterns evidence the pulse of carbon emissions released post-disturbance, but also the resilience of forest regeneration and associated net carbon uptake present in this landscape.

  • Research Category: Physiological Ecology, Population Dynamics, and Species Interactions; Large Experiments and Permanent Plot Studies; Forest-Atmosphere Exchange

  • Figures:
  • fluxseas1_7yr_expanded.jpg
    fluxseas2_7yr_expanded.jpg
    CClightsatGEP_09to15.jpg
    Cond_Hour7yr.jpg
    CC_CfluxSeries_7yr.jpg