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Harvard Forest Symposium Abstract 2016
- Title: Regional context for carbon sequestration in a mid-latitude forest
- Primary Author: Daniel Bishop (Harvard Forest)
- Additional Authors: Daniel Bishop (Harvard Forest); Neil Pederson (Harvard Forest)
- Abstract:
Carbon sequestration in oceans and terrestrial ecosystems play a significant role in moderating atmospheric CO2 concentrations. Understanding the factors that control carbon uptake by forests is critical to evaluate predictions of future atmospheric CO2 concentrations. Tree rings can be used as a fine temporal resolution proxy of aboveground carbon sequestration and often capture interannual variance of woody biomass. Using a tree-ring analysis approach, annual and subseasonal growth rates and trends of northern red oak (Quercus rubra L.) at Harvard Forest were compared to 21 additional oak-dominated forests across the northeastern US. Growth rates and aboveground carbon increment (ACI) were also compared with climatic and geographic variables to evaluate seasonal and annual drivers of carbon sequestration. Preliminary results indicate that most red oak populations have increased growth rates since the 1950s, with older, larger trees exhibiting the highest growth rates. Early summer drought, winter temperature, and gypsy moth defoliation were the primary constraints on northern red oak growth. A severe gypsy moth (Lymantria dispar L.) defoliation event at Harvard Forest was identified in 1981, facilitating an evaluation of annual and lagged multiannual effects of the isolated event on ACI. The gypsy moth defoliation significantly reduced red oak growth rates, especially of carbon-rich latewood, limiting recovery of red oak productivity more than any climatic event within the study area. Reduced growth rates were primarily driven by a severe reduction in 1981 latewood and 1982 earlywood. Climate sensitivity of earlywood and latewood growth rates will also be computed to evaluate the subseasonal and potentially lagged growth response of red oak. Lastly, a new tree-ring method was developed to estimate potential site-level productivity using relative rankings of site productivity independent of tree age. This study will produce a thorough regional context of the climatic, spatial, and ecological constraints on the terrestrial carbon cycle of northern red oak trees at Harvard Forest.
- Research Category: Forest-Atmosphere Exchange
Historical and Retrospective Studies
Regional Studies
