DISSERTATION RESEARCH: Changes in ecosystem carbon sequestration over 50 years of forest development

Duke University, Durham NC

Investigators

Abstract

Long-term observations of forest carbon accumulation, beginning at forest inception and continuing through the life of the forest, are exceedingly rare. While aboveground forest biomass is a large and easily-measured pool of carbon, carbon in soils and in dead wood (coarse woody detritus, CWD) ?so called ?slow pools??are little studied. Yet these slow pools store carbon long after trees are removed or die. This research investigates 50 years of carbon accumulation following the planting of tree seedlings in a South Carolina cotton field, and estimates the slowly cycling pools of carbon in soil and CWD in comparison to the carbon in the total forest. This work will estimate and link aboveground and belowground CWD dynamics, a step no other study has taken. While CWD has accumulated in this forest, deep soils appear to have lost carbon since forest inception, counter to assumptions that reforestation should increase or have no effect on soil organic carbon (SOC) storage. This research will examine effects of reforestation on soil carbon via detailed analyses of changes in SOC chemistry and stability during forest development. Expanded research is necessary to understand whether SOC changes are permanent or transient phenomena, and what the ramifications will be for forest carbon sequestration efforts. Finally, current carbon accounting protocols differ in data requirements and treatment of uncertainty, which results in divergent estimates of creditable carbon storage. This continued research on carbon storage and dynamics in a managed forest, and collaboration with colleagues in the international Long Term Soil Experiment network, US Forest Service, and the Nicholas Institute for Environmental Policy Solutions, will aid development of rigorous carbon offset protocols and improve estimation of carbon stocks and uncertainties by land owners and managers.