Life cycle analysis of forest carbon in the central appalachian region

Forest management and wood product processing activities such as harvesting, transportation, and lumber processing consume fossil fuels and emit carbon dioxide. This emitted carbon dioxide creates credit carbon balance which is usually overlooked while estimating the carbon benefits from woody biomass and wood products. Accountability of carbon stored in woody biomass and wood products varies when such carbon emissions are considered. Factors such as, harvesting intensity, growth rate, dead trees and forest fires all affected the estimation of forest carbon balance while harvesting system determines the carbon emission from fossil fuel consumptions. Energy sources used in sawmills for electricity are also crucial in credit carbon balance analysis. Therefore, this study assessed (1) forest carbon balance of the mixed Appalachian hardwood forests and carbon emissions due to the use of fossil fuels in harvesting systems in West Virginia, and (2) carbon balance in hardwood lumber processing in the central Appalachian region. Data were obtained from a regional sawmill survey, public database and relevant publications.;Forest carbon balance and carbon emission were analyzed within a life cycle inventory framework of cradle to gate using sensitivity analysis and stochastic simulation. The results showed that the annual carbon balance of the forests per hectare was not significantly affected by carbon loss from the volume of removal, fire and dead trees. It was also found that carbon emission from combustion of fossil fuel using manual harvesting system was less than using mechanized harvesting systems. Though a minimal amount of carbon was emitted from harvesting systems, the forest carbon displacement rate during timber processing was affected largely by hauling compared to felling, processing, skidding and loading. Carbon emission quantity from fuel consumption and forest carbon displacement rate were also affected by harvest intensity, hauling, payload size, forest type, and machine productivity.;Credit carbon balance generated from lumber processing was statistically analyzed within the gate to gate life cycle inventory framework. Stochastic simulation of carbon emission and its impact on carbon balance and carbon flux during lumber processing were carried out under different operational scenarios. Credit carbon balance from electricity consumption varied among sawmills of different production levels and operation hours per week and also attributed effect of different head saws, lighting types and air compressors used at sawmills. Credit carbon balance significantly reduced the carbon accountability of the lumber in useful life period at first order of decay of carbon. Substantial amount of carbon flux attributed from energy consumption and exports of lumber reduced the carbon storage accountability of the lumber product. Increase of the carbon accountability of the lumber products and decrease of the carbon flux ratio could be achieved through using an efficient equipments at sawmills and an appropriate mixture of energy sources for electricity supply