We describe current forest carbon stocks and recent trends, and explore options to increase carbon stocks in forests and wood products, reduce emissions from land-use change, and increase the use of wood for biofuel. The scope of analysis is approximately the Northern 1/3 of WI including the 3 major ownership groups: National Forest, other public, and private lands. This is the most heavily forested region of the State, containing about 2/3 of the total forest land area of 6.5 million hectares. We use Forest Inventory and Analysis data to estimate current and potential stocks of carbon in forests and wood products, following standard carbon accounting and estimation procedures.
Results/Conclusions
Total carbon stocks are distributed in approximate proportion to area of ownership class. About 60% of the ecosystem carbon is in the soil. Carbon density (amount of carbon stock per unit area) is high with the National Forest ownership class having a slightly higher density than the other ownership classes. Over the last decade, carbon stocks of Northern Wisconsin forests have been increasing by about one million metric tons per year, a little less than the previous decade. Most of the increase has been in live biomass. Among ownership groups, the per-hectare increase has been largest on public forestlands. A preliminary estimate of the annual addition of C to the harvested wood products pool generated in Northern Wisconsin is 0.5 million tons; therefore, total net C sequestration in Northern Wisconsin forests and wood products is approximately 1.5 million tons per year. There is some potential to increase carbon stocks through forest management -- the end-use of forest products has a significant effect on the overall C balance of a forest. Managing at the landscape scale allows the best treatments to be applied to diverse individual stand conditions. Landscape change (e.g., forest loss and fragmentation) in northern Wisconsin causes reductions in carbon stocks and could be a target for policies to avoid emissions. A recent analysis of available forest biomass for energy uses in Wisconsin estimated that 1.7 million dry tons of forest biomass could be available, meaning that it is present in the forest or at a facility and could theoretically be used for energy. However, the actual amount of biomass that is available is likely less than what is potentially available.
