A comparison of carbon stock estimates and projections for the northeastern United States

Abstract

We conducted a comparison of carbon stock estimates produced by three different methods using regional data from the USDA Forest Service Forest Inventory and Analysis (FIA). Two methods incorporated by the Forest Vegetation Simulator (FVS) were compared to each other and to the current FIA component ratio method. We also examined the uncalibrated performance of FVS growth simulations for predicting net carbon accumulation in live trees. In general, the three carbon stock estimation approaches do not produce estimates that are either equivalent or are simply convertible. A strong spatial pattern of relationships between estimates was associated with regional variation in stand top height. Uncalibrated growth projections gave downwardly biased results that were also poorly correlated with observed carbon accumulation rates, yielding little improvement in root mean square error over the use of a simple regional average. These results reinforce the need for managers and scientists to be careful in choosing methods and reporting carbon stock estimates and to use appropriate model calibration methods in projecting future carbon accumulation. © 2014 Society of American Foresters.