A proposed model for deadwood C production and decay in loblolly pine plantations

Analysis of long-term study data indicates deadwood C production in loblolly pine plantations averages between 50 and 1700 kg/ha/year in stands age 15 to 35 years. In order to accurately predict deadwood carbon stocks over the life of individual stands, information is needed on the size distribution of deadwood and the rates of decay of various-size deadwood pieces. Effects of management activities on mortality and subsequent decay should also be accounted for in model predictions of deadwood C. We describe a proposal for augmenting a loblolly pine stand-level growth and yield model to account for deadwood C production and yield over an entire rotation. Deadwood size distributions are predicted from stand-level variables. Decay rates after mortality are predicted from stand attributes and piece-size information and are used to predict C accumulation in deadwood. The resulting model will be used to predict aboveground carbon stocks in loblolly pine stands, or in regional assessments when linked to geographic databases.