Although the dynamics of tree growth and biomass carbon stocks are reasonably well understood for forests a bit older than harvestable age, such dynamics in old forest, with trees approaching their natural life span, are poorly known. In particular we have inadequate knowledge of old forest tree mortality under natural dynamics and whether gap-filling dynamics will compensate biomass loss by natural mortality agents. Another important area requiring better knowledge is the variation in soil carbon stocks with stand age, site productivity, and other environmental factors, as well as the responses of soil carbon to disturbances like biomass harvesting.