Forest management for fixing and sequestering carbon

The concept of planting trees as part of a strategy to confront the possibility of global climate change is now widely accepted. As trees grow they remove CO2 from the atmosphere and thus slow the atmospheric build-up of CO2, an important greenhouse gas. Within the global-climate-change context, there are two fundamental problems with managing trees to store carbon. First, the magnitude of fossil-fuel related emissions of CO2 is so large, 6 billion metric tons of carbon per year that it takes very large areas of tree planting to make a significant impact. Second, as trees mature their rate of growth, and hence rate of net carbon uptake, declines. lie large demand on land area suggests that there is a limit to the fraction of total CO2 emissions that we might reasonably expect to offset with growing trees. The ultimate maturation of forests suggests that there is a limit on the length of time over which offsets are feasible and that we need to ask what to do as the rate of C uptake declines. Acknowledging a that the availability of land will constrain the ability of tree planting to offset industrial emissions of CO2, we consider how the land which is available can be used most effectively. This report speculates on how much land might be available for a forest management strategy motivated (at least partially) by concerns about climate change, but our principal focus is on how a given land area can be best used to minimize net emissions of CO2 and how much might be achieved on a unit of land. We do not suggest that carbon management should be the principal criteria for land management, but we discuss the implications if it were. Confronting global and local changes in climate will be one of many objectives in land management and we explore for the most effective strategy for pursuing this objective