Estimates Of Carbon Stock Changes Research Articles

SIMPLE RULES FOR MEASURING CHANGES IN ECOSYSTEM CARBON IN FORESTRY-OFFSET PROJECTS

There is growing interest in the use of forestry-offset projects to mitigate increasing concentrations of carbon dioxide in the atmosphere. If forestry-offset projects are to be employed broadly and successfully there need to be accounting rules that are easy to operationalize and effective in preventing cheating. Since carbon is both tangible and predictable in where it occurs it is feasible to develop simple accounting rules. Such rules must be conservative with respect to the amount of carbon credited. If accounting practices based on the following simple rules are employed, costs will be kept low and projects will credit only carbon that is physically present: Changes in living aboveground biomass must always be measured in forestry -offset projects. Belowground living biomass can be estimated from aboveground living biomass in forestry- offset projects. Generalized root/shoot ratios can be used as long as conservative ratios are applied. Not all changes in soil carbon stocks need to be measured, only those for which there is a possibility the stock is declining. The necromass pool need not be measured except when there has been a recent disturbance (interval varies with ecosystem). To insure that inaccurate techniques do not lead to overestimating of carbon stock changes, imprecise estimates of the carbon content of an ecosystem compartment should be discounted. There should be no required level of accuracy associated with estimates of carbon stock changes in forestry-offset projects, but the creditable carbon should be discounted proportional to the uncertainty.