Regionally specific harvesting residue yield and recovery rates used for energy policy development

We assessed the importance of residue yield rate rho and recovery rate eta for forest biomass recovery. Studies indicate that rho ranges from 20-50% and eta from 60-80%. Estimates of available residues for energy use a combination of both factors. By using reported ranges, we obtained estimates of available biomass for given areas that varied by a factor of three. Yet, energy policies are being developed that use single values of these two factors over large geographic areas.We concluded that the wide range of reported rate values is a function of the combinations of tree form, harvesting systems, and current markets that influence utilization. Thus, more precise estimates of energy from logging residues will require development and use of regionally specific yield and recovery rates. Until rates are developed that are specific for species groups and harvesting systems, conservative values of these rates should be used (rho=20% and eta=60%).