The use of woody biomass energy has grown in importance as part of the efforts to reduce dependence on non-renewable energy sources such as fossil fuels. Though woody biomass release carbon into atmosphere when it is burned to produce energy, replanted trees absorb the same amount of carbon from atmosphere into the forest ecosystem through photosynthesis which is in proportion to the growth rate of tree species. The growth rate is depended on temperature, precipitation, soil characteristics and other environmental factors. In general the growth rate is low in boreal zone and high in tropical zone respectively. Fast growing species such as eucalyptus (Eucalyplus), poplar and Acasia manngium in Southeast Asia capture from 5 to 15 ton carbon per hector annually. Whereas Sugi (Cryptomeria japonica), one of representative plantation species in Japan, captures carbon from 2 to 3.5 ton per hector annually.

The growth of forest biomass shows high rate in the early stage and fall down with getting mature. Table 2.6.1 expresses how man-made forest stores carbon in their biomass. Hardwood forests located close to rural communities in Japan used to be the main source to provide fuel wood. Table 2.6.2 shows annual increment of these forests. If we focus on only quantity and do not care timber quality, it is reasonable to adopt cutting rotation at the maximum annual increment which is generally younger than regular timber harvesting rotation.