Carbon stock projection for four major forest plantation species in Japan

Carbon sequestration via afforestation and forest growth is effective for mitigating global warming. Accurate and robust information on forest growth characteristics by tree species, region, and large-scale land-use change is vital and future prediction of forest carbon stocks based on this information is of great significance. We presented the forest age–carbon density functions of four major forest plantation species in Japan: Cryptomeria japonica, Chamaecyparis obtusa, Pinus spp., and Larix kaempferi. We then investigated the differences in the carbon sequestration potential of forests, including wood production, between five forestry practice scenarios with varying harvesting and afforestation rates, until 2061. For all four forest types, the estimates of growth rates and past forest carbon stocks were higher than those considered thus far. The predicted carbon sequestration from 2011 to 2061, assuming that 100% of harvested carbon is retained for a long time, twice the rate of harvesting compared to the current rate, and a 100% afforestation rate in harvested area, was three to four times higher than that in a scenario with no harvesting or replanting. Our results suggest that planted Japanese forests can exhibit high carbon sequestration potential under the premise of active forest management with technology development.