Influence of stand characteristics and management activities on aboveground carbon storage in Japanese cedar and cypress plantations: Sustainable management implications

Tree plantations substantially sequester carbon in aboveground biomass and soil and serve as an alternative to forests in mitigating global warming. This study investigated the relationship between aboveground carbon and stand characteristics and management activities in two Japanese plantations (cedar and cypress) for their sustainable management viewpoint, which has not been studied before. Aboveground carbon stock ranged from 3.96 to 248.53 Mg C ha^-1 in 9- to 188-year-old Japanese cedar and 7.09 to 119.17 Mg C ha^-1 in 11- to 129-year-old Japanese cypress plantations. Annual aboveground carbon storage differed significantly between the two species. Aboveground carbon storage in Japanese cedar was affected by stand characteristics (e.g. soil moisture, electrical conductivity, soil texture especially sand and clay, site quality, and stem density) and management activities (e.g. initial silvicultural practices, stem exclusion practices, pest and wildlife management and land management). However, the same in Japanese cypress was affected by stand characteristics (e.g. soil moisture, electrical conductivity, soil texture especially sand, bulk density, site quality, stem density, and elevation) along with management activities (e.g. initial silvicultural practices, stem exclusion practices and land management). Therefore, continuous monitoring and periodic assessment of the stand characteristics and management activities may be taken into consideration in future policy-making decisions to promote aboveground carbon storage and climate change mitigation ability of these plantations in Japan on a sustained basis.