The establishment of forest plantations is an excellent silvicultural alternative to improve atmospheric carbon (C) sequestration for climate change mitigation. In recent years, the importance of forest growth and C dynamics at different stand ages have drawn huge attention for investigation. Castanopsis hystrix (C. hystrix) is an indigenous tree species widely spread across southern China. Many case studies involved in forest ecosystem C storage and dynamics have been conducted by Chinese researchers using forestry survey data. However, studies regarding C storage in C. hystrix plantation ecosystems at different stand ages are scarce, and the quantification of total plant biomass C, including understory vegetation and litter, is even rarer.

To evaluate the impacts of different stand ages on the C storage capacity of C. hystrix plantations ecosystems, Chinese researchers measured biomass and C content in trees, understory, litter, and soil components from field measurements at different stand ages, i.e., 6–, 10–, 15–, 25–, and 34–year–old stands. Results showed that the C stocks in trees, understory vegetation, litter, soil and the whole ecosystem increased steadily with stand age. C. hystrix C storage capacity in the 6–, 10–, 15–, 25–, and 34–year–old stands were 29.17, 56.18, 85.60, 132.19 and 157.79 Mg ha^？1 , respectively, while the total ecosystem C storage capacity was 68.11, 106.11, 136.13, 187.34 and 226.14 Mg ha^？1 , respectively. Meanwhile, the C sequestration rate in the 6–10, 10–15, 15–25 and 25–35–year–old stands were 675.28, 588.35, 465.97 and 284.39 g m2 year^？1, respectively. Similarly, total biomass of trees, understory, and litter increased with stand age. Our study indicated that C. hystrix plantations are still developing in the area, since live biomass and soil C continue to accumulate despite reduced C sequestration rates. The information provided here highlight the C stock and C sequestration rates of C. hystrix at different stand ages, providing baseline information on the C dynamics of young and older stand of C. hystrix in this region; Hence, such knowledge could be useful for designing more realistic policies to mitigate climate change, such as programs to maintain continuous forest growth.

For the detailed information, please see http://dx.doi.org/10.1016/j.scitotenv.2023.164974