Abstract: Carbon storage, carbon density and carbon sequestration potential of Cunninghamia lanceolata plantations in Hunan Province were estimated based on the database of the forest resource inventory in 2005 and 2010, that was done by forest resources monitoring center of Hunan Province, and the database from the national field scientific observation and research station of C. lanceolata plantation ecosystem, Huitong, Hunan Province. The results showed that the total carbon storage in C. lanceolata. plantations accounted for 30.39×10⁶ t in 2005 and 32.92×10⁶ t in 2010, and the middle-aged forests had the highest proportion of the carbon storage with carbon storage of 17.64×10⁶ t in 2005 and 17.31×10⁶ t in 2010, respectively The amount of carbon storage in C. lanceolata plantations ranged from 0.34×10⁶ t to 6.45×10⁶ t varied with different prefectures in 2010. Carbon density of Cunninghamia lanceolata plantations increased as the stand age increased, reaching the maximum (more than 23.90 tC·hm^-2) at over mature forest stage, with an average carbon density of 10.83 tC·hm^-2 in 2005 and 12.05 tC·hm^-2 in 2010, respectively, and ranged from 6.03 to16.58 tC·hm^-2 in different prefectures, which showed a trend of lower carbon density in the northern prefectures to higher carbon density in the southern prefectures. The reality carbon sequestration potential of C. lanceolata plantations in Hunan was up to 90.75×10⁶t, varying with different stand age classes allocating to middle-aged forest of 53.62×10⁶ t, to near mature forest of 32.77×10⁶ t, to young forest of 4.36×10⁶ t, respectively, and that also varied from 1.18×10⁶ to 17.39×10⁶t with different prefectures. The future carbon sequestration potential of immature C. lanceolata forests was estimated as 176.77×10⁶ t in 2020 with annual carbon sequestration potential of 17.68×10⁶ t·a^-1 and as 211.67×10⁶ t at mature stage. These results indicated that the stand quality of C. lanceolata plantations was very poor in Hunan due to higher proportion of young stage and middle-aged stage, which suggested that C. lanceolata forests. would be a huge potential carbon sinks in the future with implementation of better cultivation and management measures.

Key words: Cunninghamia lanceolata plantation, carbon storage, carbon density, carbon sequestration potential, Hunan Province