Abstract: [Objective] Economic benefits and optimal rotation period were analyzed in consideration of carbon sequestration and timber based on survey data of sample plots for a Chinese fir (Cunninghamia lanceolata) plantation in northwest of Fujian province. [Method] The stand volume and carbon storage were predicted by ARIMA time series models. And the economic benefits and optimal rotation period were calculated by using average net present value (ANPV) and land expectation value (LEV).[Result] 1)The accuracies of ARIMA models for stand volume and carbon storage were high, where the minimum R² was only 88.460%. So the results predicted by these models were acceptable and effective.2)Under the circumstances that carbon price was much less than wood price (at 5% interest rate and 173 yuan per ton carbon price), there were no significant influences on optimal rotation period in consideration of carbon sequestration benefits, but total economic benefits including carbon sequestration and timber were increasing obviously,about 6.55%-10.12%(ANPV)and 6.60%-10.72%(LEV),respectively. 3)Raising of site index, carbon price or interest rate would lead to shortening optimal rotation period. The higher site quality and carbon price, the more economic benefits in consideration of carbon sequestration and timber. When carbon price was 600 yuan per ton (at 5% interest rate), the increasing range of benefits were 25.01%-35.09%(ANPV)and 22.90%-37.19%(LEV)in different sites, respectively. In contrast, higher interest rate would reduce economic benefits, for instance, when carbon price was 123 yuan·t^-1, the total economic benefits at 4% interest rate were almost three times as much as ones at 7% interest rate (site index 14-16 m).[Conclusion] 1) It is worthy of promoting time series prediction model (ARIMA) to estimate forest growth based on survey data. 2) Under the present Chinese fir management environment, forest managers do not need to change the optimal rotation periods to obtain maximum total economic benefits including carbon sequestration and timber. It is beneficial to enhance the enthusiasm of Chinese fir operation. 3) Choosing high quality site to plant Chinese fir will increase economic benefits. 4) The higher carbon price, the more economic benefits in consideration of carbon sequestration and timber. 5) High interest rate is disadvantageous to manage Chinese fir. In conclusion, consideration of carbon sequestration and timber economic benefits will increase sharply revenues for Chinese fir managers, and it has a great significance to realizing the carbon sequestration potential of Chinese fir plantation in practice.

Key words: forest resource assessment, carbon sequestration benefit, economic mature, ARIMA, average net present value, land expectation value