关键词: 林地期望价, 碳补贴, 最优轮伐期, 碳汇成本, 杉木人工林

Abstract:

【Objective】To offer a theoretical basis for improving the supply of carbon sinks and reducing the cost of carbon sequestration, the dynamics of the optimal rotation periods and carbon sequestration costs under different carbon payment mechanisms were explored. 【Method】Based on a survey of management practices for Chinese fir plantations in Yangkou State-owned Forest Farm, Fujian Province, models for the optimal rotation period and carbon sequestration cost of Chinese fir under different carbon subsidy scenarios were derived, and the effects of site conditions, carbon prices and discount rates on the optimal rotation periods and carbon sequestration cost were investigated. 【Result】Under an ideal scenario, when the discount rate increased from 2% to 7%, the carbon sequestration cost of the fertile, general and barren land decreased by 31.42%,32.03% and 33.15%, respectively, the optimal rotation period was shortened by four years. When the carbon price increased from 20 to 350 yuan/t, the carbon sequestration cost of fertile, general and barren land increased by 19.24, 19.43 and 19.38 times, and the optimal rotation period was extended by 8, 9 and 10 years, respectively. Under the annual payment scenario, when the discount rate increased from 2% to 7%, the carbon sequestration cost of fertile, general, and barren land decreased by 70.35%, 70.66% and 71.14%, respectively, and the optimal rotation period was shortened by four years. When the carbon price increased from 20 to 350 yuan/t, the carbon sequestration cost of fertile, general and barren land increased by 15.79, 15.82 and 16.50 times, respectively. The optimal rotation periods for both general and fertile land extended for one year; but remained unchanged for the barren land. 【Conclusion】Under the two scenarios of carbon subsidy, both carbon sequestration costs and optimal rotation periods were negatively correlated with the discount rate and positively correlated with the carbon price. The carbon sequestration cost of general land is the most sensitive to the change in the carbon price for the ideal scenario, but the barren land is the most sensitive under the annual payment scenario. In short, the ideal scenario is more conducive to the development of forest ecological functions and the realization of forest ecological benefits.

Key words: net present value of forest land, carbon payment, optimal rotation period, carbon sequestration cost, Chinese fir (Cunninghamia lanceolata) plantation