Abstract:
Objective Carbon reserves and value of forest resources in China should be calculated to understand the status of forest resources and formulate a reasonable forestry development plan. Through the prediction of forest carbon stocks and carbon sequestration potential, it can improve the level of forest management and provide reference value for China to achieve the goal of carbon emission peak and carbon neutralization.
Method Based on the data of 9 forest inventories from 1973 to 2018 in China, the total carbon stocks of forest resources in China were calculated using forest volume method, and the carbon stocks and values of forest resources were calculated according to different forest types. This paper uses GM (1,1) grey model and power function model to predict the development potential of forest carbon sequestration in China, and analyzes the changing rate of carbon sequestration under different management levels by constructing the regression model of forest growth per unit area and carbon storage.
Result (1) Over the past 40 years, China’s average unit area volume of forest resources is 73.56 m3/ha, forest carbon stocks increased from 5.196 billion t in 1976 to 8.790 billion t in 2018, with an average annual increase of 0.085 57 billion t/year. The total carbon stocks of forest resources (including forest, woodland and understory vegetation) increased from 12.506 billion t to 21.439 billion t; among them, carbon stocks of plantation increased significantly, with an average annual increase of 5.05%. (2) The values of forest carbon stocks in China increased from 148.209 billion CNY in 1976 to 882.385 billion CNY in 2018, with an average annual increase of 17.480 billion CNY and a compound annual growth rate of 4.34%. Among them, the values of plantation carbon stocks increased by 8.24%. (3) The GM (1,1) grey model predicted that the forest carbon stocks will reach 10.013 billion t in 2030, the average annual increase of carbon sequestration will be 159 million t/year from 2018 to 2030, and the forest volume will reach 21.080 billion m3 in 2030; the forest carbon stocks in China will reach 18.032 billion t in 2060, and the average annual increase of carbon sequestration will be 236 million t/year from 2018 to 2060. The power function model predicted that China’s forest carbon stocks will reach 10.8 billion t in 2030, the average annual carbon sequestration will be 225 million t/year from 2018 to 2030, and the forest volume was expected to reach 22.738 billion m3 in 2030; China’s forest carbon stocks will reach 21.227 billion t in 2060, and the annual increase of carbon sequestration will be 312 million t/year from 2018 to 2060. (4) Based on the average benchmark of forest carbon stocks in recent 15 years, if the forest management level increase by 5%, the forest carbon stocks will increase by 4.30% − 6.86%; if increase by 10%, the forest carbon stocks will increase by 9.89% − 12.47%; if increase by 15%, the forest carbon stocks will increase by 15.48% − 18.09%; and if the forest management level increase by 20%, the forest carbon stocks will increase by 20.96% − 21.07%.
Conclusion Without considering the influence of external factors such as economy and policy, based on the changes of forest biomass and volume, forest carbon stocks and values in China are increased. According to this development trend, China can achieve the expected development goal of carbon emission peak and carbon neutralization for forestry in 2030 and 2060. If the current forest management level is further improved, the changing rate of forest carbon stocks will gradually increase, and the carbon sequestration potential will be huge.