Objective The paper aims to analyze the change of optimal rotation and benefits under different conditions in consideration of carbon sequestration and timber for Chinese fir plantation, and provide a scientific basis for multi-functional management and decision.
Method This study focused on Chinese fir plantation in Chongyi County and conducted in remeasurement data of 31 permanent plots, Jiangxi Province of eastern China. Based on Faustmann-Hartman model, three different scenarios were designed in this study. Scenario 1 only considered timber benefits. Scenario 2 added additional aboveground biomass pool, and Scenario 3 further considered the impact of dead organic matter pool. For each scenario, the effects of different carbon prices, rates and site index on the optimal rotation and land expected value were analyzed.
Result Under the baseline condition (carbon price: 77 CNY/t; rate: 5%; site index: 15 m), the land expected value showed a trend of first increasing and then decreasing with the increasing age. The optimal rotation for scenario 1 and 2 was 21 years, and for scenario was 20 years. Compared with scenario 1, a 23% increase of the land expected value was found for scenario 2 and a 35% increase for scenario 3. With the carbon price increasing, the optimal rotation decreased and the land expected value increased. For the same carbon price, the difference of optimal rotation among three scenarios was up to 4 years, and the difference increased with carbon price increased. With the rate increasing, the optimal rotation and land expected value showed a decreasing trend. When rate was 7%, the land expected value turned to be down to less than 10% for all three scenarios and negative land expected value was found for scenario 1. With the site index increased, the optimal rotation decreased and the land expected value increased.
Conclusion Under the present Chinese fir management environment, benefits of carbon sequestration do not have a significant effect on optimal rotation. However, an impact on land expected value exists. It is beneficial to enhance the enthusiasm of multi-functional management for Chinese fir plantation. Carbon price, rate and site quality can significantly affect the optimal rotation and land expected value.