Characteristic of tradeoffs between timber production and carbon storage for plantation under harvesting impact: A case study of Huitong National Research Station of Forest Ecosystem
中国人工林面积居世界首位,在全球气候变暖背景下,人工林在提供木材和固定CO_2等方面同时具有重要意义。然而木材生产与碳储量之间存在此消彼长的权衡关系,如何综合考虑二者权衡过程,实现区域森林综合效益最大化,是中国森林生态建设中亟待解决的问题。选择会同森林生态实验站磨哨林场作为研究区,采用人工林固定样地多年观测数据以及InVEST模型,定量评估木材生产与碳储量,构建了不同管理模式下的权衡分析方法,提出了研究区森林生态系统综合效益最佳的权衡对策。研究发现:①在采伐活动的影响下,木材生产与碳储量显著负相关(R =-0.907, P < 0.001),表现出强权衡关系;②随着采伐强度增加,木材生产与碳储量的综合效益逐渐增加,权衡值先下降后上升;每10年采伐总面积10%~20%的管理模式下,收获木材量和碳储量的综合效益相对较高且权衡值最低,是最佳森林管理模式;③研究区当前采伐强度略高于最佳采伐强度,适当降低采伐强度能够使森林获取更多的综合效益。因此,在明确森林管理目标的基础上,可借助基于标准差的权衡分析方法,提出中国南方人工林生态系统服务提升与可持续经营的权衡对策。
英文摘要:
The tradeoffs and optimizations of ecosystem services are the key research fields of ecology and geography. As the most important and complex ecosystem in terrestrial ecosystems, forest ecosystem plays a very important part in the biogeochemical cycle which include terrestrial carbon cycle and water cycle, and also provides numerous ecosystem services that are crucial to human wellbeing. China has the largest plantation area worldwide. Under the background of global warming, there are more and more concerns on timber production and carbon storage of plantations, nevertheless, they have a relationship of restricting each other. Thus, it is necessary to maximize the overall benefit of timber production and carbon storage for forest ecological development in China. We selected the Huitong National Research Station of Forest Ecosystem as our study area, and used permanent sample plot data of plantations and InVEST model to evaluate timber production and carbon storage quantitatively. Then, we constructed a conceptual framework of forest ecosystem service tradeoffs under different management regimes. Lastly, tradeoffs countermeasures for optimizing overall benefits of ecosystem services were put forward. The results showed that: (1) When timber production increased with harvesting intensity over the entire 100 year planning horizon, carbon storage decreased. There were tradeoffs between timber production and carbon storage according to the significant negative relationship. (2) When the overall benefits of timber production and carbon storage increased with harvesting intensity, the value of tradeoffs decreased. T1 and T2 scenarios, with harvesting intensity of 10%-20% every 10 years, were the optimum management regime for timber production and carbon storage to gain more benefits and less tradeoffs. (3) The current harvesting intensity in Huitong County was slightly higher than the optimum harvesting intensity. On practical dimension, these findings suggested that obvious objectives are needed to formulate the corresponding countermeasures of tradeoffs, in order to realize the improvement of ecosystem services and the optimization of ecosystem structures.