协同提升杨树人工林木材生产和固碳能力的密度调控机制与模拟

如何发挥森林的固碳作用同时不牺牲木材生产等其它效益，成为林业应对气候变化亟待解决的问题。许多研究分析了国家和林分尺度上森林管理（间伐和采伐）对森林固碳潜力的影响。但是尚没有研究探讨造林密度对木材生产力（WP）和净生态系统生产力（NEP）的权衡关系（Trade-off）的影响和机制，以及预测将来气候变化条件下WP-NEP关系如何改变。本项目拟在江苏省泗洪县陈圩林场的杨树林分结构试验林，选择3种不同林分密度的林分，结合已掌握的观测数据（气候、土壤、林木生长、土壤呼吸等），补充监测不同深度土壤温度和水分，植物性状（叶、细根碳氮含量）等指标；改进基于过程的生态学模型（TRIPLEX-Management）的碳分配模块；利用改进的模型研究林分密度控制影响WP和NEP关系的生态学机制，探究气候变化条件下WP和NEP协同提升的最优造林密度。本项目的实施可为开展应对气候变化的碳汇造林提供科学依据。

It is essential to increase forest carbon sequestration without sacrificing wood production. Numerous studies have analyzed the carbon sequestration potential of forests and forest management in the national and stand levels. However, few studies are available which assess the effects of planting density on trade-offs between wood productivity (WP) and net ecosystem productivity (NEP) and in which ecological mechanisms determine the effects. This project will be conducted in the trial of stand structure of poplar plantations in Sihong, northern Jiangsu. The objectives of this project are 1) to improve a process-based model, TRIPLEX-Management, using the most advanced carbon allocation model; 2) to test the modified model using observations; and 3) to conduct the scenario simulations (climate change and planting density) to examine the synchronous relationships between WP and NEP. We expect that this project could improve understanding and prediction of in what planting density plantations could increase both WP and NEP under the context of climate change.