生物多样性对温带针阔混交林时间稳定性的作用机制: 基于森林动态样地途径

The relationship between biodiversity and ecosystem stability has emerged as a major issue in ecological sciences today. This project will be conducted based on existing Forest Dynamics Plots established in different successional stages of temperate mixed forests in the Changbai Mountain area, northeast China. To examine temporal stability of population and reveal how their determinants change along succession from the view of asynchrony in tree growth, the individuals will be measured every month during growing seasons using dendrometer band. We will try to compare the differences in dominant species’ response to environmental fluctuations by analyzing the relationship between tree –ring widths and climatic factors, and identify the trade-off between population growth and their temporal stability using tree characters such as wood specific gravity. Based on the four communities inventories data since 2004, DNA brocading and species functional trait data, we also discuss the external ecological conditions and internal biological factors limiting forest productivity, and construct the models that can better explain and predict the relationships between biodiversity and temporal stability. Our aims are to clarify the mechanisms driving the formation and maintenance of community stability in natural forests, and validate and develop some hypotheses explaining the relationships between biodiversity and ecosystem function. In practice, this project could provide valuable reference sources for forest management and theoretical basis for sustainable utilization in these areas.

生物多样性和稳定性之间的关系是生态学研究的热点。本项目拟以长白山温带针阔混交林为研究对象，依托在不同演替阶段已建立的固定样地，在对群落长期、连续监测的基础上，结合树木生长环所记录的个体生长动态，从个体间生长异步性的角度，探讨种群时间稳定性及其影响因子随群落演替的变化规律；通过解析优势树木年轮信息，比较不同树种对环境波动响应的差异，结合植物木材密度等性状，探讨种群生长与时间稳定性的内在联系。基于2004年以来4次群落调查数据，探讨制约群落生产力动态的内在生物学要素和外在生态条件，在群落尺度上构建能够解释和预测多样性－生产力时间稳定性关系的模型，揭示温带天然林群落稳定性的形成、维持机制，验证、发展生物多样性与生态系统功能关系的相关假说，为本区域针阔混交林资源的管理与可持续利用提供理论依据。

生物多样性和稳定性之间的关系是生态学研究的热点。本项目以长白山温带针阔混交林为研究对象，依托在不同演替阶段已建立的固定样地，在对群落长期、连续监测的基础上，结合凋落物收集器和树木生长环所记录的种子雨动态和个体生长动态，分析了群落内20个木本植物物种种子生产的变异性和同步性，验证了传粉效率假说以及气象因子对种子生产的直接作用，即长白山温带阔叶红松林群落水平的种子生产动态同时决定于进化中的选择压力（传粉效率假说）和气象因子的直接作用，而捕食者饱和假说在这八年的研究中仅仅表现出微弱的作用；以25ha阔叶红松样地中712个有连续树环监测记录（2010-2018）且健康存活的树木个体为研究对象，通过采集每个个体的8个功能性状指标，在考虑种内变异的基础上，利用分层贝叶斯模型，明确气象因素、邻域组成、非生物因子和功能性状对树木生长的相对影响。在群落尺度上，整合分析了物种多样性、种间异步性、优势树种和土壤养分对地上生物量时间稳定性的直接和间接影响。研究发现，种间异步性，而非物种多样性，是维持温带森林地上生物量稳定性的主要驱动力，且其影响程度随着森林演替呈增加趋势。研究结果突出了由时间生态位分化形成的种间异步性在调节自然生态系统稳定性中的重要作用，揭示了物种多样性和树种组成(优势种)对温带天然林稳定性影响主要发生在老龄林的现象。因此，为了维持森林地上碳库的稳定性，在森林经营过程中，在物种配置时应着重考虑具有强异步性特征的树种。