云南常绿阔叶林生物多样性与生态系统功能及其影响因素

The relationships between plant species richness (SR) and ecosystem productivity (EP) can take several forms, due to the effects of climate, soil property, community history, vegetation types and other factors. The evergreen broad-leaved forests are widely distributed in Yunnan Province. Through measuring their biodiversity, biomass and associated environmental factors, this project will examine the relationships between SR and EP. The environmental factors, including topography, soil and climate, will be investigated, as well as some components of biodiversity, such as dominance, evenness, species diversity and functional diversity. The influences of these factors on EP and the relationships between SR and EP will be partitioned to find out factors that play the key roles. The aboveground biomass will be estimated using allometric equations. Moreover, both coarse and fine root biomass will be measured by applying ground penetrating radar and auger method so that the effects of these factors on underground biomass can be tested. The previous experiments either concentrated on grassland ecosystems or planted forests, in which the SR and community density were manipulated. However, the evergreen broad-leaved forests in Yunnan Province are noted for their complicated species composition and community structure. Therefore, this project is essential for biodiversity-ecosystem functioning experiments, and for the protection and sustainable utilization of forest resources.

由于受气候、土壤、群落形成历史、植被类型等多重因素的影响，物种丰富度与生态系统生产力之间的关系呈现出多种形式。本项目以在云南广泛分布的常绿阔叶林为研究对象，通过测定植物群落的生物多样性、生物量以及环境因子，探讨云南常绿阔叶林物种丰富度与生态系统生产力关系的普遍规律；检验环境因子（包括地形因子、土壤因子、气候因子）和生物多样性的其他组分（优势度、均匀度、物种多样性、功能多样性）对生态系统生产力、物种丰富度-生态系统生产力关系的影响。除了利用异速生长方程估算地上生物量，还应用探地雷达和钻土芯法测定粗根生物量和细根生物量，从而考察了各项因素对群落生物量地下部分的影响。云南常绿阔叶林类型多样，群落结构和物种组成复杂，以往研究或关注草地生态系统，或关注物种丰富度及群落密度受控的人工森林；本研究一方面能够丰富生物多样性与生态系统功能的理论研究，另一方面可为云南常绿阔叶林保护和可持续利用提供参考依据。

全球变化和人类活动引起的生物多样性空前丧失会损害生态系统过程及其服务功能，生物多样性与生态系统功能已经成为当前国际生态学研究的热点议题。目前的BEF研究中生态系统功能主要关注的是初级生产力，产生了抽样效应、生态位互补、质量比等一系列假说来阐述生物多样性对群落生产力的作用机制。本项目以云南哀牢山自然分布的4种常绿阔叶林为研究对象，按照森林群落调查的标准方法设置42个样地并对样地中的树木（共105种）进行调查取样，利用异速生长方程估算树木各部分生物量，钻土芯法测定细根生物量，获取各树种的叶片功能属性及样地环境因子数据，在此基础上，研究内容主要如下：云南常绿阔叶林物种丰富度与生态系统生产力之间关系的普遍规律；定量评估环境因素、生物多样性的各组分（树种丰富度、均匀度、功能多样性等）对常绿阔叶林地上生物量、粗根生物量、细根生物量的影响，从而验证生物多样性与生态系统功能研究的有关假说。长期以来，BEF研究主要在草地生态系统中进行，属小尺度的、在均一生境中开展的短期受控实验，将这些结果扩展到长的时间尺度和大的空间尺度上是一个很大的挑战。森林BEF研究虽属人工控制实验，但无法模拟自然森林生态系统的复杂性，以及自然森林生态系统中需要长期才能形成的种间作用。本研究能够丰富BEF研究的内容，弥补单纯人工控制实验的一些不足，其研究结果可以互为补充和印证。