亲缘关系在不同分类水平和时空尺度上对物种共存的作用

This study was carried out in a 20ha subtropical forest plot in Dinghushan Mountain, based on the dynamic monitoring data in the subtropical forest community for 15 years. We use molecular marker and gene fragment analysis to set up family tree which can accurately reflect the genetic relationship.At the same, we carry out outdoor and indoor ecological control experiment to determination the key function traits of the dominant species in our community, after that, creating their function character database. Continue to obtain and complete environmental factors and habitat conditions data, combining with computer randomization statistical test technology. By an innovative use of interdisciplinary technology and means to set up a bridge of micro and macro field, and use a research method that associated with evolution and ecology, carry out a research into different classification level (community, species and gene). First, focus dominant species as the origin point, clustered and divided other species into groups with different degrees of phylogenetic relatedness to the constructive species in whole community. we explore the quantitative and spatial distribution of species genetic group at different biodiversity levels. And then, discover the relationship among species genetic group and the role played by constructive species. And then, find out the quantitative and spatial distribution of species genetic group at different time scale (community succession stages), and spatial scale (different sampled scales). We aimed to verify is there a difference or same law exist on the mechanism of species coexistence of subtropical forest. Furthermore, we want find out the same law of function on species coexistence. Finally, discover the role of relative genetic species played on species coexistence and biological diversity maintenance at different community classification level, time and spatial scales.

本研究以鼎湖山20公顷固定监测样地连续15年动态监测的南亚热带森林群落为对象，运用分子标记和基因片段比对技术建立准确反映亲缘关系的谱系树，并进行野外调查，测定优势种的关键功能性状，建立功能性状数据库。通过完善测定环境因子和生境条件数据，结合计算机随机化统计检验技术，创新性地以交叉学科的技术和手段，搭建微观与宏观的桥梁，进行进化与生态相关联的研究。首先，在群落不同分类水平（群落、物种、基因组）上，以优势种为原点，计算亲缘距离，结合功能性状进行亲缘种组划分。其次，探索亲缘种组在不同多样性水平上的数量及空间分布，明晰其相互作用关系。进而探寻不同时间（群落演替阶段）和空间（取样尺度）上亲缘种组的数量和分布规律。旨在验证不同分类尺度和时空尺度上物种共存的机制是否存异，进一步寻找群落中物种共存的共同作用规律。最终揭示亲缘关系在群落各个尺度（分类水平、时间、空间）上对物种共存和多样性维持的

阐明优势种在邻近种的分布格局中扮演的角色，是群落构建的关键部分，也是生态学的中心议题之一。而谱系信息可帮助分析众多群落构建机制与进化在群落构建中的重要性。在本课题中，运用分子标记和DNA条码技术建立精确谱系树，获取优势种锥栗与其余物种的谱系距离（亲缘关系），并由此把20ha南亚热带常绿阔叶林DHS样地的物种分类为与锥栗不同亲缘关系的种组。通过等面积的6种同心圆对锥栗周边的亲缘种组个体进行取样，统计种组被取样所得个体数的百分比，与构建的零模型进行种组随机置换检验，研究结果表明优势种对它的亲缘物种的影响程度取决于群落演替阶段。经典理论预测竞争排斥与密度依赖机制会导致近亲种会远离群落优势种。然而，本课题研究结果发现在成熟林与整个样地中，不管在哪种取样尺度上，近亲种反而伴生于锥栗周围，远亲物种则受竞争排斥而远离，这是受到环境过滤机制的影响。由于大量的生物因素和非生物因素导致了锥栗与亲缘种组的U型数量分布格局，时空尺度也影响优势种与亲缘种的互作关系。本课题明确了南亚热带常绿阔叶林不同群落的演替阶段，并揭示了建群种与不同亲缘物种之间的物种共存机制。