植物生态学报 ›› 2017, Vol. 41 ›› Issue (7): 707-715.doi: 10.17521/cjpe.2016.0247

• 研究论文 •    下一篇

山西芦芽山针叶林草本层群落谱系结构与多样性的海拔格局

赵鸣飞1,2, 薛峰1,2, 王宇航1,2, 王国义1,2, 邢开雄1,2, 康慕谊1,2,*(), 王菁兰3   

  1. 1北京师范大学地理科学学部地表过程与资源生态国家重点实验室, 北京 100875
    2北京师范大学地理科学学部资源学院, 北京 100875
    3清华大学生命科学学院,北京 100084
  • 收稿日期:2016-07-21 接受日期:2017-04-05 出版日期:2017-07-10 发布日期:2017-08-21
  • 通讯作者: 康慕谊 E-mail:kangmy@bnu.edu.cn
  • 作者简介:

    * 通信作者Author for correspondence (E-mail:kangmy@bnu.edu.cn)

  • 基金资助:
    国家自然科学基金(41271059)和科技部科技基础性工作专项(2011FY110300)

Phylogenetic structure and diversity of herbaceous communities in the conifer forests along an elevational gradient in Luya Mountain, Shanxi, China

Ming-Fei ZHAO1,2, Feng XUE1,2, Yu-Hang WANG1,2, Guo-Yi WANG1,2, Kai-Xiong XING1,2, Mu-Yi KANG1,2,*(), Jing-Lan WANG3   

  1. 1State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China

    2College of Resources Science & Technology, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China
    and
    3School of Life Science, Tsinghua University, Beijing 100084, China
  • Received:2016-07-21 Accepted:2017-04-05 Online:2017-07-10 Published:2017-08-21
  • Contact: Mu-Yi KANG E-mail:kangmy@bnu.edu.cn
  • About author:

    KANG Jing-yao(1991-), E-mail: kangjingyao_nj@163.com

摘要:

物种多样性格局及其成因是生态学的经典问题之一。谱系方法将演化信息(即物种亲缘关系)整合到群落学研究中, 给群落学研究带来了全新视角。该研究以山西芦芽山针叶林冠层下草本群落为研究对象, 将群落物种组成数据、厘定有进化时间的谱系树与地形、土壤等生境数据相结合, 运用一般线性回归、基于距离矩阵的多元回归和谱系结构主坐标分析(PCPS)等统计方法, 探究了草本群落谱系结构与谱系多样性的海拔格局及其与生境因子的关系。结果表明: 所有样地的谱系结构指标均落在随机置信带之内, 说明中性因素对草本群落构建的影响较为强烈。同时,谱系结构与海拔梯度之间存在显著的正线性关系, 暗示确定性过程的作用也不可忽略, 种间竞争排斥可能促进了低海拔地区谱系结构呈发散趋势, 而高海拔的生境过滤引发了谱系聚集趋势。基于最近谱系距离的beta多样性与海拔差异之间呈极显著正相关关系, 同样反映了草本层物种集聚受到了生境过滤的显著影响。PCPS模型前两轴代表了55.9%的谱系-物种组成变异, 海拔是引起该变异的关键因子; PCPS二维排序图显示, 高海拔地区群落的谱系聚集可能由菊科、禾本科等大科所主导, 低海拔则显示出较高的演化分支多样性, 从而表现出谱系发散。综上所述, 该研究揭示了山西芦芽山山地针叶林冠层下草本群落谱系多样性格局, 并初步明晰了主要生态过程对物种集聚的影响规律。

关键词: 多样性海拔格局, 谱系alpha多样性, 谱系beta多样性, 谱系结构主坐标分析, 草本植物

Abstract:
Aims Incorporating phylogenetic data in the studies of species diversity patterns along elevational gradients can bridge the gap between ecological and evolutionary processes, and thus shed light on the issues related to community assemblage. We aim is to explore the elevational patterns of phylogenetic relatedness and phylodiversity in the herbaceous angiosperm assemblages of alpine conifer forest within mountain ecosystem, and to quantify the relationship between the patterns and habitat factors. Methods We sampled 17 plots (20 m × 30 m) in the coniferous forest communities at ca. 50 m altitudinal intervals along the elevation gradient. In each plot, we documented all species encountered and the environmental conditions. We used the Net Relatedness Index (NRI) and Nearest Taxon Index (NTI) to quantify the phylogenetic structures of each herbaceous assemblage, and used the Mean Pairwise Distance and Mean Nearest Taxon Distance to quantify phylogenetic beta diversity. Ordinary least square regression and multiple regression on distance matrices were employed respectively to explore the elevational trends of phylogenetic structure and phylobetadiversity. We analyzed the taxonomic composition of the herbaceous assemblages within forests, and demonstrated the relationship between the clustering of clades and the significant habitat descriptors using principal coordinates of phylogenetic structure (PCPS). Important findings The result showed that the herbaceous communities tended to be more phylogenetically overdispersed at lower elevations, suggesting that intraspecific competition potentially influences the local assemblages. In contrast, species occurring at high-elevation sites tended to be more closely related, implying that these communities are structured primarily by environmental filtering. However, we found that all of the NRI (or NTI) were confined within 95% confidence intervals, suggesting strong contributions of stochastic processes on species assembly. Phylogenetic beta diversity significantly increased with the elevational distance between community pairs, also suggesting that habitat filtering probably played an important role on structuring the herbaceous communities. The first two axes of PCPS contained 55.9% of total variation in phylogeny-weighted species composition, and were both significantly related with elevation and arboreal basal area. We found that species of large families, including Asteraceae and Poaceae, were phylogenetically clustered at high elevations, whereas the others were phylogenetically overdispersed at low elevation region. Our findings suggest that exploring the patterns of phylogenetic structures across elevational gradients is important, which can provide insights into the underlying mechanisms shaping community composition within montane ecosystems.

Key words: diversity elevational pattern, phylogenetic alpha diversity, phylogenetic beta diversity, principal coordinates of phylogenetic structure, herbaceous plants