摘要
灌丛是太行山地区最重要的生态系统类型之一,灌丛群落生物多样性的维持及其生态系统服务功能对京津冀地区的生态安全具有重要作用。本研究选择太行山最具代表性的两种灌木群落——荆条(Vitex negundo var. heterophylla)灌丛和三裂绣线菊(Spiraea trilobata)灌丛为研究对象,利用净亲缘关系指数(net relatedness index,NRI)和多元回归等方法探究了两种灌丛群落构建机制的异同及主要的环境影响因子,同时还利用谱系结构主坐标分析(principal coordinates of phylogenetic structure,PCPS)对决定群落谱系结构的关键系统发育节点进行了探究。结果表明:两种灌丛群落内灌木植物的物种多样性没有显著差异,但谱系结构差异显著。三裂绣线菊群落表现出显著的谱系发散趋势,而荆条群落谱系聚集程度高于三裂绣线菊群落,但未表现出显著的谱系结构。三裂绣线菊灌丛群落构建的驱动机制是生态位分化,荆条灌丛中生境过滤作用有所增加,与生态位分化共同驱动其群落构建过程。与干旱胁迫相关的生境过滤因素增加是荆条灌丛群落谱系聚集程度增加的重要原因。PCPS二维排序结果表明:荆条灌丛群落谱系趋向聚集与其群落内缺乏蔷薇目、壳斗目等亲缘关系较远的类群有关,而三裂绣线菊灌丛群落内物种则包含较多的演化分支。总体而言,环境过滤不是决定太行山地区灌丛群落构建的主要驱动因素,但水分条件仍然是影响区域群落谱系结构的重要因素。
Aims: Shrublands are one of the most important ecosystems in Taihang Mountains region of China. Shrub communities play an important role in maintaining biodiversity, providing ecosystem services, and promoting ecological security in the Beijing-Tianjin-Hebei region. Methods: We explored differences in community assembly and associated environmental factors for two of the most representative shrub communities in the region, Vitex negundo var. heterophylla and Spiraea trilobata, by assessing their net relatedness index(NRI) and using multiple regression. We further used principal coordinates of phylogenetic structure(PCPS) to determine the key phylogenetic nodes giving rise to the community phylogenetic structure. Results: We found that the phylogenetic structures of these two shrub communities were significantly different despite no detectable difference in their species diversity. The S. trilobata community showed significant phylogenetic overdispersion, whereas the V. negundo var. heterophylla community showed no significant phylogenetic structure, despite exhibiting a greater degree of clustering degree than S. trilobata community. Community assembly of S. trilobata shrubs was driven by niche differentiation. By contrast, habitat filtering together with niche differentiation drove community assembly of V. negundo var. heterophylla shrubs. Habitat filtering related to drought stress was the main reason for the increase in phylogenetic clustering of V. negundo var. heterophylla shrubs. The PCPS two-dimensional ranking results showed that the phylogenetic clustering trend of the V. negundo var. heterophylla shrub community was mainly attributed to the lack of distantly related groups, such as Rosales and Fagales, while the species comprising the S. trilobata shrub community contained more phylogenetic clades. Conclusion: Our results suggest that habitat filtering was not a major driver of shrub community assembly in the Taihang Mountains region and that water limitation was an important factor in determining regional community phylogenetic structure of shrubland ecosystems.
作者
董雷
王静
刘永刚
赵志平
米湘成
郭柯
Lei Dong;Jing Wang;Yonggang Liu;Zhiping Zhao;Xiangcheng Mi;Ke Guo(State Key Laboratory of Vegetation and Environmental Change,Institute of Botany,Chinese Academy of Sciences,Beijing 100093;State Key Laboratory of Systematic and Evolutionary Botany,Chinese Academy of Sciences,Beijing 100093;Research Center for Biodiversity,Chinese Research Academy of Environmental Sciences,Beijing 100012;University of Chinese Academy of Sciences,Beijing 100049)
出处
《生物多样性》
CAS
CSCD
北大核心
2021年第1期21-31,共11页
Biodiversity Science
基金
生态环境部生物多样性调查评估项目(2019HJ2096001006)。
关键词
群落构建
生态位分化
生境过滤
主坐标分析
水分限制
community assembly
niche differentiation
habitat filtering
principal coordinates analysis
water limitation