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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。
The pattern of species diversity and its causes are one of the classic problems in ecology. The pedigree method integrates evolutionary information (ie, species-relatedness) into community studies, bringing a new perspective to the study of community. In this study, the canopy communities under the canyon of Luya Mountain in Shanxi Province were selected as the research objects. Based on the data of community species composition, the phylogenetic tree determined by the evolutionary time and the data of the topography and soil, the general linear regression was used. Based on the distance matrix Multiple regression and Principal Component Analysis (PCPS) of pedigree structure were used to explore the relationship between the altitude pattern of the plant community pedigree structure and pedigree diversity and its relationship with habitat factors. The results showed that the pedigree structure indicators of all the plots were all within the random confidence bands, indicating that the neutral factors had a stronger impact on the construction of the herb community. At the same time, there is a significant positive linear relationship between pedigree structure and altitude gradient, which implies that the role of deterministic process can not be neglected. Exclusion of interspecies competition may promote the divergence of pedigree structure at low altitude, while high altitude habitat filtration triggered Pedigree aggregation trend. There was a significant positive correlation between beta diversity based on recent pedigree distances and altitude differences, which also showed that the aggregation of herbaceous species was significantly affected by the habitat filtration. The first two axes of the PCPS model represent 55.9% of the pedigree-species composition variation, and the elevation is the key factor causing the variation. The two-dimensional sequencing diagram of PCPS shows that the phytoplankton assemblages in high altitude regions may be dominated by Compositae, Poaceae, Dominant and low elevations show a higher diversity of evolutionary branches, thus exhibiting divergence of pedigree. In conclusion, the study revealed the diversity of plant communities under the canopy in the mountainous coniferous forest of Luyashan Mountain, Shanxi Province, and clarified the influence of the main ecological processes on species aggregation.