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研究不同径级尺度群落系统发育多样性有助于了解不同年龄模式下物种的亲缘关系及其群落系统发育结构;但是关于物种多度对群落系统发育结构影响的研究较少。以海南尖峰岭热带山地雨林群落为例,首先在不同径级尺度比较物种多度加权与否分别对4个广泛采用的系统发育指数的影响,继而利用其中2个经过标准化处理的系统发育多样性指数:净种间亲缘关系指数(net relatedness index,NRI)和净最近种间亲缘关系指数(nearest taxon index,NTI),结合群落的生境类型来量度不同局域生境条件下不同径级尺度木本植物系统发育关系。结果发现:(1)未考虑物种多度加权的系统发育平均成对距离(mean pairwise distance,MPD)指数比考虑物种多度加权的MPD指数显著地高估了群落整体系统发育多样性,且这种现象在小径级尺度(1 cm≤DBH<5 cm)最为明显。因此,在森林监测样地中对于中、小径级群落系统发育结构研究中建议考虑物种多度信息。(2)从群落组成整体系统发育结构来看,尖峰岭热带山地雨林在几乎所有径级尺度和生境下均倾向于系统发育发散,且随着径级的递增发散程度趋于明显(NRI<0)。(3)从群落组成局部系统发育结构来看,尖峰岭热带山地雨林在中、小径级倾向于系统发育聚集(NTI>0),而在大径级(DBH≥15 cm)则倾向于系统发育发散(NTI<0)。总之,研究群落系统发育结构时应考虑物种多度的影响以及径级尺度效应。
Studying the diversity of phylogenetic diversity of different size scales community is helpful to understand the genetic relationship and community phylogenetic structure of species under different age patterns. However, there are few studies on the influence of species abundance on the phylogenetic structure of the community. Taking the tropical montane rainforest communities in Jianfengling, Hainan as an example, we first compared the effects of different degrees of abundance on the four widely used phylogenetic indices, and then used two standardized phylogenetic diversity Indexes: net relatedness index (NRI) and net nearest nearest-neighbor index (NTI), combined with the habitat types of the communities to measure the differences in woody habitats between different size scales Plant phylogenetic relationships. The results showed that: (1) The MPD index, which did not take into account species-abundance weighting, significantly overestimated the overall phylogenetic diversity of species in comparison with the MPD index which considered species abundance-weighted The phenomenon is most obvious at the small diameter scale (1 cm ≤ DBH <5 cm). Therefore, it is suggested to consider the species abundance information in the forest monitoring plots for the study of phylogenetic structure of middle and small-sized communities. (2) Judging from the overall phylogenetic structure of the communities, the tropical montane rain forest of Jianfengling tended to diverge systematically at almost all diameter scales and habitats, and the divergence degree became more and more obvious with increasing grade diameter (NRI <0 ). (3) From the perspective of local phylogenetic structure, the tropical rainforests of Jianfengling tended to phylogenetically (NTI> 0) in the middle and small diameter classes, whereas the phytoplankton tended to be larger in the larger diameter classes (DBH> 15 cm) Divergent (NTI <0). In summary, the study of the phylogenetic structure of the community should take into account the effects of species abundance and the size-scale effect.