Data from: Phylogenetic plant community structure along elevation is lineage specific

The trend of closely related taxa to retain similar environmental preferences mediated by inherited traits suggests that several patterns observed at the community scale originate from longer evolutionary processes. While the effects of phylogenetic relatedness have been previously studied within a single genus or family, lineage-specific effects on the ecological processes governing community assembly have rarely been studied for entire communities or flora. Here, we measured how community phylogenetic structure varies across a wide elevation gradient for plant lineages represented by 35 families, using a co-occurrence index and net relatedness index (NRI). We propose a framework that analyses each lineage separately and reveals the trend of ecological assembly at tree nodes. We found prevailing phylogenetic clustering for more ancient nodes and overdispersion in more recent tree nodes. Closely related species may thus rapidly evolve new environmental tolerances to radiate into distinct communities, while older lineages likely retain inherent environmental tolerances to occupy communities in similar environments, either through efficient dispersal mechanisms or the exclusion of older lineages with more divergent environmental tolerances. Our study illustrates the importance of disentangling the patterns of community assembly among lineages to better interpret the ecological role of traits. It also sheds light on studies reporting absence of phylogenetic signal, and opens new perspectives on the analysis of niche and trait conservatism across lineages.

由遗传性状介导的近缘类群保留相似环境偏好的趋势表明，群落尺度下观测到的诸多格局源自更为漫长的演化历程。尽管此前已有研究在单属或单科范围内探讨了系统发育亲缘关系的效应，但针对整个群落或植物区系中演化支对群落构建调控生态过程的支系特异性效应的研究却较为匮乏。本研究以涵盖35个科的植物支系为研究对象，借助共现指数（co-occurrence index）与净亲缘指数（net relatedness index, NRI），探究了群落系统发育结构沿广阔海拔梯度的变化规律。我们提出了一套可分别分析各支系、并能揭示系统发育树节点处生态构建趋势的分析框架。研究发现，较为古老的节点普遍呈现系统发育聚类特征，而较年轻的节点则表现出性状过度分散现象。由此可见，近缘物种可快速演化出全新的环境耐受能力，进而辐射定植于不同群落；而古老支系则可能保留固有的环境耐受特性，凭借高效的扩散机制或通过排斥环境耐受特性更为分化的古老支系，占据相似环境中的群落生境。本研究阐明了厘清不同支系间群落构建格局的重要性，以更好地阐释性状的生态功能；同时也为那些未检测到系统发育信号的相关研究提供了新的解读视角，并为跨支系的生态位与性状保守性分析开辟了全新的研究思路。