Data from: Trait patterns across space and time suggest an interplay of facilitation and competition acting on Neotropical hummingbird-pollinated plant communities

Pollinators may influence plant community assembly through biotic filtering and/or plant-plant competition and facilitation. The relative importance of each process, however, vary according to the scale and how strongly plants share their pollinators, and possibly in relation to the pollinator groups considered. We here investigated the assembly of three Atlantic forest hummingbird-pollinated plant communities across space (among all species in the communities) and time, i.e. yearly flowering phenology (between pairs of co-flowering species), based on the pairwise distances of multiple floral traits (corolla length, anther and stigma height, colour and nectar). Because tropical hummingbird-pollinated plants are often subdivided in two pollination niches (hermits vs. non-hermits), we also analyzed these groups separately. We found that trait structure across space was clustered for some floral traits, suggesting biotic filtering and facilitation. All floral traits had weak phylogenetic signal, indicating that closely related species were not more similar than distantly related species. Moreover, floral traits were randomly structured along the phenology when analyzing all plants together. On the other hand, we found similar corolla length but divergent anther height in co-flowering pairs within the same pollination niche. Thus, plants may benefit from flowering together and avoid competition through fine adjustments in reproductive traits. Our results also suggest that clear signals of competition and facilitation among plants are only apparent when species strongly share their pollinators and depending on the traits that are considered. Our study illustrate a complex interplay of biotic filtering, facilitation and competition as processes structuring assemblages of plants sharing the same functional group of pollinators.

传粉者（Pollinators）可通过生物过滤（biotic filtering）、种间竞争（plant-plant competition）及促进作用（facilitation）调控植物群落构建（plant community assembly）。然而，各过程的相对重要性随研究尺度、植物共享传粉者的程度而异，且可能与所考量的传粉者类群相关。本研究以三处大西洋森林（Atlantic forest）中的蜂媒植物（hummingbird-pollinated plant）群落为对象，分别从空间（群落内所有物种间）与时间（即年度开花物候（flowering phenology），同花期物种（co-flowering species）对之间）两个维度，基于多个花部性状（floral traits）的成对距离（pairwise distances）开展群落构建研究。所涉花部性状包括花冠长度（corolla length）、花药高度（anther height）、柱头高度（stigma height）、花色及花蜜。由于热带蜂媒植物通常可划分为两类传粉生态位（pollination niches）（隐蜂鸟类群vs非隐蜂鸟类群，hermits vs non-hermits），本研究还针对这两个类群分别开展了分析。研究发现，部分花部性状的空间分布呈现聚集模式，暗示存在生物过滤与促进作用。所有花部性状均表现出较弱的系统发育信号（phylogenetic signal），表明近缘物种间的性状相似度并不高于远缘物种。此外，当整合所有植物类群进行分析时，花部性状沿开花物候的分布呈现随机模式。而在同一传粉生态位内的同花期物种对中，观测到花冠长度趋于相似，但花药高度存在显著分化。由此可见，植物可通过生殖性状的精细调控，实现同步开花以获得益处并避免种间竞争。本研究结果还表明，植物间竞争与促进作用的清晰信号仅在物种共享传粉者程度较高的情况下才会显现，且这一结论依赖于所考量的花部性状类型。本研究揭示了生物过滤、促进作用与种间竞争之间的复杂相互作用，正是这些过程构建了共享同一传粉者功能群（functional group）的植物类群的群落结构。