Data from: Filter-dispersal assembly of lowland Neotropical rainforests across the Andes

Numerous Neotropical rainforest species are distributed in both Amazonia and Central America, reflecting a rich history of biotic interchange between regions. However, some plant lineages are endemic to one region, due in part to the dispersal barrier posed by the northern Andean cordilleras and adjacent savannas. To investigate the role of biogeographic filtering across the northern Andes in regional community assembly, we examined environmental tolerances, functional traits, and biogeographic distributions of >1000 woody plant species (trees, shrubs, lianas) locally co-occurring in forest plots in lowland Panama (542 species) and Amazonian Ecuador (667 species). High regional abundance was strongly predictive of the probability of being geographically widespread (i.e., present on both sides of the Andes). However, we also found that species with broad environmental tolerances (those that are able to inhabit high elevations and areas of low mean annual precipitation) were more likely to have a cross-Andean distribution even after accounting for regional abundance, suggesting that biogeographic filtering for these traits has mediated cross-Andean dispersal. Regional abundance and environmental tolerances were additionally associated with a suite of life-history traits related to high dispersal-colonization ability, but most traits reflecting dispersal-colonization ability were not predictive of biogeographic distribution. Our results highlight how the process of biogeographic filtering, based primarily on environmental tolerances, has mediated regional-scale floristic assembly of Neotropical rainforests. The impacts of this process, which we term filter-dispersal assembly, are likely to be especially important to forests in Central America, where biotic interchange with Amazonia has heavily influenced regional community composition.

大量新热带界雨林（Neotropical rainforest）物种同时分布于亚马孙（Amazonia）与中美洲，这反映出区域间长期且丰富的生物交流（biotic interchange）历史。然而部分植物支系（plant lineages）仅在单一区域特有分布，这在一定程度上源于安第斯北部科迪勒拉山脉（northern Andean cordilleras）及邻近稀树草原（savannas）构成的扩散障碍。为探究安第斯北部的生物地理过滤（biogeographic filtering）过程在区域群落构建（community assembly）中的作用，我们针对巴拿马低地森林样地（含542个物种）与厄瓜多尔亚马孙区域森林样地（含667个物种）中本地共存的1000余种木本植物物种（woody plant species，包括乔木、灌木与藤本植物（lianas））的环境耐受幅、功能性状（functional traits）及生物地理分布格局展开研究。区域多度较高的物种，其实现跨区域广布（即同时分布于安第斯山脉两侧）的概率显著更高。但我们同时发现，即便在控制区域多度变量的情况下，环境耐受幅较广的物种（即能够栖息于高海拔区域与年平均降水量（mean annual precipitation）较低的区域的物种）更有可能呈现跨安第斯分布格局，这表明针对这些性状的生物地理过滤介导了跨安第斯扩散过程。区域多度与环境耐受幅还与一系列与高扩散-定殖能力（dispersal-colonization ability）相关的生活史性状（life-history traits）相关，但多数反映扩散-定殖能力的性状无法有效预测物种的生物地理分布格局。本研究结果揭示了以环境耐受幅为核心的生物地理过滤过程，如何介导新热带界雨林的区域尺度植物区系构建（floristic assembly）。我们将这一过程命名为过滤-扩散构建（filter-dispersal assembly），该过程对中美洲森林的影响尤为显著——该区域与亚马孙的生物交流曾深刻塑造了当地的群落组成。