Accelerating homogenization of the global plant–frugivore meta-network

Introductions of species by humans are causing the homogenization of species composition across biogeographic barriers. The ecological and evolutionary consequences of introduced species derive from their effects on networks of species interactions, but we lack a quantitative understanding of the impacts of introduced species on ecological networks and their biogeographic patterns globally. Here we address this data gap by analysing mutualistic seed-dispersal interactions from 410 local networks, encompassing 24,455 unique pairwise interactions between 1,631 animal and 3,208 plant species. We show that species introductions reduce biogeographic compartmentalization of the global meta-network, in which nodes are species and links are interactions observed within any local network. This homogenizing effect extends across spatial scales, decreasing beta diversity among local networks and modularity within networks. The prevalence of introduced interactions is directly related to human envi...人为物种引入正导致跨生物地理屏障的物种组成趋于均质化。外来物种引入所产生的生态与演化后果，源自其对物种互作网络的作用，但目前全球范围内，我们尚未能定量认知外来物种对生态网络及其生物地理格局的影响。为此，本研究通过分析来自410个本地互作网络的互利性种子传播互作数据，填补了这一数据缺口；该数据集涵盖了1631种动物与3208种植物之间共计24455组独特的成对互作关系。研究结果显示，人为物种引入会降低全球元网络（meta-network）的生物地理分区程度——该元网络以物种作为节点，以任意本地网络中观测到的互作关系作为连边。这种均质化效应在多个空间尺度上均有体现，会降低本地网络间的β多样性（beta diversity）以及网络内部的模块化程度。外来互作的流行程度直接与人类环