Environmental filtering and dispersal history limit plant distributions and affect biogeographical patterns, but how their relative importance varies across evolutionary timescales is unresolved. Phylogenetic beta diversity quantifies dissimilarity in evolutionary relatedness among assemblages and might help resolve the ecological and biogeographical mechanisms structuring biodiversity. Here, we examined the effects of environmental dissimilarity and geographical distance on phylogenetic and taxonomic turnover for ~270,000 seed plant species globally and across evolutionary timescales. We calculated past and present dispersal barriers using palaeogeographical reconstructions and calculated geographical linear and least-cost distances, accounting for dispersal over water, mountains or areas with unsuitable climates. Environmental dissimilarity and geographical distance jointly explained most of the deviance in taxonomic (up to 86.4%) and phylogenetic turnover (65.6%). While environmental dissimilarity consistently showed strongly positive effects, the effect of geographical distance on phylogenetic turnover was less pronounced further back in evolutionary time. Past physiogeographical barriers explained a relatively low amount of the variation across all timescales, with a slight peak at intermediate timescales (20–50 Myr bp). Our results suggest that while old lineages have generally dispersed widely, the imprint of environmental filtering on range expansion persists, providing insights into biogeographical and evolutionary processes underlying global biodiversity patterns.

环境过滤和扩散历史限制了植物的分布并影响了生物地理学模式，但它们的相对重要性如何随进化时间尺度的变化尚未解决。系统发育 β 多样性量化了组合之间进化相关性的差异，可能有助于解决构建生物多样性的生态和生物地理机制。在这里，我们研究了环境差异和地理距离对全球和跨进化时间尺度的 ~270,000 种种子植物物种的系统发育和分类周转的影响。我们使用古地理重建计算了过去和现在的扩散障碍，并计算了地理线性和最小成本距离，考虑了在水、山或气候不适宜地区的扩散。环境差异和地理距离共同解释了分类学 （高达 86.4%） 和系统发育更替 （65.6%） 的大部分偏差。虽然环境差异始终显示出强烈的积极影响，但地理距离对系统发育更替的影响在进化时间更早时不那么明显。过去的物理地理障碍解释了所有时间尺度上相对较低的变化量，在中间时间尺度 （20-50 Myr bp） 有一个轻微的峰值。我们的结果表明，虽然古老的谱系通常分布广泛，但环境过滤对范围扩大的影响仍然存在，为了解全球生物多样性模式背后的生物地理和进化过程提供了见解。