Phylogenetic turnover has emerged as a powerful tool to identify the mechanisms by which biological communities assemble. When significantly structured along environmental gradients, phylogenetic turnover evidences phylogenetic niche conservatism, a critical principle explaining patterns of species distributions at different spatio–temporal scales. Here, we quantify the contribution of geographic and macroclimatic drivers to explain patterns of phylogenetic turnover in an entire phylum of land plants, namely liverworts. We further determine whether climatic niche conservatism has constrained the distribution of liverworts in the course of their evolutionary history. Two datasets, one insular, focused on 60 archipelagos and including 2346 species, and the second global, including 6334 species in 451 oceanic and continental operational geographic units (OGUs) worldwide, were assembled. Phylogenetic turnover among OGUs was quantified through π_st statistics. π_st-through-time profiles were generated at 1 Myr intervals along the phylogenetic time-scale and used to compute the correlation between π_st, current geographic distance and macroclimatic variation with Mantel tests based on Moran spectral randomization to control for spatial autocorrelation. The contribution of macroclimatic variation to phylogenetic turnover was about four-times higher than that of geographic distance, a pattern that was consistently observed in island and global geographic settings, and with datasets including or excluding species-poor OGUs. The correlation between phylogenetic turnover and geographic distance rapidly decayed at increasing phylogenetic depth, whereas the relationship with macroclimatic variation remained constant until 100 Mya. Our analyses reveal that changes in the phylogenetic composition among liverwort floras across the globe are primarily shaped by macroclimatic variation. They demonstrate the relevance of macroclimatic niche conservatism for the assembly of liverwort floras over very large spatial and evolutionary time scales, which may explain why such a pervasive biodiversity pattern as the increase of species richness towards the tropics also applies to organisms with high dispersal capacities.

中文翻译：

---

地衣空间系统发育周转的大气候结构

系统发育周转已成为识别生物群落组装机制的有力工具。当沿着环境梯度显着构建时，系统发育周转证明了系统发育生态位保守性，这是解释不同时空尺度物种分布模式的关键原则。在这里，我们量化了地理和大气候驱动因素的贡献，以解释整个陆生植物门（即苔类植物）的系统发育更新模式。我们进一步确定气候生态位保守主义是否在其进化历史过程中限制了苔类植物的分布。两个数据集，一个是岛屿，专注于 60 个群岛，包括 2346 个物种，第二个是全球性的，包括全球 451 个海洋和大陆业务地理单位 (OGU) 中的 6334 个物种。OGUs 之间的系统发育周转通过 π 量化_st统计。沿系统发育时间尺度以 1 Myr 间隔生成π _st时间分布图，用于计算 π _st之间的相关性，当前地理距离和大气候变化与基于 Moran 光谱随机化的 Mantel 测试，以控制空间自相关。大气候变化对系统发育周转的贡献大约是地理距离的四倍，这种模式在岛屿和全球地理环境中一致观察到，数据集包括或不包括物种贫乏的 OGU。系统发育周转和地理距离之间的相关性随着系统发育深度的增加而迅速衰减，而与大气候变化的关系在 100 Mya 之前保持不变。我们的分析表明，全球地草植物群系统发育组成的变化主要受大气候变化的影响。