β‐diversity quantifies the change in taxonomic and phylogenetic composition between areas. It can be partitioned into two additive components (turnover and nestedness). Geographic distance, which reflects dispersal limitation, and climatic distance, which reflects environmental filtering, are major drivers of β‐diversity, but few studies have assessed their relative importance to β‐diversity at a global scale. Here, we investigate the relationship of β‐diversity of angiosperm genera in regional floras worldwide to climatic conditions within regions and to geographic and climatic distances between regions. We found that (1) current climate has a stronger effect on phylogenetic turnover than does Quaternary climate change; (2) of the current climate variables examined, mean annual temperature is the strongest driver of phylogenetic turnover, followed by precipitation seasonality; (3) regions with high precipitation seasonality have high phylogenetic β‐diversity and phylogenetic turnover; and (4) at a global scale, the variation in phylogenetic turnover explained jointly by geographic and climatic distances is, on average, much larger than that explained uniquely by either distance, but that geographic distance explains more variation in phylogenetic turnover than climatic distance. Synthesis. These results reveal the synergistic role of geographic isolation and climatic filtering in determining the composition of floras worldwide, with less influence of Quaternary climate changes.

中文翻译：

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世界各地被子植物属组合中β多样性的空间和气候驱动因素


β多样性量化了区域之间分类学和系统发育组成的变化。它可以分为两个加法成分（周转率和嵌套性）。地理距离（反映扩散限制）和气候距离（反映环境过滤）是β多样性的主要驱动因素，但很少有研究评估它们对全球范围内β多样性的相对重要性。在这里，我们研究了世界区域植物区系中被子植物属的β多样性与区域内的气候条件以及区域之间的地理和气候距离的关系。我们发现 （1） 当前气候对系统发育更替的影响比第四纪气候变化更强;（2） 在当前研究的气候变量中，年平均温度是系统发育更替的最强驱动因素，其次是降水季节性;（3） 降水季节性高的区域具有较高的系统发育β多样性和系统发育周转率;（4） 在全球范围内，由地理距离和气候距离共同解释的系统发育周转变化平均比由任一距离单独解释的系统发育更替变化大得多，但该地理距离比气候距离解释的系统发育更替变化更大。合成。这些结果揭示了地理隔离和气候过滤在确定全球植物区系组成方面的协同作用，第四纪气候变化的影响较小。