The contribution of the edaphic factor as a driver of recent plant diversification in a Mediterranean biodiversity hotspot

1. The high diversification rates of plant lineages in the Mediterranean Basin hotspot have been linked to a complex interaction of climatic stressors, geographic isolation and soil type, but the question remains as to which of these factors has been the most significant environmental driver of recent speciation. 2. Here, we draw on distributional data for the entire endemic flora of the Iberian Peninsula, together with DNA-based phylogenies and spatial phylogenetic methods, to explore patterns of relative phylogenetic endemism at different spatial resolutions and phylogenetic scales (superclades) and assess how environmental factors contribute to explain these patterns. 3. We found that recent diversification of angiosperms as a whole, and particularly of eudicots, has been boosted by environmental stressors including high values of soil pH and dry-seasonal climatic conditions, while diversification of monocots has not been associated with soil conditions but with high elevation ...1. 地中海盆地生物多样性热点（Mediterranean Basin hotspot）区域内的植物谱系分化速率极高，该现象此前被归因于气候胁迫因子、地理隔离与土壤类型间的复杂互作，但目前仍未明确上述因素中哪一项是驱动近期物种形成（speciation）的最关键环境驱动因子。 2. 本研究依托伊比利亚半岛全部特有植物区系的分布数据，结合DNA系统发育数据与空间系统发育分析方法，探究不同空间分辨率与系统发育尺度（超类群，superclades）下的相对系统发育特有性（relative phylogenetic endemism）模式，并评估环境因子对这些模式的贡献程度。 3. 研究发现，整体被子植物（angiosperms）尤其是真双子叶植物（eudicots）的近期分化受到了土壤pH值偏高与旱季型气候条件等环境胁迫因子的促进；而单子叶植物（monocots）的分化则与土壤条件无关，而是与高海拔相关……