Environmental factors explain the spatial mismatches between species richness and phylogenetic diversity of terrestrial mammals

Aim: Explore the spatial variation of the relationships between species richness (SR), phylogenetic diversity (PD) and environmental factors to infer the possible mechanisms underlying patterns of diversity in different regions of the globe. Location: Global. Time period: Present day. Major taxa studied: Terrestrial mammals. Methods: We used a hexagonal grid to map SR and PD of mammals and four environmental factors (temperature, productivity, elevation and climate-change velocity since the Last Glacial Maximum). We related those variables through direct and indirect pathways using a novel combination of Path Analysis and Geographically Weighted Regression to account for spatial non-stationarity of path coefficients. Results: SR, PD and environmental factors relate differently across the geographic space, with most relationships varying in both, magnitude and direction. Species richness is associated with lower phylogenetic diversity in much of the tropics and in the Americas, which ref...

目的：探究物种丰富度（species richness, SR）、系统发育多样性（phylogenetic diversity, PD）与环境因子之间关系的空间变异，以推断全球不同区域多样性格局背后的潜在机制。
地点：全球。
时间范围：现今。
研究类群：陆生哺乳动物。
方法：我们采用六边形网格对哺乳动物的SR、PD及四个环境因子（温度、生产力、海拔和末次盛冰期以来的气候变化速率）进行制图。通过路径分析（Path Analysis）与地理加权回归（Geographically Weighted Regression）的创新组合，我们构建了变量间的直接与间接路径关系，以解释路径系数的空间非平稳性。
结果：SR、PD与环境因子的关系在地理空间上存在差异，多数关系的强度与方向均有变化。在热带大部分地区及美洲，物种丰富度与较低的系统发育多样性相关，这一结果...