Aim: We mapped global patterns of tree phylogenetic endemism (PE) to identify hotspots and test hypotheses about possible drivers. Specifically, we tested hypotheses related to current climate, geographical characteristics and historical conditions and assessed their relative importance in shaping PE patterns. Location: Global. Time period: We used the present distribution of trees, and predictors covering conditions from the mid-Miocene to present. Major taxa studied: All seed-bearing trees. Methods: We compiled distributions for 58,542 tree species across 463 regions worldwide, matched these to a recent phylogeny of seed plants and calculated PE for each region. We used a suite of predictor variables describing current climate (e.g., mean annual temperature), geographical characteristics (e.g., isolation) and historical conditions (e.g., tree cover at the Last Glacial Maximum) in a spatial regression model to explain variation in PE. Results: Tree PE was highest on islands, and was higher closer to the equator. All three groups of predictor variables contributed substantially to the PE pattern. Isolation and topographic heterogeneity promoted high PE, as did high current tree cover. Among mainland regions, temperature seasonality was strongly negatively related to PE, while mean annual temperature was positively related to PE on islands. Some relationships differed among the major floristic regions. For example, tree cover at the Last Glacial Maximum was a positive predictor of PE in the Palaeotropics, while tree cover at the Miocene was a negative predictor of PE in the Neotropics. Main conclusions: Globally, PE can be explained by a combination of geographical, historical and current factors. Some geographical variables appear to be key predictors of PE. However, the impact of historic and current climate variables differs considerably among the major floristic regions, reflecting their unique histories. Hence, the current distribution of trees is the result of globally relevant geographical drivers and regional climatic histories.

中文翻译：

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当前的气候、隔离和历史推动了全球树木系统发育特有的模式

目标：我们绘制了树木系统发育特有种 (PE) 的全球模式，以识别热点并测试有关可能驱动因素的假设。具体而言，我们测试了与当前气候、地理特征和历史条件相关的假设，并评估了它们在塑造 PE 模式中的相对重要性。地点：全球。时间段：我们使用了树木的当前分布，以及涵盖从中新世中期到现在的条件的预测因子。研究的主要分类群：所有种子树。方法：我们编制了全球 463 个地区 58,542 种树种的分布，将这些分布与最近的种子植物系统发育相匹配，并计算了每个地区的 PE。我们使用了一套预测变量来描述当前气候（例如，年平均温度）、地理特征（例如，隔离）和历史条件（例如，末次冰期最大值时的树木覆盖率）在空间回归模型中解释 PE 的变化。结果：岛屿上的树 PE 最高，靠近赤道的地方更高。所有三组预测变量都对 PE 模式做出了重大贡献。隔离和地形异质性促进了高 PE，高电流树木覆盖也是如此。在大陆地区，气温季节性与PE呈强烈负相关，而海岛年平均气温与PE呈正相关。主要植物区系之间的一些关系不同。例如，末次盛冰期的树木覆盖是古热带地区 PE 的正预测因子，而中新世的树木覆盖则是新热带地区 PE 的负预测因子。主要结论：在全球范围内，PE 可以通过地理、历史因素和当前因素。一些地理变量似乎是 PE 的关键预测因素。然而，历史和当前气候变量的影响在主要植物区系之间存在很大差异，反映了它们独特的历史。因此，当前的树木分布是全球相关地理驱动因素和区域气候历史的结果。