Phylogeny and climate explain contrasting hydraulic traits in different life forms of 150 woody Fabaceae species

The contrasting hydraulic traits observed among different plant life forms are shaped by entangled environmental and evolutionary processes. However, we lack understanding of the relative importance of life form, climate and phylogeny in explaining the variance of hydraulic traits. We analysed seven hydraulic traits and eleven climatic variables of 150 Fabaceae species representing three life forms from 62 sites worldwide, using phylogenetic comparative analyses and variance partitioning. The phylogenetic signal found in most traits disappeared after considering life form, indicating that phylogenetic conservatism in traits originated from the divergence among life forms. The trait‐climate relationships were also phylogenetically dependent, implying that trait responses are driven by climate and phylogeny together. Variance partitioning showed that phylogeny and climate explained greater trait variation than life form did. Synthesis . The climate‐driven hydraulic trait responses in Fabaceae still existed with phylogeny being considered, suggesting that this large family may be particularly sensitive to climate change. Our results emphasise the need to include phylogeny in plant hydraulic adaptation studies under future climate change. 植物的水力性状在不同的植物生活型中差异显著，且是复杂的环境适应和演化过程形成的结果。然而，我们对植物生活型、气候变量和系统发育在解释植物水力性状差异的相对重要性方面仍缺乏了解。 我们构建了一个来自全球62个样点、乔灌藤三种生活型的150个豆科物种共7个水力性状和11个气候变量的数据库，用系统发育比较分析和方差分解的方法解析了上述问题。 考虑植物生活型后，大多数水力性状和气候变量中发现的系统发育信号消失了，这表明这些参数的系统发育保守性源于植物生活型之间的分化。水力性状与气候变量的关系也具有系统发育依赖性，这意味着性状变异是由气候和系统发育共同驱动的。方差分解的结果表明系统发育和气候变量比植物生活型解释了更多的水力性状变异。 即使考虑了系统发育的影响，豆科植物中气候驱动的水力性状响应仍然存在，表明这个世界广布的大科可能对气候变化特别敏感。我们的结果强调了将系统发育纳入未来气候变化下植物水分适应机理研究中的重要性。