Plant communities are composed of species that differ both in functional traits and evolutionary histories. As species’ functional traits partly result from their individual evolutionary history, we expect the functional diversity of communities to increase with increasing phylogenetic diversity. This expectation has only been tested at local scales and generally for specific growth forms or specific habitat types, for example, grasslands. Here we compare standardized effect sizes for functional and phylogenetic diversity among 1,781,836 vegetation plots using the global sPlot database. In contrast to expectations, we find functional diversity and phylogenetic diversity to be only weakly and negatively correlated, implying a decoupling between these two facets of diversity. While phylogenetic diversity is higher in forests and reflects recent climatic conditions (1981 to 2010), functional diversity tends to reflect recent and past climatic conditions (21,000 years ago). The independent nature of functional and phylogenetic diversity makes it crucial to consider both aspects of diversity when analysing ecosystem functioning and prioritizing conservation efforts.

植物群落由功能特征和进化历史不同的物种组成。由于物种的功能特征部分来自其个体进化历史，我们预计群落的功能多样性将随着系统发育多样性的增加而增加。这种预期仅在局部尺度上进行了测试，并且通常针对特定的生长形式或特定的栖息地类型，例如草原。在这里，我们使用全球 sPlot 数据库比较了 1,781,836 个植被样地的功能和系统发育多样性的标准化效应大小。与预期相反，我们发现功能多样性和系统发育多样性仅呈弱负相关，这意味着多样性的这两个方面之间存在脱钩。虽然森林的系统发育多样性较高，反映了最近的气候条件（1981 年至 2010 年），但功能多样性往往反映了最近和过去的气候条件（21,000 年前）。功能和系统发育多样性的独立性使得在分析生态系统功能和确定保护工作的优先次序时考虑多样性的两个方面变得至关重要。