Aim Intraspecific trait variation (ITV) can be large within natural plant communities, influencing local ecological processes and dynamics. Here, we shed light on how ITV in vegetative and floral traits responds to large-scale abiotic and biotic gradients (i.e. climate and species richness). Specifically, we tested if associations of ITV with temperature, precipitation and species richness reflect the predicted patterns of four hypotheses relating to stress-tolerance and competition. Furthermore, we estimate the degree of correlation between ITV in vegetative and floral traits and how it varies along the gradients. Location Global. Time period 1975-2016. Major taxa studied Herbaceous and woody plants. Methods We compiled a dataset of 18,112 measurements of the absolute extent of ITV (measured as coefficient of variation) in nine vegetative and seven floral traits from 2,774 herbaceous and woody species at 2,306 locations. Results Large-scale associations between the absolute extent of ITV and climate were trait-specific and more prominent for vegetative traits, especially leaf morphology, than for floral traits. Climate showed pronounced associations with ITV, with lower ITV values in colder areas and higher values in drier areas. The associations of species richness with ITV were inconsistent across traits. Species-specific associations across gradients were often idiosyncratic and covariation in ITV was weaker between vegetative and floral traits than within the two trait groups. Main conclusions Our results show that, depending on the traits considered, ITV either increased or decreased with climate stress and species richness, suggesting that both factors can constrain or enhance ITV, which might foster plant populations’ persistence under stressful conditions. Given the species-specific responses and covariation in ITV, associations can be hard to predict for traits and species not yet studied. We conclude that considering ITV can improve our understanding of how plants cope with stressful conditions and environmental change across spatial and biological scales.

中文翻译：

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植物和花卉性状种内变异的全球梯度部分与气候和物种丰富度有关

目的 种内性状变异 (ITV) 在天然植物群落内可能很大，影响当地的生态过程和动态。在这里，我们阐明了植物性状和花卉性状中的 ITV 如何响应大规模的非生物和生物梯度（即气候和物种丰富度）。具体而言，我们测试了 ITV 与温度、降水和物种丰富度的关联是否反映了与压力耐受性和竞争相关的四种假设的预测模式。此外，我们估计了植物性状和花卉性状中 ITV 之间的相关程度以及它如何沿梯度变化。位置全球。时间段 1975-2016。主要分类群研究草本和木本植物。方法 我们编译了一个 18 个数据集，对来自 2,306 个地点的 2,774 种草本和木本植物的 9 个植物性状和 7 个花卉性状的 ITV 绝对范围（以变异系数衡量）进行了 112 次测量。结果 ITV 的绝对范围与气候之间的大规模关联具有性状特异性，并且与植物性状相比，植物性状尤其是叶片形态更为突出。气候与 ITV 有明显的关联，寒冷地区的 ITV 值较低，干燥地区的 ITV 值较高。物种丰富度与 ITV 的关联在性状之间不一致。跨梯度的物种特异性关联通常是特异的，并且在 ITV 中，植物性状和花卉性状之间的协变比两个性状组内的要弱。主要结论 我们的结果表明，根据所考虑的特征，ITV 随气候压力和物种丰富度而增加或减少，这表明这两个因素都可以限制或增强 ITV，这可能会促进植物种群在压力条件下的持久性。鉴于 ITV 中的物种特异性反应和协变，很难预测尚未研究的性状和物种的关联。我们得出的结论是，考虑 ITV 可以提高我们对植物如何应对空间和生物尺度上的压力条件和环境变化的理解。