Institute of Ecology and Evolution, University of Bern, Bern, 3012, Switzerland.
Institute of Plant Sciences, University of Bern, Bern, 3013, Switzerland.
BMC Ecol Evol. 2024 Jul 4;24(1):92. doi: 10.1186/s12862-024-02275-6.
The increasing severity and frequency of drought pose serious threats to plant species worldwide. Yet, we lack a general understanding of how various intensities of droughts affect plant traits, in particular root traits. Here, using a meta-analysis of drought experiments (997 effect sizes from 76 papers), we investigate the effects of various intensities of droughts on some of the key morphological root traits. Our results show that root length, root mean diameter, and root area decline when drought is of severe or extreme intensity, whereas severe drought increases root tissue density. These patterns are most pronounced in trees compared to other plant functional groups. Moreover, the long duration of severe drought decreases root length in grasses and root mean diameter in legumes. The decline in root length and root diameter due to severe drought in trees was independent of drought duration. Our results suggest that morphological root traits respond strongly to increasing intensity of drought, which further depends on drought duration and may vary among plant functional groups. Our meta-analysis highlights the need for future studies to consider the interactive effects of drought intensity and drought duration for a better understanding of variable plant responses to drought.
干旱的严重程度和频率不断增加，对全球植物物种构成了严重威胁。然而，我们还缺乏对不同强度的干旱如何影响植物特征，特别是根特征的全面了解。在这里，我们通过对干旱实验的元分析（来自 76 篇论文的 997 个效应量），研究了不同强度的干旱对一些关键形态根特征的影响。我们的结果表明，当干旱强度为严重或极端时，根长、根平均直径和根面积会下降，而严重干旱会增加根组织密度。与其他植物功能群相比，这些模式在树木中更为明显。此外，严重干旱的持续时间长会导致草类植物的根长和豆科植物的根平均直径减小。树木中严重干旱导致的根长和根直径下降与干旱持续时间无关。我们的研究结果表明，形态学根特征对干旱强度的增加反应强烈，这进一步取决于干旱持续时间，并且在不同的植物功能群之间可能有所不同。我们的元分析强调了未来研究需要考虑干旱强度和干旱持续时间的交互作用，以更好地理解植物对干旱的可变响应。
