Center for Ecological Research, Northeast Forestry University, Harbin, China.
Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, Northeast Forestry University, Harbin, China.
Glob Chang Biol. 2023 May;29(10):2824-2835. doi: 10.1111/gcb.16639. Epub 2023 Feb 24.
Elevated temperature (T ) and drought often co-occur and interactively affect plant carbon (C) metabolism and thus the ecosystem C cycling; however, the magnitude of their interaction is unclear, making the projection of global change impacts challenging. Here, we compiled 107 journal articles in which temperature and water availability were jointly manipulated, and we performed a meta-analysis of interactive effects of T and drought on leaf photosynthesis (A ) and respiration (R ) at growth temperature, nonstructural carbohydrates and biomass of plants, and their dependencies on experimental and biological moderators (e.g., treatment intensity, plant functional type). Our results showed that, overall, there was no significant interaction of T and drought on A . T accelerated R under well-watered conditions rather than under drought conditions. The T × drought interaction on leaf soluble sugar and starch concentrations were neutral and negative, respectively. The effect of T and drought on plant biomass displayed a negative interaction, with T deteriorating the drought impacts. Drought induced an increase in root to shoot ratio at ambient temperature but not at T . The magnitudes of T and drought negatively modulated the T × drought interactions on A . Root biomass of woody plants was more vulnerable to drought than that of herbaceous plants at ambient temperature, but this difference diminished at T . Perennial herbs exhibited a stronger amplifying effect of T on plant biomass in response to drought than did annual herbs. T exacerbated the responses of A and stomatal conductance to drought for evergreen broadleaf trees rather than for deciduous broadleaf and evergreen coniferous trees. A negative T × drought interaction on plant biomass was observed on species-level rather than on community-level. Collectively, our findings provide a mechanistic understanding of the interactive effects of T and drought on plant C metabolism, which would improve the prediction of climate change impacts.
高温（T）和干旱常同时发生并相互作用，影响植物的碳（C）代谢，进而影响生态系统的碳循环；然而，它们相互作用的程度尚不清楚，这使得预测全球变化的影响具有挑战性。在这里，我们整理了 107 篇期刊文章，这些文章共同探讨了温度和水分可用性的联合处理，并对 T 和干旱对生长温度下叶片光合作用（A）和呼吸作用（R）、植物的非结构性碳水化合物和生物量及其对实验和生物学调节因子（例如，处理强度、植物功能类型）的依赖性的交互影响进行了荟萃分析。我们的研究结果表明，总体而言，T 和干旱对 A 没有显著的交互作用。在水分充足的条件下，T 会加速 R，而不是在干旱条件下。T 和干旱对叶片可溶性糖和淀粉浓度的交互作用分别为中性和负性。T 和干旱对植物生物量的影响呈负交互作用，T 会加剧干旱的影响。干旱会在环境温度下增加根冠比，但不会在 T 下增加。T 和干旱的作用大小负调节了 A 的 T 与干旱的相互作用。在环境温度下，木本植物的根生物量比草本植物更易受到干旱的影响，但在 T 下这种差异会减小。与一年生草本植物相比，多年生草本植物在应对干旱时，T 对植物生物量的放大效应更强。T 加剧了 A 和气孔导度对常绿阔叶树而非落叶阔叶树和常绿针叶树干旱的响应。在种水平上观察到了植物生物量对 T 和干旱的负交互作用，而不是在群落水平上。总的来说，我们的研究结果提供了对 T 和干旱对植物 C 代谢相互作用的机制理解，这将提高对气候变化影响的预测能力。
