AimClimate change is altering forest communities at an unprecedented pace. Current knowledge on trees' responses to climate shifts is based mostly on adults. Yet, germination traits and intraspecific variation can notably modulate species niches. This paper provides a quantitative review about warming effects on tree species' germination, the role of population effects and its implications under future climate.LocationGlobal; covering boreal, temperate, Mediterranean and tropical–subtropical biomes.Time Period1996–2024.Major Taxa StudiedTree species.MethodsWe reviewed 50 papers addressing 63 species and 250 populations. Then, we conducted a meta‐analysis to assess warming effects on germination percentage and time, and how germination is modulated by climate at seed origin. We further evaluated populations' adaptation to local temperature on 27 species. Finally, we estimated population‐based germination niches in eight of these species under current climate conditions and a 2080 climate scenario (SSP5‐8.5).ResultsWarming induced more consistent shifts in germination time than in percentage across biomes, hastening germination. Temperature at seed origin shaped responses to warming in boreal and temperate species. In Mediterranean and tropical–subtropical species, different responses were associated with variation in precipitation‐related variables. Local adaptation was more frequent in species from the tropics, while adaptation lags towards warmer‐than‐today conditions observed in the other biomes. Simulation of germination niches yielded slight although extensive germination reductions in tropical–subtropical species under future climate, whereas the temperate and boreal ones showed overall increases.Main ConclusionsPopulation‐level adjustments are key moderators of germination percentage and phenology response to warming. Their roles vary depending on the prevailing climate in each biome. Temperature at seed origin is an important factor modulating temperate and boreal species' responses, while precipitation‐related variables are more relevant in Mediterranean and tropical–subtropical ones. Local adaptation in the tropical species increases their vulnerability to warming.

中文翻译：

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树木发芽对温度升高的敏感性：跨生物群落、物种和种群的全球荟萃分析


目标气候变化正在以前所未有的速度改变森林群落。目前关于树木对气候变化反应的知识主要基于成年人。然而，发芽性状和种内变异可以显着调节物种生态位。本文对变暖对树种萌发的影响、种群效应的作用及其对未来气候的影响进行了定量综述。覆盖北方、温带、地中海和热带-亚热带生物群落。时间段1996-2024。研究的主要分类单元树种。方法我们回顾了涉及 63 个物种和 250 个种群的 50 篇论文。然后，我们进行了荟萃分析，以评估变暖对发芽率和时间的影响，以及种子起源地气候如何调节发芽。我们进一步评估了 27 个物种种群对当地温度的适应情况。最后，我们估计了其中八个物种在当前气候条件和 2080 年气候情景下的基于种群的发芽生态位 (SSP5-8.5)。结果变暖导致发芽时间的变化比生物群落百分比的变化更加一致，从而加速了发芽。种子起源的温度决定了北方和温带物种对变暖的反应。在地中海和热带-亚热带物种中，不同的反应与降水相关变量的变化有关。来自热带的物种的局部适应更为频繁，而在其他生物群落中观察到的适应情况则滞后于比今天更温暖的条件。对发芽生态位的模拟显示，在未来气候下，热带-亚热带物种的发芽率虽然大幅下降，但略有减少，而温带和北方物种的发芽率总体上有所增加。主要结论人口水平的调整是发芽率和物候对变暖反应的关键调节因素。它们的作用因每个生物群落的主要气候而异。种子起源温度是调节温带和北方物种反应的重要因素，而与降水相关的变量在地中海和热带-亚热带物种中更为相关。热带物种的局部适应增加了它们对变暖的脆弱性。