• Plants continue to lose water from their leaves even after complete stomatal closure. Although this minimum conductance (g_leaf‐res) has substantial impacts on strategies of water use and conservation, little is known about the potential drivers underlying the variability of this trait across species.
• We thus untangled the relative contribution of water leaks from the cuticle and stomata in order to investigate how the variability in leaf morphological and anatomical traits is related to the variation in g_leaf‐res and carbon assimilation capacity across 30 diverse species from the Brazilian Cerrado.
• In addition to cuticle permeance, water leaks from stomata had a significant impact on g_leaf‐res. The differential pattern of stomata distribution in the epidermis was a key factor driving this variation, suggesting the existence of a trade‐off between carbon assimilation and water loss through g_leaf‐res. For instance, higher g_leaf‐res, observed in fast‐growing species, was associated with the investment in small and numerous stomata, which allowed higher carbon assimilation rates but also increased water leaks, with negative impacts on leaf survival under drought. Variation in cuticle structural properties was not linked to g_leaf‐res.
• Our results therefore suggest the existence of a trade‐off between carbon assimilation efficiency and dehydration tolerance at foliar level.

中文翻译：

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叶子漏水从哪里来？权衡取舍于热带热带稀树草原物种的最低电导率的可变性以及不同的生长策略。

• 甚至在气孔完全关闭后，植物仍然会从叶子上失去水分。尽管此最低电导率（g _leaf-res）对水资源的利用和保护战略具有重大影响，但对于这一特性在物种间变异的潜在驱动因素知之甚少。
• 因此，我们弄清了角质层和气孔渗水的相对贡献，以研究巴西Cerrado的30种不同物种的叶片形态和解剖特征的变异与g_叶片资源和碳同化能力的变化如何相关。
• 除表皮渗透性外，气孔的渗漏对克_叶的影响也很大。表皮中气孔分布的差异是导致这种变化的关键因素，这表明碳同化和通过g_叶的水分流失之间存在权衡。例如，在快速生长的物种中观察到的更高的g_叶片残留量与对小而众多的气孔的投资有关，这允许更高的碳同化率，但也增加了漏水量，对干旱条件下的叶片存活产生了负面影响。角质层结构特性的变化与g_{叶res没有关系}。
• 因此，我们的结果表明，在叶面水平上碳同化效率与脱水耐受性之间存在折衷。