Abstract Variations in leaf traits at anatomical, morphological and physiological level were assessed in Acer campestre L. and Crataegus monogyna Jacq. plants in a forest understory-gap-edge light gradient inside a broadleaf deciduous forest. The relative changes of the considered parameters monitored in the two species were compared in terms of intraspecific plasticity. Overall, both species were able to acclimatize to the natural light gradient with different light regime (i.e. low light, medium light and high light), through an integrated response at the three analyzed levels. However, some differences in intraspecific plasticity were detected related to the different shade-tolerance of these species. In particular, the investigated species showed significantly differences in plasticity at morphological level (i.e. leaf area and specific leaf area) with A. campestre having a greater morphological plasticity related to its greater shade-tolerance compared to C. monogyna. At the physiological level, differences in intraspecific plasticity have been identified for those parameters describing a higher drought susceptibility in high light regime (i.e. dark respiration rate, maximum PSII photochemical efficiency and actual quantum yield of photosynthesis) suggesting that A. campestre was less capable to acclimatize to these conditions, thus confirming the trade-off between drought and shade-tolerance.

中文翻译：

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Acer campestre 和 Crataegus monogyna 沿自然光梯度的光合特性和叶片性状变化

摘要 在 Acer campestre L. 和 Crataegus monogyna Jacq 中评估了叶片性状在解剖学、形态学和生理学水平上的变化。在阔叶落叶林内的林下林下-间隙边缘光梯度中的植物。在种内可塑性方面比较了在两个物种中监测的所考虑参数的相对变化。总体而言，通过三个分析水平的综合响应，这两个物种都能够适应具有不同光照条件（即低光、中光和高光）的自然光梯度。然而，检测到种内可塑性的一些差异与这些物种的不同耐荫性有关。特别是，所研究的物种在形态水平上表现出显着的可塑性差异（即 叶面积和特定叶面积），与 C. monogyna 相比，A. campestre 具有更大的形态可塑性，与其更大的耐荫性有关。在生理水平上，已经确定了那些描述高光照条件下较高干旱敏感性的参数（即暗呼吸率、最大 PSII 光化学效率和光合作用的实际量子产率）的种内可塑性差异，这表明 A. campestre 不太能够适应这些条件，从而确认干旱和耐荫之间的权衡。