Biotic and abiotic stressors are known to modify the morphology of forest trees. Nevertheless, there is little information on the effects of tree decline on leaf and fruit morphology of oaks. To understand morphological adaptations of Persian oak (Quercus brantii Lindl.) to oak decline, we compared leaves and fruit from healthy and declining Persian oaks from six populations in the Zagros Forest of Iran. Fruits and leaves were sampled from five healthy and five declining trees from each population (30 declining and 30 healthy trees total). Fifteen leaves and fruits were sampled from each tree, for a total of 900 leaves and 900 fruit. We measured fruit length and diameter, scar diameter, cupule length, cupule span diameter, and fruit cover length as well as leaf length, petiole length, maximum lamina width, width of the lamina base, and width of the lamina apex. The leaf area was estimated from the product of length, maximum width, and a shape coefficient. Leaf trichomes were examined with SEM and classified as either mostly stellate or non-stellate. Healthy Persian oaks from five of the six populations had larger leaves, with greater lamina area, when compared with declining individuals. Moreover, the trend was the same across all six populations. Leaves of declining oaks also had distorted trichomes. Moreover, declining Persian oaks had smaller (shorter) fruit. The impact of oak-decline on Persian oak morphology, however, varied greatly among the six populations, limiting leaf and fruit size as indices of oak-decline. Leaves and fruit are smaller in declining Persian oaks, and trichomes are degraded. Nevertheless, care must be taken in using these traits as reliable proxies for tree decline, simply because the effect varies among populations.

已知生物和非生物压力因素会改变林木的形态。然而，关于树木衰退对橡树叶和果实形态的影响的信息很少。了解波斯橡树（Quercus brantii ）的形态适应性Lindl.) 与橡树衰退，我们比较了伊朗扎格罗斯森林六个种群中健康和衰退的波斯橡树的叶子和果实。从每个种群的 5 棵健康树和 5 棵衰退树（总共 30 棵衰退树和 30 棵健康树）中采样果实和叶子。从每棵树上取样 15 片叶子和果实，总共 900 片叶子和 900 个果实。我们测量了果实长度和直径、疤痕直径、杯状体长度、杯状体跨度直径和果实覆盖长度以及叶长、叶柄长度、最大叶片宽度、叶片基部宽度和叶片顶点宽度。叶面积由长度、最大宽度和形状系数的乘积估计。用SEM检查叶毛状体并分类为主要是星状的或非星状的。与衰退的个体相比，来自六个种群中的五个种群的健康波斯橡树具有更大的叶子和更大的叶片面积。此外，所有六个人群的趋势都相同。衰退橡树的叶子也有扭曲的毛状体。此外，衰落的波斯橡树果实更小（更短）。然而，橡树衰退对波斯橡树形态的影响在六个种群中差异很大，限制了叶子和果实大小作为橡树衰退的指标。衰退的波斯橡树的叶子和果实较小，毛状体退化。然而，在使用这些特征作为树木衰退的可靠代理时必须小心，因为效果因种群而异。衰退橡树的叶子也有扭曲的毛状体。此外，衰落的波斯橡树果实更小（更短）。然而，橡树衰退对波斯橡树形态的影响在六个种群中差异很大，限制了叶子和果实大小作为橡树衰退的指标。衰退的波斯橡树的叶子和果实较小，毛状体退化。然而，在使用这些特征作为树木衰退的可靠代理时必须小心，因为效果因种群而异。衰退橡树的叶子也有扭曲的毛状体。此外，衰落的波斯橡树果实更小（更短）。然而，橡树衰退对波斯橡树形态的影响在六个种群中差异很大，限制了叶子和果实大小作为橡树衰退的指标。衰退的波斯橡树的叶子和果实较小，毛状体退化。然而，在使用这些特征作为树木衰退的可靠代理时必须小心，因为效果因种群而异。