Key message

The physical and chemical properties of soil are not a determinant of oak decline. Under stress, trees keep their vital activities by changing their physiological performance.

Abstract

The phenomenon of oak decline has been reported widely in various regions in the world. Although, many studies have addressed this problem, further studies are required to accurately identify the influencing factors. In this regard, we measured and analyzed some physiochemical properties of soil and some ecophysiological attributes of oak trees in different classes of dieback in Zagros Forest. We also used the Standardized Precipitation Evapotranspiration Index (SPEI) to determine the occurrence of drought in the study site. The findings indicated that dead trees and trees with a high rate of dieback were mostly present in soils with heavy texture. Besides, a significant difference in malondialdehyde (MDA) was found in various dieback classes. Moreover, with increasing dieback, the content of Ca in the leaf increased and the N/P ratio decreased. In these conditions, oak trees change their absorption and consumption of required elements.

中文翻译：

---

橡树（Quercus brantii Lindl.）的土壤特性和生态生理反应与枯死率相关吗？

关键信息

土壤的物理和化学特性不是橡树衰退的决定因素。在压力下，树木通过改变生理机能来保持其重要活动。

抽象的

橡树衰退现象在世界各个地区都有广泛的报道。虽然许多研究已经解决了这个问题，但还需要进一步的研究来准确识别影响因素。在这方面，我们测量和分析了扎格罗斯森林不同类型枯死的土壤的一些理化特性和橡树的一些生态生理属性。我们还使用标准化降水蒸散指数 (SPEI) 来确定研究地点发生干旱的情况。研究结果表明，枯死的树木和枯死率高的树木大多存在于质地较重的土壤中。此外，丙二醛 (MDA) 在各种枯死类别中存在显着差异。此外，随着枯死的增加，叶片中Ca含量增加，N/P比降低。