Persian oak (Quercus brantii Lindl.) is a valuable native species in Iranian forests with very limited availability of data on its wood properties. The objective of the current study was to determine the influence of altitude and slope on physical properties and fiber dimensions of Persian oak wood. In addition, the relationship among wood properties, site conditions (temperature and rainfall) and growth traits of trees (tree height, DBH, basal area, age, crown diameter, crown basal area, volume and annual diameter increment) were studied by principal component analysis (PCA). Three altitude levels (1730, 1980 and 2250 m) and three slope classes (<30%, 30–45% and >45%) were considered in the current study. It was determined that trees growing in the intermediate altitude (1980 m) showed the highest oven-dry density values, and those in the lowest altitude (1730 m) revealed the lowest ones. The results also indicate significant statistical differences between altitude levels and slope classes on the fiber length, fiber diameter and volumetric swelling at the 99% confidence interval while no significant differences were found between average values of oven-dry density among different altitudes and slopes. PCA analysis indicated that altitude and temperature are the most important factors affecting the wood properties. Knowledge of the relationship between wood properties and environmental factors are essential in terms of both forestry management and wood applications.

中文翻译：

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波斯栎木的木材密度和纤维尺寸的地理变化

波斯栎（Quercus brantii林德（Lindl。）是伊朗森林中的一种有价值的本土物种，其木材特性数据的可用性非常有限。当前研究的目的是确定海拔和坡度对波斯栎木物理性能和纤维尺寸的影响。此外，通过主成分研究了木材特性，场地条件（温度和降雨）与树木生长性状（树木高度，DBH，基础面积，年龄，树冠直径，树冠基础面积，体积和年直径增量）之间的关系。分析（PCA）。在本研究中考虑了三个海拔高度（1730、1980和2250 m）和三个坡度类别（<30％，30–45％和> 45％）。可以确定，在中等高度（1980 m）上生长的树木显示出最高的烤箱干燥密度值，海拔最低的地方（1730 m）显示的最低。结果还表明，在海拔高度和坡度类别之间，纤维长度，纤维直径和体积溶胀在99％置信区间上存在显着的统计差异，而不同海拔和坡度之间的烘房干密度平均值之间没有发现显着差异。PCA分析表明，海拔和温度是影响木材性能的最重要因素。在林业管理和木材应用方面，了解木材特性与环境因素之间的关系至关重要。纤维直径和体积膨胀在99％置信区间，而不同海拔和坡度的烘箱干燥密度平均值之间没有发现显着差异。PCA分析表明，海拔和温度是影响木材性能的最重要因素。在林业管理和木材应用方面，了解木材特性与环境因素之间的关系至关重要。纤维直径和体积膨胀在99％置信区间，而不同海拔和坡度的烘箱干燥密度平均值之间没有发现显着差异。PCA分析表明，海拔和温度是影响木材性能的最重要因素。在林业管理和木材应用方面，了解木材特性与环境因素之间的关系至关重要。