A comparison of root distribution of three hardwood species grown on a hillside in the Caspian forest, Iran

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• 作者：Ehsan Abdi ; Baris Majnounian ; Hassan Rahimi ; Mahmud Zobeiri ; Zahra Mashayekhi and Hamed Yosefzadeh
• 关键词：Caspian forests ; Downslope ; Root area ratio (RAR) ; Root distribution ; Upslope
• 刊名：Journal of Forest Research
• 出版年：2010
• 出版时间：April, 2010
• 年：2010
• 卷：15
• 期：2
• 页码：99-107
• 全文大小：307.9 KB

文摘

Slope is a complex environmental factor that can subject plants to a number of mechanical stresses. The anchorage of roots and improvement of slope stability mainly depend on specific properties of root systems, such as root distribution. In the present study, 24 trees (from three species) growing on gentle slopes (10–20¡ã) were randomly chosen for root distribution analysis. The profile trenching method was used to obtain root characteristics. The findings indicated that root area ratio (RAR) decreased with depth and that maximum RAR values were observed in the upper layers; RAR values were between 0.0004 % and 6.6444 % . Average RAR values were not statistically different in upslope and downslope layers except in one case. The dot grid method (100 ¡Á 150 mm) usually overestimated the RAR values. The amount of roots decreased with depth following a power law. About 50 % and 90 % of roots were located in the first 30 and 60 cm depths, respectively. Results of analysis of covariance (ANCOVA) showed a significant effect of diameter at breast height (DBH) on total RAR but not on the total number of roots. About 70 % of roots had diameter of less than 10 mm. Spearman’s correlation showed significant negative correlation between the total number of roots and the amount of N, P, and K elements, and a positive correlation between DBH and RAR. The results serve to develop understanding of the biotechnical characteristics of root systems of Caspian species.