Distribution and tensile strength of Hornbeam (Carpinus betulus) roots growing on slopes of Caspian Forests, Iran
Biomechanical characteristics of the root system of hornbeam (Carpinus betulus) were assessed by measuring Root Area Ratio (RAR) values and tensile strength of root specimens of eight hornbeam trees growing on hilly terrain of Northern Iran. RAR values of the roots were obtained using profile trenching method at soil depth of the top 0.1 m. In total 123 root specimens were analyzed for tensile strength. Results indicate that in general, RAR decreases with depth, following a power function. The RAR values in up and down slopes have no significant statistical differences. In most cases, the maximum RAR values were located in soil depth of the top 0.1 m, with maximum rooting depth at about 0.75 m. The minimum and maximum RAR values along the profiles were 0.004% and 6.431% for down slope and 0.004% and 3.995% for up slope, respectively. The number of roots in the up and down slope trenches was not significantly different. In the same manner as for RAR, number of roots distributing with depth was satisfactorily approximated a power function. The penetration depths of above 90 percent of the roots were at soil depths of 50 cm and 60 cm for up and down slopes, respectively. Results of Spearman's bivariate correlation showed no significant correlation between the RAR value with tree diameter and gradient of slope and number of roots. The mean value of root tensile strength was 31.51 ± 1.05 MPa and root tensile strength decreased with the increase in root diameter, following a power law equation. Using ANCOVA, we found intraspecies variation of tensile strength.
作 者： Ehsan Abdi Baris Majnounian Hassan Rahimi Mahmud Zobeiri 作者单位： Ehsan Abdi,Baris Majnounian,Mahmud Zobeiri(Department of Forestry, University of Tehran, Karaj 31585-3314, Iran)Hassan Rahimi(Department of Irrigation, University of Tehran, Karaj 31585-3314, Iran)
刊 名： 林业研究（英文版） 英文刊名： JOURNAL OF FORESTRY RESEARCH 年，卷(期)： 2009 20(2) 分类号： S7 关键词： biomechanical Hornbeam Carpinus betulus root area ratio (RAR) root system root tensile strength