华北油松、落叶松根系抗拉强度与其微观结构的相关性研究

Relationship Between Tensile Strength and Selected Anatomical Features of Two Different Conifer Species' Roots in North China

为研究针叶树种单根抗拉强度与其微观结构和纤维的内在联系,为筛选合适的水土保持、边坡防护树种提供理论基础,对油松、落叶松2种北方常见树种的根系进行抗拉强度、根系解剖结构以及根系分子离析、微纤丝角测定等一系列试验研究,并运用多元回归等数学统计方法对其之间的相关性进行定量、定性分析。结果表明:油松、落叶松根系抗拉强度和根系直径负相关,呈幂指数关系;对所测定的9个指标进行分析后得出,根系抗拉强度与管胞在根系横截面所占的面积比、管胞长宽比、管胞长度均呈正相关,管胞微纤丝角对根系抗拉强度的影响最大,两者呈负相关;油松根系管胞长度、长宽比显著大于华北落叶松,而管胞微纤丝角小于华北落叶松,所以使其根系拥有较华北落叶松更大的抗拉强度,具有更好的根系固土护坡作用。

In order to provide theoretical foundation by choosing better suitable conifer species for reinforcing soil and unstable slopes in north China, several experiments including single root tensile tests, roots anatomical tests, fiber separation experiment and measuring average microfiber angle were carried out. To investigate the relationship between two conifer species＇ （Chinese pine and Larix principis-rupprechtii） root tensile strength, anatomical structure was selected. Results showed that in two species, a significant power relationship existed between tensile strength and root diameter, Chinese pine was better resistant to failure than Larix principis-rupprechtii. According to the result of multiple regression equation, the percentage of tracheid in root＇s cross section, tracheid length, length-width ratio of tracheid affected root tensile strength, and they had positive correlation; tracheid microfiber angle was the most important factor which influenced on root tensile strength, and they had negative correlation. Tracheid length, length-width ratio of tracheid of Chinese pine＇s roots were significantly better than those of Larix principis-rupprechtii, but tracheid microfiber angle of Chinese pine＇s roots was less than Larix principis-rupprechtii ＇s, so that Chinese pine＇s roots had much larger tensile strength than Larix principis-rupprechtii ＇ s.