护坡植物根系力学特性与其解剖结构关系

Relationship between mechanical characteristics and anatomical structures of slope protection plant root

为研究植物单根力学特性与其解剖结构的关系,以西宁盆地为例,对青藏高原东北部黄土区5种灌木单根抗拉特性、抗剪特性、根系解剖结构进行了一系列试验研究。结果表明:根系解剖结构中韧皮纤维、木纤维的百分含量、周皮的木质化程度及根系的木质化速度等因素影响根系力学强度,根系拉伸延长率与根系韧皮纤维含量成正比,与木纤维含量成反比;5种灌木植物中,柠条锦鸡儿单根横切面上次生韧皮部平均面积比最大,达到45%,表现为单根具有较大延伸率;四翅滨藜单根横切面上次生木质部平均面积比最大,达到50%,表现为单根具有较强的抗拉和抗剪强度。根据5种供试灌木根系力学特性及其解剖结构特征,四翅滨藜和柠条锦鸡儿根系固土护坡作用较大。

Taking Xining basin as example, the single root tensile tests, shear tests and roots anatomical tests of five species of shrub were carried out to study the relationship between mechanical characteristics of shrub roots and roots anatomical structures in the loess area of northeast Qinghai-Tibet plateau. The results showed that the main factors affected tensile and shear strength of single root including the percentage of phloem fibers and wood fibers, the degree and speed of periderm lignification. The shrubs single root elongation rate varied directly as the area percentage of secondary phloem, varied inversely as the area percentage of xylem. For five species of shrub, the largest area percentage of secondary phloem is Caragana korshinskii and reached 45% showing great single root elongation rate; the largest area percentage of xylem is Atriplex canescens and reached 50% reflecting the better mechanical characteristics. According to the root mechanical characteristics and root anatomical features, Atriplex canescens and Caragana korshinskii have a significant function in slope protection in Qinghai-Tibet plateau loess area.