5种植物根系生物力学特性

Mechanical Properties of Five Kinds of Plant Roots after Soil Erosion and Self-repair

为探究根系固土力学机理,于2019年5月初,分别对5种植物0~6 mm直根的相同根径施加70%平均极限抗拉力,进行原位瞬时轴向拉伸受损试验。3个月后,根据其愈伤后存活率、活力值、直根极限应变、弹性模量的变化,与平行对照(未受损)进行比较,分析5种植物根系固土力学特性的共同规律及种间差异。结果表明:愈伤3个月后,试验根存活率、活力值较平行对照均有明显下降,降低值由大到小依次为:沙棘、柠条、杨柴、沙打旺、紫花苜蓿。5种植物在代表根径级为0~1.5 mm时,其在愈伤后直根极限应变均值由大到小依次为紫花苜蓿(14.89±0.98)、沙棘(13.35±0.95)、杨柴(12.68±0.82)、沙打旺(12.66±0.76)、柠条(8.68±0.43);平行对照的直根极限应变均值由大到小依次为柠条(27.76±2.16)、沙棘(16.95±1.36)、杨柴(16.39±1.17)、沙打旺(16.13±1.18)、紫花苜蓿(12.59±0.69)。愈伤自修复后直根弹性模量均值由大到小依次为沙打旺(4.12±0.35)、杨柴(3.61±0.12)、紫花苜蓿(2.79±0.14)、柠条(2.21±0.21)、沙棘(1.64±0.13);平行对照的直根弹性模量均值由大到小依次为柠条(3.89±0.23)、沙棘(2.74±0.19)、杨柴(2.47±0.18)、沙打旺(2.22±0.07)、紫花苜蓿(0.86±0.073)。5种植物根系在受拉受损后经愈伤自修复后发现,草本植物根系恢复抗拉能力比灌木、半灌木强。

In order to explore the mechanical mechanism of root soil consolidation,in early May 2019,70%average ultimate tensile strength was applied to the same root diameter of 0-6 mm taproots of 5 plants,and an in situ instantaneous axial tensile damage test was carried out.After 3 months,we studied the changes in survival rate,vigor value,taproot ultimate strain,and elastic modulus of the callus,and compare with the parallel control(undamaged),and analyzed the common mechanical properties of the root system of the five plants,and the law and its inter-species differences.The results showed that after 3 months of callus,the survival rate and vigor value of the test roots were significantly lower than those of the parallel control,and the descending values were,Hippophae rhamnoides,Caragana Korshinskii,Hedysarum mongolicum,Astragalus adsurgens,and Medicago sativa in descending order.When the 5 plants represent the root diameter of 0-1.5 mm,the average taproot ultimate strain after callus is Medicago sativa(14.89±0.98),Hippophae rhamnoides(13.35±0.95),Hedysarum mongolicum(12.68±0.82),Astragalus adsurgens(12.66±0.76),and Caragana korshinskii(8.68±0.43).The mean values of the ultimate strain of taproot in the parallel control is Caragana korshinskii(27.76±2.16),Hippophae rhamnoides(16.95±1.36),Hedysarum mongolicum(16.39±1.17),Astragalus adsurgens(16.13±1.18),and Medicago sativa(12.59±0.69).The average elastic modulus of taproot after self-healing of callus in descending order is Astragalus adsurgens(4.12±0.35),Hedysarum mongolicum(3.61±0.12),Medicago sativa(2.79±0.14),Caragana korshinskii(2.21±0.21)and Hippophae rhamnoides(1.64±0.13).The mean values of elastic modulus of parallel control taproots in descending order is Caragana korshinskii(3.89±0.23),Hippophae rhamnoides(2.74±0.19),Hedysarum mongolicum(2.47±0.18),Astragalus adsurgens(2.22±0.07),and Medicago sativa(0.86±0.073).The roots of 5 plants undergo self-healing after being damaged by tension,and then the ability of herb roots to restore tension is temporarily stronger than that of shrubs and sub-shrubs.