Arid Zone Research ›› 2022, Vol. 39 ›› Issue (2): 572-583.doi: 10.13866/j.azr.2022.02.24

• Plant and Plant Physiology • Previous Articles     Next Articles

Relationship between tensile properties and microstructure of single root of three riparian plants

ZHANG Yu1(),ZHU Haili1,2,ZHANG Ke1,LI Guorong1,2,LIU Yabin1,2   

  1. 1. Department of Geological Engineering, Qinghai University, Xining 810016, Qinghai, China
    2. Key Laboratory of Cenozoic Resource & Environment in Northern Margin of the Tibetan Plateau, Xining 810016, Qinghai, China
  • Received:2021-07-06 Revised:2021-09-11 Online:2022-03-15 Published:2022-03-30

Abstract:

We aimed to analyze the tensile properties of single roots and the micromechanical mechanism of revetment by three dominant alpine meadow plants (Blysmus sinocompressus, Kobresia capillifolia, and Potentilla fruticose) in the source area of the Yellow River. The mechanical properties of single roots of these three plants and their relationship with microstructure were quantitatively analyzed through a single root tensile test and paraffin section test. As the root diameter increased (from less than 0.5 mm, 0.5-1.0 mm, to greater than 1.0 mm), the single root tensile resistance and elongation increased, whereas the single root tensile strength and Young’s modulus decreased. The tensile stress-strain curve for single roots followed a single peak curve trend. The average tensile strength of the single roots of Potentilla fruticose shrubs was 1.56 and 1.25 times greater than that of the cyperaceous Blysmus sinocompressus and Kobresia capillifolia, repsectively, whereas the average single root elongation of Blysmus sinocompressus was 1.06 and 1.36 times greater than that of Kobresia capillifolia and Potentilla fruticose, respectively. The single root tensile strength of cyperaceous plants was mainly related to the vascular column area ratio, whereas the single root tensile strength of Potentilla fruticose shrubs was closely related to the proportion of epidermis and secondary xylem. The ability to resist root system deformation in Blysmus sinocompressus and Kobresia capillifolia was stronger than that of Potentilla fruticose; therefore, these two cyperaceae plants play a role in reinforcing the soil, and slowing down the speed of deformation and failure of the river bank. Moroever, the stiffness and tensile strength of the Potentilla fruticose root system were higher, which play a role in soil consolidation and bank protection. Our results provide scientific support for screening the dominant revetment species in the source region of the Yellow River.

Key words: root diameter grade, single root tensile strength, elongation, stress-strain curve, xylem