Roots exert pullout resistance under pullout force, allowing plants to resist uprooting. However, the pullout resistance characteristics of taproot-type shrub species of different ages remain unclear. In this study, in order to improve our knowledge of pullout resistance characteristics of taproot systems of shrub species, we selected the shrub species Caragana korshinskii Kom. in different growth periods as the research plant and conducted in situ root pullout test. The relationships among the maximum pullout resistance, peak root displacement, shrub growth period, and aboveground growth indices (plant height and plant crown breadth) were analyzed, as well as the mechanical process of uprooting. Pullout resistance of 4–15 year-old C. korshinskii ranged from 2.49 (±0.25) to 14.71 (±4.96) kN, and the peak displacement ranged from 11.77 (±8.61) to 26.50 (±16.09) cm. The maximum pullout resistance and the peak displacement of roots increased as a power function (R2=0.9038) and a linear function (R2=0.8242) with increasing age, respectively. The maximum pullout resistance and the peak displacement increased with increasing plant height; however, this relationship was not significant. The maximum pullout resistance increased exponentially (R2=0.5522) as the crown breadth increased. There was no significant relationship between the peak displacement and crown breadth. The pullout resistance and displacement curve were divided into three stages: the initial nonlinear growth, linear growth, and nonlinear stages. Two modes of failure of a single root occurred when the roots were subjected to vertical loading forces: the synchronous breakage mode and the periderm preferential breakage mode. These findings provide a foundation for further investigation of the soil reinforcement and slope protection mechanisms of this shrub species in the loess area of northeastern Qinghai-Tibet Plateau, China.

LIU Yabin;SHI Chuan;YU Dongmei;WANG Shu;PANG Jinghao;ZHU Haili;LI Guorong;HU Xiasong

Department of Geological Engineering,Qinghai University,Xining 810016,China;Key Laboratory of Genozoic Resource&Environment in North Margin of the Tibetan Plateau,Xining 810016,China;Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources,Qinghai Institute of Salt Lakes,Chinese Academy of Sciences,Xining 810008,China;Qinghai Provincial Key Laboratory of Geology and Environment of Salt Lakes,Xining 810008,China

干旱区科学

[1]LIU Yabin;SHI Chuan;YU Dongmei;WANG Shu;PANG Jinghao;ZHU Haili;LI Guorong;HU Xiasong-.Characteristics of root pullout resistance of Caragana korshinskii Kom. in the loess area of northeastern Qinghai-Tibet Plateau, China)[J].干旱区科学,2022(07):811-823

taproot,Pullout,periderm

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