Characteristics of root pullout resistance of Caragana korshinskii Kom. in the loess area of northeastern Qinghai-Tibet Plateau, China

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