地盤強度と根の形状特性が樹木転倒限界に与える影響について

抄録

Tree pulling experiments that simulated flood action were conducted using Salix babylonica and Juglans ailanthifolia, exotic and invasive trees in Japanese rivers.. The resulting damage was examined in order to assess the effects of physical tree characteristics and root architecture on the maximum resistive bending moment (M_max) for overturning. In situ soil shear strength tests were conducted in order to measure soil strength parameters. Significantly correlated (p<0.05) non-linear relationships were found between M_max and tree characteristics, and H*D ² provided the best predictor of the Mwithin them. Non-linear models were fitted between M_max and D_bh for each species. The more efficient root architecture to withstand overturning is the heart-root system of S. babylonica, and the plate-root system of J. ailanthifolia is less efficient not with the same breast height diameter but with the same root volume. The average M_max of S. babylonica for overturning each species decreased linearly with increasing soil cohesion within the experimental range because root anchoring depth is restricted with increasing the soil cohesion.