Relationship Between Root Architecture and Anchorage Force of 14 Landscape Tree Species in Shanghai

Abstract:

The frequency and intensity of disastrous storm surges and typhoon events due to global climate change are increasing， leading to heightened requirements for the wind resistance of urban landscape trees. Enhancing the root anchoring force is an important way to improve the wind resistance of tree species.Fourteen tree species in Shanghai were selected to conduct a static tension test， and the anchoring force of different tree species was compared in this paper. Based on the root distribution data of 14 tree species collected by the “complete excavation method”， the correlation analysis and nonlinear regression analysis were performed to explore the correlation between root architecture and anchoring force. The preliminary results indicate that the sequence of the anchoring forces of the 14 root systems is as follows： Cyclobalanopsis gracilis > Nyssa aquatic > Acer buergerianum > Acer buergerianum > Cinnamomum japonicum > Liquidambar styraciflua > Liquidambar formosana > Cotinus coggygria >Pyrus calleryana > Ligustrum lucidum > Zelkova serrate > Quercus nuttallii > Triadica sebifera > Tilia miqueliana > Taxodiomera peizhongii； The correlation analysis screened out 11 indexes significantly correlated with root anchorage force， all of which were positively correlated. The P values of the 11 indexes are in a descending order of R₁₅₀₀，R₁₀₀₀，R₅₀₀，M_r，N_h，N_o，S_r，R_h，R_o，N_d，and D_g. It is found that indexes describing the horizontal characteristics of roots have a greater influence on the anchorage force of roots than indexes describing the vertical growth of roots. The multiple linear regression model of M_r， N_h， R_500， and F_max is obtained by multiple stepwise regression analysis F_max=－3.620+0.699M_r+0.589N_h+0.356R₅₀₀. In conclusion， this study obtained the anchoring force ranking of tree roots and found that the horizontal projection index of roots and root weight had significant effects on the anchoring force. The results enriched the wind-resistant evaluation database of landscape tree species in East China and provided theoretical support for the selection， management， and maintenance of wind-resistant landscape trees.