Research On Fiber Characteristics?Mechanical Properties And Wind Resistance Of Branches Of Main Trees In Ningbo City

Ningbo,on the eastern coast of Zhejiang province,is hit by an average of 2.6 typhoons a year.After the typhoon disaster,a large number of trees in Ningbo broke branches and dried up,this paper investigates the main arbor situation after the wind damage,statistics of the typhoon,the influence of choosing the sample tree based on fiber characteristics and mechanical properties,screening of main arbor factors that affect the ability to resist wind,investigate the tree's ability to resist the wind of ningbo,ningbo garden tree species for the future of wind resistance and disaster mitigation measures the reference and the suggestion.The main results are as follows:(1)To explore the influence of garden plants' ability to resist wind and external conditions.The 11 factors of fiber length,fiber width,cavity diameter,double wall thickness,length-width ratio,wall-cavity ratio,compression elastic modulus,compression yield strength,bending elastic modulus,bending yield strength and tensile elastic modulus were tested,measured and analyzed.The correlation analysis of the experimental data shows that the fiber aspect ratio(0.843)is positively correlated with the elastic modulus of bending(0.779).(2)Combined with the experimental results and the related literature screening six impact indicators,using the analytic hierarchy process(ahp),the clustering analysis method to analyze the experimental results,get ningbo main arbor wind resistance index weight as follows: the bending modulus of elasticity(W = 0.33)> branch fiber aspect ratio(W = 0.26)> root(W = 0.15)> tree type(W = 0.12)> crown(W = 0.08)> leaf density(W = 0.06).(3)The comprehensive evaluation method was used to analyze the above indicators,and the comprehensive scores of wind resistance of main trees were respectively from high to low: Citrus maxima(2.53)?Osmanthus fragrans(2.48)?Cinnamomum camphora(2.46)?Metasequoia glyptostroboides(2.44)?Koelreuteria bipinnata(2.42)?Magnolia grandiflora L(2.33)?Broussonetia papyrifera(2.14)?Populus euramevicana cv.‘I-214'(1.44).(4)Through the above research,it is found that the wind resistance of trees is closely related to fiber length width ratio and bending elastic modulus.Based on the field situation,the countermeasures to enhance the wind resistance of trees are put forward: 1.Tree species should be reasonable and diverse.Tree species should be selected with large fiber length-width ratio,large bending elastic modulus,deep root,reasonable root-shoot ratio,round and umbrellas,good landscape effect,adaptability to the environment and easy to manage;2.Create good site conditions to ensure the area,depth and soil quality of street tree planting zone;3.Choose a good planting method and location,choose stone pad hole method,stone root method,wind resistant tree planting method,layered collocation planting to improve the wind resistance of trees;4,strengthen tree maintenance and management measures,do regular pruning and shaping,timely reinforcement.For diseases and insect pests,prevention is the priority,and the remedy is appropriate to the case.;5,before the wind damage timely reinforcement,supplementary support,do a good job of prevention.After wind damage,timely cleaning,righting,remedial measures;6.Increase the research on the related traits of enhanced tree species,and explore how to enhance the related factors and traits that affect the wind resistance of tree species.According to the geographical environment of Ningbo,the suggestion of wind-resistant tree species which can be applied in a wide range is put forward.