Researh On The Influence Of Wind On The Trunk And Crown Of Ancient Platycladus Orientalis Of The Yellow Emperor Mausoleum

The ancient trees are very tall and large,and the branches and trunks of them have serious rot.They are easily damaged by catastrophic winds,and their destruction is sometimes fatal.Affected by wind,ancient trees often form the phenomenon of biased crown and tilt.Threatening the landscape effects and life safety of ancient trees.Based on the survey and statistics of ancient trees in the Yellow Emperor’s Tomb area,the paper analyzes the influence of wind on ancient trees and their destructive effects,in order to provide technical support for windbreak measures of ancient trees.Focus on the following research:(1)Study on the principle and damage type of wind to ancient trees.Through investigating and consulting a large number of documents,the basic principles and common types of effects of wind on ancient trees have been summarized.The two action principles are: the static load generated by the average wind pressure exerts thrust on the ancient tree;the unstable vibration caused by the pulsating wind causes fractures and damages at locations where the branch strength is weak.The common types of impacts of the ancient trees under the influence of the wind are: the phenomenon of crown deviation,tilting of the tree,broken branches,twisting and splitting,and even root lodging.(2)Study on the influence types of wind on the ancient trees of the Yellow Emperor Mausoleum and its regularity.The statistical analysis was made on the trunks,crowns,and growth conditions of 100 P.orientalis for 100 years,which were selected in Temple Area.It was found that the most obvious types of impact in the wind environment are: Bias,tree tilt,and fragmentation.Among them,more than half(53%)of the old trees have a moderate degree(10°≤D<20°)and a heavy degree(D≥20°),and the number of old trees tending to the southwest is the highest(32%).Oblique angle and the ratio of height to diameter at breast height have a significant positive correlation,that is the higher the height of the old tree,the smaller the diameter of the DBH,the greater the inclination of the old tree.The number of 61 Cooper Cyclones was significantly higher and the number of southwest and west directions was higher,accounting for 23% and 20% of the ancient trees of the eccentric crown,and the eastern side was the least,only 5%.In the moderately and heavily inclined ancient trees,about 81% of the ancient trees have the same direction of declination and the direction of inclination,that is,the number of distributions in the “West-Southwest” direction is relatively large,and the formation of the rule of inclination between the crown and the trunk is significant affected by the wind direction.(3)Study on protection measures of ancient trees under the influence of wind.In response to the phenomenon of the occurrence of crowns,tilted trees,and broken branches of a large number of ancient trees under the influence of the wind at the Yellow Emperor’s Mausoleum,as well as the existing problems in the prevention of strong winds,it is believed that the existing reinforcement measures exist to prevent wind damage.The defect proposes the support of the giant tree limb elastic ring tree hoop type support,which can not only support the old branches but also can generate downward pulling force and side wind when the upper whirlwind comes.Effectively limit its displacement and damage.