石河子市行道树结构特征

以石河子市区15条主要街道为研究对象,调查其行道树的树种组成和生长表现,分析各树种在城市绿化中的重要性以及各街道绿化树种的多样性.结果表明:石河子市主城区行道树共有9科13属17种,平均树高、胸径和冠面积分别为9.7 m、22.3 cm和45.2 m~2;从树种多样性指数(S)、Shannon-Wiener指数(H)和Simpson指数(D)来看,树种丰富、结构较复杂的道路,其多样性指数高.其中,北一路最高(H=1.66、D=0.79),北子午路(H=0.13、D=0.05)最低;市区行道树优势种为大叶白蜡(Fraxinus rhynchophylla),次优势种为白榆(Ulmus pumila)、小叶白蜡(Fraxinus chinensis)、欧洲白榆(Ulmus laevis)、苹果(Malus pumila)、圆冠榆(Ulmus densa),这6个树种是石河子市街道绿化优先选择的树种.总体而言,石河子市行道树树种结构比较单一,以几个优势种或次优势种为主,需扩大其他树种的配置比例,引进新树种,提高各道路的树种多样性.

Structure Characteristics of Urban Tree Species in Shihezi City

The important values of each species and species diversity in each of streets were analyzed by investigating the tree composition,growth performance in 15 major streets in Shihezi city.The results showed that there were 17 species,which belong to 13 genera in 9 families,and their mean height,mean DBH,mean crown area were 9.7 m,22.3 cm,45.2 m2,respectively;From perspectives of species diversity(S),Shannon-Wiener (H)and Simpson(D),the species diversity index of Beiyi Road(H=1.66,D =0.79)was the highest and Beiziwu Road(H=0.13,D=0.05)was the lowest,and diversity index is high with high species richness and complex road structure;The dominant specie was Fraxinus rhynchophylla,sub-dominant species were Ulmus pumila,Fraxinus chinensi,Ulmus laevis,Malus pumila and Ulmus densa.They were excellent trees to select for greening species in Shihezi City.Overall,the structure of street trees is too simple in this city.For improving tree species diversity,it needs to enlarge the ratio of other trees and introduces new tree species.