北京城市道路绿化管护现状浅析

Analysis of the management and protection measures of the rbah Road Greening in Beijing

城市绿化是改善城市生态环境质量的重要措施，栽植行道树也是城市绿化的组成部分。调查观测了北京市行道树生长状况和生境土壤性状，结果表明：行道树根际（0．8～1．2m^3）土壤体积密度在1．55g／cm^3左右，紧实度在2．5～3．0kg／cm^2之间，尚能满足树木生长的基本需求；而树坑外围的路基体积密度大于2．00g／cm^3、紧实度远大于4．5kg／cm^2，树木根系无法生存；行道树国槐根系生长方式有：根系强行生长伸展进入路基、根系及其躯干整体向上生长、根系在狭小的树坑之中蜗居等，并分析了行道树生长及其对城市交通设施及人群的潜在风险。指出了从树木生长发育过程来看，城市道路绿化切忌一味追求“林荫大道”和“见缝插针”栽植行道树的做法。

The urban greening is an important measure to improve the city＇s ecological environment quality, of which,planting street trees is a key constituent part. The street trees growth status and habitat soil properties in Beijing were observed and surveyed ＇in this study. The results show： soil volume density and soil compaction in street trees rhizosphere （0.8 - 120 m3） is around 1.55 g/cm3 and 2.5 -3.0 kg/cm2 ,respectively, which is still can meet the basic needs oflree growth;however, in the periphery of tree well,roadbed volume density is greater than 2.00 g/cm3 and compactness far outweigh 4.5 kg/cm2,thus tree roots unable to survive;the growth means of sophora root are：the roots striving to stretch into the roadbed ,upwardgrowth,as well as their trunk,or just dwelling narrowness,etc;the potential risk of street trees growth to urban traffic facilities and the crowd is also analyzed.The study points out that, from the view of trees growth process,the blindly pursuit of boulevard and to plant trade trees by all means should be avoid in urban road greening.