极端降雪事件对北京市城市绿化树种的损害特征

Damages of Urban Greening Trees Caused by Extreme Snow Event in Beijing

【目的】为城市绿化树种的科学管理及抵抗极端灾害能力提供一定的科学依据,研究分析了北方城市中常见绿化树种的抗雪压能力及其影响。【方法】针对2012年11月初在北京发生的特大雪灾,以城市绿化树种栽植较为齐全的北京林业大学及公路、街道两侧绿化树木为研究对象,对受灾严重的30余种树木进行调查分析。【结果】研究表明在城市绿化树种中,灌木比乔木表现出的抗雪压性强;针叶树种比阔叶树种抗雪压性强;落叶树种比常绿树种抗雪压性强;乡土树种与引进树种的抗雪压性表现不明显。就同一树种而言,生长优良单株比生长不良单株表现出更强的抗雪压能力。试验通过对侧柏、圆柏及国槐的样地调查,得出城市绿化树木的受雪压灾害程度与其胸径、树高、尖削度等有显著的关系。【结论】在城市绿化树种引进及规划建设中,应酌情参考增加灌木、针叶树种、落叶树种及乡土树种的栽植比例以减少冰冻雨雪灾害造成的经济损失。

Obj ective This study investigated effects of extreme ice-snow on common greening trees in North China.Our aim was to provide a scientific basis for management of urban greening trees and improving their resistance to extreme ice-snow disaster.[Method]An extreme snow e-vent happened in November,2012.The mechanical damages of more than 30 urban greening trees around Beijing forestry university were investigated at that time.[Results]Shrubs showed stron-ger resistance to snow disaster compared to arbors.Conifers had stronger resistance to snow dis-aster than did broad-leaf.Deciduous species exhibited stronger resistance relative to ever-green species.No obvious difference in resistance to snow disaster was detected between native and ex-otic species.With regard of same species,the resistant capability was better in trees with good growth than in trees with damage.Based on surveys in Sophora japonica ,Juniperus chinensis and Platyclaaus orientalis ,the damage size of snow disaster were significantly correlated with DBH,tree height and taper.[Conclusion]The proportion of shrubs,conifers,deciduous and n-ative species should be increased in urban greening trees,which may decrease snow-caused eco-nomic loss.