一、白榆绿篱退化的原因 白榆属多年生落叶乔木,具有抗干旱、瘠薄、炎热、寒冷,耐修剪等优点。但是白榆绿篱也有其影响管理和效果的因素,那就是:种植五年后开始出现老化、退化现象,主要原因是生理习性造成的。因为白榆本来属于高大落叶乔木,作为绿篱进行修剪是一种人为的强行遏制手段。通过 One, the reasons for the degradation of Ulmus henryi Ulmus is a perennial deciduous tree with anti-arid, infertile, hot, cold, anti-trimming and so on. However, the elm hedgerow has its influence on the management and effectiveness of the factors that: five years after planting began to appear aging, degradation, mainly due to physiological habits caused. Because elm was originally a tall deciduous tree, pruning as a hedge is a man-made forcibly deterrent. by