森林被采伐后,原有的森林生态条件遭到破坏,林地小气候、土壤等环境因子的改变,形成了植被的演替,林下耐阴植物很快绝迹了,而为喜光植物所取代。随着时间的延长,迹地杂草灌木种类日渐增加,长势日益茂盛。植被的复盖度、高度、根系盘结度、土壤坚实度等亦相继增强,这就造成了人工或天然更新幼苗与杂草灌木的竞争,它们与幼苗成长争水分、养分、光照。由于杂草灌木的生活力往往比更新幼苗强,以致造成幼苗被压抑,生长孱弱,以至死亡。杂草灌木除给更新造成极大困难外,还提高了人工更新的成本。因此,迹地更新后的林地扶育管理是一项必须的、长期的艰巨工作。如何及 Forest after being cut, the original forest ecological conditions have been destroyed, forest land microclimate, soil and other environmental factors change, forming a succession of vegetation, shade plants quickly disappeared, and replaced by the hi-light plants. With the extension of time, the species of weeds and shrubs on the trail have been increasing in number and growing. Vegetation coverage, height, root cohesion, soil firmness and so on have also been enhanced, which led to the artificial or natural renewal of seedlings and weed shrub competition, they compete with the seedling water, nutrients, light. As weeds and shrubs tend to be more viable than younger ones, the seedlings are suppressed, their growth weak, and even death. In addition to the tremendous difficulty weed shrubs have to update, it also increases the cost of manual updates. Therefore, the updated forest land management is a necessary and long-term arduous task. How to and