汉中市城市绿化大树栽植思考

Big Tree Transplanting in Urban Greening of Hanzhong

汉中市近年来绿化栽植的大树主要为树龄15a以上、胸径大于20~30cm的香樟、杜英、国槐、乐昌含笑、栾树、银杏等,栽植后2~5a内个体绿叶量降低约85%~90%,年分枝数减少80%~85%、枝条长度生长降低30%~40%,管护费用高、景观效果差。为尽快实现绿化美化效果和降低费用,可选择栽植旱莲、鹅掌楸、皂荚、青桐、刺楸、枇杷、杜仲、构树、池杉、苦楝、山桐子等乡土树种的树龄8~10a以下、胸径5~15cm的中小龄树木。

Recently big trees 15 aabove and DBH 20-30 cm like Cinnamomum camphora,Elaeocarpus decipiens,Sophora japonica,Michelia chapensis,Koelreuteria paniculata,and Ginkgo biloba have been applied for urban greening.Two to five years after planting,however,green leaves of each tree reduced by 85%to 90% percent,branching number reduced by 80% to 85%,the growth of branch declined by 30%-40%,which also costs too much in maintenance and have poor effect in greening.Indigenous trees at 8-10 aand DBH 5-15 cm are highly recommended,such as Magnolia soulangeana,Liriodendron tulipifera,Firmiana simplex,Eucommia ulmoides and so on.