Application and selection of street trees in landscape trees

行道树是指栽植在公路、街道、园区等道路系统两侧，以美化、遮阴和防护为主要目的的树木。行道树为城乡绿化的骨干苗木树种，能统一、组合城市景观，体现城市与道路特色，创造宜人的空间环境。

Roadway trees are trees planted on both sides of the road system, such as roads, streets and parks, with the main purpose of beautifying, shading and protecting. Roadway trees are the backbone seedlings of urban and rural greening, which can unify and combine the urban landscape, embody the characteristics of the city and roads, and create a pleasant space environment.

在选择行道苗木树种时，首先应选择对城市街道上不良条件有较高抗性的树种，并要求树冠大、树荫浓、发芽早、落叶迟且落叶延续期短、花果不易污染街道环境、干性强、耐修剪、干皮不怕阳光暴晒、不易发生根蘖、病虫害少、寿命较长、根系发达等条件。行道树枝下高2.5m以上，距车行道边缘的距离不应少于0.7m，以1-1.5m为宜，树距房屋的距离不宜少于5m，株间距以8-12m为宜。

When selecting street seedlings, we should first select trees that are highly resistant to adverse conditions in urban streets, and require large crowns, dense shade, early germination, late deciduous leaves and short duration of deciduous leaves, flowers and fruits are not easy to pollute the street environment, strong dryness, pruning resistance, dry bark is not afraid of sun exposure, is not prone to root tillers, diseases and insect pests. Less, longer life, and more developed roots. The height under the branch of the roadway is more than 2.5m, the distance from the edge of the roadway should not be less than 0.7m, the distance between the tree and the house should not be less than 5m, and the distance between the trees should be 8-12m.

世界四大行道树为悬铃木、白榆、椴树以及七叶树。我国木本苗木种类极其丰富，适合作行道树的苗木树种很多，如银中杨、五角枫、榆树、悬铃木、国槐、栾树、白蜡、无患子、三角枫、七叶树、重阳木、香樟、广玉兰、女贞等。另外,像银中杨、五角枫、榆树、水曲柳、椴树、国槐、白腊中亦较为常见。

The four main street trees in the world are sycamore, Ulmus pumila, Tilia and chestnut trees. There are many kinds of woody seedlings suitable for street trees in China, such as Populus alba, Five-horned Maple, Ulmus pumila, Platanus acacia, Sophora japonica, Luanchu, Baiwa, Wubingzi, Triangle Maple, Seven-leaf Tree, Zhongyang Tree, Cinnamomum camphora, Magnolia magnolia, Ligustrum lucidum and so on. In addition, silver, poplar, Acer truncatum, elm, Fraxinus mandshurica, Tilia, Sophora japonica, and white wax are also more common.