长沙市行道树绿带植物组成及其健康状况调查

对长沙市23条主次干道行道树绿带的植物组成及其健康状况进行调查,结果表明:(1)长沙市行道树绿带常用植物种类约有96种,其中约占总数29%的为高大乔木,且常绿树种的应用比例约为4/5;出现频率超过45%的树种有7种,即香樟、广玉兰、桂花、金叶女贞、红檵木、四季桂等,但香樟、广玉兰、桂花、悬铃木等树种的均匀度相对较低;(2)长沙市行道树绿带中应用的灌木有40余种,山茶、栀子、杜鹃、月季、紫薇等观花灌木较多,特别是山茶所占的比例最大,占所调查全部灌木植物总数的22.5%;(3)长沙市行道树的胸径径级结构分布比较合理,但树高等级上的分布相对不合理,且长沙市行道树绿带中的植物的健康水平总体上属于中等偏上;(4)在长沙市行道树绿带中观花植物种类有20种,观果植物8种,观叶植物11种,观形植物11种,且长沙市城市道路绿化的主色调为绿色,常绿树种和落叶树种之比为4∶1。

Composition and health status of street greenbelt in Changsha City

Based on the investigation of the trees of 23 streets in the urban area of Changsha City, the composition, growth and health status of the street trees were analyzed. The results showed as following： （ 1 ） There were 96 tree spe- cies which were commonly used as street greenbelt, and about 29% were arbor tree species, and the ratio of evergreen tree species used was about 4/5. There were 7 tree species which frequency was over 45%, while the evenness of Cinna- momum camphora, Magnolia grandiflora, Osmanthus fragrans and Platanus acerifolia were rather lower. （2） The shrubs used in the greenbelt were more than 40 tree species, and the flowering shrubs such as Camellia japonica, Gardenia jas- minoides, Rhododendron pentanthera, Rosa chinensis and Lagerstroemia indica were used more commonly, especially, the proportion of CameUiajaponica was over 22. 5%. （3） The distribution proportion of size-class of DBH （Diameter of breast height） was rather reasonable, while the size-class of height was unreasonable relatively, and theirs health status were above average. （4） There were 20 flowering plants, 8 fruit-effect plants, 11 foliage plants, 11 plants with ornamen- tal trunks and branches. Green was the predominant color of street greening in Changsha, and the ratio of evergreen and deciduous species was 4 ： 1.