中国35个城市行道树树种组成特征研究

Urban Street Tree Species Composition in 35 Cities of China

明确城市森林树种组成是城市森林建设与管理的基础。以往研究多局限在特定城市或区域,难以准确揭示其普遍规律。本研究基于百度街景选取全国35个主要城市,共设置88632个样点。并根据地理区域将这些城市划分为北方、南方、青藏和西北城市,比较不同区域城市行道树树种组成差异。结果表明:①基于街景调查我国常用行道树共99种,最常见的是杨树(Populus spp.)、柳树(Salix spp.)、香樟(Cinnamomum camphora)、雪松(Cedrus deodara)和国槐(Sophora japonica);②我国南方城市行道树种多选用阔叶树如香樟,北方和西北城市行道树则以杨树、柳树和槐树为主,青藏地区行道树以杨树和针叶树为主;③依据10/20/30经验法则,仅有昆明和桂林城市行道树在种的水平上配置较为合理,其他城市植物配置均不合理,尤其克拉玛依市的杨树相对多度高达61.2%,长沙市和杭州市的樟树比例超过树种总数的50%,单个树种优势明显,4个区域行道树树种水平上配置均不合理。今后在行道树种选择时北方、西北和青藏区域城市应减少杨树、柳树、松树和槐树等的利用,南方地区应增加适宜本土生长的其他树木种类。本研究为我国合理规划城市行道树,系统开展多城市对比和综合提升生态服务功能提供了重要参数。

Clarifying the composition of the urban forest tree is the base of urban forest construction and management.Previous studies were mostly located in a singlecity or region,and it was difficult to reveal its general rule.We selected China’s 35 majorcities,with a total of 88632 plots by using Baidu Street View(BSV).These cities were divided into Northern,Southern,Qinghai-Tibet and Northwestern cities,according to their geographical region location.We compared the differences in street tree composition between cities and between regions.Results showed that:①There were 99street trees commonly used in the 35 cities based on the street BSV survey.The most common tree species were Populus spp.,Salix spp.,Cinnamomum camphora,Cedrus deodara and Sophora japonica.②Most of the street trees in Southern cities are broad-leaved trees e.g.,Cinnamomum camphora,while in Northern and Northwestern cities,Populus spp.,Salix spp.and S.japonicawere dominant,and in the Qinghai-Tibet area,Populus spp.and conifer were dominant.③Only Kunming and Guilin street species configuration were reasonable at species levelaccording tothe 10/20/30“rule of thumb”.In particular,the relative abundance of Populus spp.was as high as 61.2%,in Karamay.The proportion of Cinnamomum camphora trees exceeds 50%of the total number of tree species in Changsha and Hangzhou.The primary reason was that single-species occupy absolute predominance which made the relative abundance ratio of other tree species less or even no.In the four areas,street tree configuration was unreasonable at the species level.To solve this problem,we should reduce the use of Populus spp.,Salix spp.,Cedrus deodara,S.japonica in the North,and other trees suitable for native growth should be added in Northwest,Qinghai-Tibet,and Southern.Our study provides important parameters for the nationalplanning of urban forest,scientific evaluation and construction,systematic comparison of multiple cities,support of urban forest management and comprehensive improvement of ecological service functions.