南京市老城区行道树的组成及结构分析

对南京市老城区125条主要路段行道树的种类组成及结构特征进行了分析。结果表明,研究区内的行道树共有乔木27种、灌木24种,其中悬铃木〔Platanus acerifolia(Ait.)Willd.〕、香樟〔Cinnamomum camphora(L.)Presl〕、国槐(Sophora japonica L.)、水杉(Metasequoia glyptostroboides Hu et Cheng)、女贞(Ligustrum lucidum Ait.)、雪松〔Cedrus deodara(Roxb.)G.Don〕和枫杨(Pterocarya stenoptera C.DC.)是南京市老城区行道树群落的优势种,决定了道路绿化景观的外貌;在7种优势树种中,悬铃木的年龄结构属稳定型,香樟、国槐和女贞处于增长阶段,水杉、雪松和枫杨则趋于老龄化。在行道树配植的4种垂直结构类型中,乔木单层结构最多,占52.8%;乔灌两层和乔灌草三层结构所占比例相近(21.6%和22.4%);乔草两层结构最少(3.2%)。本研究结果对南京市行道树的合理配置具有重要的参考价值。

Analysis on composition and structure of street trees in old urban district of Nanjing

Street trees on 125 main street segments in old urban district of Nanjing were investigated and their composition and structure characteristics were analyzed,too.The results showed that there were twenty-seven species of arbor and twenty-four species of shrub along the streets.The dominant species determining the view of street greening were Platanus acerifolia(Ait.) Willd.,Cinnamomum camphora(L.) Presl,Sophora japonica L.,Metasequoia glyptostroboides Hu et Cheng,Ligustrum lucidum Ait.,Cedrus deodara(Roxb.) G.Don and Pterocarya stenoptera C.DC.Among seven dominant species,the age structure of P.acerifolia was stable,and that of C.camphora,S.japonica and L.lucidum was growing,and that of the rest ones was declining.Among four types of vertical structure of street trees,the type of single-layer arbor was dominant,amounting to 52.8%;the type of two-layer of arbor and shrub was similar with that of three-layer of arbor,shrub and grass in the percentage of 21.6% and 22.4% respectively;while the type of two-layer of arbor and grass was the least with a percentage of 3.2%.This research result would give a reasonable reference to plant street trees of Nanjing in the future.