<正>在采用抽样调查方法对武汉市区道路绿化进行调查的基础上，分析了武汉市道路绿地的物种组成、物种丰富度、频度及植物多样性组成。结果表明：武汉市区道路绿地植物种类共有64种，其中木本植物55种，占总数的85.9%。木本植物中常绿树种37种，落叶树种18种；乔木19种，灌木36种。在乔木层中，桂花、二球悬铃木、樟树、欧美杨、雪松、广玉兰等的出现频度及丰富度均较高；灌木层中出现频度及丰富度较高的植物有：红花檵木、海桐、石楠、月季、紫叶李等，并针对城市绿化现状与存在的问题提出了道路绿地建设的建议和对策。

Combined with the construction survey practice of steel-pylon in the third Yangtse River bridge of Nanjing, though the experiment of one-way trigonometric leveling astronomical refraction above the river at night simulating the on-the-spot environment, the changing regulanity of astronomical refraction quotiety was analyzed, and the ways of reducing the effct that astronomical refraction made on the precision of the bigonometic leveling were introduced. The, essay aimed at guiding the assembly of the steel-pylon at night. Tbe conclusions are practical to enhance the precision of bigohometric leveling.