城市绿地滞尘作用机理和规律的研究进展

城市绿地的滞尘作用是城市绿地重要的生态功能之一。综述了城市绿地的滞尘机理、变化规律。城市绿地的滞尘机理主要分为3种方式：滞留、附着和粘附;城市绿地滞尘能力与滞尘时间、城市环境、植物种、植物群落结构等因素存在密切的联系。不同植物滞尘能力的差异很大,总体规律表现为乔木植物〉灌木植物〉草本植物;但就单位叶面积来说,滞尘能力均以草本植物〉灌木植物〉乔木植物〉藤本植物;主要原因是垂直高度不同,灌草能有效截留地面的扬尘（城市中灰尘的主要来源）。研究表明,同种类植物种在封闭式环境条件下叶片滞尘量明显低于开敞式环境条件下的滞尘量,因此,在城市不同环境中的植物滞尘能力表现为工业区〉商业交通区〉居住区〉清洁区。随着季节和滞尘时间的变化,每种植物都存在一个滞尘限度,如果无雨水或人为干扰,最终达到一个动态平衡。从城市绿地群落的垂直结构看,乔—灌—草型的绿地具有相对较好的滞尘作用,是目前较为理想的绿地类型;另外,在城市绿地面积明显不足的情况下,以藤本植物为主的垂直绿化将成为城市绿化发展的新方向。同时,在城市绿地滞尘机理、规律以及植物滞尘能力评价等方面仍需要进一步深入研究。

Research advances on mechanisms and rules of dust retention of the urban green areas

The dust retention effects of urban green areas is one of important ecological functions. In the paper, the dust retention and change rules of the urban green areas are reviewed. Detention, attachment and adhesion are the three kinds of main modes of the dust retention mechanisms; however, the dust retention’s capacity of urban green areas is closely related with the time of dust retention, environment of urban, plant species and structure of plant community. The dust retention’s capacity of different plants is greatly different, the general rules of which is arbor shrub herb, however, from the unit leaf area, is herb shrub arbor liana flora; it is that due to difference of the vertical height, the dust （the main source of dust in the city） can be effectively intercepted by herb and shrub. Research shows that the dust retention’s quantity of leaves of the same kind plants in the enclosed condition is obviously lower than the mooring conditions, therefore, the dust retention’s capacity of plants in the city of different environment is industrial area commercial and traffic area residential area clean area. As seasonal and time change of dust retention, each plant has a threshold of dust retention, in the contitions of no rain or human interference, eventually reach a dynamic balance. From the vertical community structure of urban green area, the type of arbor—shrub—herb is relatively good dust retention, and is the ideal types of green area. In addition, in the condition of lack of urban green area, vertical virescence with liana flora as greening plant will become the new direction of development of urban green area. At the same time, the dust retention’s mechanism and principle of urban green area and the evaluation of dust detentions need to research further.