太原地区常用地被植物及植被结构吸附PM2.5等细颗粒物能力研究

目的]研究太原地区常用地被植物及植被结构吸附PM_(2.5)等细颗粒物的能力。方法]以太原市常用园林地被植物为试验材料,研究鸢尾、景天、玉簪、萱草4种地被植物PM_(2.5)等细颗粒物的吸附能力。记录2017年4—8月太原市PM_(2.5)浓度值,研究太原市夏秋季PM_(2.5)污染特征。结果]4种地被植物吸附PM_(2.5)等细颗粒物的能力从大到小依次为玉簪、鸢尾、萱草、景天,其中白花玉簪吸附细颗粒物的效果最好,1 g鲜重、干重附尘量分别比八宝景天高4.4倍和2.0倍,吸附尘埃质量达到2.8倍,排序结果与其单位叶面积吸附PM_(2.5)等细颗粒物的能力相差不大;净化系数结果表明,3种植被结构净化系数均为正值,以大学校园中的乔灌草相结合的植被结构吸附PM_(2.5)能力较强;通过比较太原市PM_(2.5)浓度的季节性变化,发现太原市春末夏初PM_(2.5)浓度值偏高。结论]地被植物对太原城市景观建设、调节生态环境起到重要作用。

Study on Ability of Ground Cover Plant of Taiyuan to Adsorb PM2.5

Objective]To study the ability of plants and vegetation structures to adsorb PM2.5and other fine particles in Taiyuan area. Method] Four ground cover plants of Taiyuan(Iris germanica L.,Hemerocallis fulva, Sedum spectabile, Hosta plantaginea) were selected to study their capacities in adsorbing PM2.5. Meanwhile,the PM2.5concentration in Taiyuan between April 2017 and August 2017 was recorded,and the charac-teristics of PM2.5pollution in summer and autumn in Taiyuan were studied. Result]The results showed that the ability to adsorb PM2.5was in the order of Hosta plantaginea,Iris germanica L.,Hemerocallis fulva,Sedum spectabile. Among them,the effect to adsorb PM2.5of Hosta plantaginea was the best. Fresh weight and dry weight per gram were 4.4 times and 2.0 times higher than that of Sedum,and the quality of dust adsorption was 2.8 times higher than that of Sedum. The sorting result was the same as the ability to adsorb PM2.5of unit leaf area. The result of the coeffi-cient of purification showed that,the purification coefficient of three planting structure was positive,With trees and shrubs in combination with ground cover plants in university campus the adsorption capacity of PM2.5was stronger. By comparing the seasonal variation of PM2.5concentration in Taiyuan City,it was found that the PM2.5concentration was particularly high in the late spring and early summer of Taiyuan. At this time most of ground cover plants were not fully grown. Conclusion]The ground cover plants were played an important role in the construction of Taiyuan landscape and the regulation of ecological environment.