园林树木吸收汞(Hg)的评价方法

Evaluation Methods of Hg Absorption by Ornamental Trees

为明确园林树木吸收Hg的评价方法,了解常见园林树木对汞(Hg)的吸收能力强弱,以北京市陶然亭公园、中科院植物园、紫竹院公园为样地,将测定的30种树种的不同器官(叶片、枝条)、不同年份(2016年、2018年)Hg含量数据,采用不同聚类进行排序,并分析对比不同排序的差异。结果表明:1)采用2 a测定木本植物叶器官的Hg含量,能更稳定地指征不同树木吸收重金属Hg的能力强弱。2)按照上述评价方法,基于单位重量角度看,阔叶树种单位重量吸收Hg含量能力强于针叶树种,流苏树、蒙椴、紫丁香3种园林树木吸收Hg的能力较强,白皮松、白扦等9种针叶植物吸收Hg的能力较弱。本研究以园林绿地中成年园林树木为对象,测定结果对了解园林树木单位重量吸收Hg能力和更为准确的评价不同树木差异有指导作用。

In order to clarify the evaluation method of mercury(Hg)absorption by garden trees and to understand the capabilities of common garden trees to absorb Hg,the contents of Hg in different plant organs(leaves,branches)and different years(2016,2018)of 30 plant species occurring in Taoranting Park,Botanical Garden of Chinese Academy of Sciences,and Zizhuyuan Park in Beijing were measured.The measured data were sequenced by different clustering methods.Differences in the results of ranks were analyzed and compared.The results showed that 1)the ability of different trees to absorb heavy metal Hg could be more stably indicated by the determination of Hg content in leaves and organs of woody plants for two years.2)According to the above evaluation methods,the absorptive capacity to Hg per unit weight of broad-leaved tree species was stronger than that of coniferous tree species.Chionanthus retusus,Tilia mongolica and Syringa oblata had stronger ability to absorb Hg,while nine coniferous plants,such as Pinus bungeana and Picea meyeri had weaker ability to absorb Hg.The results of measurement can be used to understand the capacity to Hg absorption per unit weight of garden trees and to evaluate the differences of different trees more accurately.