植被在大气汞收支中作用的研究进展与展望

在汞的生物地球化学循环中,对于"源"和"汇"的认识还存在许多不确定性。大气汞收支不平衡的问题使得植被在汞循环中的作用日益凸现;开展植被在大气汞收支中作用的研究有助于为全球汞减排政策的制定提供参考。本文首先概述了植被中汞的来源和影响因素及其与大气汞的源汇关系;进而重点论述了植被参与大气汞收支的主要方式:凋落物沉降、生物质燃烧和植被表面与大气汞的动态交换,并阐述了植被在大气汞污染监测中的应用;最后在总结我国相关研究的基础上展望了未来的发展方向。

The Role of Vegetation in Atmospheric Mercury Budgets: Progresses and Perspectives

There are some uncertainties on the sinks and sources of mercury (Hg) in the Hg biogeochemical cycle. The estimated Hg emissions to the atmosphere are significantly greater than the known sinks, resulting in the mass unbalance for atmospheric Hg. Therefore the role of vegetation in Hg biogeochemical cycle has attracted more and more attentions. The studies of the role of vegetation in atmospheric Hg budgets can provide important information for the global Hg-reduced strategies. In this paper, we briefly review the origination of Hg in vegetation and its controlling factors, as well as the source/sink relationship to atmospheric Hg. Then three main manners involved in the atmospheric Hg budgets were emphasized in detail, including litterfall, biomass burning and bi-directional exchange of Hg between the surfaces of vegetation and atmosphere. In addition, the application of vegetation as biomonitorsof atmospheric Hg pollution was discussed. Finally, the progresses of mercury in vegetationin China were presented and some suggestions on future research were put forward.