Ma Ming, Du Hongxia, Wang Dingyong
College of Resources and Environment, Southwest University, Chongqing, 400715, China.
Chongqing Key Laboratory of Bio-Resource for Bioenergy, Southwest University, Chongqing, 400715, China.
Bull Environ Contam Toxicol. 2019 May;102(5):650-656. doi: 10.1007/s00128-019-02569-2. Epub 2019 Mar 15.
Mercury (Hg) is one of the most toxic heavy metal pollutants, which can be easily transmitted and enriched through the food chain, posing severe threat to human beings. Forest ecosystems are one of the most active environments for biogeochemical cycles of Hg. It is essential to research on Hg cycling in the forest ecosystem, which contributes to a comprehensive understanding of global biogeochemical cycle of Hg. However, there is still a lack of consensus on whether the forest ecosystem is a "source" or "sink" of Hg in the global Hg cycle so far. Therefore, it is necessary to elucidate the current state of knowledge on Hg deposition, transformation and fate in the forest ecosystem, especially the existing puzzles or issues encountered by scientists worldwide. This review highlights the complexity and uncertainties of Hg cycling in forest ecosystems. It is proposed that a new perspective is required to further understand the role of forest ecosystems in global Hg cycle based on a sufficient understanding of Hg exchange fluxes at the interface of air-soil and air-plant, Hg deposition flux through litterfall, and accurate construction of Hg mass balance system.
汞（Hg）是毒性最强的重金属污染物之一，它能够通过食物链轻易地传播和富集，对人类构成严重威胁。森林生态系统是汞生物地球化学循环最为活跃的环境之一。研究森林生态系统中的汞循环至关重要，这有助于全面了解全球汞生物地球化学循环。然而，迄今为止，关于森林生态系统在全球汞循环中是汞的“源”还是“汇”，仍未达成共识。因此，有必要阐明森林生态系统中汞沉降、转化和归宿的现有知识状态，特别是全球科学家所遇到的现存谜题或问题。本综述强调了森林生态系统中汞循环的复杂性和不确定性。建议在充分了解气-土界面和气-植界面的汞交换通量、通过凋落物的汞沉降通量以及准确构建汞质量平衡系统的基础上，需要一个新的视角来进一步理解森林生态系统在全球汞循环中的作用。
