Climate and Vegetation As Primary Drivers for Global Mercury Storage in Surface Soil
Climate and Vegetation As Primary Drivers for Global Mercury Storage in Surface Soil
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气候和植被是全球表层土壤汞储存的主要驱动因素
DOI：
10.1021/acs.est.9b02386
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发表时间：
2019
影响因子：
11.4
通讯作者：
Feng Xinbin
中科院分区：
文献类型：
--
作者：
Wang Xun;Yuan Wei;Lin Che-Jen;Zhang Leiming;Zhang Hui;Feng Xinbin
土壤是全球最大的汞水库。表层土壤汞浓度数据是理解环境汞循环的基础。然而，目前对土壤中汞的数量和全球分布的了解仍然不足。利用稳定的汞同位素分析和地理空间数据，研究了0~20 cm表层土壤中汞的浓度及其全球空间分布。据估计，全球表层土壤中的汞储量为1088±379Gg。地表汞储量的32%位于热带/亚热带林区，23%位于温带/北方林区，28%位于草原、草原和灌丛，7%位于冻土带，10%位于荒漠和干旱灌丛。汞同位素特征的证据表明，作为表层土壤汞的主要来源，植被吸收是大气汞干沉积的原因。考虑到气候变化对植被发育的影响，全球气候变化可能是影响表层土壤汞空间分布的一个重要强迫因素。这一积极的强迫循环极大地冲淡了人为来源汞排放造成的影响，在评估《汞公约》规定的减少汞使用和排放的有效性时需要加以考虑。
Soil is the largest Hg reservoir globally. Data of Hg concentration in surface soil are fundamental to understanding environmental Hg cycling. However, present knowledge on the quantity and global distribution of Hg in soil remains deficient. Using stable Hg isotopic analyses and geospatial data, the concentration and global spatial distribution of Hg in surface soil of 0–20 cm depth have been developed. It is estimated that 1088 ± 379 Gg of Hg is stored in surface soil globally. Thirty-two percent of the surface Hg storage resides in tropical/subtropical forest regions, 23% in temperate/boreal forest regions, 28% in grassland and steppe and shrubland, 7% in tundra, and 10% in desert and xeric shrubland. Evidence from Hg isotopic signatures points to atmospheric Hg0dry deposition through vegetation uptake as the primary source of Hg in surface soil. Given the influence of changing climate on vegetative development, global climate change can act as an important forcing factor for shaping spatial distribution of Hg in surface soil. This active forcing cycle significantly dilutes the impacts caused by Hg release from anthropogenic sources, and needs to be considered in assessing the effectiveness of reducing Hg use and emissions as specified inMinamata Convention on Mercury.