Global Mercury Assimilation by Vegetation
Global Mercury Assimilation by Vegetation
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DOI：
10.1021/acs.est.1c03530
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发表时间：
2021-10-07
影响因子：
11.4
通讯作者：
Obrist, Daniel
中科院分区：
文献类型：
--
作者：
Zhou, Jun;Obrist, Daniel
植被对汞的同化是全球环境中最大的汞质量通量之一。我们利用综合数据库合成的组织汞浓度乘以各自的年生物量产量（NPP），通过自下而上的缩放方法估算全球植被对汞的同化。由于全球年NPP接近年植被死亡，与全球NPP相关的汞质量近似于汞从植物到土壤的转移，这代表了植被介导的大气沉积的估计值。大气和土壤对汞的年同化估计为3062 +/- 607 Mg yr(-1)，其中地上组织吸收为2491 +/- 551 Mg yr(-1)，根部吸收为571 +/- 253 Mg yr（-1）。仅考虑地上组织时，大气汞的同化量为2422 +/- 483 Mg / yr（-1）。当考虑到根汞可能部分来自先前叶面吸收并在内部运输到根时，大气同化增加到2705 +/- 504 Mg / yr（-1）。植被同化大气汞的估计值比目前的模型和凋落物估计值高出54-137%，这主要是因为在沉积物和所有全球生物群系中包含了地衣、苔藓和木本组织。在地下，大约50%的根汞是从土壤中吸收的，其生态和生物地球化学后果目前尚不清楚。
Assimilation of mercury (Hg) by vegetation represents one of the largest global environmental Hg mass fluxes. We estimate Hg assimilation by vegetation globally via a bottom-up scaling approach using tissue Hg concentrations synthesized from a comprehensive database multiplied by respective annual biomass production (NPP). As global annual NPP is close to annual vegetation die-off, Hg mass associated with global NPP approximates the transfer of Hg from plants to soils, which represents an estimate of vegetation-mediated atmospheric deposition. Annual vegetation assimilation of Hg from combined atmospheric and soil uptake is estimated at 3062 +/- 607 Mg yr(-1), which is composed of 2491 +/- 551 Mg yr(-1) from aboveground tissue uptake and 571 +/- 253 Mg yr(-1) from root uptake. Assimilation of atmospheric Hg amounts to 2422 +/- 483 Mg yr(-1) when considering aboveground tissues only. Atmospheric assimilation increases to 2705 +/- 504 Mg yr(-1) when considering that root Hg may be partially derived from prior foliar uptake and transported internally to roots. Estimated atmospheric Hg assimilation by vegetation is 54-137% larger than the current model and litterfall estimates, largely because of the inclusion of lichens, mosses, and woody tissues in deposition and all global biomes. Belowground, about 50% of root Hg was taken up from soils with currently unknown ecological and biogeochemical consequences.