Significance of the Terrestrial Sink in the Biogeochemical Sulfur Cycle
Significance of the Terrestrial Sink in the Biogeochemical Sulfur Cycle
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DOI：
10.1029/2021gl097009
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发表时间：
2022
影响因子：
5.2
通讯作者：
Y. Joo;M. Sim;M. E. Elwood Madden;G. Soreghan
中科院分区：
文献类型：
--
作者：
Y. Joo;M. Sim;M. E. Elwood Madden;G. Soreghan
黄铁矿风化和埋藏的不平衡是大气和海洋氧化的主要机制，但控制陆地硫循环的关键过程仍然模糊不清。在这里，我们研究了一个高产的冰川补给流域陆地硫循环的组成部分，并使用全球质量平衡模型来约束河流硫通量。挪威约斯特达尔流域的溪流和植物碎屑的化学成分表明，孔隙水中正在发生硫同位素区分。全球模型还证实了额外的、以前被忽视的黄铁矿埋藏，其同位素分异值适中（<20‰），与淡水生态系统报告的值相似。总的来说，我们的结果表明，风化作用产生的大量硫酸盐仍然被困在陆地环境中。随着地质时间的推移，陆地硫汇可能随着陆地造林等重大生物地球化学事件而起伏不定。
An imbalance in pyrite weathering and burial is a primary mechanism responsible for oxygenation of the atmosphere and oceans, but key processes governing the terrestrial sulfur cycle remain nebulous. Here, we investigate components of the terrestrial sulfur cycle in a highly productive, glacier‐fed catchment, and use a global mass balance model to constrain riverine sulfur fluxes. Chemistry of stream water and plant debris in the Jostedal watershed, Norway suggests sulfur isotope discrimination is occurring in the porewater. Global models also corroborate additional, previously overlooked pyrite burial with a modest isotope fractionation (<20‰), similar to values reported from freshwater ecosystems. Collectively, our results indicate that a significant amount of sulfate produced by weathering remains trapped in terrestrial environments. This terrestrial sulfur sink might have waxed and waned over geologic time in response to major biogeochemical events such as terrestrial afforestation.