Spatial distribution and biogeochemistry of redox active species in arctic sedimentary porewaters and seeps
Spatial distribution and biogeochemistry of redox active species in arctic sedimentary porewaters and seeps
复制标题
北极沉积孔隙水和渗漏中氧化还原活性物质的空间分布和生物地球化学
DOI：
10.1039/d1em00505g
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Chin, Yu-Ping
中科院分区：
文献类型：
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作者：
Hudson, Jeffrey M.;Michaud, Alexander B.;Emerson, David;Chin, Yu-Ping
北极湖泊沉积物中氧化还原活性物种在碳循环中起着重要的调节作用，但关于它们的空间分布、丰度和氧化态的信息却很少。在这里，我们使用伏安微电极来量化原位浓度的氧化还原活性物种在高垂直分辨率（毫米至厘米）的贫营养北极湖泊（图里克湖，AK，美国）的底栖孔隙水。Mn（II），Fe（II），O2，和Fe（III）-有机络合物被检测为主要的氧化还原活性物种在这些孔隙水，表明Fe（II）的氧化和还原溶解的Fe（III）和Mn（IV）矿物。我们观察到显着的空间异质性，其丰度和分布的功能内的湖泊和深度的位置。微生物分析和固相铁（III）的测量进行了在图里克湖核心之一，以确定地球化学氧化还原梯度和微生物群落之间的关系。我们的数据显示，铁循环涉及氧化（FeOB）和还原（FeRB）细菌。此外，我们分析了一个大的微生物铁垫在冻土渗漏附近的北极流（Oksrukuyik溪），我们观察到铁（II）和可溶性铁（III）在一个高度还原的环境。氧化还原活性物质在所有网站的变量分布产生洞察的性质和分布的重要终端电子受体在湖泊和苔原环境中能够施加显着的影响碳循环。
Redox active species in Arctic lacustrine sediments play an important, regulatory role in the carbon cycle, yet there is little information on their spatial distribution, abundance, and oxidation states. Here, we use voltammetric microelectrodes to quantify the in situ concentrations of redox-active species at high vertical resolution (mm to cm) in the benthic porewaters of an oligotrophic Arctic lake (Toolik Lake, AK, USA). Mn(II), Fe(II), O2, and Fe(III)-organic complexes were detected as the major redox-active species in these porewaters, indicating both Fe(II) oxidation and reductive dissolution of Fe(III) and Mn(IV) minerals. We observed significant spatial heterogeneity in their abundance and distribution as a function of both location within the lake and depth. Microbiological analyses and solid phase Fe(III) measurements were performed in one of the Toolik Lake cores to determine the relationship between biogeochemical redox gradients and microbial communities. Our data reveal iron cycling involving both oxidizing (FeOB) and reducing (FeRB) bacteria. Additionally, we profiled a large microbial iron mat in a tundra seep adjacent to an Arctic stream (Oksrukuyik Creek) where we observed Fe(II) and soluble Fe(III) in a highly reducing environment. The variable distribution of redox-active substances at all the sites yields insights into the nature and distribution of the important terminal electron acceptors in both lacustrine and tundra environments capable of exerting significant influences on the carbon cycle.