Constraining modern-day silicon cycling in Lake Baikal
Constraining modern-day silicon cycling in Lake Baikal
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DOI：
10.1002/2016gb005518
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发表时间：
2017-03-01
影响因子：
5.2
通讯作者：
Horstwood, M. S. A.
中科院分区：
文献类型：
--
作者：
Panizzo, V. N.;Swann, G. E. A.;Horstwood, M. S. A.
限制大陆硅循环是一个关键的要求，在试图了解营养通量的海洋和硅和碳循环之间的联系在不同的时间尺度。本文介绍了西伯利亚中部贝加尔湖及其流域溶解硅（δ Si-30（DSi））的硅同位素数据。贝加尔湖不仅是世界上最古老、水量最大的湖泊，而且位于世界第七大流域内，向北冰洋输出大量淡水。从河流沃茨占类似的92%，每年流入湖泊的数据表明，没有季节性变化或人为影响河流三角洲Si-30（DSi）的组成。三角洲Si-30（DSi）内的塞伦加三角洲，通过其中62%的河流流量通过的变化的情况下，表明在这个系统中的生物吸收和溶解之间的净平衡。这项研究的一个关键特点是使用三角洲Si-30（DSi）检查DSi利用和出口的季节和空间变化在整个湖泊。使用一个开放系统模型，对深水三角洲Si-30（DSi）值从湖，我们估计，20 - 24%的DSi进入贝加尔湖输出到沉积物记录。虽然突出了湖泊可能对大陆DSi的封存产生的影响，但2003年和2013年的混合层三角洲Si-30（DSi）值显示了春季水华养分利用率的显著空间变异性，北部相对于南部盆地的利用率较低。
Constraining the continental silicon cycle is a key requirement in attempts to understand both nutrient fluxes to the ocean and linkages between silicon and carbon cycling over different time scales. Silicon isotope data of dissolved silica (delta Si-30(DSi)) are presented here from Lake Baikal and its catchment in central Siberia. As well as being the world's oldest and voluminous lake, Lake Baikal lies within the seventh largest drainage basin in the world and exports significant amounts of freshwater into the Arctic Ocean. Data from river waters accounting for similar to 92% of annual river inflow to the lake suggest no seasonal alteration or anthropogenic impact on river delta Si-30(DSi) composition. The absence of a change in delta Si-30(DSi) within the Selenga Delta, through which 62% of riverine flow passes, suggests a net balance between biogenic uptake and dissolution in this system. A key feature of this study is the use of delta Si-30(DSi) to examine seasonal and spatial variations in DSi utilization and export across the lake. Using an open system model against deepwater delta Si-30(DSi) values from the lake, we estimate that 20-24% of DSi entering Lake Baikal is exported into the sediment record. While highlighting the impact that lakes may have upon the sequestration of continental DSi, mixed layer delta Si-30(DSi) values from 2003 and 2013 show significant spatial variability in the magnitude of spring bloom nutrient utilization with lower rates in the north relative to south basin.