Characterization of transport and deposition of terrestrial organic matter in the southern North Sea using the BIT index
Characterization of transport and deposition of terrestrial organic matter in the southern North Sea using the BIT index
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DOI：
10.4319/lo.2006.51.5.2196
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发表时间：
2006-09-01
影响因子：
4.5
通讯作者：
Damste, Jaap S. Sinninghe
中科院分区：
文献类型：
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作者：
Herfort, Lydie;Schouten, Stefan;Damste, Jaap S. Sinninghe
我们应用了最近推出的代理，BIT（分支和异戊二烯四醚）指数，以确定陆地有机质（TOM）运输从河流莱茵河和默兹河及其支流到北海南部。该指数基于泉古菌，一种主要来自水生泉古菌的类异戊二烯甘油二烷基甘油四醚（GDGT）和土壤细菌产生的支链GDGT。在海水中测量到高达1.6 ng L（-1）的分支GDGT，表明在北海南部存在TOM。BIT指数与盐度呈负相关，表明这TOM最近提供的河流。在河水中检测到大量的分支GDGT（35 ng L（-1）），在瑞士泥炭沼泽水中测得的高分支GDGT浓度（5，900 ng L（-1））表明分支GDGT从泥炭和土壤到海洋的河流运输。在河水中测得的高泉古菌浓度（4.4 ng L（-1））可能来自生活在河流中的泉古菌以及土壤和泥炭中的有机物质。通过对比北海南部表层沉积物的BIT指数、δ（13）C值和C：N比值，确定TOM沉积。BIT指数（0.07 ~ 0.26）和δ（13）C（-20.6 ~-22.9%）均显示出北海南部TOM沉积的显著小尺度差异，但从C：N比值来看，这种差异并不明显。δ（13）C和分支GDGT浓度之间存在良好的相关性，表明绝对GDGT浓度为BIT指数提供了额外的信息。
We have applied a recently introduced proxy, the BIT (branched and isoprenoid tetraether) index, to determine terrestrial organic matter (TOM) transport from the rivers Rhine and Meuse and their tributaries to the southern North Sea. This index is based on crenarchaeol, an isoprenoidal glycerol dialkyl glycerol tetraether (GDGT) predominantly derived from aquatic Crenarchaeota and branched GDGTs produced by soil bacteria. Up to 1.6 ng L(-1) of branched GDGTs were measured in seawater, demonstrating the presence of TOM in the southern North Sea. BIT indices were inversely correlated with salinity, indicating that this TOM was recently supplied by rivers. The substantial amount of branched GDGTs (35 ng L(-1)) detected in river water and the high branched GDGT concentration measured in the water of a Swiss peat bog (5,900 ng L(-1)) suggest fluvial transport of branched GDGTs from peats and soils to the oceans. The high crenarchaeol concentration measured in river water (4.4 ng L(-1)) was probably derived from crenarchaeota living in rivers and organic material from soil and peat. The BIT index, delta(13)C value, and C : N ratio of surface sediments deposited in the southern North Sea were compared to determine TOM deposition. BIT index (0.07 to 0.26) and delta(13)C (-20.6 to -22.9%) both showed substantial small-scale differences in TOM deposition in the southern North Sea, but this pattern was not obvious from the C : N ratios. A good correlation was found between delta(13)C and branched GDGT concentrations, indicating that the absolute GDGT concentrations give additional information to the BIT index.