An Examination of Historical Inorganic Sedimentation and Organic Matter Accumulation in Several Marsh Types within the Mobile Bay and Mobile—Tensaw River Delta Region
An Examination of Historical Inorganic Sedimentation and Organic Matter Accumulation in Several Marsh Types within the Mobile Bay and Mobile—Tensaw River Delta Region
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莫比尔湾和莫比尔-坦索河三角洲地区几种沼泽类型历史无机沉积和有机物积累的研究
DOI：
10.2112/si63-007.1
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发表时间：
2013
影响因子：
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通讯作者：
R. Poore
中科院分区：
文献类型：
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作者：
Christopher G. Smith;L. Osterman;R. Poore
摘要史密斯，C.G.； Osterman, L.E. 和 Poore, R.Z.，2013 年。对莫比尔湾和莫比尔-滕索河三角洲地区几种沼泽类型的历史无机沉积和有机物积累的研究。在：布洛克，J.C.；巴拉斯 (J.A.) 和威廉姆斯 (S.J.) （编辑），理解和预测墨西哥湾北部沿海生态系统的变化，沿海研究杂志，特刊第 63 号，第 68-83 页，椰子溪（佛罗里达州），ISSN 0749-0208。质量积累速率（MAR；g cm-2 y-1）、线性沉积速率（LSR；cm y-1）以及源自过量铅 210 (210Pb) 剖面和从莫比尔坦索河三角洲和莫比尔湾地区沼泽地收集的六个沉积物岩心测量的库存的岩心地质年代学记录了过去 120 年连续和事件驱动的无机沉积的重要性。淡水沼泽中的 MAR 在不同地点和不同时间之间变化很大（0.24 和 1.31 g cm-2 y-1）。最高 MAR 发生在 20 世纪 50 年代和 1960 年代，对应莫比尔河和坦索河沿岸创纪录的排放事件。相比之下，盐沼地点的 MAR 在过去 120 年中几乎增加了三倍（0.05 至 0.18 g cm-2 y-1 或 0.23 至 0.48 cm y-1）。从 1880 年到 1960 年，有机积累保持相当稳定（~20%），而 1960 年之后观察到间歇性的高无机沉积脉冲。无机沉积的脉冲与几个主要飓风（例如飓风卡米尔、弗雷德里克、乔治和伊万）一致。因此，过去 120 年中盐沼 MAR 增加了近三倍，这似乎部分取决于风暴事件造成的无机沉积。这项研究表明，虽然飓风、洪水和其他自然灾害是对人类基础设施和沿海生态系统的众所周知的威胁，但这些事件也会将沉积物输送到沼泽，从而有助于减轻海平面上升 (SLR) 和沉降等其他压力。
ABSTRACT Smith, C.G.; Osterman, L.E., and Poore, R.Z., 2013. An examination of historical inorganic sedimentation and organic matter accumulation in several marsh types within the Mobile Bay and Mobile—Tensaw River delta region. In: Brock, J.C.; Barras, J.A., and Williams, S.J. (eds.), Understanding and Predicting Change in the Coastal Ecosystems of the Northern Gulf of Mexico, Journal of Coastal Research, Special Issue No. 63, pp. 68–83, Coconut Creek (Florida), ISSN 0749-0208. Mass accumulation rates (MAR; g cm-2 y-1), linear sedimentation rates (LSR; cm y-1), and core geochronology derived from excess lead-210 (210Pb) profiles and inventories measured in six sediment cores collected from marsh sites from the MobileTensaw River Delta and Mobile Bay region record the importance of both continuous and event-driven inorganic sedimentation over the last 120 years. MAR in freshwater marshes varied considerably between sites and through time (0.24 and 1.31 g cm-2 y-1). The highest MARs occurred in the 1950s and 1960s and correspond to record discharge events along the Mobile and Tensaw Rivers. In comparison, MAR at salt marsh sites increased almost threefold over the last 120 years (0.05 to 0.18 g cm-2 y-1 or 0.23 to 0.48 cm y-1). From 1880 to 1960, organic accumulation remained fairly constant (∼20%), while intermittent pulses of high inorganic sedimentation were observed following 1960. The pulses in inorganic sedimentation coincide with several major hurricanes (e.g., Hurricanes Camille, Fredric, Georges, and Ivan). The nearly threefold increase in MAR in salt marshes during the last 120 years would thus appear to be partially dependent on inorganic sedimentation from storm events. This study shows that while hurricanes, floods, and other natural hazards are well-known threats to human infrastructure and coastal ecosystems, these events also transport sediment to marshes that help abate other pressures such as sea-level rise (SLR) and subsidence.