Complicated biogeochemical cycling and differential organic matter reactivity make quantifying the relative contribution of a given source of organic carbon to the standing stock within an estuary difficult. Here, a new model of tidal marsh‐estuary organic carbon cycling is presented for the Rhode River, MD, a well‐studied tributary of the Chesapeake Bay, USA. A dissolved organic carbon (DOC) budget was estimated by summing the source and sink terms and the advection of water within the tributary. 13.1% and 15.3% of the total DOC input to the Rhode River entered from the marsh and the watershed, respectively, and 52.6% was derived from phytoplankton production. Extrapolating to the entire year, 35.5 Mg of DOC is exported to the main stem of Chesapeake Bay annually, which accounts for 12.3% of the total allochthonous and autochthonous inputs to the estuary. Removing the modeled marsh at the head of the Rhode River decreased export of DOC to the main stem by 39.2%, and up to 56% of the estuarine DOC standing stock can be attributed to the marsh. The model described here can be used across temperate estuarine systems and provides a new methodology for quantifying the amount of DOC that can be attributed to or lost by specific source and sink pathways.

中文翻译：

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使用增强的生物地球化学模型的综合河口溶解有机碳收支

复杂的生物地球化学循环和不同的有机物反应性使得难以量化河口内给定有机碳源对站立种群的相对贡献。在这里，为美国切萨皮克湾经过深入研究的罗得河医学博士提出了一种潮汐沼泽-河口有机碳循环的新模型。通过对支流中的水源和汇项以及水的对流进行求和，可以估算出溶解有机碳（DOC）的预算。罗德河的DOC总输入量分别从沼泽和流域进入，分别占13.1％和15.3％，其中52.6％来自浮游植物。推断全年，每年有35.5毫克的DOC出口到切萨皮克湾的主干，占总量的12。入河口的所有异源和异源输入的3％。除去罗德河上游的模型沼泽，DOC向主干的出口减少了39.2％，而高达56％的河口DOC存货可归因于沼泽。此处描述的模型可在温带河口系统中使用，并提供了一种新的方法来量化可归因于特定源和汇路径或从中流失的DOC数量。