There is growing evidence that a substantial fraction of the dissolved organic and inorganic carbon (DOC and DIC) and particulate organic carbon (POC) can be exported from mangroves to the ocean. Yet our understanding of C fluxes in mangrove forests is limited to only few regional studies that exclude the world's longest sediment dispersal system connected to the Amazon River. The present study aims at (1) examining tidal fluctuations of DOC, POC, and DIC; their isotopes; and optical properties such as chromophoric dissolved organic matter (CDOM) and (2) estimating their exchange fluxes between the mangroves and adjacent coastal water in the Sinnamary estuary, French Guiana. Time series observation highlighted that physical processes coupled to tides controlled diel dynamics and sources of DOC (e.g., litter leaching and pore water seepage) and POC (microphytobenthos, sediment resuspension, and bioturbation activities). Intense benthic remineralization could account for high water column pCO₂ and DIC exchange flux during the low tide. Mangrove‐derived DOC export to inner shelf (8.14 g C m⁻² day⁻¹) was exceeding import of POC and DIC from the mud bank and marine sources to the mangroves (1.35 and 0.90 g C m⁻² day⁻¹, respectively). Because of specific dynamics of the Amazon mobile muds, local geomorphology, water column stratification, and environmental forcing, Guianese mangroves cannot be seen as simple C exporters to the Atlantic waters. These first data setting on C fluxes for the region should be included along with other studies to improve global mangrove C budget estimate.

中文翻译：

---

美洲河口系统（南美法属圭亚那）和大西洋之间红树林衍生的有机和无机碳交换

越来越多的证据表明，大部分溶解的有机碳和无机碳（DOC和DIC）以及颗粒有机碳（POC）可以从红树林出口到海洋。但是，我们对红树林中碳通量的了解仅限于少数地区性研究，其中不包括连接到亚马逊河的世界上最长的沉积物扩散系统。本研究旨在（1）检查DOC，POC和DIC的潮汐波动；他们的同位素；以及诸如发色溶解性有机物（CDOM）的光学特性，以及（2）估算法属圭亚那Sinnamary河口红树林与邻近沿海水之间的交换通量。时间序列观测结果表明，与潮汐相关的物理过程控制着diel动力学和DOC的来源（例如，垃圾的浸出和孔隙水的渗入）和POC（微植物底栖动物，沉积物的再悬浮和生物扰动）。强烈的底栖矿化可能是高水柱的原因在退潮时，p CO ₂和DIC交换通量。来自红树林的DOC出口到内层架（8.14 g C m ^-2 天^-1）超过了从泥浆库和海洋源向红树林的POC和DIC的进口量（分别为1.35 g C m ^-2 天^-1） ）。由于亚马逊流动泥浆的特定动力学，局部地貌，水柱分层和环境强迫，因此，不能将圭亚那红树林视为向大西洋水域的简单C出口商。这些关于该地区碳通量的最初数据设置应与其他研究一起纳入，以改善全球红树林碳预算估算。