Abstract Enhanced deposition is common near river mouths where large amounts of sediment is available. Our study focuses on the effects of sediment deposition on a mangrove forest in the Mekong river delta, Vietnam. At this site, the mangrove forest fringe is characterized by Sonneratia spp. and both mud and sand are present. High deposition rates bury mangrove roots and pneumatophores, causing forest dieback. Field measurements indicate that dead trees in a ghost forest have roots buried in about 1.20 m of sediments, while surviving trees have a typical root depth of 0.6 m. Saplings revegetating the dieback area have a root depth around 0.2 m. Root depth is further related to forest basal area and number of pneumatophores per square meter. Sediment burial covers the pneumatophores smothering the mangroves roots and decreasing the health of the forest. Remote sensing images indicate that the dieback occurred in 2014, with a sharp drop in Normalized Difference Vegetation Index (NDVI). The forest partly recovered in the following 5 years reaching the NDVI value of 2013. Our study is adding a new understanding of the coupling between mangrove forest evolution and sediment transport in tropical deltas.

中文翻译：

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沉积物沉积影响越南湄公河三角洲的红树林

摘要 在有大量沉积物的河口附近，沉积增强是很常见的。我们的研究重点是沉积物沉积对越南湄公河三角洲红树林的影响。在这个地点，红树林边缘的特征是海桑属植物。泥土和沙子都存在。高沉积率掩埋了红树林根和气管，导致森林枯死。实地测量表明，鬼林中死树的根深埋在约 1.20 m 的沉积物中，而幸存的树木的典型根深为 0.6 m。重新植被枯死区的树苗根深约 0.2 m。根深还与森林基面积和每平方米气管数量有关。沉积物掩埋了气管，窒息了红树林的根部并降低了森林的健康。遥感图像表明枯萎发生在 2014 年，归一化差异植被指数 (NDVI) 急剧下降。森林在接下来的 5 年中部分恢复，达到 2013 年的 NDVI 值。我们的研究为热带三角洲红树林演化与沉积物输送之间的耦合关系增加了新的认识。