The high sea-level stand during the mid-Holocene is a benchmark in mangrove dynamics along the north-east/south-east coast of Brazil and provides a reference point for landward and seaward mangrove migrations corresponding to changes in relative sea level (RSL). However, evidence of the impacts associated with RSL fall on the northern Brazilian coast is scarce. Multi-proxy data from the highest tidal flats of the Bragança Peninsula in northern Brazil revealed modern herbaceous areas were occupied by mangroves Rhizophora and Avicennia from ~6250 to ~5850 cal a bp, and only Avicennia between ~5850 and ~5000 cal a bp. The same tidal flats were vegetation-free between ~5000 and ~4300 cal a bp. A combination of a high sea-level stand (0.6 ± 0.1 m) at ~5000 cal a bp and a dry early–middle Holocene in the Amazon probably caused an increase in porewater salinity of tidal flats, which resulted in a mangrove succession from Rhizophora to Avicennia dominance. RSL fall accentuated this process, contributing to mangrove degradation between ~5000 and ~4300 cal a bp. RSL fall, and a wetter period over the past ~4300 cal a bp caused a mangrove migration from highest to lowest flats, followed by expansion of herbaceous vegetation on the highest flats.

中文翻译：

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全新世中期高海平面和气候对亚马逊红树林的影响

全新世中期的高海平面是巴西东北/东南海岸红树林动态的基准，并为与相对海平面 (RSL) 变化相对应的向陆和向海红树林迁移提供参考点. 然而，与 RSL 下降相关的影响对巴西北部海岸的影响的证据很少。来自巴西北部布拉干萨半岛最高潮滩的多代理数据显示，现代草本区域被红树林Rhizophora和Avicennia占据，范围从 ~6250 到 ~5850 cal a bp，只有Avicennia在 ~5850 到 ~5000  cal a bp 之间。相同的潮滩在 ~5000 到 ~4300 cal a 之间没有植被基点。在〜5000高海平面支架（0.6±0.1米）的组合CAL一个碱基对和在亚马逊干早中全新世可能引起在滩涂孔隙水盐度的增加，这导致了从红树林演替红海到Avicennia 的统治地位。RSL 下降加剧了这一过程，导致红树林退化在 ~5000 到 ~4300 cal a bp 之间。RSL 下降，以及过去约 4300 cal a bp的湿润期导致红树林从最高处向最低处迁移，随后最高处的草本植被扩张。