Holocenic proxies of sedimentary organic matter and the evolution of Lake Arari-Amazon Region

► We analyze the impact of the water discharge changes of Amazon River on the mangrove. ► During the early and mid-Holocene occurred a marine influence on the Lake Arari-Marajó Island. ► From 2270 to 1000 cal yr B.P., the mangroves were replaced by freshwater vegetation. ► During the last 1000 yrs occurred a transition lagoon/lake. ► The climatic changes identified on the Amazon Region have produced impacts on the wetlands.