Landscape changes in the southern Amazonian foreland basin during the Holocene inferred from Lake Ginebra, Beni, Bolivia

Abstract

AbstractOur study is located in northern Beni and aims to improve knowledge on regional landscape changes from the last 8600 years, based on pollen and charcoal analyses from a lacustrine sediment core from Lake Ginebra. Our results showed that gallery forest and lacustrine sediment were observed from 8645 until 3360 cal yr BP. After a change from a lacustrine to a swamp environment at 1700 cal yr BP, the Cerrados and the Mauritia swamp became installed 1000 years ago on our study site. The environmental changes we observed over the last 8600 years in the Ginebra record reinforce the evidence of a west–east climatic gradient with the persistence of rain forest throughout the Holocene on the western side and the presence of the Cerrados until the late Holocene on the eastern side. Moreover, the persistence of a wet forest in the early to mid-Holocene in southwestern Amazonia highlighted some local responses to the global trend that could be related to the distance from the Andes; while in the late Holocene, both an increase in insolation and strengthening of the South American summer monsoon system enabled the installation of a seasonal flooded savanna in northern Beni and of the rain forest in eastern Beni.