Climate, sea-level, and anthropogenic influences on coastal vegetation of the southern Bahia, Northeastern Brazil, during the mid-late Holocene

Autor(es)

Figueiredo, Beatriz L. ^{[1, 2]} ; Alves, Igor Charles C. ^[2] ; Cohen, Marcelo C. L. ^[2] ; Pessenda, Luiz C. R. ^[1] ; Franca, Marlon Carlos ^[3] ; Francisquini, Mariah Izar ^[1] ; de Souza, V, Adriana ; Culligan, Nicholas ^[4]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, CENA 14C Lab, Av Centenario 303, BR-13400000 Piracicaba, SP - Brazil

^[2] V, Fed Univ Para, Grad Program Geol & Geochem, Av Perimentral 2651, BR-66077530 Belem, Para - Brazil

^[3] Fed Inst Para, Av Alm Barroso 1155, BR-66090020 Belem, Para - Brazil

^[4] Louisiana State Univ, Coll Coast & Environm, Dept Oceanog & Coastal Sci, Baton Rouge, LA 70803 - USA

• Tipo de documento: Artigo Científico
• Fonte: Geomorphology; v. 394, DEC 1 2021.
• Citações Web of Science: 0

Resumo

The Atlantic Forest and mangrove dynamics along the Brazilian coast have been affected by climate, relative sea-level (RSL), and anthropogenic forces. Individualizing the effects of these drivers on paleoecological records is a challenge. This was addressed by pollen analysis along three cores sampled from lakes on a coastal plateau, pri-marily influenced by rainfall, and from a fluvial valley, influenced by sea-level and fluvial discharge, in northeast-ern Brazil. Pollen records from the fluvial valley indicated the presence of mangroves along an estuary in the mid-Holocene. During the past-5800 cal yr BP, mangroves, adapted to brackish water, were replaced by herbaceous vegetation adapted to freshwater in the fluvial valley. Concurrently (-5680-240 cal yr BP), expansion of Atlantic Forest and contraction of herbaceous vegetation occurred on the coastal plateau. This divergence of pollen re-cords between two distinct sedimentary environments (lakes on a coastal plateau and fluvial valleys) was attrib-uted to RSL and climate effects. The combination of RSL fall and higher fluvial discharge favored seaward mangrove migration and expansion of herbaceous vegetation along the fluvial valley during the mid-late Holo-cene. However, the increase in rainfall on the coastal plateau favored the expansion of arboreal vegetation and contraction of herbaceous vegetation. At-1700 CE, an abrupt shift from arboreal to herbaceous vegetation oc-curred on the coastal plateau. This vegetation change is likely attributed to European colonization on the south-ern coast of the state of Bahia, which was colonized by Portuguese navigators-1500 CE. Part of the Atlantic Forest has naturally regenerated and was preserved as a national park in recent decades. This study showed that although the sampling sites are close, pollen assemblages can differ considerably depending on the depositional environment. Therefore, pollen analyses in different depositional environments are necessary to assess individ-ually driving forces impacts on coastal vegetation dynamics during the Holocene. (c) 2021 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 11/00995-7 - Estudos paleoambientais interdisciplinares na costa do Espírito Santo
• Beneficiário: Luiz Carlos Ruiz Pessenda
• Modalidade de apoio: Auxílio à Pesquisa - Programa de Pesquisa sobre Mudanças Climáticas Globais - Temático
• Processo FAPESP: 17/03304-1 - Impactos das mudanças climáticas e das flutuações do nível do mar nos manguezais brasileiros em escalas secular e milenar
• Beneficiário: Luiz Carlos Ruiz Pessenda
• Modalidade de apoio: Auxílio à Pesquisa - Programa de Pesquisa sobre Mudanças Climáticas Globais - Regular