Interdisciplinary paleovegetation study in the Fernando de Noronha Island (Pernambuco State), northeastern Brazil

Abstract

The aim of this research was to reconstruct vegetation changes (with climate inferences) that occurred during the Holocene in the Fernando de Noronha Island, Pernambuco State, northeastern Brazil. The research approach included the use of geochemical (mineralogy, elemental), carbon isotopes (δ 13 C, 14 C) and pollen analyses in soil organic matter (SOM) and sediments collected in Lagoa da Viração and Manguezal do Sueste. The carbon isotopes data of SOM indicated that there was no significant vegetation changes during the last 7400 BP, suggesting that the climate was not the determinant factor for the vegetation dynamics. The pollen analysis of the sediment of a core collected in the Lagoa da Viração showed the absence of Quaternary material in the period between 720 BP and 90 BP. The mineralogical analysis of deeper layer showed the presence of diopside indicating this material was developed "in situ". Only in the shallow part of the core were found pollen of similar plant species of the modern vegetation. The geochemistry and isotope results, in association with the sediment type and pollen analyses of sediment samples of Manguezal do Sueste, indicated variations in the vegetation and in its location since the middle Holocene. Such variations can be associated with climatic events and sea level oscillations and also with anthropogenic events considering the last five hundred years.

Heavy metal concentrations in soils from a remote oceanic island, Fernando de Noronha, Brazil

“…The average annual temperature is 25 • C and the rainfall averages 1400 mm per year. Climate changes, as well as variations in the sea level, are thought to have occurred during the Pleistocene (Pessenda et al 2008).…”

“…Soil sampling was performed as part of a previous study aiming to reconstruct the vegetation and climate changes during the Holocene (Pessenda et al 2008). The soil profiles were identified as Haplic Cambisols according to the World Reference Base Classification System (FAO 1990).…”

Processos Sedimentares Sazonais E Análise Da Fração Arenosa No Sistema Ambiental Do Sueste, Fernando De Noronha, Estado De Pernambuco

“…A área de estudo é o Arquipélago de Fernando de Noronha, em particular, o sistema costeiro da baía do Sueste, localizada na costa meridional da ilha principal. O ecossistema manguezal composto apenas pela espécie Laguncularia recemosa representa o único bosque de mangue em ilha oceânica no Atlântico Sul (Pessenda et al, 2008) e está diretamente conectado à drenagem intermitente do córrego Maceió, que contribui com a água doce necessária à manutenção deste ecossistema. Entretanto, devido à construção da Barragem do Xaréu e da Rodovia BR-363 esta contribuição foi drasticamente reduzida nos últimos anos, afetando seu comportamento hidrológico bem como a morfodinâmica praial (Teixeira et al, 2003;Pessenda et al, 2008).…”

Spatial sedimentary distribution, seasonality and the characteristics of organic matter on Fernando de Noronha insular shelf

“…In recent decades an increase has been observed in the number of studies conducted on calcareous beach systems on oceanic islands, such as those by Kench (1997), Norcross et al (2002), Smith and Cheung (2002), Eversole and Fletcher (2003), Genz et al (2007), Pessenda et al (2008), Pereira et al (2010); Manso et al (2011), and Barcellos et al (2011Barcellos et al ( , 2016a. However, studies on sedimentology, with a multi-proxy approach, on oceanic island shelves are still few.…”