Evidence of a late glacial warming event and early Holocene cooling in the southern Brazilian coastal highlands

Abstract

A high-resolution pollen record of the Atlantic rain forest (ARF) biome from the coastal Serra do Tabuleiro mountains of southern Brazil documents an 11,960 yr history of vegetation and climate change. A marked expansion of Weinmannia into the grassland vegetation marks the latter part of the Younger Dryas, reflecting warm and relatively wet conditions. Between 11,490 and 9110 cal yr BP, grasslands became dominant again, indicating a long cold and dry phase, probably in response to the stronger influence of cold South Atlantic seawater and to Antarctic cold fronts. Between 9110 and 2640 cal yr BP, four distinct phases with strong or moderate expansions of different ARF biome taxa were recorded, reflecting warmer and relatively dry conditions with changes in rainfall and length of the annual dry season. After 2640 cal yr BP, the modern ARF biome became established with high amounts of ferns, reflecting somewhat cooler and wetter conditions with a reduced annual dry season. In particular, after 1000 cal yr BP tree ferns increased, reflecting wetter conditions with no dry season.

Climate change and biogeographic connectivity across the Brazilian cerrado

“…In Amazonia and Araucaria ‐forest habitats of southern Brazil, palynological records show cool‐adapted taxa intermingling with lowland species to form floras without a modern analogue. A suite of species that are currently only found in moist mid‐elevation forests, which included Myrsine, Podocarpus, Ilex and Weinmannia , are consistent members of glacial age forest in cerrado, Atlantic coastal forest and southern Amazonian habitats (Behling, ; Behling, Lichte, & Miklos, ; Behling & de Oliveira, ; Bush, Silman, & Urrego, ; D'Apolito, Absy, & Latrubesse, ; Hermanowski, da Costa, & Behling, ; Ledru et al, , ; De Oliveira et al, ; Salgado‐Labouriau et al, ).…”

Environmental variability at the margin of the South American Monsoon System recorded by a high-resolution sediment record from Lagoa Dourada (South Brazil)

“…Palynological investigations at Serra dos Orgaos (22.5 °S) describe a warm and wet Younger Dryas (YD) chronozone (Behling and Safford, 2010). Similar climatic conditions are reconstructed with pollen from Serra do Tabuleiro at 28 °S (Behling and Oliveira, 2017). Additionally, the reconstruction of precipitation using stable isotopes of a speleothem from Botuverá Cave at 27 °S (Cruz et al, 2005) also characterizes the YD as wet comparable to the Late Holocene.…”

“…The pollen record from Serra do Tabuleiro (28 °S) provides a nicely dated and densely analyzed Early Holocene record (Behling and Oliveira, 2017). After the warm and wet second half of the YD, Campos vegetation (grassland) with a warm and dry climate dominated the Early Holocene until 8000 cal.…”

“…After a warm and dry onset of the Holocene, precipitation started to increase, causing a change from Campos to the development of forest at Serra do Tabuleiro (Behling and Oliveira, 2017). Increased moisture advection from the Amazon Basin with a weakening of polar advection results in an expansion of forests in South Brazil dated to 7700-4390 cal.…”

In search of the ice age tropics, a tribute to Prof. Daniel Livingstone and Prof. Paul Colinvaux

“…The record from Lake Acarabixi (Rodriguez-Zorro et al, 2018) lends weight to inferences that Amazonia was already forested at the onset of the Holocene (following Colinvaux et al, 1996), although the composition of the fossil pollen shows marked differences between the early Holocene and modern times. The Serra do Tabuleiro peat bog record, presented by Behling and de Oliveira (2018) is from the Atlantic rain forest and captures the transition from open woodland to Atlantic rain forest at the onset of the Holocene. Raczka et al (2018) present the first study from the lowland Neotropics on fossil pollen and Sporormiella to reconstruct the history of megafaunal loss from two sites in southeastern Brazil.…”