The southern Brazilian tropical forest during the penultimate Pleistocene glaciation and its termination

Author(s)

Aviles, Adriana Mercedes Camejo ; Ledru, Marie-Pierre ; Ricardi-Branco, Fresia ; Marquardt, Gisele C. ; Bicudo, Denise de Campos

• Document type: Journal article
• Source: JOURNAL OF QUATERNARY SCIENCE; v. 39, n. 3, p. 13-pg., 2024-01-31.

Abstract

To describe the composition of the penultimate glacial Brazilian Atlantic forest, we analyzed pollen, charcoal and diatoms deposited in the section from 871 to 1400 cm of core CO14 drilled in the Colonia basin in southeastern Brazil. The landscape was characterized by a cool grassland with three conifer genera: Araucaria, Podocarpus and Ephedra. Total arboreal pollen frequency did not change during the transition from glacial to interglacial conditions. Changes in Podocarpus frequency and concentration showed out-of-phase responses with austral summer insolation at an orbital scale while, at a millennial scale, both northern and southern hemisphere ice volume controlled the interplay between positions of the Inter-Tropical Convergence Zone and South Tropical Front (STF), which in turn defined the latitudinal distribution of rainfall. The disappearance of Podocarpus and the decrease of Araucaria observed between similar to 167 and 160 ka were related to a dry interval which was not observed elsewhere. During Termination II a progressive decrease in conifer pollen taxa was in phase with a southward shift in the STF and increase in Atlantic sea surface temperatures. Our results show that southern hemisphere conifer distribution is strongly linked to austral summer insolation and winter precipitation and will be threatened by the southward expansion of the summer rainfall boundary. (c) 2024 The Authors.Journal of Quaternary SciencePublished by John Wiley & Sons Ltd. (AU)

• FAPESP's process: 13/50297-0 - Dimensions US-BIOTA São Paulo: a multidisciplinary framework for biodiversity prediction in the Brazilian Atlantic forest hotspot
• Grantee: Cristina Yumi Miyaki
• Support Opportunities: BIOTA-FAPESP Program - Thematic Grants
• FAPESP's process: 17/50341-0 - Challenges for biodiversity conservation facing climate changes, pollution, land use and occupation (PDIp)
• Grantee: Luiz Mauro Barbosa
• Support Opportunities: Research Grants - State Research Institutes Modernization Program