Intermittent development of forest corridors in northeastern Brazil during the last deglaciation: Climatic and ecologic evidence

Author(s)

Bouimetarhan, Ilham ^{[1, 2]} ; Chiessi, Cristiano M. ^[3] ; Gonzalez-Arango, Catalina ^[4] ; Dupont, Lydie ^{[1, 2]} ; Voigt, Ines ^{[1, 2]} ; Prange, Matthias ^{[1, 2]} ; Zonneveld, Karin ^{[1, 2]}

Affiliation

^[1] Univ Bremen, MARUM Ctr Marine Environm Sci, POB 330440, D-28334 Bremen - Germany

^[2] Univ Bremen, Fac Geosci, POB 330440, D-28334 Bremen - Germany

^[3] Univ Sao Paulo, Sch Arts Sci & Humanities, Av Arlindo Bettio 1000, BR-03828000 Sao Paulo, SP - Brazil

^[4] Univ Los Andes, Dept Biol Sci, Bogota 4976 - Colombia

• Document type: Journal article
• Source: QUATERNARY SCIENCE REVIEWS; v. 192, p. 86-96, JUL 15 2018.
• Web of Science Citations: 6

Abstract

The semi-arid northeastern (NE) Brazil vegetation is largely dominated by Caatinga, one of the largest and richest dry forests in the world. Caatinga is a strategic biome, since it has borders with Cerrado, Atlantic forests and the Amazon, acting as a potential corridor (or barrier) for biotic interchange between these regions during evolutionary times. Therefore, accurate reconstructions of past vegetation, ecological and hydrological changes in this area are critical to understanding the dynamics of biome boundaries that may play an important role in dispersal and diversification mechanisms and, more specifically, the link between the long-term climate variability and tropical biodiversity. Here, we present high-resolution palynological and elemental data from marine core GeoB16205-4 retrieved off the Parnaiba River mouth (NE Brazil) mainly covering the Younger Dryas (YD). We show that the YD interval was predominantly wet in NE Brazil, yet it was not homogenous and two distinct phases could be distinguished. A marked intensification of wet conditions between similar to 12.3 and 11.6 cal kyr BP was recorded by the expansion of tropical rainforest and tree ferns. These results are in agreement with the transient TraCE-21k coupled climate model simulation. We infer that the second pluvial phase of the YD is related to a weak AMOC due to meltwater pulses in the North Atlantic, which forces a southward shift of the Intertropical Convergence Zone and its associated rainfall. Our records provide new evidence on the establishment of an ``eastern forest corridor{''} in the nowadays semi-arid Caatinga allowing for past biotic interchanges of plant species. (C) 2018 Elsevier Ltd. All rights reserved. (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