New Holocene pollen records from the Brazilian Caatinga

Author(s)

De Medeiros, Vanda B. ^[1] ; De Oliveira, Paulo E. ^{[1, 2]} ; Santos, Rudney A. ^[1] ; Barreto, Alcina M. F. ^[3] ; De Oliveira, Marcelo A. T. ^[4] ; Pinaya, Jorge L. D. ^[5]

Affiliation

^[1] Univ Sao Paulo, Dept Sedimentary & Environm Geol, Inst Geosci, Rua Lago 562, Cidade Univ, BR-05508080 Sao Paulo, SP - Brazil

^[2] Field Museum Nat Hist, Dept Bot, 1400 S Lake Shore Dr, Chicago, IL 60605 - USA

^[3] Univ Fed Pernambuco, Dept Geol, Ctr Technol & Geosci, Ave Acad Helio Ramos S-N, Cidade Univ, BR-50740530 Recife, PE - Brazil

^[4] Univ Fed Santa Catarina, Dept Geosci, CFH, POB 5175, BR-88040970 Florimopolis, SC - Brazil

^[5] Univ Sao Paulo, Politech Sch, Av Prof Luciano Gualberto 380, Cidade Univ, BR-05508010 Sao Paulo, SP - Brazil

• Document type: Journal article
• Source: Anais da Academia Brasileira de Ciências; v. 90, n. 2, 1, p. 2011-2023, AUG 2018.
• Web of Science Citations: 2

Abstract

We present two pollen diagrams from the semi-arid Caatinga of the Catimbau National Park, in Pernambuco and from a Mauritia palm forest in the Caatinga/Cerrado ecotone of southern Piaui, NE Brazil, spanning the last 10,000 cal. yrs BP and the last 1,750 cal yrs BP, respectively. These two records contain a signature of the local vegetation and permit the correlation of the pollen signal with regional climatic changes. The Catimbau record shows Zizyphus sp., a typical Caatinga taxon, in all three pollen zones indicating regional Caatinga vegetation and the predominance of local arboreal taxa adapted to high humidity from 10,000 to ca. 6,000 cal. yrs BP with a gradual tendency towards drier conditions revealed by a deposition hiatus between 6,000 to ca. 2,000 cal. yrs BP. This abrupt loss of sediments in both localities is interpreted as a consequence of the establishment of modern semi-arid climates. The subsequent return of humidity is signaled by increased sedimentation rates and C-14 date inversions in agreement with high precipitation, revealed by sigma O-18 ratios in speleothems from NE Brazil. Modern sediments deposited in the last 500 years reflect local conditions with the maintenance of humidity by geological faulting and surfacing water tables. (AU)

• FAPESP's process: 15/01782-8 - Interactions between late Pleistocene/Holocene floristic and megafaunal migration corridors of the Caatinga in the State of Pernambuco, Brazil
• Grantee: Vanda Brito de Medeiros
• Support Opportunities: Scholarships in Brazil - Doctorate