https://doi.org/10.1177/0959683616683260
The Holocene
1–12
© The Author(s) 2017
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DOI: 10.1177/0959683616683260
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Introduction
Several studies have demonstrated that the Amazon forest was
influenced by a cold and dry climate conditions during the Last
Glacial Maximum (LGM) climate (Absy et al., 1991; Cohen
et al., 2014; D’Apolito et al., 2013; Haffer, 1969; Haffer and
Prance, 2001; Ledru et al., 1998, 2001; Van de Hammen and
Absy, 1994). However, other works have shown alternative inter-
pretations in conventional pollen-based climate reconstructions,
indicating no forest fragmentation and relatively stable climate
condition during the LGM (Bush et al., 2004a, 2004b; Colinvaux
and De Oliveira, 2000; Colinvaux et al., 1996, 2001).
Based on speleothem records, Cheng et al. (2013) indicated a
drastic shift from severely dry to substantially wet conditions
from the LGM to the early- to mid-Holocene (~10,000–5000 yr
BP) in the eastern Amazonia. In contrast, western Amazon records
a shift from relatively wet to moderately dry conditions for this
period. This suggests the presence of a dipole of precipitation
associated with a walker cell that gives rise to an east-west bipolar
see-saw pattern of monsoon precipitation (Cruz et al., 2009).
However, Baker and Fritz (2015) re-evaluated the eastern records
presented by Cheng et al. (2013) and indicated that the Holocene
Modern pollen rain as a background for
palaeoenvironmental studies in the Serra
dos Carajás, southeastern Amazonia
José Tasso Felix Guimarães,
1
Tarcísio Magevski Rodrigues,
2
Luiza Santos Reis,
1,3
Mariana Maha Jana Costa de Figueiredo,
1
Delmo Fonseca da Silva,
2
Ronnie Alves,
1,4
Tereza Cristina Giannini,
1
Léa Maria Medeiros Carreira,
5
Anna Christina Rio Dias,
5
Edilson Freitas da Silva,
5
Prafulla Kumar Sahoo,
1
Marcio Sousa da Silva
1
and Pedro Walfir Martins Souza-Filho
1,6
Abstract
Several alternative interpretations of the pollen records of lake sediments in the Amazonia may arise due to a lack of understanding of the modern
environments, mainly related to pollen–vegetation relationship. Therefore, in this work, we studied the modern pollen rain in sediments of the
Amendoim Lake, plateaus of the Serra Sul dos Carajás, southeastern Amazonia. This study indicates the predominance of pollen grains from forest
formation (ombrophilous forests and capão florestal) over montane savanna in the lake sediments, despite the fact that montane savanna occupies
~90% of the drainage basin. Additionally, these sediments reflect stronger signal of pollen from ombrophilous forests that occur in the slopes of
the plateau. Important components of montane savanna such as Vellozia and Cereus were not observed in the modern pollen rain, which may be
related to their shorter flowering periods restricted to the beginning of wetter conditions. The absence of Sacoglottis, Trichilia, Clusia, Emmotum,
Guapira and Simarouba in the pollen rain is likely associated with different pollination strategy. The occurrence of windblown pollen of Alchornea,
Pseudolmedia, Ilex and Cecropia, which are found from low to highlands of the Carajás region, reinforces a regional vegetation signal in sediments.
Several plants from the studied site have been improperly described, according to taxonomy and ecology. For example, the current occurrence of
Ilex and Styrax in the study site clearly suggests that they cannot be used as indicators of colder palaeoclimate conditions, as previously described. In
addition, Poaceae can be found in drier to wetter substrate conditions, and abundance of their pollen grains in lakes can significantly vary according
to relief morphology and cannot indicate palaeovegetation openness. Therefore, this work is a good background for further palaeobotany studies
for this region.
Keywords
Amazonia, Holocene, montane savanna, palynology, pollen rain, rainforest, Serra dos Carajás
Received 19 July 2016; revised manuscript accepted 27 October 2016
1
Instituto Tecnológico Vale, Brazil
2
Departamento de Ferrosos Norte, Gerência de Meio Ambiente–Minas
de Carajás, Brazil
3
Centro de Energia Nuclear na Agricultura, Piracicaba, Brazil
4
Programa de Pós-graduação em Ciência da Computação, Instituto de
Ciências Exatas e Naturais, Universidade Federal do Pará, Brazil
5
Coordenação de Botânica, Museu Paraense Emílio Goeldi, Brazil
6
Programa de Pós-graduação em Geologia e Geoquímica, Instituto de
Geociências, Universidade Federal do Pará, Brazil
Corresponding author:
José Tasso Felix Guimarães, Instituto Tecnológico Vale, Rua Boaventura
da Silva 955, Nazaré, 66055-090 Belém, Pará, Brazil.
Email: tasso.guimaraes@itv.org
683260HOL 0 0 10.1177/0959683616683260The HoloceneGuimarães et al.
research-article 2016
Research paper