Palaeoecology and climate of the Amazon basin during the last glacial cycle

Colinvaux, Paul A.; Oliveira, Paulo Eduardo de

doi:10.1002/1099-1417(200005)15:4<347::aid-jqs537>3.0.co;2-a

Cited by 62 publications

(21 citation statements)

References 44 publications

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“…Evidence here is based on very few key sites but reviews of pollen evidence from the Amazon Basin have recognised a hiatus, in most of the critical sections that lasted several thousand years either side of the LGM (Ledru et al, 1998). This situation has led to ambiguity concerning the climates and vegetation in the region during the LGM, making it difficult to resolve conflicts of view concerning the impact of cooler and drier conditions at this time (Clapperton, 1993;Ledru, 1993;Colinvaux et al, 2000;Colinvaux and De Oliveira, 2002). Anhuf et al (2006), however conclude that nearly 50% of the forest was lost: the rainforest/savanna border contracting 200 km from the north and 300 km from the south, reducing the rainforest to extensive refugia, as indicated by many previous authors (see Latrubesse, 2003).…”

Section: South Americasupporting

confidence: 91%

Understanding the impacts of Late Quaternary climate change in tropical and sub-tropical regions

Thomas

2008

Geomorphology

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Section: South Americasupporting

confidence: 91%

Understanding the impacts of Late Quaternary climate change in tropical and sub-tropical regions

Thomas

2008

Geomorphology

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“…One research focus in tropical South America has traditionally been the Andean Altiplano and the 2000). In addition, palynological studies help to improve our understanding of the paleoenvironmental history of the Amazon basin and the adjacent lowlands (van der Hammen and Absy, 1994;Ledru et al, 1996Ledru et al, , 1998Behling, 1998;Colinvaux and Oliveira, 2000;van der Hammen and Hooghiemstra, 2000;Behling, 2002). All these investigations have provided evidence for a complex late Quaternary landscape evolution in tropical South America characterized by major geomorphic, hydrological and ecological changes.…”

Section: Introductionmentioning

confidence: 58%

Late Quaternary paleosol–sediment-sequences and landscape evolution along the Andean piedmont, Bolivian Chaco

2008

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“…The finding had important ecological implications because it indicated that Peté n's seasonal tropical forest is no older than $11 ka (Deevey et al, 1983;Leyden, 1984). Contemporaneous lowering of African lake levels led some researchers to propose that aridity may have been pantropical during the last glaciation, but this hypothesis has been called into question (Liu and Colinvaux, 1985;Colinvaux and De Oliveira, 2000;Mayle et al, 2000). With observations in the early 1990s of millennial-scale climate variability in Greenland ice cores, it soon became evident that considerable tropical climate variability also existed during the last glacial period with both relatively wetter and drier conditions (Peterson et al, 2000;Gonzá lez et al, 2008).…”

Section: Article In Pressmentioning

confidence: 99%

An 85-ka record of climate change in lowland Central America

Hodell

Anselmetti

Ariztegui

et al. 2008

Quaternary Science Reviews

235

231

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a b s t r a c tDrill cores obtained from Lake Peté n Itzá , Peté n, Guatemala, contain a $85-kyr record of terrestrial climate from lowland Central America that was used to reconstruct hydrologic changes in the northern Neotropics during the last glaciation. Sediments are composed of alternating clay and gypsum reflecting relatively wet and dry climate conditions, respectively. From $85 to 48 ka, sediments were dominated by carbonate clay indicating moist conditions during Marine Isotope Stages (MIS) 5a, 4, and early 3. The first gypsum layer was deposited at $48 ka, signifying a shift toward drier hydrologic conditions and the onset of wet-dry oscillations. During the latter part of MIS 3, Peté n climate varied between wetter conditions during interstadials and drier states during stadials. The pattern of clay-gypsum (wet-dry) oscillations during the latter part of MIS 3 ($48-23 ka) closely resembles the temperature records from Greenland ice cores and North Atlantic marine sediment cores and precipitation proxies from the Cariaco Basin. The most arid periods coincided with Heinrich Events when cold sea surface temperatures prevailed in the North Atlantic, meridional overturning circulation was reduced, and the Intertropical Convergence Zone (ITCZ) was displaced southward. A thick clay unit was deposited from 23 to 18 ka suggesting deposition in a deep lake, and pollen accumulated during the same period indicates vegetation consisted of a temperate pine-oak forest. This finding contradicts previous inferences that climate was arid during the Last Glacial Maximum (LGM) chronozone (2172 ka). At $18 ka, Peté n climate switched from moist to arid conditions and remained dry from 18 to 14.7 ka during the early deglaciation. Moister conditions prevailed during the warmer Bolling-Allerod (14.7-12.8 ka) with the exception of a brief return to dry conditions at $13.8 ka that coincides with the Older Dryas and meltwater pulse 1A. The onset of the Younger Dryas at 12.8 ka marked the return of gypsum and hence dry conditions. The lake continued to precipitate gypsum until $10.3 ka when rainfall increased markedly in the early Holocene.

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Palaeoecology and climate of the Amazon basin during the last glacial cycle

Cited by 62 publications

References 44 publications

Understanding the impacts of Late Quaternary climate change in tropical and sub-tropical regions

Understanding the impacts of Late Quaternary climate change in tropical and sub-tropical regions

Late Quaternary paleosol–sediment-sequences and landscape evolution along the Andean piedmont, Bolivian Chaco

An 85-ka record of climate change in lowland Central America

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