Late Quaternary vegetation and climate dynamics in southeastern Amazonia inferred from Lagoa da Confusão Tocantins State, northern Brazil
Hermann Behling
Abstract
Late Quaternary vegetation and climate dynamics have been reconstructed by pollen analysis of a lacustrine sediment core from Lagoa da Confusiio. The lake lies about 160 km southwest of Palmas, capital of Tocantins State. The study area is located in the cerrado (savanna) and cerrado/Amazon rain forest transition region of southeastern Amazonia. The record, dated by 4 AMS radiocarbon dates, provide insight into vegetation and climate dynamics of late Pleistocene and Holocene age. Pollen data indicate that the study region was dominated by cerrado (savanna), first of the campo limpo type (grassland savanna) between 60,300-51,700 (chronology A) or 29,000-27,400 14C yr B.P. (chronology B) and than of the campo sujo type between 51,700-24,670 (chronology A) or 27,400-14,000 14C yr B.P. (chronology B). Existing small areas of gallery forests increased slightly during the second period. Amazon forest taxa occurred sparsely in the study region. The palaeovegetatio infer a markedly drier climate (low precipitation and long annual dry season) during the glacial periods compared to the modern climate. A sedimentary gap probably occurred during the full glacial and1or Lateglacial period, suggesting drier climatic conditions than during the two earlier periods. During the early and mid Holocene the campo cerrado type (savanna woodland) was dominant and the landscape was more forested by the stronger presence of gallery forest and Amazon forest trees. Precipitation was higher, and the length of the annual dry season was shorter than during the late Pleistocene periods. After 5460 14C yr B.P. campo cerrado was still dominant, but forest cover increased markedly by the expansion Amazon forest populations and palm trees, reflecting the wettest climate period recorded. The results from Lagoa da Confusao support the general trend of dry glacial conditions, as reported from other tropical South American lowland regions. The expansion of the Amazon rain forest since the mid Holocene in northwestern and southwestern Amazonia is now also confirmed for the southeastern Amazon region.
Cite this activity
Behling H. (2002) Late Quaternary vegetation and climate dynamics in southeastern Amazonia inferred from Lagoa da Confusão Tocantins State, northern Brazil. 17(1/2): 27-40.
@article{Behling2002,
Title = {Late Quaternary vegetation and climate dynamics in southeastern Amazonia inferred from Lagoa da Confusão Tocantins State, northern Brazil},
Author = {Behling, Hermann},
Editor = {},
Year = {2002},
Pages = {27-40},
Volume = {17},
Abstract = {Late Quaternary vegetation and climate dynamics have been reconstructed by pollen analysis of a lacustrine sediment core from Lagoa da Confusiio. The lake lies about 160 km southwest of Palmas, capital of Tocantins State. The study area is located in the cerrado (savanna) and cerrado/Amazon rain forest transition region of southeastern Amazonia. The record, dated by 4 AMS radiocarbon dates, provide insight into vegetation and climate dynamics of late Pleistocene and Holocene age. Pollen data indicate that the study region was dominated by cerrado (savanna), first of the campo limpo type (grassland savanna) between 60,300-51,700 (chronology A) or 29,000-27,400 14C yr B.P. (chronology B) and than of the campo sujo type between 51,700-24,670 (chronology A) or 27,400-14,000 14C yr B.P. (chronology B). Existing small areas of gallery forests increased slightly during the second period. Amazon forest taxa occurred sparsely in the study region. The palaeovegetatio infer a markedly drier climate (low precipitation and long annual dry season) during the glacial periods compared to the modern climate. A sedimentary gap probably occurred during the full glacial and1or Lateglacial period, suggesting drier climatic conditions than during the two earlier periods. During the early and mid Holocene the campo cerrado type (savanna woodland) was dominant and the landscape was more forested by the stronger presence of gallery forest and Amazon forest trees. Precipitation was higher, and the length of the annual dry season was shorter than during the late Pleistocene periods. After 5460 14C yr B.P. campo cerrado was still dominant, but forest cover increased markedly by the expansion Amazon forest populations and palm trees, reflecting the wettest climate period recorded. The results from Lagoa da Confusao support the general trend of dry glacial conditions, as reported from other tropical South American lowland regions. The expansion of the Amazon rain forest since the mid Holocene in northwestern and southwestern Amazonia is now also confirmed for the southeastern Amazon region.},
}
TY - JOUR
AU - Behling, Hermann
TI - Late Quaternary vegetation and climate dynamics in southeastern Amazonia inferred from Lagoa da Confusão Tocantins State, northern Brazil
PY - 2002
SP - 27-40
VL - 17
AB - Late Quaternary vegetation and climate dynamics have been reconstructed by pollen analysis of a lacustrine sediment core from Lagoa da Confusiio. The lake lies about 160 km southwest of Palmas, capital of Tocantins State. The study area is located in the cerrado (savanna) and cerrado/Amazon rain forest transition region of southeastern Amazonia. The record, dated by 4 AMS radiocarbon dates, provide insight into vegetation and climate dynamics of late Pleistocene and Holocene age. Pollen data indicate that the study region was dominated by cerrado (savanna), first of the campo limpo type (grassland savanna) between 60,300-51,700 (chronology A) or 29,000-27,400 14C yr B.P. (chronology B) and than of the campo sujo type between 51,700-24,670 (chronology A) or 27,400-14,000 14C yr B.P. (chronology B). Existing small areas of gallery forests increased slightly during the second period. Amazon forest taxa occurred sparsely in the study region. The palaeovegetatio infer a markedly drier climate (low precipitation and long annual dry season) during the glacial periods compared to the modern climate. A sedimentary gap probably occurred during the full glacial and1or Lateglacial period, suggesting drier climatic conditions than during the two earlier periods. During the early and mid Holocene the campo cerrado type (savanna woodland) was dominant and the landscape was more forested by the stronger presence of gallery forest and Amazon forest trees. Precipitation was higher, and the length of the annual dry season was shorter than during the late Pleistocene periods. After 5460 14C yr B.P. campo cerrado was still dominant, but forest cover increased markedly by the expansion Amazon forest populations and palm trees, reflecting the wettest climate period recorded. The results from Lagoa da Confusao support the general trend of dry glacial conditions, as reported from other tropical South American lowland regions. The expansion of the Amazon rain forest since the mid Holocene in northwestern and southwestern Amazonia is now also confirmed for the southeastern Amazon region.
ER -
