Model of wetland development of the Amapá coast during the late Holocene
José T.F. Guimarães
Marcelo C.L. Cohen
Marlon C. França
Rúben J. Lara
Hermann Behling
Abstract
The modern vegetation types, sedimentary sequences, pollen records and radiocarbon dating obtained from three sediment cores from Calçoene Coastal Plain were used to provide a palaeoecological history during the late Holocene of Amapá coastal wetland according to flood regime, sea-level and climatic changes. Based on these records, four phases of vegetation development are presented and they probably reflect the interaction between the flow energy to the sediment accumulation and the brackish/freshwater influence in the vegetation. This work suggests interchanges among time periods characterized by marine and fluvial influence. The longitudinal profile did not reveal the occurrence of mangrove in the sediment deposited around 2100 yr B.P. During the second phase, the mud progressively filled the depressions and tidal channels. The mangrove probably started its development on the channel edge, and the herbaceous field on the elevated sectors. The third phase is characterized by the interruption of mangrove development and the increase of "várzea" vegetation that may be due to the decrease in porewater salinity related to a decrease in marine water influence. The last phase is represented by the mangrove and "várzea" increase. The correlation between current patterns of geobotanical unit distribution and palaeovegetation indicates that mangrove and "várzea" forests are migrating over the herbaceous field on the topographically highest part of the studied coast, which can be related to a relative sea-level rise.
Guimarães J.T.F., Cohen M.C.L., França M.C., Lara R.J. and Behling H. (2010) Model of wetland development of the Amapá coast during the late Holocene. Anais da Academia Brasileira de Ciências 82(2): 451-465. 10.1590/S0001-37652010000200021
@article{Guimarães2010,
Title = {Model of wetland development of the Amapá coast during the late Holocene},
Author = {Guimarães, José T.F. and Cohen, Marcelo C.L. and França, Marlon C. and Lara, Rúben J. and Behling, Hermann},
Editor = {},
Journal = {Anais da Academia Brasileira de Ciências},
Year = {2010},
Pages = {451-465},
Volume = {82},
Doi = {10.1590/S0001-37652010000200021},
Abstract = {The modern vegetation types, sedimentary sequences, pollen records and radiocarbon dating obtained from three sediment cores from Calçoene Coastal Plain were used to provide a palaeoecological history during the late Holocene of Amapá coastal wetland according to flood regime, sea-level and climatic changes. Based on these records, four phases of vegetation development are presented and they probably reflect the interaction between the flow energy to the sediment accumulation and the brackish/freshwater influence in the vegetation. This work suggests interchanges among time periods characterized by marine and fluvial influence. The longitudinal profile did not reveal the occurrence of mangrove in the sediment deposited around 2100 yr B.P. During the second phase, the mud progressively filled the depressions and tidal channels. The mangrove probably started its development on the channel edge, and the herbaceous field on the elevated sectors. The third phase is characterized by the interruption of mangrove development and the increase of "várzea" vegetation that may be due to the decrease in porewater salinity related to a decrease in marine water influence. The last phase is represented by the mangrove and "várzea" increase. The correlation between current patterns of geobotanical unit distribution and palaeovegetation indicates that mangrove and "várzea" forests are migrating over the herbaceous field on the topographically highest part of the studied coast, which can be related to a relative sea-level rise.},
}
TY - JOUR
AU - Guimarães, José T.F.
AU - Cohen, Marcelo C.L.
AU - França, Marlon C.
AU - Lara, Rúben J.
AU - Behling, Hermann
TI - Model of wetland development of the Amapá coast during the late Holocene
T2 - Anais da Academia Brasileira de Ciências
PY - 2010
SP - 451-465
VL - 82
DO - 10.1590/S0001-37652010000200021
AB - The modern vegetation types, sedimentary sequences, pollen records and radiocarbon dating obtained from three sediment cores from Calçoene Coastal Plain were used to provide a palaeoecological history during the late Holocene of Amapá coastal wetland according to flood regime, sea-level and climatic changes. Based on these records, four phases of vegetation development are presented and they probably reflect the interaction between the flow energy to the sediment accumulation and the brackish/freshwater influence in the vegetation. This work suggests interchanges among time periods characterized by marine and fluvial influence. The longitudinal profile did not reveal the occurrence of mangrove in the sediment deposited around 2100 yr B.P. During the second phase, the mud progressively filled the depressions and tidal channels. The mangrove probably started its development on the channel edge, and the herbaceous field on the elevated sectors. The third phase is characterized by the interruption of mangrove development and the increase of "várzea" vegetation that may be due to the decrease in porewater salinity related to a decrease in marine water influence. The last phase is represented by the mangrove and "várzea" increase. The correlation between current patterns of geobotanical unit distribution and palaeovegetation indicates that mangrove and "várzea" forests are migrating over the herbaceous field on the topographically highest part of the studied coast, which can be related to a relative sea-level rise.
ER -
