Distribution of palynomorphs in marine sediments: A record for seasonal wind patterns over NW Africa and adjacent Atlantic

Hooghiemstra, H.; Agwu, Chiori O C

doi:10.1007/bf01770180

Cited by 47 publications

(22 citation statements)

References 10 publications

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“…During the subsequent sea-level rise, only pioneer species from the Amaranthaceae, tolerating highly saline environments with a permanent tidal influence and having good colonizing abilities, could expand under these stressful conditions. The development of mangroves at ∼ 14.8 kyr BP might reflect either the expansion of mangrove vegetation along the Rufiji Delta or the erosion of mangrove peat during sea-level rise (Hooghiemstra and Agwu, 1986;Dupont and Agwu, 1991;Lézine at al., 1995Lézine at al., , 1996Dupont, 1999;Kim et al, 2005;Scourse et al, 2005). Mangroves are most common in wetter habitats and swamps where brackish water accumulates.…”

Section: Expansion Of the Salt Marshes And Mangroves: Deglacial Ecolomentioning

confidence: 99%

“…Mangroves are most common in wetter habitats and swamps where brackish water accumulates. They are known to be very sensitive to sea-level fluctuations and runoff variability (Hooghiemstra and Agwu, 1986;Dupont and Agwu, 1991;Lézine et al, 1995Lézine et al, , 1996Woodroffe, 1999). Their development would suggest a permanent marine influence but also less saline coastal environments as they do not survive in hypersaline soils due to the rapid sea-level increase (Woodroffe, 1999).…”

Section: Expansion Of the Salt Marshes And Mangroves: Deglacial Ecolomentioning

confidence: 99%

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Northern Hemisphere control of deglacial vegetation changes in the Rufiji uplands (Tanzania)

et al. 2015

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Abstract. In tropical eastern Africa, vegetation distribution is largely controlled by regional hydrology, which has varied over the past 20 000 years. Therefore, accurate reconstructions of past vegetation and hydrological changes are crucial for a better understanding of climate variability in the tropical southeastern African region. We present high-resolution pollen records from a marine sediment core recovered offshore of the Rufiji River delta. Our data document significant shifts in pollen assemblages during the last deglaciation, identifying, through changes in both upland and lowland vegetation, specific responses of plant communities to atmospheric (precipitation) and coastal (coastal dynamics and sea-level changes) alterations. Specifically, arid conditions reflected by a maximum pollen representation of dry and open vegetation occurred during the Northern Hemisphere cold Heinrich event 1 (H1), suggesting that the expansion of drier upland vegetation was synchronous with cold Northern Hemisphere conditions. This arid period is followed by an interval in which forest and humid woodlands expanded, indicating a hydrologic shift towards more humid conditions. Droughts during H1 and the shift to humid conditions around 14.8 kyr BP in the uplands are consistent with latitudinal shifts of the intertropical convergence zone (ITCZ) driven by high-latitude Northern Hemisphere climatic fluctuations. Additionally, our results show that the lowland vegetation, consisting of well-developed salt marshes and mangroves in a successional pattern typical for vegetation occurring in intertidal habitats, has responded mainly to local coastal dynamics related to marine inundation frequencies and soil salinity in the Rufiji Delta as well as to the local moisture availability. Lowland vegetation shows a substantial expansion of mangrove trees after ∼ 14.8 kyr BP, suggesting an increased moisture availability and river runoff in the coastal area. The results of this study highlight the decoupled climatic and environmental processes to which the vegetation in the uplands and the Rufiji Delta has responded during the last deglaciation.

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Section: Expansion Of the Salt Marshes And Mangroves: Deglacial Ecolomentioning

confidence: 99%

Section: Expansion Of the Salt Marshes And Mangroves: Deglacial Ecolomentioning

confidence: 99%

Northern Hemisphere control of deglacial vegetation changes in the Rufiji uplands (Tanzania)

et al. 2015

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“…For the other maps (Pinus, Quercus, Artemisia, Ephedra, Asteraceae Tubuliflorae, Chenopodiaceae-Amaranthaceae, Poaceae, Cyperaceae, Mitracarpus, Combretaceae-Melastomataceae, Alchornea, Elaeis, monolete verrucate fern spores, Rhizophora, Acacia type; Fig. 23) new data obtained from the Gulf of Guinea are presented together with data from the Northeast Atlantic already published by HOOGHIEMSTRA et al (1986).…”

Section: Introductionmentioning

confidence: 96%

“…Previously, isopoll maps from modern marine sediment samples from the Atlantic Ocean were published by MELIA (1984), AGWU (1986), andHOOGHIEMSTRA et al (1986). The pollen content of air masses over the Atlantic was studied by MELIA (1984), AGWU (1988), and CALLE-JA & VAN CAMPO (1990).…”

Section: Introductionmentioning

confidence: 98%

“…From the studies of HOOGHIEMSTRA & AGWU (1986) and HOOGHIEMSTRA et al (1986) it became clear that mapping of the modern distribution of pollen grains in marine surface sediments is essential for the interpretation of fossil pollen spectra in marine cores. We extended the regional scope of that work southwards allowing us to study the distribution of pollen grains in the Gulf of Guinea and the influence of wind and water transport into that area of the Atlantic Ocean.…”

Section: Introductionmentioning

confidence: 99%

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Environmental control of pollen grain distribution patterns in the Gulf of Guinea and offshore NW-Africa

Dupont

Agwu

1991

Geol Rundsch

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Zusammenfassung AbstractThe areas of marine pollen deposition are related to the pollen source areas by aeolian and fluvial transport regimes, whereas wind transport is much more important than river transport. Pollen distribution patterns of Pinus, Artemisia, ChenopodiaceaeAmaranthaceae, and Asteraceae Tubuliflorae trace atmospheric transport by the northeast trades. Pollen transport by the African Easterly Jet is reflected in the pollen distribution patterns of ChenopodiaceaeAmaranthaceae, Asteraceae Tubuliflorae, and

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Pollen and Spores in Marine Sediments from the East Atlantic -A View from the Ocean into the African Continent

Dupont

1999

Use of Proxies in Paleoceanography

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Distribution of palynomorphs in marine sediments: A record for seasonal wind patterns over NW Africa and adjacent Atlantic

Cited by 47 publications

References 10 publications

Northern Hemisphere control of deglacial vegetation changes in the Rufiji uplands (Tanzania)

Northern Hemisphere control of deglacial vegetation changes in the Rufiji uplands (Tanzania)

Environmental control of pollen grain distribution patterns in the Gulf of Guinea and offshore NW-Africa

Pollen and Spores in Marine Sediments from the East Atlantic -A View from the Ocean into the African Continent

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