LATE QUATERNARY VALLEY AND SLOPE DEPOSITS AND THEIR PALAEOENVIRONMENTAL SIGNIFICANCE IN THE UPPER CONGO BASIN, CENTRAL AFRICA

2013 ◽  
pp. 65-102
Keyword(s):  
Late Quaternary ◽  
Central Africa ◽  
Congo Basin ◽  
Slope Deposits

scholarly journals State and evolution of the African rainforests between 1990 and 2010

2013 ◽  
Vol 368 (1625) ◽  
pp. 20120300 ◽  
Author(s):  
Philippe Mayaux ◽  
Jean-François Pekel ◽  
Baudouin Desclée ◽  
François Donnay ◽  
Andrea Lupi ◽  
...  
Keyword(s):  
West Africa ◽  
Forest Cover ◽  
Central Africa ◽  
Congo Basin ◽  
Landsat Images ◽  
Deforestation Rate ◽  
Rural And Urban ◽  
Moderate Resolution ◽  
Underlying Causes ◽  
Moderate Resolution Imaging Spectroradiometer

This paper presents a map of Africa's rainforests for 2005. Derived from moderate resolution imaging spectroradiometer data at a spatial resolution of 250 m and with an overall accuracy of 84%, this map provides new levels of spatial and thematic detail. The map is accompanied by measurements of deforestation between 1990, 2000 and 2010 for West Africa, Central Africa and Madagascar derived from a systematic sample of Landsat images—imagery from equivalent platforms is used to fill gaps in the Landsat record. Net deforestation is estimated at 0.28% yr −1 for the period 1990–2000 and 0.14% yr −1 for the period 2000–2010. West Africa and Madagascar exhibit a much higher deforestation rate than the Congo Basin, for example, three times higher for West Africa and nine times higher for Madagascar. Analysis of variance over the Congo Basin is then used to show that expanding agriculture and increasing fuelwood demands are key drivers of deforestation in the region, whereas well-controlled timber exploitation programmes have little or no direct influence on forest-cover reduction at present. Rural and urban population concentrations and fluxes are also identified as strong underlying causes of deforestation in this study.

New Evidence of Human Activities During the Holocene in the Lowland Forests of the Northern Congo Basin

Radiocarbon ◽  
2014 ◽  
Vol 56 (1) ◽  
pp. 209-220 ◽  
Author(s):  
Julie Morin-Rivat ◽  
Adeline Fayolle ◽  
Jean-François Gillet ◽  
Nils Bourland ◽  
Sylvie Gourlet-Fleury ◽  
...  
Keyword(s):  
Iron Age ◽  
Human Activities ◽  
Intermediate Phase ◽  
Central Africa ◽  
Bimodal Distribution ◽  
Congo Basin ◽  
Radiocarbon Dates ◽  
Late Iron Age ◽  
Two Phases ◽  
Botanical Remains

In the last decade, the myth of the pristine tropical forest has been seriously challenged. In central Africa, there is a growing body of evidence for past human settlements along the Atlantic forests, but very little information is available about human activities further inland. Therefore, this study aimed at determining the temporal and spatial patterns of human activities in an archaeologically unexplored area of 110,000 km2 located in the northern Congo Basin and currently covered by dense forest. Fieldwork involving archaeology as well as archaeobotany was undertaken in 36 sites located in southeastern Cameroon and in the northern Republic of Congo. Evidence of past human activities through either artifacts or charred botanical remains was observed in all excavated test pits across the study area. The set of 43 radiocarbon dates extending from 15,000 BP to the present time showed a bimodal distribution in the Late Holocene, which was interpreted as two phases of human expansion with an intermediate phase of depopulation. The 2300–1300 BP phase is correlated with the migrations of supposed farming populations from northwestern Cameroon. Between 1300 and 670 BP, less material could be dated. This is in agreement with the population collapse already reported for central Africa. Following this, the 670–20 BP phase corresponds to a new period of human expansion known as the Late Iron Age. These results bring new and extensive evidence of human activities in the northern Congo Basin and support the established chronology for human history in central Africa.

Evidence for Megalake Chad, north-central Africa, during the late Quaternary from satellite data

2006 ◽  
Vol 230 (3-4) ◽  
pp. 230-242 ◽  
Author(s):  
Marc J. Leblanc ◽  
Christian Leduc ◽  
Frank Stagnitti ◽  
Peter J. van Oevelen ◽  
Chris Jones ◽  
...  
Keyword(s):  
Satellite Data ◽  
Late Quaternary ◽  
Central Africa ◽  
North Central

scholarly journals Response of African humid tropical forests to recent rainfall anomalies

2013 ◽  
Vol 368 (1625) ◽  
pp. 20120306 ◽  
Author(s):  
Salvi Asefi-Najafabady ◽  
Sassan Saatchi
Keyword(s):  
West Africa ◽  
Tropical Forests ◽  
Large Scale ◽  
Forest Canopy ◽  
Central Africa ◽  
Extreme Rainfall ◽  
Research Unit ◽  
Congo Basin ◽  
West And Central Africa ◽  
Rainfall Anomalies

During the last decade, strong negative rainfall anomalies resulting from increased sea surface temperature in the tropical Atlantic have caused extensive droughts in rainforests of western Amazonia, exerting persistent effects on the forest canopy. In contrast, there have been no significant impacts on rainforests of West and Central Africa during the same period, despite large-scale droughts and rainfall anomalies during the same period. Using a combination of rainfall observations from meteorological stations from the Climate Research Unit (CRU; 1950–2009) and satellite observations of the Tropical Rainfall Measuring Mission (TRMM; 1998–2010), we show that West and Central Africa experienced strong negative water deficit (WD) anomalies over the last decade, particularly in 2005, 2006 and 2007. These anomalies were a continuation of an increasing drying trend in the region that started in the 1970s. We monitored the response of forests to extreme rainfall anomalies of the past decade by analysing the microwave scatterometer data from QuickSCAT (1999–2009) sensitive to variations in canopy water content and structure. Unlike in Amazonia, we found no significant impacts of extreme WD events on forests of Central Africa, suggesting potential adaptability of these forests to short-term severe droughts. Only forests near the savanna boundary in West Africa and in fragmented landscapes of the northern Congo Basin responded to extreme droughts with widespread canopy disturbance that lasted only during the period of WD. Time-series analyses of CRU and TRMM data show most regions in Central and West Africa experience seasonal or decadal extreme WDs (less than −600 mm). We hypothesize that the long-term historical extreme WDs with gradual drying trends in the 1970s have increased the adaptability of humid tropical forests in Africa to droughts.

scholarly journals Isotopic and microbotanical insights into Iron Age agricultural reliance in the Central African rainforest

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Madeleine Bleasdale ◽  
Hans-Peter Wotzka ◽  
Barbara Eichhorn ◽  
Julio Mercader ◽  
Amy Styring ◽  
...  
Keyword(s):  
Iron Age ◽  
Pennisetum Glaucum ◽  
Isotope Analysis ◽  
Central Africa ◽  
Congo Basin ◽  
Early Iron Age ◽  
Dental Calculus ◽  
Subsistence Strategies ◽  
Animal Remains ◽  
Environmental Requirements

Abstract The emergence of agriculture in Central Africa has previously been associated with the migration of Bantu-speaking populations during an anthropogenic or climate-driven ‘opening’ of the rainforest. However, such models are based on assumptions of environmental requirements of key crops (e.g. Pennisetum glaucum) and direct insights into human dietary reliance remain absent. Here, we utilise stable isotope analysis (δ13C, δ15N, δ18O) of human and animal remains and charred food remains, as well as plant microparticles from dental calculus, to assess the importance of incoming crops in the Congo Basin. Our data, spanning the early Iron Age to recent history, reveals variation in the adoption of cereals, with a persistent focus on forest and freshwater resources in some areas. These data provide new dietary evidence and document the longevity of mosaic subsistence strategies in the region.

scholarly journals Six new dactylogyrid species (Platyhelminthes, Monogenea) from the gills of cichlids (Teleostei, Cichliformes) from the Lower Congo Basin

Parasite ◽  
2018 ◽  
Vol 25 ◽  
pp. 64 ◽  
Author(s):  
Michiel W.P. Jorissen ◽  
Antoine Pariselle ◽  
Tine Huyse ◽  
Emmanuel J. Vreven ◽  
Jos Snoeks ◽  
...  
Keyword(s):  
Central Africa ◽  
Accessory Piece ◽  
Parasite Fauna ◽  
West African ◽  
Congo Basin ◽  
Left Bank ◽  
Basal Bulb

The Lower Congo Basin is characterized by a mangrove-lined estuary at its mouth and, further upstream, by many hydrogeographical barriers such as rapids and narrow gorges. Five localities in the mangroves and four from (upstream) left bank tributaries or pools were sampled. On the gills of Coptodon tholloni, Coptodon rendalli, Hemichromis elongatus, Hemichromis stellifer and Tylochromis praecox, 17 species of parasites (Dactylogyridae & Gyrodactylidae, Monogenea) were found, eight of which are new to science. Six of these are herein described: Cichlidogyrus bixlerzavalai n. sp. and Cichlidogyrus omari n. sp. from T. praecox, Cichlidogyrus calycinus n. sp. and Cichlidogyrus polyenso n. sp. from H. elongatus, Cichlidogyrus kmentovae n. sp. from H. stellifer and Onchobdella ximenae n. sp. from both species of Hemichromis. On Cichlidogyrus reversati a ridge on the accessory piece was discovered that connects to the basal bulb of the penis. We report a putative spillback effect of the native parasites Cichlidogyrus berradae, Cichlidogyrus cubitus and Cichlidogyrus flexicolpos from C. tholloni to the introduced C. rendalli. From our results, we note that the parasite fauna of Lower Congo has a higher affinity with the fauna of West African and nearby freshwater ecoregions than it has with fauna of other regions of the Congo Basin and Central Africa.

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