5 results on '"Oslisly, Richard"'
Search Results
2. Modeling the potential distribution of the threatened Grey-necked Picathartes Picathartes oreas across its entire range.
- Author
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Tsetagho, Guilain, Bradfer-Lawrence, Tom, Taku, Awa II, Abernethy, Katharine A., Abwe, Ekwoge E., Tsi Angwafo, E., Atuo, Fidelis, Fichtler, Martin, Fotso, Roger, Shirley, Matthew H., Morgan, Bethan J., Languy, Marc, Maisels, Fiona, Oslisly, Richard, Powell, Luke, Smith, Thomas, Thomassen, Henri A., Waltert, Matthias, Wolfe, Jared, and Whytock, Robin C.
- Abstract
Summary: Understanding the distribution and extent of suitable habitats is critical for the conservation of endangered and endemic taxa. Such knowledge is limited for many Central African species, including the rare and globally threatened Grey-necked Picathartes Picathartes oreas , one of only two species in the family Picathartidae endemic to the forests of Central Africa. Despite growing concerns about land-use change resulting in fragmentation and loss of forest cover in the region, neither the extent of suitable habitat nor the potential species' distribution is well known. We combine 339 (new and historical) occurrence records of Grey-necked Picathartes with environmental variables to model the potential global distribution. We used a Maximum Entropy modelling approach that accounted for sampling bias. Our model suggests that Grey-necked Picathartes distribution is strongly associated with steeper slopes and high levels of forest cover, while bioclimatic, vegetation health, and habitat condition variables were all excluded from the final model. We predicted 17,327 km
2 of suitable habitat for the species, of which only 2,490 km2 (14.4%) are within protected areas where conservation designations are strictly enforced. These findings show a smaller global distribution of predicted suitable habitat forthe Grey-necked Picathartes than previously thought. This work provides evidence to inform a revision of the International Union for Conservation of Nature (IUCN) Red List status, and may warrant upgrading the status of the species from "Near Threatened" to "Vulnerable". [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
3. NEW EVIDENCE OF HUMAN ACTIVITIES DURING THE HOLOCENE IN THE LOWLAND FORESTS OF THE NORTHERN CONGO BASIN.
- Author
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Morin-Rivat, Julie, Fayolle, Adeline, Gillet, Jean-François, Bourland, Nils, Gourlet-Fleury, Sylvie, Oslisly, Richard, Bremond, Laurent, Bentaleb, Ilham, Beeckman, Hans, and Doucet, Jean-Louis
- Subjects
HOLOCENE Epoch ,PLANT remains (Archaeology) ,ARCHAEOLOGY ,RADIOCARBON dating - Abstract
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. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
4. WEST CENTRAL AFRICAN PEOPLES: SURVEY OF RADIOCARBON DATES OVER THE PAST 5000 YEARS.
- Author
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Oslisly, Richard, Bentaleb, Ilham, Favier, Charly, Fontugne, Michel, Gillet, Jean François, and Morin-Rivat, Julie
- Subjects
RADIOCARBON dating ,ARCHAEOLOGICAL human remains ,ARCHAEOLOGY ,ANTIQUITIES ,SOCIAL evolution ,HINTERLAND ,DEMOGRAPHIC change - Abstract
Tracing human history in west central Africa suffers from a scarcity of historical data and archaeological remains. In order to provide new insight into this problem, we reviewed 733 radiocarbon dates of archaeological sites from the end of the Late Stone Age, Neolithic Stage, and Early and Late Iron Age in Cameroon, Gabon, Central African Republic, Equatorial Guinea, Republic of Congo, and the western Democratic Republic of Congo. This review provides a spatiotemporal framework of human settlement in the forest biome. Beyond the well-known initial spread of Iron Age populations through central African forests from 2500 cal BP, it depicts the geographical patterns and links with the cultural evolution of the successive phases of human expansion from 5000 to 3000 cal BP and then from 3000 to 1600 cal BP, of the hinterland depopulation from 1350 to 860 cal BP, and of recolonization up to 500 cal BP. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
5. Lowland rainforest response to hydrological changes during the last 1500 years in Gabon, Western Equatorial Africa
- Author
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Ngomanda, Alfred, Jolly, Dominique, Bentaleb, Ilhem, Chepstow-Lusty, Alex, Makaya, M'voubou, Maley, Jean, Fontugne, Michel, Oslisly, Richard, and Rabenkogo, Nicaise
- Subjects
RAIN forests ,FOREST hydrology ,CLIMATE change - Abstract
Abstract: Pollen and δ
13 CTOM data obtained from two contrasting lake sequences (Lakes Kamalété and Nguène), located 200 km apart in the lowland rainforest of Gabon, provide complementary local and regional 1500-yr records of high resolution (15–30 yr) vegetation change. A combination of aquatic, semi-aquatic and terrestrial pollen showed in both records that the tropical rainforest increased during periods of high rainfall and decreased during drought intervals. The strong fluctuations of water balance at decadal scale during the “Medieval Warm Period” (∼1100–800 cal yr BP) coincided with a noticeable increase in shade-intolerant taxa, indicating recurring rainforest canopy disturbance. The δ13 CTOM signal showed high-amplitude variations in both records, which positively correlates with the rainforest dynamics and local vegetation changes. The similar trends in both the pollen and the δ13 CTOM signals between these sites demonstrate the regional broadly synchronous timing of shifting hydrological conditions. The largely positive co-variation between strong fluctuations of hydrological conditions and changes in rainforest structure and composition indicate that regional climatic change is probably the driving force for major rainforest dynamics in Gabon. Any significant anthropogenic impact on vegetation has not been clearly identified, and this issue still needs to be resolved independently by obtaining detailed archeological records across the interval 1400–800 BP, which currently seem to be extremely rare or not easily available. [Copyright &y& Elsevier]- Published
- 2007
- Full Text
- View/download PDF
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