A5014541940- Geology and Paleoclimatology Research
- African Botany and Ecology Studies
- Pleistocene-Era Hominins and Archaeology
- Ecology and Vegetation Dynamics Studies
- Geological formations and processes
- Mosquito-borne diseases and control
- Pacific and Southeast Asian Studies
- Archaeology and Rock Art Studies
- Fire effects on ecosystems
- Plant and animal studies
- Agriculture and Rural Development Research
- COVID-19 epidemiological studies
- Silicon Effects in Agriculture
- Viral Infections and Vectors
- Species Distribution and Climate Change
- Archaeology and ancient environmental studies
- Isotope Analysis in Ecology
- Ecosystem dynamics and resilience
- Conservation, Biodiversity, and Resource Management
- Plant Diversity and Evolution
- Tree-ring climate responses
- Zoonotic diseases and public health
- Coastal wetland ecosystem dynamics
- Animal Disease Management and Epidemiology
- Geochemistry and Geologic Mapping
Institut des Sciences de l'Evolution de Montpellier
2014-2024
Centre National de la Recherche Scientifique
2013-2024
Université de Montpellier
2014-2024
Institut de Recherche pour le Développement
2012-2024
École Pratique des Hautes Études
2016-2024
Université Paris Sciences et Lettres
2021
CHU Dijon Bourgogne
2017
Centre National pour la Recherche Scientifique et Technique (CNRST)
2013-2015
Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques
2005-2006
CEA Paris-Saclay
2003-2006
Central Africa includes the world's second largest rainforest block. The ecology of region remains poorly understood, as does its vegetation and archaeological history. However, over past 20 years, multidisciplinary scientific programmes have enhanced knowledge old human presence palaeoenvironments in forestry block Africa. This first regional synthesis documents significant cultural changes five millennia describes how they are linked to climate. It is now well documented that climatic...
Fires have played an important role in creating and maintaining savannas over the centuries are also one of main natural disturbances forests. The functional fires forests can be investigated through examining sedimentary charcoal order to reconstruct long-term fire history. However, relationship between vegetation structure tropical grassy ecosystems remains elucidated. Here, we compared recent records from lake sediments three (forest, savanna, forest–savanna mosaic) with land cover...
Significance We develop a biogeographic approach to analyzing the presence of alternative stable states in tropical biomes. Whilst forest–savanna bistability has been widely hypothesized and modeled, empirical evidence remained scarce controversial, here, applying our method Africa, we provide large-scale that there are tree species composition vegetation. Furthermore, results have produced more accurate maps forest savanna distributions which take into account differences composition,...
Summary Objective To evaluate a new method of deriving the reproductive number for vector‐borne diseases from early epidemic curves with incubations in vectors and hosts. Method We applied model to several dengue epidemics different climatic regions Brazil: Brasilia, Belém, Fortaleza, Boa Vista. Results The leads higher estimates than previous models. Conclusion At present, Aedes aegypti densities, meeting more compatible strains viruses mosquitoes, may lead re‐emergence urban yellow fever epidemics.
The importance of spatial heterogeneity and scales (at a village or neighbourhood scale) has been explored with individual-based models. Our reasoning is based on the Chilean Easter Island (EI) case, where first dengue epidemic occurred in 2002 among relatively small population localized one village. Even this simple situation, real not consistent homogeneous Conversely, including contact different (intra-households, inter-house, inter-areas) allows recovery only EI epidemiological curve but...
To estimate the basic reproduction number (R0) of dengue fever including both imported and autochthonous cases.The study was conducted based on epidemiological data 2003 epidemic in Brasília, Brazil. The is estimated from curve, fitting linearly increase initial cases. Aiming at simulating an with cases, a 'susceptible-infectious-resistant' compartmental model designed, which cases were considered as external forcing. ratio between R0 versus used estimator real R0.The comparison numbers...
ABSTRACT Aim To describe patterns of tree cover in savannas over a climatic gradient and range spatial scales test if there are identifiable climate‐related mean structures, always increases with water availability is continuous trend or stepwise cover. Location Central Tropical Africa. Methods We compared new analysis satellite data botanical, phytogeographical environmental data. Results Along the transect, six vegetation structures were distinguished according to their average cover,...
The populations of light-demanding trees that dominate the canopy central African forests are now aging. Here, we show lack regeneration these began ca. 165 ya (around 1850) after major anthropogenic disturbances ceased. Since 1885, less itinerancy and disturbance in forest has occurred because colonial administrations concentrated people villages along primary communication axes. Local formerly gardened by creating scattered openings, which were sufficiently large for establishment trees....
Abstract Changes in C 4 grass distribution and abundance are frequently observed Quaternary, Holocene future environmental‐change scenarios. However, the factors driving these dynamics not fully understood, conflicting theories have been reported. In this paper, we present a very large dataset of modern altitudinal profiles 3 grasses covering entire Neotropical Andes, which was compared with actual climate data. The results multivariate analysis demonstrate that, mean annual temperature is...
Summary Rift Valley fever is an endemic vector‐borne disease in West Africa, which mainly affects domestic ruminants and occasionally humans. The aetiological mechanisms of its endemicity remain under debate. We used a simple spatially explicit model to assess the possibility without wild animals providing permanent virus reservoir. Our takes into account vertical transmission some mosquito species, rainfall‐driven emergence their eggs local distant contacts because herd migration....
Summary Understanding the environmental determinants of forests deciduousness i.e. proportion deciduous trees in a forest stand, is great importance when predicting impact ongoing global climate change on forests. In this study, we examine (i) how varies relation to rainfall and geology, (ii) whether influence geology could be related differences soil fertility water content between geological substrates. The study was conducted mixed moist semi‐deciduous northern part Congo basin. We...
We analysed changes in mean annual air temperature (MAAT), vegetation and biomass burning on a long continuous lake-peat sediment record from the Colônia basin, southeastern Brazil, examining responses of wet tropical rainforest over last 180 ka. Stronger southern atmospheric circulation up to latitude was found for penultimate glacial with lower temperatures than during glacial, while strengthening South American summer monsoon (SASM) started interglacial progressively enhanced longer...
Summary Objective To determine the influence of climate and environmental vector control with or without insecticide on Aedes aegypti larval indices pupae density. Methods An 18‐month longitudinal survey infestation Ae. immature stages was conducted for 1015 residences (premises) Vila Planalto, an area Brasilia where Breteau Index about 40 before study. This divided into five zones: a zone management alone four zones treatment (methoprene, Bti, temephos). We tested significant differences...
Summary Dengue, similar to other arboviral diseases, exhibits complex spatiotemporal dynamics. Even at town or village level, individual‐based spatially explicit models are required correctly reproduce epidemic curves. This makes modelling the regional level (province, country continent) very difficult and cumbersome. We propose here a first step build hierarchized model by constructing simple analytical expression which reproduces output from macroscopic parameters describing each...
Abstract. Past vegetation and climate changes reconstructed using two pollen records from Lakes Maridor Nguène, located in the coastal savannas inland rainforest of Gabon, respectively, provide new insights into environmental history western equatorial African rainforests during last 4500 cal yr BP. These indicate that Africa did not exist mid-Holocene instead region was covered by evergreen rainforests. From ca. 4000 BP a progressive decline rainforest, accompanied expansion semi-deciduous...