A5052294714- Geology and Paleoclimatology Research
- Marine and environmental studies
- Geological formations and processes
- Aquatic Ecosystems and Phytoplankton Dynamics
- Pleistocene-Era Hominins and Archaeology
- Diatoms and Algae Research
- Archaeology and ancient environmental studies
- African Botany and Ecology Studies
- Isotope Analysis in Ecology
- Tree-ring climate responses
- Silicon Effects in Agriculture
- Pacific and Southeast Asian Studies
- Marine Invertebrate Physiology and Ecology
- Aquatic Ecosystems and Biodiversity
- Plant Water Relations and Carbon Dynamics
- Soil and Environmental Studies
- Geochemistry and Elemental Analysis
- Climate variability and models
- Mediterranean and Iberian flora and fauna
- Evolution and Paleontology Studies
- Geological and Geophysical Studies Worldwide
- Maritime and Coastal Archaeology
- Agriculture and Rural Development Research
- Landslides and related hazards
- Ecology and Vegetation Dynamics Studies
Centre de Recherche et d’Enseignement de Géosciences de l’Environnement
2009-2024
Aix-Marseille Université
2008-2023
Institut de Recherche pour le Développement
2008-2023
Centre National de la Recherche Scientifique
2004-2023
Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement
2023
Sustainable Europe Research Institute
1990-2022
Laboratoire Méditerranéen de Préhistoire Europe Afrique
2002-2014
Smithsonian Institution
2004
National Museum of Natural History
2004
Beicip Franlab (France)
2004
Plio-Pleistocene global climate change is believed to have had an important influence on local habitats and early human evolution in Africa. Responses of hominin lineages been difficult test, however, because this procedure requires well documented evidence for connections between environment. Through high-resolution pollen data from Hadar, Ethiopia, we show that the Australopithecus afarensis accommodated substantial environmental variability 3.4 2.9 million years ago. A large biome shift,...
Background The lack of instrumental data before the mid-19th-century limits our understanding present warming trends. In absence direct measurements, we used proxies that are natural or historical archives recording past climatic changes. A gridded reconstruction spring-summer temperature was produced for Europe based on tree-rings, documentaries, pollen assemblages and ice cores. majority proxy series have an annual resolution. For a better inference long-term climate variation, they were...
Late Pleistocene and/or Holocene high-resolution palynological studies are available for the south basin of Caspian Sea (CS), world's largest lake. However, north and middle basins have not been object reconstructions. This new study presents pollen, spores dinoflagellate cysts records obtained from a 10 m-long sediment core recovered in basin, which currently has brackish waters is surrounded by arid semi-arid vegetation. An age–depth model built based on six radiocarbon dates ostracod...
Abstract. This paper presents a reconstruction of the summer temperatures over Greater Alpine Region (44.05°–47.41° N, 6.43°–13° E) during last millennium based on network 38 multi-centennial larch and stone pine chronologies. Tree ring series are standardized using an Adaptative Regional Growth Curve, which attempts to remove age effect from low frequency variations in series. The proxies calibrated June August mean HISTALP high-elevation temperature time spanning 1818–2003. method combines...
Pollen and dinoflagellate cysts have been analysed in a core from the south basin of Caspian Sea, providing picture respectively past vegetation water salinity for Late Pleistocene to middle Holocene. A relatively sharp lithological change at 0.86 m depth reflects shift detrital silts carbonates-rich fine silts. From this upwards, Holocene chronology is built based on ten radiocarbon dates ostracod shells bulk carbonates. point view, deserts steppes were partially replaced most sheltered...
Abstract Palaeoclimatic estimates of mean annual temperature and rainfall in the southern Tanganyika basin between 25,000 9000 yr B.P. have been established from two pollen sequences based on best-analogue method. The results give evidence a decrease about 4.2°C during last glaciation, value consistent with that previously obtained catchment area Burundi Highlands. This cooling was synchronous precipitation 180 mm/yr. Postglacial climatic conditions were by 12,700 B.P., warming wetness...
This paper provides the first set of quantitative reconstructions annual precipitation for mid‐Holocene Africa, based on pollen data. The estimates are 85 sites 14 C dated at 6000 ± 500 years B.P and distributed over whole Africa. To improve reliability pollen‐based climate reconstruction, two methods used: “modern analogues technique” (MAT) “plant functional types” (PFT) methods. We then conduct a model‐data comparison five distinct regions, allowing an evaluation model outputs (the...
Dinoflagellate cyst assemblages were analysed in four short sediment cores collected the south Basin of Caspian Sea for assessing environmental changes over last few millennia. Two these dated by radionuclides. The sedimentation rate one them was very high, order 20 mm per year. interpretation sequences is supported a collection 27 lagoonal or marine surface samples. A sharp increase concentration dinocyst occurs after 1967, especially owing to Lingulodinium machaerophorum. Considering nine...
Abstract Aluto is a silicic volcano in central Ethiopia, flanked by two large population centers and home to an expanding geothermal power plant. Here we present data from lake sediment cores sampled 12 25 km the volcano, which record at least 24 distinct eruptions Holocene. Tephra layers are correlated using variety of techniques, including major trace element geochemistry as well textural morphological features scanning electron microscopy‐backscatter imaging. The purpose provide Holocene...
Abstract. Continental atmospheric relative humidity (RH) is a key climate parameter. Combined with temperature, it allows us to estimate the concentration of water vapor, which one main components global cycle and most important gas contributing natural greenhouse effect. However, there lack proxies suitable for reconstructing, in quantitative way, past changes continental humidity. This reduces possibility making model–data comparisons necessary implementation models. Over 10 years,...
Abstract. Pollen data collected in Africa at high (Kuruyange, valley swamp, Burundi) and low altitude (Victoria, lake, Uganda; Ngamakala, pond, Congo) showed that after 6 ky before present (BP), pollen of deciduous trees increase their relative percentage, suggesting thus the reduction annual amount precipitation and/or an length dry season. Until now, pollen-climate transfer functions only investigated mean precipitation, due to absence modern pollen-assemblage analogs under diversified...
1. Introduction The lack of long-term data on the response aquatic systems to water-level and climatic changes is seen as an impediment assessment vulnerability risks that large water-bodies face with respect ongoing future global changes. Petroleum, fishing (e.g. for caviar) tourism industries, governments are struggling understand vulnerabilities risk associated unprecedented rate environmental change consequences ecosystems natural resources such water upon which we closely depend (Zonn...
Paleo-hydrologic and -vegetation proxy data from the Tanganyika basin are integrated in energy water balance equations to infer past evaporation precipitation during last glacial maximum (LGM). Our approach is first validated on modern system. Large variations assigned input variables simulate interannual variability. Equations then applied LGM. We change those parameters inferred proxies (basin lake surfaces, temperature, land albedo). LGM simulation suggests (in percent of mean values)...