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1. Erosion of insect diversity in response to 7000 years of relative sea-level rise on a small Mediterranean island

Author

Valérie Andrieu-Ponel, Yoann Poher, Philippe Ponel, Frédéric Médail, Frédéric Guiter, Institut méditerranéen de biodiversité et d'écologie marine et continentale (IMBE), Avignon Université (AU)-Aix Marseille Université (AMU)-Institut de recherche pour le développement [IRD] : UMR237-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU), Institut de Recherche pour le Développement (IRD), Avignon Université (AU), and Centre National de la Recherche Scientifique (CNRS)-Institut de recherche pour le développement [IRD] : UMR237-Aix Marseille Université (AMU)-Avignon Université (AU)

Subjects
0106 biological sciences, Mediterranean climate, 010504 meteorology & atmospheric sciences, Fauna, Biodiversity, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Wetland, 010603 evolutionary biology, 01 natural sciences, 14. Life underwater, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, Ecology, Evolution, Behavior and Systematics, Holocene, 0105 earth and related environmental sciences, Nature and Landscape Conservation, geography, geography.geographical_feature_category, Ecology, biology, Tamarix, 15. Life on land, biology.organism_classification, 13. Climate action, [SDE]Environmental Sciences, Threatened species, Species richness
Abstract

International audience; We have investigated the potential effects of global sea-level rise on Mediterranean coastal wetlands by studying the Coleoptera and pollen fossil remains in a 7000-year sedimentary record, which we obtained from a coastal marshy area on a small Mediterranean island (Cavallo, southern Corsica). Using beetle structural diversity and plant composition as recorded prior to marine and human influences as a `past analogue', we reconstructed the impact of the Holocene relative sea-level rise on the coastal ecosystem. Our results show that beetle species richness and diversity were highest when freshwater was predominant, which was the case until about 6200 years ago. We also found that a major increase in salinity had occurred over the last 5300 years, experiencing a peak rate of increase at about 3700 years ago. These changes are clearly reflected in the fossil records of the following key taxa: halophilous beetles (Ochthebius sp., Pterostichus cursor), halophilous plants (Chenopodiaceae, Tamarix) and non-pollen palynomorphs (microforaminiferal linings). In particular, we note that the majority (60%) of wetland beetle fauna became locally extinct in response to the salinity changes, and these changes were exacerbated by the recent aggravation of human pressures on the island. The major part of this diversity loss occurred 3700 years ago, when the relative Mediterranean sea-level rose above -1.5 +/- 0.3 meters. These findings demonstrate the value of fossil beetle assemblage analysis as a diagnostic for the response of coastal wetland biodiversity to past salinity increases, and serve as a means of forecasting the effects of sea-level rise in the future. The conservation of inland freshwater bodies could ultimately prove essential to preserving freshwater insect diversity in threatened coastal environments.

Published
2017
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2. Palaeoenvironmental change and glacier fluctuations in the high Tian Shan Mountains during the last millennium based on sediments from Lake Ala Kol, Kyrgyzstan

Author

Marine Rousseau, Pierre Sabatier, Elodie Brisset, Philippe Sorrel, Cécile Miramont, François Demory, Frédéric Guiter, Laboratoire Chrono-environnement (UMR 6249) (LCE), Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Institut méditerranéen de biodiversité et d'écologie marine et continentale (IMBE), Avignon Université (AU)-Aix Marseille Université (AMU)-Institut de recherche pour le développement [IRD] : UMR237-Centre National de la Recherche Scientifique (CNRS), Environnements, Dynamiques et Territoires de Montagne (EDYTEM), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Chrono-environnement - CNRS - UBFC (UMR 6249) (LCE), Environnements, Dynamiques et Territoires de la Montagne (EDYTEM), Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry]), Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement [Lyon] (LGL-TPE), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon)

Subjects
010506 paleontology, Paleomagnetism, [SDE.MCG]Environmental Sciences/Global Changes, Central asia, 010502 geochemistry & geophysics, Oceanography, 01 natural sciences, Central Asia, Precipitation, [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology, Little ice age, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, Ecology, Evolution, Behavior and Systematics, 0105 earth and related environmental sciences, Earth-Surface Processes, geography, geography.geographical_feature_category, Plateau, Paleohydrology, Paleontology, Glacier, Proglacial lake, Rock magnetism, 13. Climate action, Clastic rock, Physical geography, Geology
Abstract

International audience; A suite of limnological proxies measured in clastic sediments of the glacier-fed Lake Ala Kol (NE Kyrgyzstan) document palaeoenvironmental change and glacier fluctuations in the central Tian Shan over the last millennium. Rock magnetic and geochemical data provide supporting evidence for three glacier expansion episodes occurring in 1200–1400 CE, 1500–1850 CE and 1900–1950 CE and glacier retreat periods during 1000–1200 CE and the intervening periods. The maximal glacier extent, as inferred from high κLF, Si/inc + coh, Ca/inc + coh and low ARM30/ARM, is recorded between 1500 and 1850 CE and corresponds to cold and wet conditions during the Little Ice Age in the high central Tian Shan. Periods of glacier waxing and waning recorded at Lake Ala Kol present a close correspondence to ice accumulation rate in the northern Tibetan Plateau, suggesting that precipitation changes are the main driver of glacier fluctuations in central Tian Shan during the last millennium, although temperature may have exerted a more complex influence on centennial timescales.

Published
2020
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3. New insights on lake sediment DNA from the catchment: importance of taphonomic and analytical issues on the record quality

Author

Gentile Francesco Ficetola, Jérôme Poulenard, Kevin Walsh, Fernand David, Erwan Messager, Elodie Brisset, Pierre Sabatier, Anne-Lise Develle, Laurent Fouinat, Ludovic Gielly, Fabien Arnaud, Rémi Sinet, Manon Bajard, Charline Giguet-Covex, Frédéric Guiter, Pierre Taberlet, Environnements, Dynamiques et Territoires de la Montagne (EDYTEM), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), BioArch-Department of Archaeology, Environnements, Dynamiques et Territoires de Montagne (EDYTEM), Laboratoire d'Ecologie Alpine (LECA ), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Department of Environmental Science and Policy [Milano], Università degli Studi di Milano = University of Milan (UNIMI), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut méditerranéen de biodiversité et d'écologie marine et continentale (IMBE), Avignon Université (AU)-Aix Marseille Université (AMU)-Institut de recherche pour le développement [IRD] : UMR237-Centre National de la Recherche Scientifique (CNRS), Institut Català de Paleoecologia Humana i Evolució Social (IPHES), Àrea de Prehistòria, Universitat Rovira i Virgili, Universitat Rovira i Virgili, DiPEE Chambéry-Grenoble (University Grenoble Alpes and University Savoie Mont Blanc), the Zone Atelier Alpes (ZAA), the PEPS de site Grenoble and the Conseil Général of Isère (AAP on biodiversity), the Parc National des Ecrins, Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry]), Università degli Studi di Milano [Milano] (UNIMI), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA), Laboratoire d'Ecologie Alpine (LECA), Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Université Joseph Fourier - Grenoble 1 (UJF)-Université Grenoble Alpes (UGA), Department of Environmental Science and Policy, Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), and Centre National de la Recherche Scientifique (CNRS)-Institut de recherche pour le développement [IRD] : UMR237-Aix Marseille Université (AMU)-Avignon Université (AU)

Subjects
0301 basic medicine, 0106 biological sciences, Geologic Sediments, Taphonomy, Earth science, Drainage basin, lcsh:Medicine, EarthArXiv|Physical Sciences and Mathematics|Earth Sciences, EarthArXiv|Life Sciences|Ecology and Evolutionary Biology, 01 natural sciences, bepress|Life Sciences, EarthArXiv|Life Sciences, Limnology, Human Activities, Glacial period, EarthArXiv|Physical Sciences and Mathematics|Earth Sciences|Sedimentology, lcsh:Science, ComputingMilieux_MISCELLANEOUS, bepress|Life Sciences|Ecology and Evolutionary Biology|Terrestrial and Aquatic Ecology, Multidisciplinary, geography.geographical_feature_category, EarthArXiv|Physical Sciences and Mathematics|Earth Sciences|Geology, Palaeoecology, Agriculture, Plants, [SDE]Environmental Sciences, Erosion, Soil horizon, Molecular ecology, Agricultural landscapes, Environmental Monitoring, bepress|Physical Sciences and Mathematics, bepress|Physical Sciences and Mathematics|Earth Sciences|Sedimentology, [SDE.MCG]Environmental Sciences/Global Changes, 010607 zoology, bepress|Physical Sciences and Mathematics|Earth Sciences, EarthArXiv|Physical Sciences and Mathematics|Earth Sciences|Soil Science, bepress|Life Sciences|Ecology and Evolutionary Biology, 010603 evolutionary biology, Article, C2FN, 03 medical and health sciences, Humans, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, EarthArXiv|Life Sciences|Ecology and Evolutionary Biology|Terrestrial and Aquatic Ecology, geography, bepress|Physical Sciences and Mathematics|Earth Sciences|Geology, lcsh:R, Sediment, EarthArXiv|Physical Sciences and Mathematics|Earth Sciences|Geochemistry, DNA, 15. Life on land, [SDE.ES]Environmental Sciences/Environmental and Society, EarthArXiv|Physical Sciences and Mathematics, bepress|Physical Sciences and Mathematics|Earth Sciences|Soil Science, Lakes, 030104 developmental biology, Soil water, Environmental science, bepress|Physical Sciences and Mathematics|Earth Sciences|Geochemistry, lcsh:Q
Abstract

Over the last decade, an increasing number of studies have used lake sediment DNA to trace past landscape changes, agricultural activities or human presence. However, the processes responsible for lake sediment formation and sediment properties might affect DNA records via taphonomic and analytical processes. It is crucial to understand these processes to ensure reliable interpretations for “palaeo” studies. Here, we combined plant and mammal DNA metabarcoding analyses with sedimentological and geochemical analyses from three lake-catchment systems that are characterised by different erosion dynamics. The new insights derived from this approach elucidate and assess issues relating to DNA sources and transfer processes. The sources of eroded materials strongly affect the “catchment-DNA” concentration in the sediments. For instance, erosion of upper organic and organo-mineral soil horizons provides a higher amount of plant DNA in lake sediments than deep horizons, bare soils or glacial flours. Moreover, high erosion rates, along with a well-developed hydrographic network, are proposed as factors positively affecting the representation of the catchment flora. The development of open and agricultural landscapes, which favour the erosion, could thus bias the reconstructed landscape trajectory but help the record of these human activities. Regarding domestic animals, pastoral practices and animal behaviour might affect their DNA record because they control the type of source of DNA (“point” vs. “diffuse”).

Published
2019
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4. Histoire de l’environnement et des usages anthropiques sur l’île de Cavallo (archipel des Lavezzi, Corse)

Author

Yoann Poher, Frédéric Médail, Philippe Ponel, Frédéric Guiter, Institut méditerranéen de biodiversité et d'écologie marine et continentale (IMBE), Avignon Université (AU)-Aix Marseille Université (AMU)-Institut de recherche pour le développement [IRD] : UMR237-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut de recherche pour le développement [IRD] : UMR237-Aix Marseille Université (AMU)-Avignon Université (AU), and PONEL, Philippe

Subjects
[SDE] Environmental Sciences, Ecology, Biodiversity, Forestry, Chalcolithic, 15. Life on land, insularité, paléoécologie, remontée relative du niveau marin, île de Méditerranée, changements environnementaux, impacts humains, language.human_language, Prehistory, Geography, Sea level rise, relative sea-level rise, Mediterranean island, human impacts, insularity, palaeoecology, Environmental changes, 13. Climate action, [SDE]Environmental Sciences, language, 14. Life underwater, Environmental history, Corsican, ComputingMilieux_MISCELLANEOUS, Ecology, Evolution, Behavior and Systematics
Abstract

This study synthetizes the terrestrial environmental history of the Cavallo Island, the largest Corsican satellite island (120 ha), located in the Strait of Bonifacio. Ecosystems dynamics and terrestrial biodiversity have been deciphered for 7,000 years thanks to the paleoecological analysis of fossil pollen and beetle remains. These results underligne the profound changes in the structure and specific composition of terrestrial communities of vascular plants and insects. These changes are related to the relative sea level rise and to anthropogenic impacts. Over time, Cavallo Island represented a hunting territory for prehistoric men from the Neolithic/ Chalcolithic period, then a famous site of granite exploitation by the Romans, a refuge and a haunt for many pirates or corsairs, an “insular enclosure” facilitating the free pastures of cattle brought in “nautical transhumance” by the Bonifaciens. In the early 1970, it became an “island of billionaires” and a territory of lawlessness with a sulfurous reputation. This ultimate episode caused the most impacts on the natural environment : Ecosystems were deeply altered by an uncontrolled urbanization that has had profound consequences on terrestrial biodiversity (destruction and fragmentation of natural habitats ; biological invasions ; filling, pollution and eutrophication of wetlands)., Ce travail dresse l’histoire environnementale terrestre de l’île de Cavallo, l’île satellite corse la plus vaste (120 ha), située dans le détroit de Bonifacio. La dynamique des écosystèmes et de la biodiversité terrestre a pu être reconstituée depuis 7 000 ans grâce à l’analyse paléoécologique conjointe des pollens fossiles et des restes de coléoptères. Ces résultats montrent les profonds changements de structure et de composition spécifique des communautés terrestres de végétaux vasculaires et d’insectes. Ces modifications sont liées à la remontée relative du niveau marin et aux impacts anthropiques. Tour à tour, l’île de Cavallo a représenté un territoire de chasse pour les hommes du Néolithique/ Chalcolithique, puis un site bien connu d’exploitation de granite par les Romains, un territoire refuge et un repaire pour les nombreux pirates ou corsaires, une île-enclos facilitant les libres pâtures du bétail amené en «transhumance marine» par les Bonifaciens. Elle est devenue, au début des années 1970, une «île de milliardaires» et un territoire de non-droit à la réputation sulfureuse. Cet ultime épisode a engendré le plus d’impacts sur le milieu naturel : l’environnement a été profondément altéré par une urbanisation non contrôlée, dont les conséquences sur la biodiversité terrestre ont été profondes (destruction et fragmentation des habitats naturels ; invasions biologiques ; comblement, pollution et eutrophisation des zones humides)., Médail Frédéric, Guiter Frédéric, Poher Yoann, Ponel Philippe. Histoire de l’environnement et des usages anthropiques sur l’île de Cavallo (archipel des Lavezzi, Corse). In: Ecologia mediterranea, tome 43 n°2, 2017. Le patrimoine naturel de l'île de Cavallo (archipel des Lavezzi, Corse) : écologie, biogéographie et conservation. pp. 5-22.

Published
2017
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5. Diatom-oxygen isotopic record from high-altitude Petit Lake (2200 m a.s.l) in the Mediterranean Alps: shedding light on a climatic pulse

Author

Frédéric Guiter, Anne Alexandre, Rosine Cartier, Corinne Sonzogni, Martine Couapel, Jean-Charles Mazur, Cécile Miramont, Christine Paillès, Florence Sylvestre, and Elodie Brisset

Subjects
Mediterranean climate, Water balance, geography, geography.geographical_feature_category, Erosion, Lake ecosystem, Drainage basin, Environmental science, Climate change, Precipitation, Physical geography, Holocene
Abstract

The 4.2 kyrs event, used as a marker of holocene stratigraphy, has been described as a rapid climate change in the northern hemisphere triggering droughts in the Mediterranean region. However, the severity and geographical extent of this event are still the subject of investigation considering the small number of palaeoclimatic records for this time period, and the presence of contrasted climatic expressions between areas. At Petit Lake (France, Mediterranean Alps, 2200 m a.s.l) a multiproxy study of Holocene lake sediments has revealed major changes in erosion processes and phytoplanktonic assemblages in the lake ecosystem around 4200 cal. BP. According to pollen analysis, deforestation is unlikely to be the main explanation of environmental changes as the watershed was covered by open vegetation for the duration of the study period. To test the implication of climate, our study presents an analysis of oxygen isotopes (δ18O) in diatoms describing hydrological modalities during the 4.2 kyrs event in the Mediterranean Alps. The highest values of δ18Odiatom occur from 4400 to 3900 cal. BP and are interpreted as an increase in water evaporation and/or a decrease in freshwater inputs to the lake system. Changes in water balance might have been associated with a change in precipitation sources towards a greater influence of precipitation coming from the Mediterranean area. These results are concomitant to an increase in erosion in the watershed and high representation of very low-dispersal pollen in the sediments suggesting the presence of intense runoff. This new isotopic record together with previously-published proxy-data, allows us to describe the 4.2 kyrs event at Petit Lake as an increase in Mediterranean climate influences in the region, amounting to a general dry period punctuated by episodes of intense runoff occurring on the catchment slopes.

Published
2018
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6. Reconstructing the landscape evolution and the human occupation of the Lower Sagone River (Western Corsica, France) from the Bronze Age to the Medieval period

Author

Matteo Vacchi, Frédéric Guiter, Claude Vella, Philippe Dussouillez, Doriane Delanghe, Yannick Crest, Daniel A. Contreras, Daniel Istria, Andrés Currás, Matthieu Ghilardi, Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA), Laboratoire d'Archéologie Médiévale et Moderne en Méditerranée (LA3M), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Fondation Maison des sciences de l'homme (FMSH), Institut méditerranéen de biodiversité et d'écologie marine et continentale (IMBE), Centre National de la Recherche Scientifique (CNRS)-Institut de recherche pour le développement [IRD] : UMR237-Aix Marseille Université (AMU)-Avignon Université (AU), Histoire naturelle de l'Homme préhistorique (HNHP), Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Université de Perpignan Via Domitia (UPVD), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Avignon Université (AU)-Aix Marseille Université (AMU)-Institut de recherche pour le développement [IRD] : UMR237-Centre National de la Recherche Scientifique (CNRS), Muséum national d'Histoire naturelle (MNHN)-Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Université de Perpignan Via Domitia (UPVD), Centre National de la Recherche Scientifique (France), Currás, Andrés, and Currás, Andrés [0000-0002-1828-7455]

Subjects
Palynology, 010506 paleontology, Archeology, geography, geography.geographical_feature_category, [SHS.ARCHEO]Humanities and Social Sciences/Archaeology and Prehistory, [SDE.MCG]Environmental Sciences/Global Changes, Drainage basin, Vegetation, 15. Life on land, 010502 geochemistry & geophysics, 01 natural sciences, Archaeology, [SDE.ES]Environmental Sciences/Environmental and Society, Alluvial plain, law.invention, Bronze Age, law, Sedimentary rock, Radiocarbon dating, Chronostratigraphy, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Geology, 0105 earth and related environmental sciences
Abstract

This paper aims to reconstruct the landscape evolution together with the vegetation history of the lower Sagone Valley, Western Corsica, which was occupied from the Bronze Age to the Medieval Period. Adopting a geoarchaeological approach, the combination of sedimentological, palynological, and geophysical data enables the reconstruction of various stages in the landscape evolution of the Lower Sagone River over the last 4000 years, together with the history of human occupation. The methods consist of a palaeoenvironmental study of 9 boreholes drilled in the modern deltaic plain, at a maximum distance of 500 m from the present-day shoreline. The laboratory analyses included mollusk identification and measurements of the grain-size distribution (by wet sieving). A series of 21 radiocarbon dates on charcoal, plant remains, wood fragments, and marine mollusk samples formed the basis for a chronostratigraphy. In order to reconstruct the vegetation history of the catchment, with particular attention to anthropogenic activity, pollen analysis was conducted on clay samples from the deepest borehole, and they revealed a semi-open forest during the Bronze Age and Late Iron Age with extensive pastoral activity and limited cereal cultivation. Electric Resistivity Tomography (ERT) of 3 profiles across the alluvial plain was conducted in order to reveal the geometry of the sedimentary bodies. The salient features are the presence of a freshwater lake during the Mid- to Late Bronze Age (from 1500 to 1100 cal. BCE), its transformation into an open marine bay from ca. 1100 until 500 cal. BCE, and the formation of a confined lagoon from 500 cal. BCE to 200 cal. CE.

Published
2017
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7. Novel insights from coleopteran and pollen evidence into the Lateglacial/Holocene transition in Aubrac, French Massif Central

Author

Valérie Andrieu-Ponel, Nathalie Van der Putten, Christine Paillès, Frédéric Guiter, Philippe Ponel, Patrick Rioual, Emmanuel Gandouin, Michelle Leydet, Morteza Djamali, Jacques-Louis de Beaulieu, Institut méditerranéen de biodiversité et d'écologie marine et continentale (IMBE), Avignon Université (AU)-Aix Marseille Université (AMU)-Institut de recherche pour le développement [IRD] : UMR237-Centre National de la Recherche Scientifique (CNRS), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA), Institute of Geology and Geophysics, Chinese Academy of Sciences, Faculty of Science, Lund University, Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Lund University [Lund], and Earth and Climate

Subjects
010506 paleontology, 010504 meteorology & atmospheric sciences, Oldest Dryas, Lateglacial, Palaeoenvironments, Older Dryas, Oceanography, medicine.disease_cause, 01 natural sciences, Pollen, medicine, Stadial, Younger Dryas, Ecology, Evolution, Behavior and Systematics, Holocene, 0105 earth and related environmental sciences, Earth-Surface Processes, geography, Plateau, geography.geographical_feature_category, Ecology, Paleontology, Massif central, Vegetation, 15. Life on land, Coleoptera, 13. Climate action, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Geology
Abstract

International audience; The aim of this study is to describe the environmental and climate changes that occurred in the mountains of Aubrac at the transition between the Lateglacial and the Holocene, from a comparative analysis of fossil Coleoptera and pollen, and a series of 23 C-14 dates. The changes affecting the ecological categories of Coleoptera lead to a division of the sequence into 5 beetle assemblage zones (BAZ): the lowermost BAZ A is characterized by extremely poor assemblages (periglacial environment); BAZ B (Oldest Dryas and Lateglacial Interstadial) is marked by regular occurrences of taxa associated with open environments, aquatic taxa associated with running and highly oxygenated water, and cold adapted taxa with relatively low numbers; BAZ C (Younger Dryas) corresponds to two important events: a particular abundance of cold adapted taxa and a marked decrease of running water taxa, beetles associated with herbaceous vegetation and open environments are also well represented; BAZ D (Early Holocene) corresponds to the total disappearance of cold adapted taxa; the transition BAZ C/BAZ D is marked also by a dramatic peak of running water taxa; the uppermost BAZ E (Early/Mid Holocene) is marked by a total absence of running water taxa which are replaced by standing water or taxa tolerant of a range of water conditions, a particular abundance of wetland taxa, and taxa associated with herbaceous vegetation and open environments. Beetle and pollen data suggest that the harsh climatic conditions prevailing in the Aubrac mountains did not allow warm dependent fauna and trees to establish during the Lateglacial Interstadial, at least in the Roustieres region, and that wide open landscapes occupied the plateau at that time. The Older Dryas, a cold spell previously recorded at La Taphanel (Cantal), is not visible in the Roustieres record, probably because of the higher altitude at Roustieres, whereas the Younger Dryas is strongly expressed. During the Holocene, concordant beetles and pollen data enable to reconstruct the rapid recolonization of the plateau by mesophilous trees (Ulmus, Quercus), suggesting the possible presence of refugia to the southern slopes of the Aubrac plateau. Insect/pollen comparisons provide evidence for hydrological changes in the former lake of Roustieres and suggest that lacustrine water level changes often used as indicator of precipitation regime changes should be taken with caution. (C) 2016 Elsevier B.V. All rights reserved.

Published
2016
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8. Environmental and climate reconstruction of the late-glacial-Holocene transition from a lake sediment sequence in Aubrac, French Massif Central: Chironomid and diatom evidence

Author

Patrick Rioual, Stephen J. Brooks, D. Belkacem, Philippe Ponel, Christine Paillès, Michelle Leydet, N. Van der Putten, Morteza Djamali, J.-L. de Beaulieu, Harry John Betteley Birks, J.N. Haas, Emmanuel Gandouin, Valérie Andrieu-Ponel, Frédéric Guiter, Institut méditerranéen de biodiversité et d'écologie marine et continentale (IMBE), Avignon Université (AU)-Aix Marseille Université (AMU)-Institut de recherche pour le développement [IRD] : UMR237-Centre National de la Recherche Scientifique (CNRS), Institute of Geology, Chinese Academy of Sciences [Beijing] (CAS), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), Department of Life Sciences, Natural History Museum, Department of Biology and Bjerknes Centre for Climate Research, Environmental Change Research Centre, University College London, University of Innsbruck, Institute of Botany, Lund University, Faculty of Science, Institute of Geology and Geophysics [Beijing] (IGG), Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Bjerknes Centre for Climate Research (BCCR), Department of Biological Sciences [Bergen] (BIO / UiB), University of Bergen (UiB)-University of Bergen (UiB), University College of London [London] (UCL), Institute of Botany [Innsbruck], Universität Innsbruck [Innsbruck], Lund University [Lund], Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA), Petrology, and Earth and Climate

Subjects
Subfossil insects, 010506 paleontology, Peat, 010504 meteorology & atmospheric sciences, Oldest Dryas, [SDE.MCG]Environmental Sciences/Global Changes, Climate change, Western Europe, Oceanography, 01 natural sciences, Paleontology, Palaeolimnology, SDG 14 - Life Below Water, Glacial period, Younger Dryas, Ecology, Evolution, Behavior and Systematics, Holocene, 0105 earth and related environmental sciences, Earth-Surface Processes, geography, geography.geographical_feature_category, biology, Past aquatic ecosystem, Massif, 15. Life on land, biology.organism_classification, Corynocera ambigua, Diatom, 13. Climate action, [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology, Temperature reconstruction, Physical geography, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Geology
Abstract

International audience; The analysis of fossil chironomid and diatom assemblages from a sedimentary record from Les Roustieres peat bog (Massif Central, France, 1196 m asl) allows the reconstruction of past environmental and climate changes during the late-glacial and early Holocene. Chironomid assemblages showed that the infilling of the palaeolake had commenced during the Oldest Dryas (GS-2b) as suggested by the rapid decrease in chironomid species associated with the cold and deep zone of lakes and by their replacement by littoral and eutrophic taxa. Quantitative July temperature reconstructions, based on the chironomid data, suggest that mean July air temperature (Tjul) ranged between 6 degrees C and 11 degrees C at the termination of the Oldest Dryas period (GS-2b). Climate began to warm at the start of the Bolling period (GI-1e), between 15,000 and 14,800 cal yr BP, with a rise in Tjul of about 4 degrees C. This climate warming is contemporaneous with lake eutrophication as suggested by diatoms and chironomids. Maximum temperatures of 13-14 degrees C were reached around 13,600 cal yr BP during the Allered period (GI-1c-GI-1a). The Younger Dryas period (GS-1) is marked by a return to cold conditions with Tjul of about 10 degrees C during a first phase, then 13 degrees C in its terminal part. A probable increase in the duration of the ice-cover may have favoured arctic and alpine diatom species. The early-Holocene climate improvement is marked by a rise in Tjul of about 3 degrees C. (C) 2016 Elsevier B.V. All rights reserved.

Published
2016
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9. A hundred year record of industrial and urban development in French Alps combining Hg accumulation rates and isotope composition in sediment archives from Lake Luitel

Author

Pierre Sabatier, Frédéric Guiter, Anne-Lise Develle, Carole Desplanque, David Amouroux, Caiyan Feng, Jean Louis Reyss, Fabien Arnaud, Laurent Charlet, Julien Barre, Stéphane Guédron, Institute F.-A. Forel, University of Geneva, Versoix, Switzerland, Institut des Sciences de la Terre (ISTerre), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut national des sciences de l'Univers (INSU - CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université Joseph Fourier - Grenoble 1 (UJF), Institut des sciences analytiques et de physico-chimie pour l'environnement et les materiaux (IPREM), Université de Pau et des Pays de l'Adour (UPPA)-Centre National de la Recherche Scientifique (CNRS), Environnements, Dynamiques et Territoires de la Montagne (EDYTEM), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), Ecosystèmes continentaux et risques environnementaux (ECCOREV), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Institut méditerranéen de biodiversité et d'écologie marine et continentale (IMBE), Avignon Université (AU)-Aix Marseille Université (AMU)-Institut de recherche pour le développement [IRD] : UMR237-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Géophysique Interne et Tectonophysique (LGIT), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Laboratoire Central des Ponts et Chaussées (LCPC)-Institut des Sciences de la Terre (ISTerre), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut national des sciences de l'Univers (INSU - CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Université de Pau et des Pays de l'Adour (UPPA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Environnements, Dynamiques et Territoires de Montagne (EDYTEM), Office National des Forêts, 9 quai Créqui, 38000 Grenoble, France, Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Océan et Interfaces (OCEANIS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut Pluridisciplinaire de Recherche sur l'Environnement et les Matériaux (IPREM), Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry]), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)

Subjects
Delta, mercury, 010504 meteorology & atmospheric sciences, chemistry.chemical_element, Fractionation, 010501 environmental sciences, 01 natural sciences, C2FN, Isotopes, Geochemistry and Petrology, 11. Sustainability, Industry, isotopes, 0105 earth and related environmental sciences, Hydrology, geography, Radionuclide, geography.geographical_feature_category, industry, Isotope, Terrigenous sediment, Urban area, Geology, Mercury, Mass-independent fractionation, Mercury (element), lake sediment, Lake sediment, chemistry, 13. Climate action, Environmental chemistry, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Water well, urban area
Abstract

International audience; This study reconstructs the history of multiple industrial and urban mercury (Hg) emissions recorded in the sediment archive of Lake Luitel (France) from AD similar to 1860 to AD 2011. For this purpose, we provide a well constrained short-lived radionuclides continuous age-depth relationship of the sediment sequence (mean accumulation rate of 5.18 +/- 0.28 mm.yr(-1)) with Hg accumulation rates (Hg AR), Hg isotopic composition and extensive historical data. Hg AR were stable around 45 mu g.m(-2).y(-1) from 1860 to WWI and rose to reach their maximum at the end of WWII (250 mu g m(-2) y(-1)) followed by a gradual decreased to reach about 90 mu g m(-2) y(-1) in the current period. Normalization to a terrigenous Hg proxy highlighted the dominance of atmospheric Hg inputs to the lake. The combination of Hg AR with isotopic signatures through the use of binary mixing (Delta Hg-199 vs 1/Hg AR) models and isotopic plots (and comparison to literature data) allowed us to identify the main industrial and urban historical inputs. The major outcome of this study is that the Hg mass independent fractionation (MIF) signature did not enable the identification of particular anthropogenic sources but reflected an integrated pool of industrial and urban emissions which tend to shift to less negative MIF values (mean: -0.15 +/- 0.04%) during their period of maximum emissions. Temporal MIF and Hg AR variations depict the rising Hg emissions from the industrial revolution (1860-1910) to the modern industrial and urban development period (1950-1980). Mass dependent fractionation (MDF) signatures enabled the identification of major contributors in relation to their relative intensities lying between two endmember pools: (i) the combustion activities (smelters, cement factories and urban heating) with more negative delta Hg-202 values, and (ii) the chemical and electrometallurgical activities (electrochemistry, chlor-alkali) with higher delta Hg-202 values. Unconformities of MIF and MDF signatures were observed during WWI, WWII and interwar period, and were attributed to drastic and rapid changes in regional industrial activities. Finally, recent laws regarding Hg emissions (1998-2011) prove their efficiency as Hg AR decreased with a return to more negative MIF and MDF signatures such as during the industrial revolution period. Our study highlights that the combination of Hg isotopic data with Hg AR in sediment archives is a useful tool for reconstructing the history of anthropogenic Hg emissions, and has the potential to identifiy their relative contributions. (C) 2016 Elsevier B.V. All rights reserved.

Published
2016
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10. Nouvelles contributions à l’histoire tardiglaciaire et holocène de la végétation en Algérie : analyses polliniques de deux profils sédimentaires du complexe humide d’El-Kala

Author

Mohamed Benslama, Jérémy Migliore, Morteza Djamali, Maurice Reille, Jacques-Louis de Beaulieu, Frédéric Guiter, and Valérie Andrieu-Ponel

Subjects
Geography, General Immunology and Microbiology, North africa, Forestry, General Medicine, General Agricultural and Biological Sciences, Vegetation dynamics, General Biochemistry, Genetics and Molecular Biology
Abstract

Resume Deux sequences polliniques provenant des marais littoraux d’El-Kala ont ete etudiees en vue de retracer l’histoire de la vegetation regionale. Les assemblages polliniques etayes par huit datations 14 C ont revele, dans le marais de Bourdim une histoire recente dominee localement par une aulnaie-saulaie ; l’abondance d’ Erica arborea indique que la vegetation regionale est constituee par une suberaie tres degradee. La sequence de Garaat El-Ouez presente deux periodes distinctes : les assemblages superieurs sont comparables a ceux de Bourdim ; par contre, ceux de la base sont domines par Pinus , des Poaceae et diverses herbacees heliophiles, avec presence de Cedrus . Ils temoignent d’une vegetation forestiere ouverte attribuee par trois datations a la fin de la derniere glaciation et demontrent l’existence de refuges regionaux de Cedrus sous un climat relativement clement.

Published
2010
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11. Lateglacial/Holocene environmental changes in the Mediterranean Alps inferred from lacustrine sediments

Author

Emmanuel Malet, Cécile Miramont, Edward J. Anthony, Frédéric Guiter, Elodie Brisset, Jacques-Louis de Beaulieu, Fabien Arnaud, Marie Revel, Claire Delhon, Ecosystèmes continentaux et risques environnementaux (ECCOREV), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Institut méditerranéen de biodiversité et d'écologie marine et continentale (IMBE), Avignon Université (AU)-Aix Marseille Université (AMU)-Institut de recherche pour le développement [IRD] : UMR237-Centre National de la Recherche Scientifique (CNRS), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), Géoazur (GEOAZUR 7329), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Institut Universitaire de France, Culture et Environnements, Préhistoire, Antiquité, Moyen-Age (CEPAM), Université Nice Sophia Antipolis (... - 2019) (UNS), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Environnements, Dynamiques et Territoires de la Montagne (EDYTEM), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut de recherche pour le développement [IRD] : UMR237-Aix Marseille Université (AMU)-Avignon Université (AU), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD), Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA), Institut Universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA), Gestion des ressources naturelles , environnements et sociétés (GReNES), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Nice Sophia Antipolis (... - 2019) (UNS), Institut Méditerranéen d'Ecologie et de Paléoécologie (IMEP), Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS)-Avignon Université (AU)-Université de Provence - Aix-Marseille 1, Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (1965 - 2019) (UNS), Environnements, Dynamiques et Territoires de Montagne (EDYTEM), Université Paul Cézanne - Aix-Marseille 3-Université de Provence - Aix-Marseille 1-Avignon Université (AU)-Centre National de la Recherche Scientifique (CNRS), Université Côte d'Azur (UCA)-Observatoire de la Côte d'Azur, and Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut national des sciences de l'Univers (INSU - CNRS)

Subjects
Archeology, cirque glacier, Lateglacial, [SDE.MCG]Environmental Sciences/Global Changes, Holocene climatic optimum, Rock glacier, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Paleontology, Deglaciation, Younger Dryas, Glacial period, [SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology, [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, Ecology, Evolution, Behavior and Systematics, Gyttja, Global and Planetary Change, geography, geography.geographical_feature_category, pollen stratigraphy, Mediterranean Alps, Geology, Glacier, 14C ages, 15. Life on land, Cirque glacier, Lake sediment, 13. Climate action, [SDU.STU.ST]Sciences of the Universe [physics]/Earth Sciences/Stratigraphy, [SDE]Environmental Sciences
Abstract

International audience; This study investigates sediment cores from the Mediterranean alpine lakes located in upvalley cirques upper than 1700 metres a.s.l. using sedimentological, palynological and geomorphological studies, in order to document environmental changes following the last phase of glacier retreat. These results are considered in the framework of the deglaciation characterized from 16 sediment cores from high-altitude lakes and mires including 104 14C ages and geomorphological studies of the Mediterranean Alps. Considering each sediment core proxy as an independent observation, i.e., comparisons between 14C ages and palynostratigraphy, between 14C ages and lithostratigraphy, between palynostratigraphy and lithostratigraphy, these data are aimed at contributing to a better understanding of the timing of postglacial environmental changes. The 14C ages combined with pollen biostratigraphy indicate that the deglaciation of cirque catchments is dated between 14,500 and 13,000 cal. BP, i.e., during the Lateglacial Interstadial (Greenland Interstadial-1e). The sixteen lacustrine and mire sediment records are systematically characterized by three units from bottom to top: organic-poor blue clay, beige to light-brown silty clay and organic rich dark brown gyttja lithotype. During the Younger Dryas, lakes located below 2300 m a.s.l. were ice-free and their pollen record indicates steppe conditions. The sedimentary facies also informs on the timing of glacial-dominated processes. The onset of organic-rich gyttja is dated at 11,000 cal. BP suggesting the last influence of cirque glaciers in these lakes at the beginning of the Holocene. The timing of the onset of this organic rich unit differs in sites (±2000 years) probably due to an altitudinal and exposure gradient of the glacial cirques. The presence of gyttja from 11,000 cal. BP to Present indicates biogenic infilling lake for all the Holocene. Even though the literature have indicated rock glacier advances occurred during the Holocene (Subboreal and LIA) in the south of the Alps, no significant sedimentological patterns related to glacier fluctuations are recorded in Lake Vens. The glacier fluctuations in the Mediterranean Alps are concomitant with those dated in the non-Mediterranean Alps, thus suggesting a main common climate forcing. However, the increase in terrigenous sediment inputs since 1800 cal. BP is mainly due to human activities.

Published
2015
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12. Lateglacial palaeoenvironments and palaeoclimates from Conty and Houdancourt, northern France, reconstructed from Beetle remains

Author

Nicole Limondin-Lozouet, Chantal Leroyer, Jean-François Pastre, Russell Coope, Pierre Antoine, André-Valentin Munaut, Frédéric Guiter, Philippe Ponel, Institut Méditerranéen d'Ecologie et de Paléoécologie (IMEP), Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS)-Avignon Université (AU)-Université de Provence - Aix-Marseille 1, Royal Holloway [University of London] (RHUL), Laboratoire de géographie physique : Environnements Quaternaires et Actuels (LGP), Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Ministère de la Culture et de la Communication (MCC), Centre National de Préhistoire (CNP), Université Catholique de Louvain = Catholic University of Louvain (UCL), and Université Paul Cézanne - Aix-Marseille 3-Université de Provence - Aix-Marseille 1-Avignon Université (AU)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010506 paleontology, Archeology, Global and Planetary Change, geography, geography.geographical_feature_category, Floodplain, Fauna, Geology, Vegetation, Older Dryas, 010502 geochemistry & geophysics, medicine.disease_cause, 01 natural sciences, [SHS]Humanities and Social Sciences, Allerød oscillation, Paleontology, Pollen, [SDE]Environmental Sciences, Geochronology, medicine, Sedimentology, ComputingMilieux_MISCELLANEOUS, Ecology, Evolution, Behavior and Systematics, 0105 earth and related environmental sciences
Abstract

Two Lateglacial insect sequences are described (a) from Conty, in the Selle valley and (b) from Houdancourt in the Oise valley, both in northern France. These investigations are part of a multidisciplinary investigation involving archaeology, sedimentology, geomorphology, geochronology and palaeontology (pollen, macroscopic plant remains, vertebrates, molluscs and insect fossils). The sequences of insect assemblages date from the latter part of the Bolling to the end of the Allerod periods. Environmental analysis of these faunas shows that rivers with riffles and pools meandered across flood plains. The river was extensively fringed with reedy vegetation. The only trees growing close to the river were of Salix and/or Populus . All the insect assemblages indicate that the thermal climates during the Bolling and Allerod periods were similar to one another and during both periods were very nearly as warm as that of the present day. No insect fossils were recovered from the sediments attributed to the Older Dryas interval though other evidence from these sites suggests that this event was decidedly colder than those immediately preceding and succeeding it. Comparisons are made between Lateglacial climatic patterns in northern France with those elsewhere in Europe.

Published
2005
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13. Vegetation dynamics in north-western Mediterranean regions: Instability of the Mediterranean bioclimate

Author

Valérie Andrieu-Ponel, Jacques-Louis de Beaulieu, Yannick Miras, and Frédéric Guiter

Subjects
Mediterranean climate, Palynology, Geography, Orbital forcing, Ecology, Sclerophyll, Interglacial, Macrofossil, Plant Science, Evergreen, Ecology, Evolution, Behavior and Systematics, Holocene
Abstract

Pollen and plant macrofossil records from a selection of sites in Spain, France and Italy are used to explore the origin and the development of the Mediterranean vegetation. The role of evergreen and summergreen taxa is discussed. The expansion of sclerophyllous trees during the Pleistocene interglacials is well correlated with the orbital forcing. During the Holocene, the large number of data illustrates latitudinal and longitudinal differences in vegetation dynamics. Multidisciplinary studies identify short terms climatic fluctuations. The debate is still open between those who attribute an increase of sclerophyllous forests during the late Holocene to a trend toward aridity and those who consider this dynamic as human-induced.

Published
2005
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14. First evidence of 'in situ' Eemian sediments on the high plateau of Evian (Northern Alps, France): implications for the chronology of the Last Glaciation

Author

Jean-Pierre Hebrard, Gérard Nicoud, Frédéric Guibal, Simon Brewer, Jacques-Louis de Beaulieu, Valérie Andrieu-Ponel, Frédéric Guiter, Philippe Ponel, Anne Triganon, Institut Méditerranéen d'Ecologie et de Paléoécologie (IMEP), Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS)-Avignon Université (AU)-Université de Provence - Aix-Marseille 1, Laboratoire d'Hydrogéologie d'Avignon (LHA), Avignon Université (AU), Environnements, Dynamiques et Territoires de la Montagne (EDYTEM), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA), Université Paul Cézanne - Aix-Marseille 3-Université de Provence - Aix-Marseille 1-Avignon Université (AU)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), Environnements, Dynamiques et Territoires de Montagne (EDYTEM), and Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010506 paleontology, Archeology, 010504 meteorology & atmospheric sciences, [SDE.MCG]Environmental Sciences/Global Changes, Context (language use), Evian, 01 natural sciences, Eemian sediments, Deglaciation, Glacial period, [SDU.STU.AG]Sciences of the Universe [physics]/Earth Sciences/Applied geology, Geomorphology, Ecology, Evolution, Behavior and Systematics, 0105 earth and related environmental sciences, Global and Planetary Change, geography, Eemian, geography.geographical_feature_category, Plateau, Macrofossil, Geology, Glacier, Last Glacial Maximum, 15. Life on land, last glaciation, Northern Alps, France, Physical geography
Abstract

International audience; A 2 m profile of organic sediments, interbedded between two tills, was taken from the Evian high plateau at Hameau de Maravant, 860 m a.s.l. (Haute-Savoie, Western Alps, France). Pollen, plant macrofossils and insect remains were used to reconstruct the local palaeoenvironment, which consisted of a moss and Carex mire, surrounded by a dense Abies and Picea mixed forest. Pollen and macrofossil data indicate that this peat layer was deposited at the end of the Eemian interglacial. The lower till should therefore be assigned to the penultimate glaciation and the upper till to the maximum extent of the Rhône glacier during the Würm. A comparison of the results with previous studies carried out in the Geneva area and other alpine valleys has yielded a detailed reconstruction of the past fluctuations of the Rhône glacier: 1. a first Early/Lower Würmian advance, reaching the region around Lyon; 2. a subsequent retreat of ice; 3. a second moderate readvance, restricted to the surroundings of Geneva, followed by a final deglaciation. A continuous lacustrine sequence has been obtained from the nearby Roseire peat-bog (890 m a.s.l). Pollen and radiometric results show the establishment of a former palaeolake during the Upper Pleniglacial, probably before ca. 22 450±850 cal years BP, thus implying that the high plateau was ice-free from that time. These new data appear to suggest that the maximal extension of the Rhône glacier occurred prior to the Last Glacial Maximum (OIS 2) and, according to a well-documented geomorphological context, probably during the Lower Würmian Pleniglacial.

Published
2005
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15. 1400 years of extreme precipitation patterns over the Mediterranean French Alps and possible forcing mechanisms

Author

Edouard Bard, Jean-Jacques Delannoy, Pierre Sabatier, Eric Chaumillon, Jean-Louis Reyss, Kazuyo Tachikawa, Bruno Wilhelm, Frédéric Guiter, Jean-Robert Disnar, Elodie Brisset, Fabien Arnaud, Christian Crouzet, Emmanuel Malet, Environnements, Dynamiques et Territoires de la Montagne (EDYTEM), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences de la Terre (ISTerre), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut national des sciences de l'Univers (INSU - CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université Joseph Fourier - Grenoble 1 (UJF), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), Institut méditerranéen de biodiversité et d'écologie marine et continentale (IMBE), Avignon Université (AU)-Aix Marseille Université (AMU)-Institut de recherche pour le développement [IRD] : UMR237-Centre National de la Recherche Scientifique (CNRS), LIttoral ENvironnement et Sociétés - UMR 7266 (LIENSs), Université de La Rochelle (ULR)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences de la Terre d'Orléans - UMR7327 (ISTO), Bureau de Recherches Géologiques et Minières (BRGM) (BRGM)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry]), Université Joseph Fourier - Grenoble 1 (UJF)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-PRES Université de Grenoble-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Chaire Evolution du climat et de l'océan, Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), LIttoral ENvironnement et Sociétés - UMRi 7266 (LIENSs), Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Bureau de Recherches Géologiques et Minières (BRGM) (BRGM), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Océan et Interfaces (OCEANIS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Environnements, Dynamiques et Territoires de Montagne (EDYTEM), Collège de France - Chaire Evolution du climat et de l'océan, LIttoral ENvironnement et Sociétés (LIENSs), La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)

Subjects
Mediterranean climate, 010506 paleontology, 010504 meteorology & atmospheric sciences, Atmospheric circulation, [SDE.MCG]Environmental Sciences/Global Changes, Solar activity, Drainage basin, Forcing (mathematics), 01 natural sciences, Arts and Humanities (miscellaneous), Flood intensity, Precipitation, 0105 earth and related environmental sciences, Earth-Surface Processes, geography, geography.geographical_feature_category, Flood myth, Paleoflood, 13. Climate action, North Atlantic oscillation, Climatology, Erosion, General Earth and Planetary Sciences, Last millennium, North Atlantic Oscillation, Geology
Abstract

Investigation of Lake Allos sediments revealed ~ 160 graded layers, interpreted as flood deposits, over the last 1400 yr. Comparisons with records of historic floods support the interpretation of flood deposits and suggest that most recorded flood events are the result of intense meso-scale precipitation events. As there is no evidence for any major changes in erosion processes in the catchment since the Medieval Warm Period (MWP), we interpret the Allos record in terms of repeated intense precipitation events over the last millennium, with a low flood frequency during the MWP and more frequent and more intense events during the Little Ice Age. This interpretation is consistent with the pattern of increasingly humid conditions in the northwestern Mediterranean region. This long-term trend is superimposed on high frequency oscillations that correlate with solar activity and autumnal North Atlantic Oscillation (NAO). Finally, a comparison of flood records across the northwestern Mediterranean region showed that intense precipitation events in Allos (east of the Rhône Valley) were out of phase with events in the Cévennes (west of the Rhône) but in phase with events in eastern Spain. Supported by meteorological analyses, this suggests an oscillation in atmospheric circulation patterns over the northwestern Mediterranean.

Published
2012
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16. The Holocene deposits of Lake Petit (2200 m a.s.l., Southern French Alps) : climatic and anthropogenic controls on mountain sediment dynamics ?

Author

Franck Sumera, Fabien Arnaud, Cécile Miramont, Bruno Wilhelm, Christine Paillès, Elodie Brisset, Jean-Robert Disnar, Claire Delhon, Frédéric Guiter, Edward J. Anthony, Institut méditerranéen de biodiversité et d'écologie marine et continentale (IMBE), Centre National de la Recherche Scientifique (CNRS)-Institut de recherche pour le développement [IRD] : UMR237-Aix Marseille Université (AMU)-Avignon Université (AU), Institut Méditerranéen d'Ecologie et de Paléoécologie (IMEP), Université Paul Cézanne - Aix-Marseille 3-Université de Provence - Aix-Marseille 1-Avignon Université (AU)-Centre National de la Recherche Scientifique (CNRS), Environnements, Dynamiques et Territoires de la Montagne (EDYTEM), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Centre d'Études Préhistoire, Antiquité, Moyen-Age (CEPAM), Université Nice Sophia Antipolis (... - 2019) (UNS), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences de la Terre d'Orléans - UMR7327 (ISTO), Bureau de Recherches Géologiques et Minières (BRGM) (BRGM)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), Centre Camille Jullian - Histoire et archéologie de la Méditerranée et de l'Afrique du Nord de la protohistoire à la fin de l'Antiquité (CCJ), Aix Marseille Université (AMU)-Ministère de la Culture et de la Communication (MCC)-Centre National de la Recherche Scientifique (CNRS), Avignon Université (AU)-Aix Marseille Université (AMU)-Institut de recherche pour le développement [IRD] : UMR237-Centre National de la Recherche Scientifique (CNRS), Environnements, Dynamiques et Territoires de Montagne (EDYTEM), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS)-Avignon Université (AU)-Université de Provence - Aix-Marseille 1, Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry]), Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Bureau de Recherches Géologiques et Minières (BRGM) (BRGM), and Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA)

Subjects
Mediterranean climate, Palynology, 010506 paleontology, geography, geography.geographical_feature_category, Sediment, Massif, 15. Life on land, 010502 geochemistry & geophysics, 01 natural sciences, Deposition (geology), Oceanography, Productivity (ecology), [SDU]Sciences of the Universe [physics], Period (geology), Geology, Holocene, 0105 earth and related environmental sciences, Earth-Surface Processes
Abstract

International audience; Numerous archaeological studies carried out in high-elevation areas of the Southern French Alps have documented ancient human occupation of mountains, mainly characterized by pastoral and mining activities. Besides, the area was affected by both continental and Mediterranean climate instability throughout the Holocene. Lake Petit, located in the Mercantour massif, was investigated in order to reconstruct past interactions between humans, the environment and climate, using a multidisciplinary approach. This study was carried out on a 144 cm-long gravity core providing a continuous record spanning the last 5000 years. Our multi-proxy investigation (sedimentological, geochemical and palynological analyses), allowed us to reconstruct three main phases, evidencing a progressive destabilization of the local environment. The first phase (ca. 4800 to 4300 cal. BP) was characterized by relatively stable environmental conditions, as attested by a high lake productivity (deposition of pure diatomite) and by the local presence of trees (presence of conifer stomata). The second phase (ca. 4300 to 1500 cal. BP) could correspond to a drastic cleaning of landscapes since the lake record highlights an abrupt switch in sediment source marked by an input of terrestrial organic matter. Regular occurrences of anthropogenic pollen assemblages might indicate early pastoral activity in the lake vicinity, while wetter conditions characteristic of the Neoglacial period may have trigger hillslopes destabilization. The most recent phase (since ca. 1500 cal. BP) is marked by a final degradation of the environment: the lake productivity dramatically decreased contemporaneously with a fall of the AP/NAP pollen curve. This phase also exhibits the highest values of anthropogenic pollen taxa and concentrations of lead. It undoubtedly corresponded to one of an intensive agro-pastoral pressure as well to local mining activities.

Published
2011

17. 10,000 years of vegetation history of the Aa palaeoestuary, St-Omer Basin, northern France

Author

Valérie Andrieu-Ponel, Jacques Brulhet, Philippe Ponel, Brigitte Van Vliet-Lanoë, Morteza Djamali, Maryse Alvitre, Emmanuel Gandouin, Jacques-Louis de Beaulieu, Evelyne Franquet, Murielle Meurisse, Marcel Brocandel, Frédéric Guiter, Institut Méditerranéen d'Ecologie et de Paléoécologie (IMEP), Université Paul Cézanne - Aix-Marseille 3-Université de Provence - Aix-Marseille 1-Avignon Université (AU)-Centre National de la Recherche Scientifique (CNRS), Processus et bilan des domaines sédimentaires (PBDS), Université de Lille, Sciences et Technologies-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Domaines Océaniques (LDO), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Observatoire des Sciences de l'Univers-Institut d'écologie et environnement-Centre National de la Recherche Scientifique (CNRS), Agence Nationale pour la Gestion des Déchets Radioactifs (ANDRA), and Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS)-Avignon Université (AU)-Université de Provence - Aix-Marseille 1

Subjects
010506 paleontology, human impact, Fluvial, Wetland, Structural basin, 010502 geochemistry & geophysics, medicine.disease_cause, 01 natural sciences, Pollen, medicine, Ecology, Evolution, Behavior and Systematics, 0105 earth and related environmental sciences, geography, geography.geographical_feature_category, Ecology, Paleontology, 15. Life on land, Preboreal, pollen analysis, Paleobotany, Subatlantic, flood plain, Physical geography, medicine.symptom, Vegetation (pathology), [SDU.STU.PG]Sciences of the Universe [physics]/Earth Sciences/Paleontology, marine transgression
Abstract

International audience; The analysis of sediments and pollen from three sedimentary profiles in the St-Omer basin (Pas-de-Calais, France) has allowed the reconstruction of local and regional vegetation history from the late Preboreal to the Subatlantic. Hydrological changes induced vegetation changes, with freshwater marshy vegetation dominating during fluvial episodes, and halophilous grasslands, typical of shore areas, dominating during episodes of salt water input (five marine episodes, so-called St-Omer I to St-Omer V). Pollen markers indicative of human presence and agricultural activities, along with contemporaneous signals of forest disturbance, are recorded from ca 4000 cal BP onwards.

Published
2009
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18. A late Holocene pollen record from Lake Almalou in NW Iran: evidence for changing land-use in relation to some historical events during the last 3700 years

Author

Emmanuel Gandouin, Mojtaba Salimian, Valérie Andrieu-Ponel, Manuel Berberian, Philippe Ponel, Frédéric Guiter, M. Shah-Hosseini, Jacques-Louis de Beaulieu, Naomi F. Miller, Hamid Lahijani, Morteza Djamali, Institut Méditerranéen d'Ecologie et de Paléoécologie (IMEP), Université Paul Cézanne - Aix-Marseille 3-Université de Provence - Aix-Marseille 1-Avignon Université (AU)-Centre National de la Recherche Scientifique (CNRS), AUTRES, University of Pennsylvania Museum of Archaeology and Anthropology (Penn Museum), Iranian National Center for Oceanography, and Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS)-Avignon Université (AU)-Université de Provence - Aix-Marseille 1

Subjects
010506 paleontology, Archeology, History, 010504 meteorology & atmospheric sciences, Environmental change, Climate change, Wetland, Iran, medicine.disease_cause, 01 natural sciences, Pollen, medicine, Holocene, 0105 earth and related environmental sciences, 2. Zero hunger, geography, geography.geographical_feature_category, Sahand, Vegetation, 15. Life on land, Archaeology, 13. Climate action, Iron Age, [SDE]Environmental Sciences, Period (geology), Anthropogenic activities, Pollen record, Fruticulture
Abstract

International audience; A pollen diagram was prepared from Lake Almalou, a volcanic crater wetland located on the eastern flanks of the Sahand Volcanic Complex in NW Iran. The core provides a 3700-year record of human activity and environmental change in an upland region. We attempt to relate vegetation changes to both climatic change and historical events. Variations of anthropogenic pollen indicators suggest several phases of intensified human activities. Two strongly expressed agricultural phases are dated at about 2450-2220 cal BP (Achaemenid Empire) and 230-30 cal BP (collapse of Safavid Dynasty to the modern period). Historical rather than climatic events appear to be the main controlling factors for upland land-use dynamics. Fru-ticulture has been practiced in the region at least since the Iron Age, reaching its maximum importance 1500-1250 cal BP during the reign of Sassanid Empire; it declined by the time of Islamic conquest of Iran (651 AD). The Little Ice Age is tangibly recorded by higher lake water levels most probably due to both lower summer temperatures and higher annual precipitations. Low values of cereal-type and cultivated tree pollen during this period may indicate a change in the lifestyle from the cultivation of fields and orchards to a more nomadic life dominated by summer pasture. The modern period (1850 AD onwards) is characterized by expansion of agricultural activities to upland areas and intensified pastoralism.

Published
2009
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19. Insect evidence for environmental and climate changes from Younger Dryas to Sub-Boreal in a river floodplain at St-Momelin (St-Omer basin, northern France), Coleoptera and Trichoptera

Author

Philippe Ponel, Evelyne Franquet, Valérie Andrieu-Ponel, G. Russell Coope, Brigitte Van Vliet-Lanoë, Jacques Brulhet, Marcel Brocandel, Emmanuel Gandouin, Frédéric Guiter, Institut Méditerranéen d'Ecologie et de Paléoécologie (IMEP), Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS)-Avignon Université (AU)-Université de Provence - Aix-Marseille 1, Institut méditerranéen de biodiversité et d'écologie marine et continentale (IMBE), Avignon Université (AU)-Aix Marseille Université (AMU)-Institut de recherche pour le développement [IRD] : UMR237-Centre National de la Recherche Scientifique (CNRS), Université Paul Cézanne - Aix-Marseille 3-Université de Provence - Aix-Marseille 1-Avignon Université (AU)-Centre National de la Recherche Scientifique (CNRS), University of London [London], Processus et bilan des domaines sédimentaires (PBDS), Université de Lille, Sciences et Technologies-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Agence Nationale pour la Gestion des Déchets Radioactifs (ANDRA), and Centre National de la Recherche Scientifique (CNRS)-Institut de recherche pour le développement [IRD] : UMR237-Aix Marseille Université (AMU)-Avignon Université (AU)

Subjects
010506 paleontology, Floodplain, Range (biology), Lateglacial, Fauna, [SDE.MCG]Environmental Sciences/Global Changes, Holocene climatic optimum, Palaeoenvironment, 010502 geochemistry & geophysics, Oceanography, Palaeoclimate, 01 natural sciences, Younger Dryas, Ecology, Evolution, Behavior and Systematics, Holocene, 0105 earth and related environmental sciences, Earth-Surface Processes, geography, geography.geographical_feature_category, Ecology, Trichoptera, Paleontology, 15. Life on land, Coleoptera, Boreal, 13. Climate action, [SDE]Environmental Sciences, MCR, Chronozone, Physical geography, [SDV.EE.BIO]Life Sciences [q-bio]/Ecology, environment/Bioclimatology, Geology
Abstract

International audience; The St-Omer area is a rapidly subsiding basin in which long sequences of Weichselian and Holocene sediments are preserved. A core 21 m long, extracted from near St-Momelin about ten km north of St-Omer, has been analysed for insect fossils. Four Faunal Units (SMi-1 to SMi-4) are described based on changes in both coleopteran and trichopteran assemblages. The basal Faunal Unit (SMi-1) includes many cold-adapted species and is attributed to the Younger Dryas chronozone. The transition to Holocene sedimentation was abrupt. Faunal units SMi-2 to SMi-4 are attributable to the Holocene. They lack all the cold-adapted species found in the basal sediments and in their place are insect assemblages very similar to the present day fauna in this region. This sequence spans the period from the Pre-Boreal to the Sub-Boreal. Faunal Unit SMi-2 includes insects from the Pre-Boreal, the Boreal and most of the Atlantic periods. This fauna was fairly sparse and made up largely of species living in freshwater habitats. The Faunal Unit SMi-3 includes the insect assemblages from the Late-Atlantic to Sub-Boreal periods. This fauna was much more diverse and indicated a river meandering across its floodplain and bordered by a mature forest at a time when the climate was warmer than that of the present day. This chronostratigraphical sequence of events is supported by 14C dates and by lithological data. Thermal climatic conditions have been quantified using the Mutual Climatic Range method. During the Younger Dryas period (SMi-1), Tmax (the mean July temperature) was in the region of 10 °C and Tmin (the mean temperature of January/February) was close to − 11/− 12 °C. After the sudden climatic amelioration at the start of the Holocene (SMi-2 to SMi-4) Tmax probably fluctuated throughout the early Holocene between 16 °C to 19 °C and Tmin between 0 °C to 5 °C; figures that are close to those of the present day. This climatic history is compared with others in northern Europe.

Published
2007
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20. Past environment and climate changes at the last Interglacial/Glacial transition (Les Échets, France) inferred from subfossil chironomids (Insecta)

Author

Elisabeth Lallier-Vergès, Jacques Brulhet, Daniel Veres, Valérie Andrieu-Ponel, Jacques-Louis de Beaulieu, Emmanuel Gandouin, Maurice Reille, Frédéric Guiter, Philippe Ponel, Didier Kéravis, Ulrich von Grafenstein, Evelyne Franquet, Institut méditerranéen de biodiversité et d'écologie marine et continentale (IMBE), Avignon Université (AU)-Aix Marseille Université (AMU)-Institut de recherche pour le développement [IRD] : UMR237-Centre National de la Recherche Scientifique (CNRS), Institut Méditerranéen d'Ecologie et de Paléoécologie (IMEP), Université Paul Cézanne - Aix-Marseille 3-Université de Provence - Aix-Marseille 1-Avignon Université (AU)-Centre National de la Recherche Scientifique (CNRS), Agence Nationale pour la Gestion des Déchets Radioactifs (ANDRA), Institut des Sciences de la Terre d'Orléans (ISTO), Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Géochrononologie Traceurs Archéométrie (GEOTRAC), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Glaces et Continents, Climats et Isotopes Stables (GLACCIOS), Department of Physical Geography and Quaternary Geology, Stockholm University, The study is part of a large multiproxy palaeoecological program supported by ANDRA, CNRS, NSF, the Lund University and IMEP., Centre National de la Recherche Scientifique (CNRS)-Institut de recherche pour le développement [IRD] : UMR237-Aix Marseille Université (AMU)-Avignon Université (AU), Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS)-Avignon Université (AU)-Université de Provence - Aix-Marseille 1, Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)

Subjects
0106 biological sciences, 010506 paleontology, Pleistocene, [SDE.MCG]Environmental Sciences/Global Changes, Mid Europe, Palaeoenvironment, Biozone, Lake water level, 01 natural sciences, Paleolimnology, Chironomids, Palaeolimnology, 92.60.Ry, Littoral zone, Climate change, 14. Life underwater, Glacial period, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, 0105 earth and related environmental sciences, Global and Planetary Change, Eemian, Subfossil, Ecology, 010604 marine biology & hydrobiology, 15. Life on land, Geography, 13. Climate action, [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology, Interglacial, General Earth and Planetary Sciences
Abstract

International audience; Subfossil chironomid assemblages spanning the last Interglacial/Glacial transition at Les Échets (France) highlight the environmental and climatic changes that took place at this crucial period. The Early Eemian warming is marked by increased percentages of warmwater taxa and decreased percentages of coldwater taxa. In the Middle Eemian, a lowering in water level is indicated by a rise of littoral taxa. In the Late Eemian, chironomids indicate anoxic deep waters and rise of water level, probably induced by increased rainfall. Mélisey I and II and the beginning of the glacial period are marked by the reappearance of coldwater taxa, lower percentages of warmwater taxa, and dominance of littoral taxa, probably correlated with lower water level and climate aridity. St Germain I and II are marked by higher percentages of warmwater taxa, lower percentages, or absence of both coldwater and littoral taxa.

Published
2007
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21. [Palynological evidence of anthropogenic pressure: effect on pollination dynamics in the Evian area since the middle Neolithic: the pollen record of La Beunaz (971 m a.s.l., northern Alps, France)]

Author

Frédéric, Guiter, Valérie, Andrieu-Ponel, Jacques-Louis, de Beaulieu, Philippe, Ponel, Gérard, Nicoud, and Bernard, Blavoux

Subjects
Geography, Fossils, Plant Development, Pollen, Germination, Carbon Radioisotopes, France, Environment, Plant Physiological Phenomena, Demography
Abstract

This paper presents a pollen diagram from La Beunaz peat-bog (southeast of Evian, Haute-Savoie, France), which provides the first detailed record of human impact on vegetation of the southern bank of Lake Geneva since the Middle Neolithic. The radiocarbon-dated pollen profile is correlated with micro-charcoal record and archaeological data. The results suggest that several phases of deforestations since 4615+75/-70 years BP occurred, in relation to human activities (agriculture, pastoralism). Tombs and vestiges of lacustrine villages indicate that the region was intensively and recurrently occupied by man during at that time.

Published
2005

22. Impact anthropique sur la végétation de la région d'Évian depuis le Néolithique moyen : l'enregistrement pollinique de la Beunaz (971 m n.g.f., Haute-Savoie, France)

Author

Valérie Andrieu-Ponel, Frédéric Guiter, Philippe Ponel, Jacques-Louis de Beaulieu, Bernard Blavoux, Gérard Nicoud, Institut Méditerranéen d'Ecologie et de Paléoécologie (IMEP), Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS)-Avignon Université (AU)-Université de Provence - Aix-Marseille 1, Environnements, Dynamiques et Territoires de la Montagne (EDYTEM), Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry]), Université Paul Cézanne - Aix-Marseille 3-Université de Provence - Aix-Marseille 1-Avignon Université (AU)-Centre National de la Recherche Scientifique (CNRS), Environnements, Dynamiques et Territoires de Montagne (EDYTEM), and Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)

Subjects
2. Zero hunger, 010506 paleontology, General Immunology and Microbiology, [SDE.MCG]Environmental Sciences/Global Changes, Néolithique, Forestry, General Medicine, 15. Life on land, 010502 geochemistry & geophysics, Vegetation dynamics, 01 natural sciences, General Biochemistry, Genetics and Molecular Biology, Haute-Savoie, Anthropisation, Geography, 13. Climate action, France, General Agricultural and Biological Sciences, Anthropogenic factor, Micro-charbons, Analyse pollinique, [SDU.STU.AG]Sciences of the Universe [physics]/Earth Sciences/Applied geology, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract

Resume L'etude paleoecologique d'un profil sedimentaire preleve dans la tourbiere de la Beunaz (au sud-est d'Evian, Haute-Savoie, France) a permis, pour la premiere fois, de reconstituer en detail l'evolution de la vegetation du plateau d'Evian. Les donnees polliniques, radiometriques et micro-anthracologiques ont montre que le couvert forestier a subi de profondes perturbations des 4615 + 75 / – 70 ans BP, notamment en raison d'episodes reguliers de deforestation. Il s'agissait probablement de defrichements a vocation agro-pastorale, car de nombreux vestiges archeologiques contemporains de ces periodes attestent une occupation humaine dense sur l'ensemble de la rive sud du lac Leman. Pour citer cet article : F. Guiter et al., C. R. Biologies 328 (2005).

Published
2005

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