The sedimentary and remote-sensing reflection of biomass burning in Europe
Aim: We provide the first European-scale geospatial training set relating the charcoal signal in surface lake sediments to fire parameters (number, intensity and area) recorded by satellite moderate resolution imaging spectroradiometer (MODIS) sensors. Our calibration is intended for quantitative reconstructions of key fire-regime parameters by using sediment sequences of microscopic (MIC from pollen slides, particles 10-500 µm) and macroscopic charcoal (MAC from sieves, particles > 100 µm). Location: North-south and east-west transects across Europe, covering the mediterranean, temperate, alpine, boreal and steppe biomes. Time period: Lake sediments and MODIS active fire and burned area…
Caractérisation des changements environnementaux dans la basse vallée du Doubs (Neublans, Jura) durant le 1er millénaire après J.-C. Le rôle de l'Homme et de la rivière
International audience
A Review of 2000 Years of Paleoclimatic Evidence in the Mediterranean
[EN] The integration of climate information from instrumental data and documentary and natural archives; evidence of past human activity derived from historical, paleoecological, and archaeological records; and new climate modeling techniques promises major breakthroughs for our understanding of climate sensitivity, ecological processes, environmental response, and human impact. In this chapter, we review the availability and potential of instrumental data, less well-known written records, and terrestrial and marine natural proxy archives for climate in the Mediterranean region over the last 2000 years. We highlight the need to integrate these different proxy archives and the importance for…
Dynamiques et ruptures dans l'histoire des basses terres mayas. Questions et méthodes à partir du programme " La Joyanca " (Nord-ouest du Petén, Guatemala).
Les résultats qui sont présentés ici sont issus d'un programme ayant un double objectif. D'une part, en relation étroite avec les recherches archéologiques, il s'agissait de préciser la chronologie de l'occupation du site sur la longue durée et de reconstituer l'organisation locale de l'espace à l'époque maya. D'autre part, il a été pris pour hypothèse que l'analyse des formes contemporaines de colonisation pouvait aider, sur la base de la méthode régressive, à reconstituer les logiques agraires passées. Les premières recherches menées dans le nord-ouest du Petén livrent des résultats inattendus et relativement contradictoires. D'un côté, la corrélation entre les études sur les dynamiques c…
Sur les traces d'Erik le Rouge (film et conférence)
International audience
Holocene fire activity during low-natural flammability periods reveals scale-dependent cultural human-fire relationships in Europe
Abstract Fire is a natural component of global biogeochemical cycles and closely related to changes in human land use. Whereas climate-fuel relationships seem to drive both global and subcontinental fire regimes, human-induced fires are prominent mainly on a local scale. Furthermore, the basic assumption that relates humans and fire regimes in terms of population densities, suggesting that few human-induced fires should occur in periods and areas of low population density, is currently debated. Here, we analyze human-fire relationships throughout the Holocene and discuss how and to what extent human-driven fires affected the landscape transformation in the Central European Lowlands (CEL). W…
Observations of land use transformations during the Neolithic using exploratory spatial data analysis: contributions and limitations
International audience; The settlement pattern analysis in archaeology implies some methodological questions. In this paper, we question some issues about the use of geostatistical methods for the observation of land use transformations during the Neolithic. We have developed two examples in Burgundy (France): the first one on a regional scale and the second one on a micro-regional scale. Using different ESDA approaches (Ripley’K function, Nearest Neighbour Distance, Kernel Density Estimation), we would like to underline what the methodological and archaeological contributions and their limits are. Both experiences point out that the results obtained depend not only on the analytical scale,…
Towards America: environmental consequences of the Viking occupation in Greenland.
The impact of Norse occupation in south Greenland: pollen, NPP's and sedimentological analyses from lakes and peat deposits.
Broadleaf deciduous forest counterbalanced the direct effect of climate on Holocene fire regime in hemiboreal/boreal region (NE Europe)
Abstract Disturbances by fire are essential for the functioning of boreal/hemiboreal forests, but knowledge of long-term fire regime dynamics is limited. We analysed macrocharcoal morphologies and pollen of a sediment record from Lake Lielais Svētiņu (eastern Latvia), and in conjunction with fire traits analysis present the first record of Holocene variability in fire regime, fuel sources and fire types in boreal forests of the Baltic region. We found a phase of moderate to high fire activity during the cool and moist early (mean fire return interval; mFRI of ∼280 years; 11,700–7500 cal yr BP) and the late (mFRI of ∼190 years; 4500–0 cal yr BP) Holocene and low fire activity (mFRI of ∼630 y…
Environmental consequences of the Norse occupation in south Greenland: first results of pollen and NPP's data from a peat bog (Qassiarsuk).
Pollen and non-pollen palynomorph evidence of medieval farming activities in southwestern Greenland
International audience; Radiocarbon dating, pollen and non-pollen palynomorph analyses from a lake core were used to establish the timing and effects of farming activities around Lake Igaliku, Eastern Settlement, Greenland. The absence of agro-pastoral impact before the medieval colonization by Europeans provides an opportunity to understand the development of farming activity in a pristine landscape. The results show that the first phase of clearance and grazing pressure, without the expansion of the Norse apophyte (native plant, in habitats created by humans) Rumex acetosa type, could have occurred in the 9–10th century A.D. The presence of Norse settlers and livestock is clearly recorded…
Identification des indices environnementaux d'anthropisation dans la séquence sédimentaire historique du lac d'Igaliko (Groenland)
Palaeoecological and geochemical evidences of early metallurgy in Burgundy (Morvan and Nivernais - France)
Land use change, soil erosion and alluvial dynamic in the lower Doubs Valley over the 1st millenium AD (Neublans, Jura, France)
International audience; Geochemical and particle size analyses, surface scanning magnetic susceptibility, microscopic charcoal counting and pollen analysis, have been carried out on two cores from the lower Doubs valley in order to reconstruct the land use history. The interpretation of anthropogenic pollen indicators and micro-charcoal deposits is discussed in relation to the lithological variation of sedimentary accumulation and evolution of the settlement. The environmental changes which occurred during the 1st and the 6th century AD reflect the impact of human activities on the landscape in the immediate surroundings of the site. Multiproxy indicators indicate that soil erosion as a con…
Contribution to the Holocene North Atlantic wind activity reconstruction from Lake Igaliku, South Greenland
International audience