Laurent Bremond

Laurent Bremond
Ecole Pratique des Hautes Etudes | EPHE · UMR Centre of Bio-Archeology and Ecology

Phd Lecturer EPHE

About

98
Publications
18,436
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
2,366
Citations
Introduction
• Understand and determine the environmental constraint (climate, soil, human impact) on the vegetation distributions and functioning, • Develop the used of vegetation marker such as phytoliths, pollen and charcoals to quantified the vegetation and perturbation changes in term of long-term ecology, • Improve predictive vegetation models by comparing with fossils vegetation proxies,
Additional affiliations
January 2008 - present
French National Centre for Scientific Research
Education
September 2000 - December 2003
Aix-Marseille Université
Field of study
  • geosciences

Publications

Publications (98)
Article
Full-text available
Quaternary climatic changes have been invoked as important drivers of species diversification worldwide. However, the impact of such changes on vegetation and animal population dynamics in tropical regions remains debated. To overcome this uncertainty, we integrated high-resolution paleoenvironmental reconstructions from a sedimentary record coveri...
Article
Full-text available
The recovery and identification of wood charcoals from soil not associated to archaeological excavation is called pedoanthracology. Researchers in this field use different sampling methods, and only one study, in a temperate context, has compared their efficiency so far. In this paper, we compare the efficiency of three sampling methods on charcoal...
Article
Holocene paleoecological studies in tropical Africa are rare because most lakes either dried out at the termination of the African Humid Period or have since filled up. However, tropical sedge marshes can be an alternative to perform long-term ecological studies. The Lopé National Park (LNP) in Gabon is a mosaic of forest and savanna enclosed in th...
Article
Understanding processes that explain phytolith assemblages and their concentration in the soil and sediments is essential to interpret long-term ecological changes. The present study shows modern phytolith assemblages and their relationship with the vegetation cover in the Caatinga biome, state of Ceará, northeastern Brazil. We collected recent sam...
Article
Full-text available
A multi-proxy study on a sediment core from Pedro Palo Lake, a mid-altitude endorheic Andean Lake in northern South America, was carried out to understand the effects of human activities and climate variability on tropical mountain freshwater ecosystems. Results indicate that between ~ 7980 and 4110 cal year BP the lake maintained well-mixed, mesot...
Chapter
Full-text available
Known as anthracology, the study and identification of buried wood charcoal helps to reconstruct past environments and landscapes, as well as wood and land uses. The chronology of fires and human activities can be assessed by radiocarbon dating of charcoal pieces. Born in Europe, anthracology has been increasingly used in the tropics for the last t...
Article
Full-text available
In Amazonia, a growing body of studies has shown that rainforests were affected by human occupation in many areas during pre-Columbian times, inducing changes in their floristic compositions. The northern part of Amazonia, and in particular the Guiana Shield, is much less studied, although past human occupations have also been documented in this re...
Article
In the Congo Basin, paleoenvironmental data are scarce, due to the lack of natural lakes. Using marshes sedimentary deposits as alternative archives requires the calibration of modern pollen assemblages, which are totally absent for these type of deposits. The aim of this study is to understand and qualify how well surface marsh sediment pollen ass...
Article
The northeastern region of Brazil is the most densely populated and biodiverse semi-arid regions of the planet. Effects of the natural climate variability and colonization on the landscape have been described since the beginning of the 16th century but little is known about their effects on natural resources. Climate projections predict temperature...
Article
The Earth has experienced large changes in global and regional climates over the past one million years. Understanding processes and feedbacks that control those past environmental changes is of great interest for better understanding the nature, direction and magnitude of current climate change, its effect on life, and on the physical, biological...
Article
Full-text available
Tropical tree floras are highly diverse and many genera and species share similar anatomical patterns, making the identification of tropical wood charcoal very difficult. Appropriate tools to characterize charcoal anatomy are thus needed to facilitate and improve identification in such species-rich areas. This paper presents the first computer-aide...
Article
Full-text available
Patterns of fire are changing across African savannahs, rainforests, fynbos, woodlands, and Afroalpine and montane forests, with direct environmental and socio-ecological consequences. Fire variability has implications for biodiversity (Beale et al. 2018), vegetation patterns, grazing quality, carbon emissions, protected area management, and landsc...
Article
Cet article présente les résultats d'analyses de la variation des assemblages de diatomées le long de la carotte prélevée dans le marais Paurosa (0°12'47,4'S; 11°35'19,3' E) qui se trouve dans une mosaïque forêt-savane au Nord du Parc National de la Lopé au Gabon. Les données obtenues ont permis de reconstruire l'histoire paléohydrologique de ce ma...
Article
Until now, sedimentary DNA (sedDNA) studies have only focused on cold and temperate regions were DNA is relatively well preserved. Consequently, the tropics, where vegetation is hyperdiverse and natural archives are rare, have been neglected and deserve attention. In this study, we used next-generation sequencing to barcode sedDNA from Lake Sele, l...
Article
Full-text available
Tree cover is a key variable for ecosystem functioning, and is widely used to study tropical ecosystems. But its determinants and their relative importance are still a matter of debate, especially because most regional and global analyses have not considered the influence of agricultural practices. More information is urgently needed regarding how...
Data
Age estimations of the trees at the mode of the diameter distribution for the four genera that are monospecific in the SRI. The mode of the diameter distribution across the SRI, information on growth data, including number of trees (n), the diameter (dbh) range and the mean and standard error of the annual diameter increment (SE), and age estimatio...
Data
Age data for the four study species based on published tree-ring data. Mean ages and corresponding estimated dates are shown in Figure 2 (Main Text). C = Cameroon; RC = Republic of the Congo; CAR = Central African Republic; n = number of stem discs. DOI: http://dx.doi.org/10.7554/eLife.20343.010
Data
Relative performance of commonly used growth models for the four genera that are monospecific in the SRI. Growth model functions used to analyze the variation in tree growth (MAId, in cm.yr−1) with tree size (DBH, in cm) are detailed below. For the biological interpretation of parameters, Max is the maximum growth or growth optimum (in cm.yr−1), Do...
Data
Data documenting paleoenvironmental changes (Figures 1 and 3, Main Text) during the last 1000 years in the SRI. C = Cameroon; RC = Republic of the Congo; CAR = Central African Republic; W Africa = West Africa. Numbers refer to the map (Figure 1 Main Text). References are indicated. DOI: http://dx.doi.org/10.7554/eLife.20343.012
Data
Chronology of the historical events from the beginning of the 15th century to the present occurring or influencing human populations in the SRI. Precise dates or time spans are related to local or more general events. References are indicated. DOI: http://dx.doi.org/10.7554/eLife.20343.015
Data
Trait information and characteristics of the diameter distribution for the 176 study genera across the SRI. Botanical family was extracted from the African Plant Database of the Conservatoire et Jardin botaniques de la Ville de Genève and South African National Biodiversity Institute, Pretoria (http://www.ville-ge.ch/musinfo/bd/cjb/africa/recherche...
Data
Synthesis of the 63 AMS radiocarbon and the two OSL dates documenting human activities (Figure 3 Main Text) during the last 1000 years in the SRI. C = Cameroon; RC = Republic of the Congo; CAR = Central African Republic; AA = AMS Laboratory, University of Arizona (USA); Beta = Beta Analytic (USA); Erl = Erlangen AMS Facility (Germany); Gif = Gif-su...
Data
SQL codes for the Bayesian analysis of the radiocarbon dates. DOI: http://dx.doi.org/10.7554/eLife.20343.014
Article
Full-text available
The populations of light-demanding trees that dominate the canopy of central African forests are now aging. Here, we show that the lack of regeneration of these populations began ca. 165 ya (around 1850) after major anthropogenic disturbances ceased. Since 1885, less itinerancy and disturbance in the forest has occurred because the colonial adminis...
Article
Sedimentological and geochemical analyses and 14C dating were performed for a sedimentary core sample from the Lopé 2 marsh in the northern zone of Gabon's Lopé National Park. The results produced a division of the core sample into three main units. The basal part of the core sample was dated to 2,320 years cal BP. At this time, the Lopé 2 marsh wa...
Article
The tropical moist forests (TMF) of the Congo Basin are extremely diverse in terms of structure and functional diversity. Previous paleoecological work suggests that these forests have experienced dramatic changes over the last millennia, related to climate or humans. These disturbances still influence today's repartition of forests and savannas as...
Article
Surface soil samples were collected in three mountainous massifs in north-eastern Brazil to characterize the different vegetation types according to their respective pollen assemblages. Complementary approach between pollen and vegetation data shows that the pollen rain accurately reflects the following three main forest types: i) a dense ombrophil...
Article
Full-text available
The Colônia Deep Drilling Project held its first International Continental Scientific Drilling Program (ICDP) workshop in September 2014 at the University of São Paulo (Brazil). Twenty-seven experts from six countries discussed the feasibility and the expectations of a deep drilling in the structure of Colônia located at the southwestern margin of...
Presentation
Full-text available
Review of the events that happened in the northern Congo basin during the last 1,000 yr. Positive impact of human disturbances on the regeneration of light-demanding trees. Negative impact of the European colonization and following events on human populations and tree regeneration.
Poster
Full-text available
We aim to improve our knowledge of the dynamic of the vegetation in Central Africa during the last 5 kyrs and to discuss the main hypothesis described in the literature - humans versus climatic impacts - both suggested as responsible of the Congo basin rainforest decline observed between 3 and 2.5 kyrs. We use the carbon isotopic composition of wel...
Poster
Full-text available
The canopy of central African moist forests is dominated by light-demanding trees. Most of these species show a distribution of diameters that indicates a regeneration shortage. Here we show through the combined analysis of botanical, palaeoecological, archaeological and historical data that most of these trees are not older than ca. 180 years. Thi...
Poster
Full-text available
In palaeoenvironmental studies, charred botanical remains have rarely been identified to the species level before being sent to radiocarbon dating. Moreover, the age of most tropical spp. and thereby the age of the carbon sequestered during plant growth is not known. Dating unidentified charred wood in the tropics should be thus treated with cautio...
Poster
Full-text available
Wood charcoals are often uncovered in the soils of the tropical regions. They remain little studied, however, and this observation is even truer for charcoals coming from the dense humid forests of Central Africa. Here we aim at showing the interest of the analysis of soil charcoals in this region so as to understand the dynamics of past forest env...
Book
Full-text available
http://www.cnrs.fr/fr/pdf/inee/prospective-eco-tropicale/#/1/
Article
A multidating approach was carried out on slackwater flood deposits, preserved in valley side rock cave and terrace, of the Gardon River in Languedoc, southeast France. Lead-210, caesium-137, and geochemical analysis of mining-contaminated slackwater flood sediments have been used to reconstruct the history of these flood deposits. These age contro...
Conference Paper
Full-text available
Recently, several authors gathered data about the presence of past human populations in tropical regions covered by dense forest nowadays. In central Africa, there is a growing body of evidence for past human settlements along the Atlantic coast, but very little information is available further inland. In this perspective, soil records seem to be t...
Conference Paper
Full-text available
In comparison with the wood charcoals uncovered in the soils of the temperate regions, charcoals from the tropical regions remain little studied yet, in particular those from the dense humid forests of Central Africa. Here we aim at showing the interest of the analysis of soil charcoals so as to understand the current environments through some exam...
Conference Paper
Full-text available
Tropical forests are not believed as pristine anymore. Their structure and specific composition are induced by past climatic and human disturbances over years. In the African moist forests, the emergent trees are mainly light-demanding. These trees are considered to derive from the recent disturbances of the last centuries. Most of them are exploit...
Data
Our research shows that tropical forests of Central Africa are highly diverse: some are very dynamic and more or less disturbed, others are less so; some have a great diversity of trees, others very little. This variety is the wealth of the second largest rainforest in the world and explains its potential to react differently to different anthropog...
Article
Full-text available
In the last decade, the myth of the pristine tropical forest has been seriously challenged. In central Africa, there is a growing body of evidence for past human settlements along the Atlantic forests, but very little information is available about human activities further inland. In this study, we aimed at determining the temporal and spatial patt...
Article
Full-text available
Fires have played an important role in creating and maintaining savannas over the centuries and are also one of the main natural disturbances in forests. The functional role of fires in savannas and forests can be investigated through examining sedimentary charcoal in order to reconstruct long-term fire history. However, the relationship between ch...
Poster
Full-text available
La forêt tropicale africaine a longtemps été considérée comme vierge du passage de l’homme. Cependant, plusieurs études récentes en paléoécologie et archéologie ont démontré la présence d’activités humaines anciennes à partir d’indices paléoenvironnementaux (i.e. pollens de plantes anthropophiles) et d’artefacts (i.e. tessons de céramique). Ces étu...
Article
Full-text available
To examine the climate of the mid Holocene and early human settings in the Andes when the Altiplano was recording the most arid phase of the Holocene, we analysed plant-related proxies (pollen, phytoliths, diatoms, stable isotopes) from a sediment core sampled at high elevation in the Eastern Cordillera of Bolivia. Our study was carried out in the...
Article
So far, no phytolith extraction protocols have been tested for accuracy and repeatability. Here we aim to display a phytolith extraction method combining the strengths of two widely used protocols, supplemented with silica microspheres as exogenous markers for quantifying phytolith concentrations. Phytolith concentrations were estimated for samples...
Article
Full-text available
Testate amoebae that inhabit peat are sensitive indicators of water table position. In this study, we used testate amoebae in sediments from a mire in the western Alps (Lac du Thyl) to: (1) reconstruct the hydrology of the site over the last 7,000 years, (2) determine how hydrological changes affected testate amoebae diversity and (3) infer past tr...
Article
Full-text available
Wildfire activity in North American boreal forests increased during the last decades of the 20th century, partly owing to ongoing human-caused climatic changes. How these changes affect regional fire regimes (annual area burned, seasonality, and number, size, and severity of fires) remains uncertain as data available to explore fire-climate-vegetat...
Article
Aim To describe patterns of tree cover in savannas over a climatic gradient and a range of spatial scales and test if there are identifiable climate-related mean structures, if tree cover always increases with water availability and if there is a continuous trend or a stepwise trend in tree cover. Location Central Tropical Africa. Methods We compar...
Article
Changes in C4 grass distribution and abundance are frequently observed in Quaternary, Holocene and future environmental-change scenarios. However, the factors driving these dynamics are not fully understood, and conflicting theories have been reported. In this paper, we present a very large dataset of modern altitudinal distribution profiles of C3...
Conference Paper
Long-term ecological records are essential to understanding past responses of vegetation to climate change and human activity. As part of a multi-disciplinary project (Coforchange), we undertook research into the past conditions that prevailed during the Holocene in a region that currently holds the world's second largest rainforest. Tropical Moist...