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projets stratégiques

Les projets stratégiques du CEBA sont la mise en œuvre opérationnelle du programme scientifique. La première phase de projets stratégiques est financée jusqu’à fin 2015 et en 2016, une seconde phase est engagée.

Projets stratégiques 2016-2019

DIAMOND – DIssecting And MONitoring amazonian Diversity

PI: Jérôme Murienne (EDB, Toulouse), Jérôme Orivel (EcoFoG, Kourou)

sp-ceba-2016-diamondCharacterizing biodiversity still remains a challenge, particularly in remote and species-rich tropical regions. The labex CEBA has contributed significantly to a long-term effort in describing biodiversity over the French Guianian territory mainly through the funding of the DIADEMA project. The ambition of the DIAMOND project is to continue this effort and to implement innovative biodiversity monitoring approaches based on environmental DNA. We will also provide a better quantification of the different facets of biodiversity across groups by building an extensive and unprecedented multitaxa biodiversity database for French Guiana. By dissecting the spatial turnover of the taxonomic, phylogenetic and functional components of diversity, we will provide significant advances in our understanding of species distribution and community assemblage. With insight from communities’ dissimilarities across environmental and geographical regions, we will use novel modeling approaches to provide continuous maps of taxonomic, phylogenetic and functional diversity of whole communities across all regions in French Guiana. Finally, the project will also strongly contribute to an effective transfer of knowledge to the scientific community and local stakeholders.

DROUGHT – Functional diversity and response to drought in tropical forests

PI: Damien Bonal (EEF, Nancy)

Bois cathédrale © Damien BonalIn DROUGHT, we want to improve our knowledge on plant interspecific variability in resistance to drought and on the way models simulate tropical forest ecosystem responses to drought. We will combine a series of observational and experimental approaches in order to (i) evaluate the strategies of large sets of tropical trees, lianas and epiphytes to cope with drought (physiological or morphological mechanisms of avoidance or tolerance), (ii) identify trade-offs among functional strategies, (iii) identify the role of biotic factors, including mycorrhizae and endophytes involved in drought avoidance/tolerance strategies, (iv) evaluate drought impact on tropical ecosystem functions, (v) understand drought response patterns at community and ecosystem scale.
Through our research on the vulnerability of tropical plants and ecosystems to drought, we will help providing predictions of future biodiversity and ecosystem functioning under future climatic regimes. Results from DROUGHT will thus not only allow publishing scientific papers, but they will also contribute predicting the future role of these ecosystems in the global carbon balance.
The proposed research addresses some of the most important objectives of Labex CEBA by studying the functional diversity of tropical plants (trees, lianas, epiphytes) (WP2) and interactions among species (plants, mycorrhizae, endophytes) (WP4). It will contribute to improve the links between biodiversity and ecosystem processes through the development of modelling concepts and parameterisations of models in collaboration with modellers, particularly those from the CEBA-METIST strategic project. Furthermore, it will contribute to the Educational issues of CEBA, through the possibilities of training periods offered to M1 and M2 students and seminars/conferences given by CEBA or non-CEBA partners when they will visit French Guiana.

LongTime – LONG Term Impact of ancient AMErindian settlements on Guianese forests

PI: Jean-François Molino (AMAP, Montpellier), Guillaume Odonne (LEEISA)

aap_strategique_ceba2016_longtime_revisedA growing body of archaeological and pedological evidence, accumulated since the 1990s, suggests that Amazonian rainforests might have been much more densely occupied and intensely modified by Amerindian societies before the First Contact than previously thought. These discoveries, by challenging the very existence of “pristine” tropical rainforests, have forced ecologists to consider pre‐industrial human activities as one of the potential drivers influencing biodiversity of Amazonian rainforests. Indeed, several case studies in central and western Amazonia have already confirmed that the impact of ancient Amerindian societies is still locally perceptible in soil and forest composition. Such studies are, however, rare in French Guiana, notwithstanding the presence of all the required skills in both human sciences (archaeology, anthropology, ethnoecology) and environmental sciences (ecology, forestry, pedology). We thus believe that it is time for the CEBA to address this important topic.
The LongTIme project will build on the skills of several complementary CEBA and non‐CEBA teams, including Amerindian experts, to evaluate the influence of past Amerindian societies on present day soils and forest structure, composition and diversity across various temporal and spatial scales. Based on our respective experience and available datasets, we will implement specific protocols for a combined landscape‐scale evaluation of the intensity of past human occupation and of the impact of this occupation on soils and biodiversity patterns. These protocols will be applied during several field missions, during which knowledgeable Amerindians from across French Guiana will be invited to give their own traditional vision of the landscape and of the processes leading to current biodiversity patterns.
We expect substantial mutual benefits from collaborations with the DIAMOND and REKABIOS teams in all project phases, as well as in data analyses and interpretation. Through this novel transdisciplinary approach, as well as with new datasets and publications in all of our scientific fields, LongTIme will contribute to a better understanding of biodiversity patterns in French Guianese rainforests and thus provide key elements for environmental policy makers and for the modeling of forest changes in response to future land use and climate changes.

METIST – Modelling tropical diversity and forest functioning in space and time

PI : Jérôme Chave (EDB, Toulouse), Bruno Hérault (EcoFoG, Kourou)

sp-ceba-2016-metistThere is mounting interest for applying modeling approaches to project future states of biodiversity and ecosystem functions in response to environmental changes. Although these approaches are currently being developed, few of them offer to study both biodiversity and ecosystem functioning facets in a single modeling framework. This is in part because modeling approaches have a different history and have been developed at different spatial scales. Individual-based dynamic forest simulators provide a means to bridge ecosystem-based and biodiversity viewpoints and to assimilate field and remote sensing data efficiently. The need for such integrated models is particularly pressing in tropical forests, as these forests play a pivotal role in the carbon cycle and they are exposed to major risks, such as land-use conversion, climatic changes, and logging. In the METIST project, we propose to (1) develop an individual-based forest dynamic simulator including the carbon, water, and nutrient balances, and including a species-level parameterization of the main plant-level processes for the tropical forest of French Guiana; (2) mobilize high-resolution remote sensing data (aerial LiDAR scanning) to inform plant allometry and canopy structural properties, as well as topographical features; (3) mobilize forest dynamic data to validate the model, implement a forest management module and a forest fire module; (4) as a exercise of the model’s scaling properties, scale-up the simulations to the entire area of French Guiana (c.a. 84,000 km2) making use of recent progress in our understanding of tree species distribution and ecological processes at this scale; (5) provide scenarios to assess the impacts of land use change, forest management and climatic change on selected forest types of French Guiana. The findings of this project should have an impact beyond French Guiana, in other Neotropical forests. It should also provide to the scientific community of Labex CEBA a modeling tool to assimilate information from several research lines (forest ecology, remote sensing, climate science, socioeconomics), and suggest optimal development paths for the coastal forests for regional policy and local managers of natural areas, who are faced with practical challenge of maintaining wood production while protecting biodiversity and carbon stocks.

MicroBIOMES – MICRObial BIOdiversities : Modelling Environments and Strategies

PI : Benoît de Thoisy (IPG, Cayenne), Jean-François Guégan (MIVEGEC, Montpellier)

p1000011The MicroBIOMES program proposes a multidisciplinary approach expected to describe the diversity of microbiomes in vertebrate and arthropod populations and species in French Guiana. Communities’ traits, anthropogenic disturbances and habitat heterogeneity, and their links with both host and microbial species diversity, abundance and persistence, and virulence of the pathogens will be specifically investigated. This research project will rely on several biological models (including viruses, bacteria, micro- and macro-parasites, either with telluric or aquatic, and zoonotic reservoirs) that will act on a complementary way, allowing to investigate the diversity of host/microbial communities, including their pathogen components, at different hierarchical levels of organization and spatial scales, from an intra individual scale (α diversity), to community level (“compound diversity”, or β-diversity), and from a locality, e.g. a pond, a forest habitat, to the regional scale of French Guiana and the Guiana shield. The project MicroBIOMES will (i) explore the adjustments and drivers of diversity between those levels and scales, and (ii) analyse how these host/microbial diversities may be important to consider for health issues.
The research project logically flows i) from the acquisition of new molecular, biological and ecological data, ii) to the development of typical and derived measures of diversity and community structure for microbial communities, iii) to the description of spatial patterns of microbial communities structure and composition, iv) to the theoretical description of processes that shape these microbial communities, and v) finally to the development of mathematical models of infectious disease transmission with the fusion of microbial community characteristics and genome-derived measures of evolutionary relatedness capable of indicating the ecological dynamics of some microbial strains or species en route for generating new pathogens.
Overall, our research project will permit quantification of the forces shaping complex microbial communities in and across different host groups, and it will analyze the role of microbial communities stability and dynamics in the genesis of new pathogen forms.

NEOTROPHYL – Inferring the drivers of Neotropical diversification using an integrative macroevolutionary approach

PI : Frédéric Delsuc (ISEM, Montpellier)

neotrophyl_logoDue to its unique geological history and tropical ecology, the South American biota bears many of the known biodiversity hotspots in the world, including the richest (the Tropical Andes). The establishment of complew riverine systems, the uplift of the Andes, and Cenozoic climatic changes have all influenced Amazonian diversity. Despite an increasing number of evolutionary studies on Neotropical groups, the relative contribution of each factor is still poorly understood. The historical causes and regional determinants remain debated with new hypotheses being regularly put forward. THe ensuing question “What gave rise to the Neotropical rainforest’s staggering biodiversity?” is one of the most debated topics in evolutionary ecology. The debate has mostly focused on the relative contribution of abiotic versus biotic factors driving the Neotropical diversification. On the one hand, the role of historical determinants, extrinsic to species, is supposed to be key in the evolutionary history of regional groups. Changes in the physical environment like the rise of the Andes or the repeated marine transgressions have been paramount int the evolution of regional landscapes, which in turn affected the diversification and biogeography of species. On the other hand, the role of factors that are intrinsic to the species, like life-history traits or dispersal abilities are thought to be more important. For instance, a recent phylogenetic study of Amazonian birds suggested that environmental changes that occured in South America during the Cenozoic did not significantly impact speciation. We postulate that the origin and evolution of the Neotropical biodiversity resulted from a more complex history in which both factors interacted. A statistically sound macroevolutionary perspective integrating how environments changed over time and how species traits evolved is required to identify and understand the triggers of Neotropical biodiversity. The overarching goal of the NEOTROPHYL project is to conduct a series of integrative macroevolutionary analyses aiming at unraveling the biogeographic and diversification patterns that shaped Neotropical biodiversity. NEOTROPHYL will build upon data and results previously obtaines in the PHYLOGUIANAS strategic project, but we will also expland our sampling taxonomically by including new biological models, and geographically by targeting groups with a Panamazonian distribution. NEOTROPHYL will thus consits of analyses performed at fine taxonomic (phylogeographic) scale (genera or species complexes) to ersolve species boundaries and test the role of glacial refugia throughout the Neotropics, and at higher taxonomic (phylogenetic) level (orders and families) to explore historical biogeographic patterns and identify the key drivers of diversification in the Neotropics.

REK-ABIOS – Regime of Knowledge for Amazonian Biodiversity

PI : Yann Bérard (CRPLC, Martinique)

abattis2The aim of this research project is to highlight the regime of production, regulation and appropriation of knowledge for Amazonian biodiversity based on extensive field surveys in two countries of the Guiana Shield: French Guiana and northern Brazil (Amapá, Pará). The concept of regime of knowledge is intended to bring together the modes of knowledge (notions of objectivity and more broadly “the other”, tools and standards of evidence, forms of knowledge validation, hierarchy of the disciplines, etc.) and the modes of government (hierarchy of values, ownership rules, forms of government, role of public authorities, etc.) that characterise the evolution of democratic societies over the long term. The elucidation of this regime in the case of Amazonian biodiversity aims to answer one question that can be therefore summarised as: what knowledge for what policy/policies? This research project hypothesises a plurality of epistemic registers relating to the regime of knowledge for Amazonian biodiversity, which are indigenous, academic and governmental. In this regard, several types of knowledge corresponding to different tools of government are studied in depth: protected areas (biodiversity conservation: zoning, regulations, payments for environmental services); valuation of biodiversity (management, control: regulations, international convention, access and benefit sharing); compensation (ecological engineering, natural asset reserves, certificates of environmental reserve quotas). In order to successfully carry out this programme, the project is based on French and foreign partnerships built around a multidisciplinary research team able to process, through their uniqueness and in a coordinated manner, the various epistemic registers involved in the regime of knowledge for Amazonian biodiversity. Within this perspective, the project aims to answer essential questions for both users of biodiversity and those who characterise or govern it. By focusing on the links between modes of knowledge and modes of government, the project intends to provide a greater contribution to empower the expertise of the stakeholders in order to support: 1) conservation policies and the management of protected areas; 2) valuation and regulation of access to biodiversity in order to implement access to genetic resources and the fair and equitable sharing of benefits arising from their use; 3) the definition of an environmental compensation standard in relation to a sustainable use of natural resources.

Projets stratégiques 2011-2015

DIADEMA – DIssecting Amazonian Diversity by Enhancing a Multiple taxonomic-groups Approach

PI: Christopher Baraloto (UMR EcoFoG, Kourou)

Tropical diversity is extraordinarily high both at local and regional scales, including a significant turnover in species composition across habitats and regions. Yet we still know little about the factors underlying species distributions for most species groups. In particular, the relative roles of historical biogeography, dispersal limitations and abiotic and biotic filters in limiting species distributions remain a subject of debate. As a result, the extent to which local communities are random samples of the regional species pool persists as a fundamental question in tropical ecology. Most studies examining this question have focused on particular species groups, such as plants or amphibians, and these studies alone represent substantial investments. A comparison of local vs regional community structure among species groups in the same region has yet to be attempted, despite the value it would provide to address the mechanisms behind structuration of biodiversity of different groups at different scales, not to mention to identify conservation priorities. The DIADEMA project aims at providing a comprehensive evaluation of tropical biodiversity across broad geographic and environmental gradients in French Guiana. We will integrate data for eight species groups (plants, arthropods, amphibians, large animals, fish, freshwater invertebrates, earthworms and fungi), with the potential to expand pending collaborations with non-CEBA partners. We believe our teams are in a unique position to make this contribution to both basic and applied science given the extensive infrastructure in biodiversity research that has been established in French Guiana over the past decades. The databases and modeling approaches we offer to develop in DIADEMA will contribute to an increased understanding of the factors that influence species turnover in the most diverse ecosystems on earth. Most of the groups on which we focus are critically understudied in the tropics, and no attempt to date has been made to study them simultaneously for the same sites, especially with a well-replicated experimental design. The datasets we have already generated and will continue to assemble will therefore be essential for regional estimates of biodiversity, to assist policy makers to choose protected areas across the region, and to improve models of biodiversity dynamics in response to climate and land use change scenarios.

AMAZOMICS – Genomics of adaptation in Amazonian ecosystems

PI: Ivan Scotti (UMR EcoFoG, Kourou)

The goal of this project is to provide evidence of the genomic effects of adaptive processes in Amazonian ecosystems. The project will address this question in seven biological models in which it is possible to observe disruptive and/or directional selection, and will make use of up-to-date sequencing techniques, statistical analyses and modeling tools to describe and interpret such processes in the light of the processes driving biodiversity patterns. All the case studies will undergo the same kinds of analyses, so that general results will be obtained in spite (and maybe, due to) the diversity of biological models and ecological processes addressed here. Novel modeling tools will be proposed to link genotype, environment, ontogeny, phenotype and fitness in natural populations. This new development, if proven to be reliable, will pave the way towards the generalization of genomic methods to the study of the ecological genetics of natural ecosystems. The proposed project will have the side effect of fostering the emergence of a coherent ecological-evolutionary genetic community centred on the study of biodiversity-generating processes in tropical ecosystems.

BIOHOPSYS – Biodiversity and dynamic interactions in multiple host-parasite systems

PIs: Jean-François Guégan (MIVEGEC Montpellier), Mathieu Nacher (EA EPaT, Cayenne)

The research project BIOHOPSYS aims at investigating the local impacts of environmental changes (e.g. habitat modification, climate change) on zoonotic and vector-borne diseases (nearly 60% of emerging infections), in relation to biodiversity heterogeneity and change. The programme is localized in French Guiana (FG), both a hotspot of biodiversity, particularly at threat due to land use, climate and demographic changes, and a region with high potential risk of zoonotic and vector-borne emerging diseases in the near future. FG is an specifically well suited model to investigate local impacts of environmental changes on the interactions between biodiversity and infectious diseases due to its geographical localization near the equator line and its socio-economical conditions which mirror in part those of a developing country. The objectives of BIOHOPSYS are (1) to analyze five infectious diseases and their hosts in relation to biodiversity modification and environmental change, (2) to model their transmission dynamics according to habitat and ecosystem alteration, climate change and biodiversity loss, and (3) to propose scenarios of disease transmission accordingly. Analyses of local situations and their evolution will help to inform policy-makers and public health authorities on conditions at higher risks for increasing disease transmission and spread in humans.

PHYLOGUIANAS – Biogeography and pace of diversification in the Guiana Shield

PIs: Jérôme Chave (EDB Toulouse), Alain Franc (BioGeCo Bordeaux)

The historical causes and regional determinants of the outstanding Amazonian diversity remain speculative, and the ability of tropical biomes to withstand major environmental changes, poorly known. Predicting how biodiversity will respond to these environmental changes is a major challenge facing ecologists, and a macroevolutionary perspective help understand how environmental changes have affected biodiversity in the past. Here we propose to build on phylogenomics techniques and regional paleoclimatic modeling to bridge a gap in the knowledge of the macroevolutionary patterns for selected lineages in the Guiana Shield. This project will primarily focus on the Guiana Shield, a Precambrian craton within the South American plate which has remained emerged and located around the tropics for the past 200 Myr. We will assemble and compile data for three groups of organisms: harvestmen (Opiliones) in the arthropods, anurans (specifically genus Anomaloglossus), and flowering plants (specifically the tribe Sipaneeae in the Rubiaceae, the Chrysobalanaceae and the Caryocaraceae). Fully resolved phylogenetic trees will be constructed using state of the art techniques in phylogenomics. The past 100 Ma of climatic changes in South America will be modelled using regional models and reconstructed topography. Finally, this unique information will be used to address the three following questions: (1) what proportion of the Guiana Shield lineages are likely to have arisen in situ, versus those that may have arisen elsewhere in the Neotropics and subsequently dispersed toward the Guiana Shield? (2) How old are the Guianan lineages and are they older or younger than other Neotropical lineages (and what role may the Tertiary/Quaternary climate history have played in the diversification of Amazonian lineages)? (3) Which proportion of species and lineages show major break points in their distributions (putative areas of vicariance) in this region? Through the quality of the field sampling, a network of experienced collaborating taxonomists and novel techniques, we hope to bring a renewed perspective to the patterns of diversification in the Guiana Shield. We also hope to foster a renewed interest for a region of great importance in biogeography and conservation biology, within the frame of Labex CEBA.

FUN-CHEM – FUNctional CHEModiversity

PIs: Didier Stien (ICSN Gif-sur-Yvette), Christophe Duplais (UMR EcoFoG, Cayenne)

Within 7 operational WP, the FUN-CHEM project will dissect interspecific molecular interaction processes in the Amazon. The general concept is to look at chemical diversity in a new light, using innovative approaches and methodologies. In the end, FUN-CHEM will identify functional compounds and will therefore contribute to the understanding of ecosystem functioning. Eventually, FUN-CHEM will also attempt to discover valorisation paths for the most active/promising natural products.

ABIOS – Amazonian Biodiversity in Society

PI: Yann Bérard (CRPLC, Martinique)

The ABIOS project is aimed at creating an active community of humanities and social science researchers, interacting with other naturalist sections of the CEBA, developing and funding studies in specific areas representative for the various meanings of the concept of biodiversity in French Guiana. For a naturalistic approach, French Guiana’s biodiversity is outstanding and relatively well preserved. However, French Guiana is also confronted with significant demographic, economic, urban, agricultural and climate changes, leading to the devising of a set of institutional responses for the sustainable management of natural resources. In this context, it is important to understand how and why biodiversity is mobilized to achieve political, legal and economic objectives, what the required representations and data are, what the favoured methods for managing it are, and how the results of scientific research on biodiversity are interpreted and used. To answer these questions, the scientific team built for the ABIOS project develops an ambitious and innovative research programme that takes into account the plurality of representations applied to French Guiana’s biodiversity and to the methods for managing it: whether this is considered as restrictive (e.g. oppositions to the Parks or the bioprospection framework) or as creating development opportunities (e.g. hopes placed in the genetic resources and carbon markets). In this view, the methodology selected is meant to be resolutely pragmatic, comparative and transferable to other territories or regional areas. On a broader level, the creation of the CEBA presents the humanities and social science with an opportunity to create a scientific community of international standing through naturalist programmes, able to provide insight and concrete keys to understanding the challenges raised by the global changes which French Guiana is currently experiencing. By this, the ABIOS project also aims at embracing the stakeholders’ expertise in order to support, among others, the implementation of genetic resources and benefit-sharing (ABS), the reduction of emissions from deforestation and forest degradation (REDD+), the management of protected areas and natural resources, public policy planning or research support priorities.