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International audience; . Trees are known to emit methane (CH4) and nitrous oxide (N2O), with tropical wetland trees being considerable CH4 sources. Little is known about CH4 and especially N2O exchange of trees growing in tropical rain forests under nonflooded conditions. . We determined CH4 and N2O exchange of stems of six dominant tree species, cryptogamic stem covers, soils and volcanic surfaces at the start of the rainy season in a 400-yr-old tropical lowland rain forest situated on a basaltic lava flow (R eunion Island). We aimed to understand the unknown role in greenhouse gas fluxes of these atypical tropical rain forests on basaltic lava flows. . The stems studied were net sinks for atmospheric CH4 and N2O, as were cryptogams, which seemed to be co-responsible for the stem uptake. In contrast with more commonly studied rain forests, the soil and previously unexplored volcanic surfaces consumed CH4. Their N2O fluxes were negligible. . Greenhouse gas uptake potential by trees and cryptogams constitutes a novel and unique finding, thus showing that plants can serve not only as emitters, but also as consumers of CH4 and N2O. The volcanic tropical lowland rain forest appears to be an important CH4 sink, as well as a possible N2O sink.

International audience; Biodiversity is a key player in ecosystem characteristics and dynamics. Acting as a driver, italso results from ecosystem functioning. Understanding this complex interplay betweenbiological and physical components is one of the main current challenges in the context of landuse changes and climate warming. The acquisition of knowledge on biodiversity requiresmultidisciplinary approaches and mobilises numerous research teams. Data are collected orcomputed in large quantity but are most often poorly standardised and therefore heterogeneous.In this context the development of semantic interoperability is a major challenge for the sharingand reuse of these data. This objective is implemented within the framework of the AnaEE(Analysis and Experimentation on Ecosystems) Research Infrastructure dedicated toexperimentation on ecosystems and biodiversity. A distributed Information System (IS) isdeveloped, based on the semantic interoperability of its components using commonvocabularies (AnaeeThes thesaurus and OBOE-based ontology extended for disciplinaryneeds) for modelling the studied system. This modelling covers the measured variablesincluding biodiversity, as well as the different components of the experimental or observationalcontext, from sensor to plot and network. Driven by the ontology, the approach relies on theatomic decomposition of each of the components into observed entities, their characteristicsand qualifiers, their units or naming standards. The modelling of the system allows the semanticannotation of relational databases or flat files for the production of URIs based graph databases.A first pipeline automates the annotation process and the production of the semantic data. Asecond pipeline is devoted to the exploitation of these semantic data by generating i) metadatarecords formatted according to the geospatial extension for the Data Catalog Vocabularystandard and the ISO 19139 standard, and ii) Network Common Data Form data files. Theimplementation of this integrated semantic management of data is presented here for phytoand zoo-plankton data collected from water columns in Lake Geneva over a 30 years period,as well as for environmental data about water temperature and nutrients. The work carried outcontributes to the development and use of semantic vocabularies within the biodiversity andecology research community, leading to semantically enriched metadata records andinteroperable data sets. The genericity of the tools make them usable in different contexts ofdata production, management and ontologies involved in semantic modelling.

International audience; The study of ecosystem functioning requires multidisciplinary approaches and mobilises numerous research teams. The data produced are very abundant but their reuse and integration is often difficult due to their low level of standardisation. The development of semantic interoperability is a major challenge for the sharing and reuse of these data. This objective is implemented within the framework of the AnaEE research infrastructure dedicated to experimentation on ecosystems. The modelling of the experimental system is based on the OBOE ontology extended for disciplinary needs. It covers the measured variables, the different components of the experimental context, from sensor and plot to network, by the atomic decomposition of the observed entities, their characteristics and their qualification, the units and naming standards. This modelling allows the semantic annotation of relational databases and flat files for the production of graph databases. Carried out on all the data generated by the experimental platforms, this practice produces semantically interoperable data that meets the linked opendata standards. The work carried out contributes to the development and use of semantic vocabularies within the ecology research community.

International audience; The AnaEE (Analysis and Experimentation on Ecosystems, ESFRI) Research Infrastructure offers experimental facilities for studying ecosystems and biodiversity. A distributed Information System (IS) is developed, based on semantic interoperability of its components and the use of common vocabularies (AnaeeThes thesaurus and an OBOE-basedontology). Discovery and access portals are fed by information (rdf triples) produced by the semantic annotation of AnaEE distributed resources: relational databases and modeling platforms. A first pipeline is developed for the automation of the annotation process and the production of the semantic data, annotation that may represent a huge conceptual and practical work. A second pipeline is devoted to the exploitation of these semantic data through the generation i) of standardized ISO and GeoDCAT metadata records and ii) of data files (NetCDF format) from selected perimeters (experimental sites, years, experimental factors, measured variables...). Genericity of the tools make them usable in different contexts of ontologies and databases.

International audience; This study tested the possible root biomass improvements in crop rotations after the conversion of grasslands, and crop samples from maize, winter wheat, and winter barley were collected during 2011-2013 from a long-term experimental site in Lusignan, France (http://www.soere-acbb). Root biomass C quantification was performed using delta C-13 isotopic signatures to determine the presence of both C3 and C4 plants. We also calculated the recovery rate of maize root biomass C. The results showed that after crop rotations, 0-60 cm root biomass C values were 44.1, 34.2, and 18.7 g C m(-2) for maize, winter wheat, and winter barley respectively. The Root biomass C of crops after conversion to grassland was approximately 2-3 times those observed after crop rotations. However, incorporating ley grassland duration into crop rotations showed limited improvements in shoot biomass C and grain yield of the crops, regardless of the decreased rate of N fertilizer for maize. Moreover, root biomass C had a significant relationship with N supply from residues (P

The AnaEE France (Analysis and Experimentation on Ecosystems) Research Infrastructure offers experimental facilities for studying ecosystems and biodiversity. The data generated by the AnaEE platforms are most often managed in relational databases and their interoperability is one of the major challenge.Pipelines were developped for the automation of the production and exploitation of RDF data from platform databases. They exploit semantic vocabularies (AnaeeThes thesaurus and an ontology based on OBOE) and enable data interoperability., AnaEE-France offre des services distribués d'expérimentation sur les écosystèmes continentaux. La gestion des données produites par ces plateformes constitue un enjeu majeur. Des pipelines sont développés pour l'automatisation de la production et de l'exploitation de données rdf à partir des bases de données des plateformes. Ils exploitent des référentiels sémantiques (thésaurus AnaeeThes et une ontologie basée sur OBOE) et permettent l'interopérabilité des données.