Éditeur(s) : HAL CCSD European Geosciences Union
Résumé : International audience
Measurements of branch xylem density, D_x, were made for 1466 trees representing 503 species, sampled from 80 sites across the Amazon basin. Measured values ranged from 240 kg m^?3 for a Brosimum parinarioides from Tapajos in West Pará, Brazil to 1130 kg m^?3 for an Aiouea sp. from Caxiuana, Central Pará, Brazil. Analysis of variance showed significant differences in average D_x across the sample plots as well as significant differences between families, genera and species. A partitioning of the total variance in the dataset showed that geographic location and plot accounted for 33% of the variation with species identity accounting for an additional 27%; the remaining "residual" 40% of the variance accounted for by tree to tree (within species) variation. Variations in plot means, were, however, hardly accountable at all by differences in species composition. Rather, it would seem that variations of xylem density at plot level must be explained by the effects of soils and/or climate. This conclusion is supported by the observation that the xylem density of the more widely distributed species varied systematically from plot to plot. Thus, as well as having a genetic component branch xylem density is a plastic trait that, for any given species, varies according to where the tree is growing and in a predictable manner. Exceptions to this general rule may be some pioneers belonging to Pourouma and Miconia and some species within the genera Brosimum, Rinorea and Trichillia which seem to be more constrained in terms of this plasticity than most species sampled as part of this study.
ISSN: 1810-6277

hal-00298004
https://hal.archives-ouvertes.fr/hal-00298004
https://hal.archives-ouvertes.fr/hal-00298004/document
https://hal.archives-ouvertes.fr/hal-00298004/file/bgd-5-2003-2008.pdf

Éditeur(s) : HAL CCSD Wiley Open Access
Résumé : Biodiversity continues to decline in the face of increasing anthropogenic pressures such as habitat destruction, exploitation, pollution and introduction of alien species. Existing global databases of species' threat status or population time series are dominated by charismatic species. The collation of datasets with broad taxonomic and biogeographic extents, and that support computation of a range of biodiversity indicators, is necessary to enable better understanding of historical declines and to project - and avert - future declines. We describe and assess a new database of more than 1.6 million samples from 78 countries representing over 28,000 species, collated from existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world. The database contains measurements taken in 208 (of 814) ecoregions, 13 (of 14) biomes, 25 (of 35) biodiversity hotspots and 16 (of 17) megadiverse countries. The database contains more than 1% of the total number of all species described, and more than 1% of the described species within many taxonomic groups - including flowering plants, gymnosperms, birds, mammals, reptiles, amphibians, beetles, lepidopterans and hymenopterans. The dataset, which is still being added to, is therefore already considerably larger and more representative than those used by previous quantitative models of biodiversity trends and responses. The database is being assembled as part of the PREDICTS project (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems - ). We make site-level summary data available alongside this article. The full database will be publicly available in 2015.
ISSN: 2045-7758

hal-01204216
https://hal.archives-ouvertes.fr/hal-01204216
DOI : 10.1002/ece3.1303
PRODINRA : 280886

Éditeur(s) : HAL CCSD
Résumé : International audience
Cumulative human impacts have led to the degradation of marine ecosystems and thedecline of biodiversity in the European and contiguous seas. Effective conservationmeasures are urgently needed to reverse these trends. Conservation must entail societalchoices, underpinned by human values and worldviews that differ between the countriesbordering these seas. Social, economic and political heterogeneity adds to the challenge ofbalancing conservation with sustainable use of the seas. Comprehensive macro-regionalcoordination is needed to ensure effective conservation of marine ecosystems andbiodiversity of this region. Under the European Union Horizon 2020 framework programme,the MarCons COST action aims to promote collaborative research to support marinemanagement, conservation planning and policy development. This will be achieved bydeveloping novel methods and tools to close knowledge gaps and advance marineconservation science. This action will provide support for the development of macro-regional and national policies through six key actions: to develop tools to analysecumulative human impacts; to identify critical scientific and technical gaps in conservationefforts; to improve the resilience of the marine environment to global change and biologicalinvasions; to develop frameworks for integrated conservation planning across terrestrial,freshwater, and marine environments; to coordinate marine conservation policy acrossnational boundaries; and to identify effective governance approaches for marine protectedarea management. Achieving the objectives of these actions will facilitate the integration ofmarine conservation policy into macro-regional maritime spatial planning agendas for theEuropean and contiguous seas, thereby offsetting the loss of biodiversity and ecosystemservices in this region.
Research Ideas and Outcomes

hal-01474085
https://hal-univ-perp.archives-ouvertes.fr/hal-01474085
https://hal-univ-perp.archives-ouvertes.fr/hal-01474085/document
https://hal-univ-perp.archives-ouvertes.fr/hal-01474085/file/RIO_article_11884.pdf
DOI : 10.3897/rio.3.e11884

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
White-sand forests are thought to host many ectomycorrhizal fungi, as demonstrated by the numerous fruiting body collections made by Rolf Singer in the lower Rio Negro in the late 1970s. Despite recognition of the importance of ectomycorrhizal fungi in white-sand forests, there has not yet been a systematic examination of diversity and taxonomic composition across white-sand forests, or more widely across lowland Amazonian forests. In an effort to broaden our view of ectomycorrhizal fungal diversity and distribution on white-sand forests, we collected ectomycorrhizal fruiting bodies in 10 plots of white-sand forests in Brazil and French Guiana between 2012 and 2014. We collected 221 specimens and 62 morphospecies, from the 10 plots, confirming that all studied white-sand forests host ectomycorrhizal fungi. Additionally, we searched for taxa associated with white sands among specimens deposited in Brazilian herbaria. We report 1006 unique ectomycorrhizal specimen records in 18 Brazilian herbaria, of which 137 specimens and 64 species are reported from white-sand forests, mainly in the state of Amazonas, Brazil. Russulaceae and Amanitaceae were frequent in all habitats, and Cortinarius were more frequent on white sands. Our results highlight the high diversity and heterogeneity of ectomycorrhizal communities on white-sand forests, and the wide distribution of ectomycorrhizal fungi throughout Brazil, irrespective of soil type.
Florestas em solos arenosos são consideradas como hospedeiras de muitos fungos ectomicorrízicos (EM), como demonstrado pelas numerosas coletas feitas por Rolf Singer na região do Rio Negro, Amazonas, no final dos anos 70. Apesar do reconhecimento da importância dos fungos ectomicorrízicos em florestas em solos arenosos, não houve nenhum estudo sistemático da diversidade e da composição taxonômica nas florestas em solos arenosos ou mesmo mais amplamente nas terras baixas da Floresta Amazônica. Para ter uma visão global da diversidade e da distribuição de fungos EM em florestas em solos arenosos, foram coletados basidiomas desses fungos em 10 parcelas de florestas em solos arenosos no Brasil e na Guiana Francesa entre 2012 e 2014. Além disso, uma busca foi feita por espécimes depositados em herbários brasileiros que tinham a informação de serem coletas feitas em solo arenoso. Nas 10 parcelas amostradas foram coletados 221 espécimes e 62 morfoespécies, o que confirma que todas as florestas em solos arenosos hospedam fungos EM. Recuperamos 1006 espécimes registrados em 18 herbários brasileiros, dos quais 137 espécimes e 52 espécies são registros de florestas em solos arenosos principalmente no estado do Amazonas, Brasil. Russulaceae e Amanitaceae foram frequentes em todos os habitats e Cortinarius foi o táxon mais frequente em solo arenoso. Os resultados apresentados enfatizam a alta diversidade e heterogeneidade das comunidades de EM em florestas em solos arenosos, assim como a ampla distribuição de fungos em todo o Brasil, não exclusivamente em florestas em solos arenosos.
ISSN: 0006-3606

hal-01278423
https://hal-sde.archives-ouvertes.fr/hal-01278423
DOI : 10.1111/btp.12297

Éditeur(s) : HAL CCSD Wiley/Blackwell
Résumé : 4 pages
International audience
This article documents the addition of 268 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Alburnoides bipunctatus, Chamaerops humilis, Chlidonias hybrida, Cyperus papyrus, Fusarium graminearum, Loxigilla barbadensis, Macrobrachium rosenbergii, Odontesthes bonariensis, Pelteobagrus vachelli, Posidonia oceanica, Potamotrygon motoro, Rhamdia quelen, Sarotherodon melanotheron heudelotii, Sibiraea angustata, Takifugu rubripes, Tarentola mauritanica, Trimmatostroma sp. and Wallago attu. These loci were cross-tested on the following species: Alburnoides fasciatus, Alburnoides kubanicus, Alburnoides maculatus, Alburnoides ohridanus, Alburnoides prespensis, Alburnoides rossicus, Alburnoides strymonicus, Alburnoides thessalicus, Alburnoides tzanevi, Carassius carassius, Fusarium asiaticum, Leucaspius delineatus, Loxigilla noctis dominica, Pelecus cultratus, Phoenix canariensis, Potamotrygon falkneri, Trachycarpus fortune and Vimba vimba.
ISSN: 1755-098X

hal-00823716
https://hal.archives-ouvertes.fr/hal-00823716
DOI : 10.1111/1755-0998.12095
PUBMED : 23521844

Éditeur(s) : HAL CCSD American Association for the Advancement of Science
Résumé : The biodiversity-productivity relationship (BPR) is foundational to our understanding of the global extinction crisis and its impacts on ecosystem functioning. Understanding BPR is critical for the accurate valuation and effective conservation of biodiversity. Using ground-sourced data from 777,126 permanent plots, spanning 44 countries and most terrestrial biomes, we reveal a globally consistent positive concave-down BPR, showing that continued biodiversity loss would result in an accelerating decline in forest productivity worldwide. The value of biodiversity in maintaining commercial forest productivity alone-US$166 billion to 490 billion per year according to our estimation-is more than twice what it would cost to implement effective global conservation. This highlights the need for a worldwide reassessment of biodiversity values, forest management strategies, and conservation priorities.
ISSN: 0036-8075

hal-01607784
https://hal.archives-ouvertes.fr/hal-01607784
DOI : 10.1126/science.aaf8957
PRODINRA : 389856

Éditeur(s) : HAL CCSD eLife Sciences Publication
Résumé : When 2 Mha of Amazonian forests are disturbed by selective logging each year, more than 90 Tg of carbon (C) is emitted to the atmosphere. Emissions are then counterbalanced by forest regrowth. With an original modelling approach, calibrated on a network of 133 permanent forest plots (175 ha total) across Amazonia, we link regional differences in climate, soil and initial biomass with survivors' and recruits' C fluxes to provide Amazon-wide predictions of post-logging C recovery. We show that net aboveground C recovery over 10 years is higher in the Guiana Shield and in the west (21 +/- 3 Mg C ha(-1)) than in the south (12 +/- 3 Mg C ha(-1)) where environmental stress is high (low rainfall, high seasonality). We highlight the key role of survivors in the forest regrowth and elaborate a comprehensive map of post-disturbance C recovery potential in Amazonia.
ISSN: 2050-084X

hal-01606806
https://hal.archives-ouvertes.fr/hal-01606806
DOI : 10.7554/eLife.21394
PRODINRA : 389858

Éditeur(s) : HAL CCSD
Résumé : International audience
VIth Southern Connection Congress
Bariloche, Argentina

hal-01115100
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01115100

Éditeur(s) : HAL CCSD
Résumé : National audience
7èmes Journées Scientifiques du CNFRA
Paris, France

hal-01111171
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01111171

Éditeur(s) : HAL CCSD Wiley
Résumé : Over the past three decades, many small-scale floristic studies of white-sand forests across the Amazon basin have been published. Nonetheless, a basin-wide description of both taxonomic and phylogenetic alpha and beta diversity at regional scales has never been achieved. We present a complete floristic analysis of white-sand forests across the Amazon basin including both taxonomic and phylogenetic diversity. We found strong regional differences in the signal of phylogenetic community structure with both overall and regional Net Relatedness Index and Nearest Taxon Index values found to be significantly positive leading to a pattern of phylogenetic clustering. Additionally, we found high taxonomic dissimilarity but low phylogenetic dissimilarity in pairwise community comparisons. These results suggest that recent diversification has played an important role in the assembly of white-sand forests causing geographic neo-endemism patterns at the regional scale.
ISSN: 0006-3606

hal-01532549
https://hal.archives-ouvertes.fr/hal-01532549
DOI : 10.1111/btp.12298
PRODINRA : 353398