Auteurs, date et publication :
Auteurs Mario Amalfi , Gerardo Robledo , Cony Decock
Publication : Mycological progress
Date : 2025
Volume : 13
Issue : 4
Pages : 995
Catégorie(s)
#CNRS #FORET NouraguesRésumé
This paper assesses the options available to researchers analysing multilevel (including longitudinal) data, with the aim of supporting good methodological decision-making. Given the confusion in the literature about the key properties of fixed and random effects (FE and RE) models, we present these models’ capabilities and limitations. We also discuss the within-between RE model, sometimes misleadingly labelled a ‘hybrid’ model, showing that it is the most general of the three, with all the strengths of the other two. As such, and because it allows for important extensions—notably random slopes—we argue it should be used (as a starting point at least) in all multilevel analyses. We develop the argument through simulations, evaluating how these models cope with some likely mis-specifications. These simulations reveal that (1) failing to include random slopes can generate anti-conservative standard errors, and (2) assuming random intercepts are Normally distributed, when they are not, introduces only modest biases. These results strengthen the case for the use of, and need for, these models.
Auteurs, date et publication :
Auteurs Andrew Bell , Malcolm Fairbrother , Kelvyn Jones
Publication : Quality & Quantity
Date : 2019
Volume : 53
Issue : 2
Pages : 1051-1074
Catégorie(s)
#CNRS #ENSRésumé
Advancing the field of ecology relies on understanding generalities and developing theories based on empirical and functional relationships that integrate across organismal to global spatial scales and span temporal scales. Significant advances in predicting responses of ecological communities to globally extensive anthropogenic perturbations, for example, require understanding the role of environmental context in determining outcomes, which in turn requires standardized experiments across sites and regions. Distributed collaborative experiments can lead to high-impact advances that would otherwise be unachievable. Here, we provide specific advice and considerations relevant to researchers interested in employing this emerging approach using as a case study our experience developing and running the Nutrient Network, a globally distributed experimental network (currently >75 sites in 17 countries) that arose from a grassroots, cooperative research effort. We clarify the design, goals and function of the Nutrient Network as a model to empower others in the scientific community to employ distributed experiments to advance our predictive understanding of global-scale ecological trends and responses. Our experiences to date demonstrate that globally distributed experimental science need not be prohibitively expensive or time-consuming on a per capita basis and is not limited to senior scientists or countries where science is well funded. While distributed experiments are not a panacea for understanding ecological systems, they can substantially complement existing approaches.
Auteurs, date et publication :
Auteurs Elizabeth T. Borer , W. Stanley Harpole , Peter B. Adler , Eric M. Lind , John L. Orrock , Eric W. Seabloom , Melinda D. Smith
Publication : Methods in Ecology and Evolution
Date : 2025
Volume : 5
Issue : 1
Pages : 65-73
Catégorie(s)
#CEREEP #CNRS #ENSAuteurs, date et publication :
Auteurs Weslly Franco , Natalia Ladino , Jacques HC Delabie , Alain Dejean , Jérôme Orivel , Mélanie Fichaux , Sarah Groc , Maurice Leponce , Rodrigo M Feitosa
Publication : Zootaxa
Date : 2025
Volume : 4674
Issue : 5
Pages : 509-543
Catégorie(s)
#CNRS #FORET NouraguesRésumé
This paper presents the first record of Chomelia triflora from Brazil, to date a species only known from French Guiana. After examining herbaria collections and doing fieldwork in the Brazilian Amazon, we found that the species also occurs in and around the Ducke Reserve in the state of Amazonas, Brazil. Our finding increases the data about the Brazilian Amazon and contributes to the better knowledge of Chomelia in Brazil.
Auteurs, date et publication :
Auteurs Maria do Céo R. Pessoa , Claes Persson , Alexandre Antonelli , Maria Regina de V. Barbosa
Publication : Check List
Date : 2017
Volume : 13
Issue : 4
Pages : 159-162
Catégorie(s)
#CNRS #FORET NouraguesAuteurs, date et publication :
Auteurs R Pessoa Maria do Céo , Claes Persson , Alexandre Antonelli , Maria Regina de V Barbosa
Publication : Check List
Date : 2023
Volume : 13
Pages : 159
Catégorie(s)
#CNRS #FORET NouraguesAuteurs, date et publication :
Auteurs José Teston , Margarida Freitas
Publication : Check List
Date : 2025
Volume : 11
Pages : 1
Catégorie(s)
#CNRS #FORET NouraguesRésumé
Well-defined productivity–precipitation relationships of ecosystems are needed as benchmarks for the validation of land models used for future projections. The productivity–precipitation relationship may be studied in two ways: the spatial approach relates differences in productivity to those in precipitation among sites along a precipitation gradient (the spatial fit, with a steeper slope); the temporal approach relates interannual productivity changes to variation in precipitation within sites (the temporal fits, with flatter slopes). Precipitation–reduction experiments in natural ecosystems represent a complement to the fits, because they can reduce precipitation below the natural range and are thus well suited to study potential effects of climate drying. Here, we analyse the effects of dry treatments in eleven multiyear precipitation–manipulation experiments, focusing on changes in the temporal fit. We expected that structural changes in the dry treatments would occur in some experiments, thereby reducing the intercept of the temporal fit and displacing the productivity–precipitation relationship downward the spatial fit. The majority of experiments (72%) showed that dry treatments did not alter the temporal fit. This implies that current temporal fits are to be preferred over the spatial fit to benchmark land-model projections of productivity under future climate within the precipitation ranges covered by the experiments. Moreover, in two experiments, the intercept of the temporal fit unexpectedly increased due to mechanisms that reduced either water loss or nutrient loss. The expected decrease of the intercept was observed in only one experiment, and only when distinguishing between the late and the early phases of the experiment. This implies that we currently do not know at which precipitation–reduction level or at which experimental duration structural changes will start to alter ecosystem productivity. Our study highlights the need for experiments with multiple, including more extreme, dry treatments, to identify the precipitation boundaries within which the current temporal fits remain valid.
Auteurs, date et publication :
Auteurs Marc Estiarte , Sara Vicca , Josep Peñuelas , Michael Bahn , Claus Beier , Bridget A. Emmett , Philip A. Fay , Paul J. Hanson , Roland Hasibeder , Jaime Kigel , Gyorgy Kröel‐Dulay , Klaus Steenberg Larsen , Eszter Lellei‐Kovács , Jean-Marc Limousin , Romà Ogaya , Jean-Marc Ourcival , Sabine Reinsch , Osvaldo E. Sala , Inger Kappel Schmidt , Marcelo Sternberg
Publication : Global Change Biology
Date : 2025
Volume : 22
Issue : 7
Pages : 2570-2581
Catégorie(s)
#CNRS #FORET PuechabonRésumé
Land use has an effect on seed strategies. It is debated, however, whether disturbances such as mowing select for one dominant regeneration strategy (e.g. ruderals) or allows for more species with diverse recruitment strategies to establish. We tested if there is a filtering of seed traits in subalpine grasslands and what is the effect of mowing on community mean seed traits and their diversity. We measured seed mass and seed number of most species from subalpine grasslands in the French Alps, in an experiment consisting of short- and long-term mowing. We calculated for each treatment average seed mass and number as well as functional divergence. Mowing had no effect either on mean seed trait values or trait diversity, but rather reversed the effect of moisture on seed traits. Most importantly, besides soil moisture, communities followed a continuum from grasslands dominated by species with heavy seeds to grasslands with high divergence in seed mass. These results suggest the existence of an axis of functional divergence–convergence for seed mass in response to factors other than disturbance, though we were not able to identify which. Functional space (i.e. available niches along seed trait dimensions) exists for species with varied strategies in some of the communities, as opposed to others where species with heavy seed masses prevail. Reproductive strategies and the availability of diverse regeneration niches may determine a more important assembly rule of plant species in subalpine communities than previously considered.
Auteurs, date et publication :
Auteurs Flore Viard-Crétat , Francesco de Bello , Ove Eriksson , Marie-Pascale Colace , Sandra Lavorel
Publication : Basic and Applied Ecology
Date : 2025
Volume : 12
Issue : 5
Pages : 423-431
Catégorie(s)
#CNRS #Lautaret #UGARésumé
Polar regions are characterized by rocky terrains with sparse vegetation and oligotrophic soils, i.e. “fellfields”. In such ecosystems, microbial communities should be essential for soil-plant functioning but their diversity is poorly explored. The sub-Antarctic Kerguelen Islands fellfields are characterized by an endemic long-lived cushion plant, Lyallia kerguelensis which rhizosphere may be a shelter for microbes in this harsh environment. Cushions are affected by necrosis and we expect the rhizomicrobiome composition to be related to plant necrosis. We analysed bacterial and fungal communities in bulk- and rhizospheric soils from L. kerguelensis in five different fellfields across the Kerguelen Islands using 16S rRNA and ITS1 metabarcoding. We found that soil microbial communities were composed of both restricted and cosmopolitan taxa. While all sites were dominated by the same bacterial taxa (Chloroflexi, Actinobacteria, α-Proteobacteria and Acidobacteria), the relative abundance of the main fungal phyla (Ascomycota, Basidiomycota, Mortierellomycota and Rozellomycota) highly differed between sites. L. kerguelensis rhizomicrobiome was at least as diverse as the bulk soil, making the rhizosphere a possible reservoir of microbial diversity. It was composed of the same main bacterial phyla than detected in the bulk soil while the composition of the rhizosphere fungal communities was specific to each plant. No common microorganisms were identified regarding cushion necrosis extent across plants and sites, but several microbial putative functions were shared, suggesting a possible shift in soil functioning with cushion necrosis increase. Our study brings new information on the diversity and composition of the microbial communities of fellfield soils in a sub-Antarctic Island and the rhizomicrobiome of a characteristic endemic cushion plant.
Auteurs, date et publication :
Auteurs Lorène Julia Marchand , Françoise Hennion , Michèle Tarayre , Marie-Claire Martin , Benoit Renaud Martins , Cécile Monard
Publication : Frontiers in Soil Science
Date : 2025
Volume : 2