Auteurs, date et publication :
Auteurs Céline Leroy , Arthur QuyManh Maes , Eliane Louisanna , Heidy Schimann , Nathalie Séjalon‐Delmas
Publication : New Phytologist
Date : 2025
Catégorie(s)
#CNRS #FORET NouraguesAuteurs, date et publication :
Auteurs Jérémy Lemaire , François Brischoux , Olivier Marquis , Rosanna Mangione , Paco Bustamante
Publication : Archives of Environmental Contamination and Toxicology
Date : 2025
Pages : 1-10
Catégorie(s)
#ANR-Citation #CNRS #FORET NouraguesRésumé
Diet studies are essential to understand animal ecology and ecosystem dynamics, especially in the case of large omnivores. These studies are particularly relevant in areas where human disturbance is intense and, thus, species dietary patterns might change due to the easy accessibility of food resources of human origin, which may hinder the ecosystem services these species provide. We assessed the diet of brown bears (Ursus arctos) by DNA metabarcoding in Tatra National Park (southern Poland), a highly touristic protected area. Brown bears' diet showed a marked seasonality, a characteristic feature of brown bear populations relying on natural foods. Graminoids represented the main food during spring, while fleshy-fruited plants became more important from mid-summer. Fleshy-fruited plants were present in 56% of faeces and during the entire activity period of bears, revealing that fruits play a pivotal role in the feeding ecology of Tatra brown bears. Two berry species, Vaccinium myrtillus and Rubus idaeus, were the most frequently detected (in 42% and 20% of faeces, respectively). The large consumption of fleshy-fruited plants, and particularly of berries, suggests that, despite high levels of human disturbance in the area, brown bears still play a key role as seed dispersers. Management strategies focused on an effective waste management, control of berry picking, strict regulations about human activities in specific areas during sensitive periods in the feeding ecology of bears, and the lack of artificial food provisioning are crucial to ensure the seed dispersal processes and associated ecosystem services that bears and other frugivores provide.
Auteurs, date et publication :
Auteurs Alberto García-Rodríguez , Nuria Selva , Tomasz Zwijacz-Kozica , Jörg Albrecht , Clement Lionnet , Delphine Rioux , Pierre Taberlet , Marta De Barba
Publication : Biological Conservation
Date : 2025
Volume : 264
Pages : 109376
Catégorie(s)
#CNRS #eDNARésumé
Spatial rarity is often used to predict extinction risk, but rarity can also occur temporally. Perhaps more relevant in the context of global change is whether a species is core to a community (persistent) or transient (intermittently present), with transient species often susceptible to human activities that reduce niche space. Using 5-12 years of data on 1,447 plant species from 49 grasslands on 5 continents, we show that local abundance and species persistence under ambient conditions are both effective predictors of local extinction risk following experimental exclusion of grazers or addition of nutrients; persistence was a more powerful predictor than local abundance. While perturbations increased the risk of exclusion for low persistence and abundance species, transient but abundant species were also highly likely to be excluded from a perturbed plot relative to ambient conditions. Moreover, low persistence and low abundance species that were not excluded from perturbed plots tended to have a modest increase in abundance following perturbance. Lastly, even core species with high abundances had large decreases in persistence and increased losses in perturbed plots, threatening the long-term stability of these grasslands. Our results demonstrate that expanding the concept of rarity to include temporal dynamics, in addition to local abundance, more effectively predicts extinction risk in response to environmental change than either rarity axis predicts alone.
Auteurs, date et publication :
Auteurs Peter A. Wilfahrt , Ashley L. Asmus , Eric W. Seabloom , Jeremiah A. Henning , Peter Adler , Carlos A. Arnillas , Jonathan D. Bakker , Lori Biederman , Lars A. Brudvig , Marc Cadotte , Pedro Daleo , Anu Eskelinen , Jennifer Firn , W. Stanley Harpole , Yann Hautier , Kevin P. Kirkman , Kimberly J. Komatsu , Ramesh Laungani , Andrew MacDougall , Rebecca L. McCulley
Publication : Ecology
Date : 2025
Volume : n/a
Issue : n/a
Pages : e03504
Catégorie(s)
#CEREEP #CNRS #ENSRésumé
Climate change impacts forest functioning and dynamics, and large uncertainties remain regarding the interactions between species composition, demographic processes and environmental drivers. There are few robust tools available to link these processes, which precludes accurate projections and recommendations for long-term forest management. Forest gap models present a balance between complexity and generality and are widely used in predictive forest ecology. However, their relevance to tackle questions about the links between species composition, climate and forest functioning is unclear. In this regard, demonstrating the ability of gap models to predict the growth of forest stands at the annual parameterization scale resolution—representing a sensitive and integrated signal of tree functioning and mortality risk—appears as a fundamental step. In this study, we aimed at assessing the ability of a gap model to accurately predict forest growth in the short term and potential community composition in the long term, across a wide range of species and environmental conditions. To do so, we present the gap model ForCEEPS, calibrated using an original parameterization procedure for the main tree species in France. ForCEEPS was shown to satisfactorily predict forest annual growth (averaged over a few years) at the plot level from mountain to Mediterranean climates, regardless of the species. Such an accuracy was not gained at the cost of losing precision for long-term predictions, as the model showed a strong ability to predict potential community compositions. The mechanistic relevance of ForCEEPS parameterization was explored by showing the congruence between the values of key model parameter and species functional traits. We further showed that accounting for the spatial configuration of crowns within forest stands, the effects of climatic constraints and the variability of shade tolerances in the species community are all crucial to better predict short-term productivity with gap models. Synthesis. The dual ability of predicting short-term functioning and long-term community composition, as well as the balance between generality and realism (i.e. predicting accuracy) of the new generation of gap models may open great perspectives for the exploration of the biodiversity–ecosystem functioning relationships, species coexistence mechanisms and the impacts of climate change on forest ecosystems. A free Plain Language Summary can be found within the Supporting Information of this article.
Auteurs, date et publication :
Auteurs Xavier Morin , Harald Bugmann , François de Coligny , Nicolas Martin-StPaul , Maxime Cailleret , Jean-Marc Limousin , Jean-Marc Ourcival , Bernard Prevosto , Guillaume Simioni , Maude Toigo , Michel Vennetier , Eugénie Catteau , Joannès Guillemot
Publication : Functional Ecology
Date : 2025
Volume : 35
Issue : 4
Pages : 955-975
Catégorie(s)
#CNRS #FORET FontBlanche #FORET Puechabon #INRAERésumé
A host-plant and its associated microbiota depend on one another. However, the assembly process and the functioning of host-associated microbiota are poorly understood. Herein, rice was used as model plant to investigate the assemblage of bacterial microbiota, including those in the seed, root endosphere and rhizosphere. We also assessed the degree to which endosphere and rhizosphere communities were influenced by vertical transmission through seed and identified the core microbes that potentially associated with plant phenotypic properties. Plant microhabitat, rather than subspecies type, was the major driver shaping plant-associated bacterial microbiota. Deterministic processes were primarily responsible for community assembly in all microhabitats. The influence of vertical transmission from seed to root-associated bacterial communities appeared to be quite weak (endosphere) or even absent (rhizosphere). A core microbial community composed of 15 generalist species persisted across different microhabitats and represented key connectors in networks. Host-plant functional traits were linked to the relative abundance of these generalist core microbes and could be predicted from them using machine learning algorithms. Overall, bacterial microbiota is assembled by host-plant interactions in a deterministic-based manner. This study enhances our understanding of the driving mechanisms and associations of microbiota in various plant microhabitats and provides new perspectives to improve plant performance.
Auteurs, date et publication :
Auteurs Junjie Guo , Ning Ling , Yong Li , Kaisong Li , Huiling Ning , Qirong Shen , Shiwei Guo , Philippe Vandenkoornhuyse
Publication : New Phytologist
Date : 2025
Volume : 230
Issue : 5
Pages : 2047-2060
Catégorie(s)
#CNRS #EcoGenO #Université de RennesRésumé
Aim Plant–soil interactions can be major driving forces of community responses to environmental changes in terrestrial ecosystems. These interactions can leave signals in aboveground plant functional traits and belowground microbial activities and these signals can manifest in observed covariations. However, we know little about how these plant–soil linkages vary in response to environmental conditions at biogeographic scales for which experiments are impossible. Here, we investigate patterns of direct and indirect linkages between plant functional traits, soil microbial activities and environmental conditions in mountain grasslands along elevational gradients. Location The French Alps. Taxon Vascular plants and soil microbiota. Methods We analysed observational grassland data sampled along 14 elevational gradients across the entire French Alps (between 1500 and 2800 m of elevation). Using Graphical Lasso, we inferred a partial correlation network to tease apart direct and indirect plant–soil linkages without defining the direction of interactions a priori. Results We found tight spatial associations of plant traits with microbial activities, climate driving the former and soil properties the latter. In these plant–soil linkages, the dominance of specific plant traits was more important than their diversity. We then showed that in sites with conservative plant traits and reduced organic matter quality, soil microbes invested strongly in nutrient acquisition. Main conclusions By investigating plant–soil linkages along elevational gradients in the French Alps, we showed that plant functional traits and belowground microbial activity are tightly linked and how they depend on environmental conditions. Overall, we demonstrated how soil functioning can be integrated in studies of ecosystem shifts under environmental change at large spatial scales.
Auteurs, date et publication :
Auteurs Sarah-Sophie Weil , Camille Martinez-Almoyna , Gabin Piton , Julien Renaud , Louise Boulangeat , Arnaud Foulquier , Amélie Saillard , Philippe Choler , Jérôme Poulenard , Orchamp Consortium , Tamara Münkemüller , Wilfried Thuiller
Publication : Journal of Biogeography
Date : 2025
Volume : 48
Issue : 11
Pages : 2755-2770
Catégorie(s)
#CNRS #Lautaret #UGARésumé
Fertilisation experiments have demonstrated that nutrient availability is a key determinant of biomass production and carbon sequestration in grasslands. However, the influence of nutrients in explaining spatial variation in grassland biomass production has rarely been assessed. Using a global dataset comprising 72 sites on six continents, we investigated which of 16 soil factors that shape nutrient availability associate most strongly with variation in grassland aboveground biomass. Climate and N deposition were also considered. Based on theory-driven structural equation modelling, we found that soil micronutrients (particularly Zn and Fe) were important predictors of biomass and, together with soil physicochemical properties and C:N, they explained more unique variation (32%) than climate and N deposition (24%). However, the association between micronutrients and biomass was absent in grasslands limited by NP. These results highlight soil properties as key predictors of global grassland biomass production and point to serial co-limitation by NP and micronutrients.
Auteurs, date et publication :
Auteurs Dajana Radujković , Erik Verbruggen , Eric W. Seabloom , Michael Bahn , Lori A. Biederman , Elizabeth T. Borer , Elizabeth H. Boughton , Jane A. Catford , Matteo Campioli , Ian Donohue , Anne Ebeling , Anu Eskelinen , Philip A. Fay , Amandine Hansart , Johannes M. H. Knops , Andrew S. MacDougall , Timothy Ohlert , Harry Olde Venterink , Xavier Raynaud , Anita C. Risch
Publication : Ecology Letters
Date : 2025
Volume : 24
Issue : 12
Pages : 2713-2725
Catégorie(s)
#CEREEP #CNRS #ENSRésumé
Tropical forests are generally considered to stand upon nutrient-poor soils, but soil nutrient concentrations and availabilities can vary greatly at local scale due to topographic effects on erosion and water drainage. In this study we physically and chemically characterised the soils of 12 study plots situated along a catena with a shallow slope in a tropical rainforest in French Guiana both during the wet and the dry season to evaluate seasonal differences. Soils along the catena were all Acrisols, but differed strongly in their water drainage flux. Over time, this differential drainage has led to differences in soil texture and mineral composition, affecting the adsorption of various nutrients, most importantly phosphorus. The more clayey soils situated on the slope of the catena had higher total concentrations of carbon, nitrogen, phosphorus and several micronutrients, while extractable nutrient concentrations were highest in the sandiest soils situated at the bottom of the catena. We found that carbon, nitrogen and extractable nutrients all varied seasonally, especially in the surface soil layer. These results are interesting because they show that, even at the local scale, small differences in topography can lead to large heterogeneity in nutrient concentrations, which can have large impacts on plant and microbial community organisation at the landscape level.
Auteurs, date et publication :
Auteurs Leandro Van Langenhove , Lore T. Verryckt , Clement Stahl , Elodie A. Courtois , Ifigenia Urbina , Oriol Grau , Dolores Asensio , Guille Peguero , Olga Margalef , Vincent Freycon , Josep Penuelas , Ivan A. Janssens
Publication : SOIL RESEARCH
Date : 2025
Volume : 59
Issue : 2
Pages : 130-145
Catégorie(s)
#ANR-Citation #CNRS #FORET NouraguesRésumé
Data assimilation of snow observations significantly improves the accuracy of snow cover simulations. However, remotely-sensed snowpack observations made in areas of complex topography are typically subject to large error and biases, creating a challenge for data assimilation. To improve the reliability of ensemble snowpack simulations, this study investigated the appropriate conditions for assimilating MODIS-like synthetic surface reflectances. We used a simulation system that included the Particle Filter data assimilation technique. More than 270 ensemble simulations involving assimilation of synthetic observations were conducted in a twin experiment procedure for three snow seasons. These tests were aimed at establishing the spectral combination of MODIS-like reflectances that convey the more information in the assimilation system, rendering the most reliable snowpack simulation, and determining the maximum observation errors that the assimilation system could tolerate. The assimilation of the first seven MODIS-like bands, covering visible and near-infrared wavelengths, provided the best scores compared with any other band combination, and thus are highly recommended for use when possible. The simulation system tolerated a maximum deviation from ground truth of 5% without loss of performance. However, the assimilation of the first seven bands of true MODIS surface of reflectance fails on improving simulation results in rouged mountain areas.
Auteurs, date et publication :
Auteurs J. Revuelto , B. Cluzet , N. Duran , M. Fructus , M. Lafaysse , E. Cosme , M. Dumont
Publication : Journal of Hydrology
Date : 2025
Volume : 603
Pages : 126966