Résumé
Abstract. Background and Aims Dominant tree species in northern temperate forests, for example oak and beech, produce desiccation-sensitive seeds. Despite the
Auteurs, date et publication :
Auteurs Thierry Joët , Jean-Marc Ourcival , Mathilde Capelli , Stéphane Dussert , Xavier Morin
Publication : Annals of Botany
Date : 2016
Volume : 117
Issue : 1
Pages : 165-176
Catégorie(s)
#CNRS #FORET PuechabonAuteurs, date et publication :
Auteurs Delphine Legrand , Nicolas Larranaga , Romain Bertrand , Simon Ducatez , Olivier Calvez , Virginie M. Stevens , Michel Baguette
Publication : Proceedings of the Royal Society B: Biological Sciences
Date : 2016
Volume : 283
Issue : 1839
Pages : 20161533
Catégorie(s)
#CNRS #Metatron terrestreRésumé
Ecological models predict that the effects of mammalian herbivore exclusion on plant diversity depend on resource availability and plant exposure to ungulate grazing over evolutionary time. Using an experiment replicated in 57 grasslands on six continents, with contrasting evolutionary history of grazing, we tested how resources (mean annual precipitation and soil nutrients) determine herbivore exclusion effects on plant diversity, richness and evenness. Here we show that at sites with a long history of ungulate grazing, herbivore exclusion reduced plant diversity by reducing both richness and evenness and the responses of richness and diversity to herbivore exclusion decreased with mean annual precipitation. At sites with a short history of grazing, the effects of herbivore exclusion were not related to precipitation but differed for native and exotic plant richness. Thus, plant species’ evolutionary history of grazing continues to shape the response of the world’s grasslands to changing mammalian herbivory.
Auteurs, date et publication :
Auteurs Jodi N. Price , Judith Sitters , Timothy Ohlert , Pedro M. Tognetti , Cynthia S. Brown , Eric W. Seabloom , Elizabeth T. Borer , Suzanne M. Prober , Elisabeth S. Bakker , Andrew S. MacDougall , Laura Yahdjian , Daniel S. Gruner , Harry Olde Venterink , Isabel C. Barrio , Pamela Graff , Sumanta Bagchi , Carlos Alberto Arnillas , Jonathan D. Bakker , Dana M. Blumenthal , Elizabeth H. Boughton
Publication : Nature Ecology & Evolution
Date : 2022
Volume : 6
Issue : 9
Pages : 1290-1298
Catégorie(s)
#CEREEP #CNRS #ENSAuteurs, date et publication :
Auteurs Renate Radek , Katja Meuser , Jürgen FH Strassert , Oguzhan Arslan , Anika Teßmer , Jan Šobotník , David Sillam‐Dussès , Ricardo A Nink , Andreas Brune
Publication : Journal of Eukaryotic Microbiology
Date : 2025
Volume : 65
Issue : 1
Pages : 77-92
Catégorie(s)
#CNRS #FORET NouraguesRésumé
Isoprene, the main volatile released by plants, is known to protect the photosynthetic apparatus in isoprene emitters submitted to oxidative pressures caused by environmental constraints. Whether ambient isoprene contributes to protect negligible plant emitters under abiotic stress conditions is less clear, and no study has tested if ambient isoprene is beneficial during drought periods in plant species that naturally release negligible isoprene emissions. This study examines the effect of exogenous isoprene (20 ppbv) on net photosynthesis, stomatal conductance and production of H2O2 (a reactive oxygen species: ROS) in leaves of Acer monspessulanum (a negligible isoprene emitter) submitted to three watering treatments (optimal, moderate water stress and severe water stress). Results showed that A. monspessulanum exhibited a net photosynthesis increase (+30%) and a relative leaf H2O2 decrease when saplings were exposed to an enriched isoprene atmosphere compared to isoprene-free conditions under moderate water deficit. Such physiological improvement under isoprene exposure was not observed under optimal watering or severe water stress. These findings suggest that when negligible isoprene emitters are surrounded by a very high concentration of isoprene in the ambient air, some plant protection mechanism occurs under moderate water deficit probably related to protection against ROS damage eventually impeding photosynthesis drop.
Auteurs, date et publication :
Auteurs Elena Ormeño , Justine Viros , Jean-Philippe Mévy , Alain Tonetto , Amélie Saunier , Anne Bousquet-Mélou , Catherine Fernandez
Publication : Plants
Date : 2020
Volume : 9
Issue : 2
Pages : 159
Catégorie(s)
#CNRS #FORET O3HPAuteurs, date et publication :
Auteurs Blaise Tymen , Maxime Réjou‐Méchain , James W Dalling , Sophie Fauset , Ted R Feldpausch , Natalia Norden , Oliver L Phillips , Benjamin L Turner , Jérôme Viers , Jérôme Chave
Publication : Journal of Ecology
Date : 2023
Volume : 104
Issue : 1
Pages : 149-159
Catégorie(s)
#CNRS #FORET NouraguesRésumé
Cushion-forming species occur in all cold and dry environments worldwide, where they play important engineering roles. Understanding the origins of cushion plants may thus provide insights into the evolutionary assembly of biomes under extreme climatic conditions. Here we investigate the evolutionary and biogeographic history of cushions in Angiosperms based on a global checklist of all cushion plants, along with phylogenetic, climatic, and biogeographic information. Our aim is to measure the frequency of this evolutionary convergence and to identify its historic, environmental, and biogeographic drivers. We show that cushions appeared at least 115 times in Angiosperms and that they mainly belong to families that occupy the coldest and driest environments on Earth. We found that cushions have intensively diversified in the Himalayas, the Andes, or New Zealand, while other regions like Patagonia have probably been hubs enabling cushion species to migrate between different alpine regions. We conclude that the cushion life form is a remarkable example of convergent key innovation, which has favored the colonization of cold and dry habitats.
Auteurs, date et publication :
Auteurs Florian C. Boucher , Sébastien Lavergne , Mireille Basile , Philippe Choler , Serge Aubert
Publication : Perspectives in Plant Ecology, Evolution and Systematics
Date : 2025
Volume : 20
Pages : 22-31
Catégorie(s)
#CNRS #Lautaret #UGARésumé
Vegetation phenology is the study of the timing of seasonal events that are considered to be the result of adaptive responses to climate variations on short and long time scales. In the field of remote sensing of vegetation phenology, phenological metrics are derived from time series of optical data. For that purpose, considerable effort has been specifically focused on developing noise reduction and cloud-contaminated data removal techniques to improve the quality of remotely-sensed time series. Comparative studies between time series composed of satellite data acquired under clear and cloudy conditions and from radiometric data obtained with high accuracy from ground-based measurements constitute a direct and effective way to assess the operational use and limitations of remote sensing for predicting the main plant phenological events. In the present paper, we sought to explicitly evaluate the potential use of MODerate resolution Imaging Spectroradiometer (MODIS) remote sensing data for monitoring the seasonal dynamics of different types of vegetation cover that are representative of the major terrestrial biomes, including temperate deciduous forests, evergreen forests, African savannah, and crops. After cloud screening and filtering, we compared the temporal patterns and phenological metrics derived from in situ NDVI time series and from MODIS daily and 16-composite products. We also evaluated the effects of residual noise and the influence of data gaps in MODIS NDVI time series on the identification of the most relevant metrics for vegetation phenology monitoring. The results show that the inflexion points of a model fitted to a MODIS NDVI time series allow accurate estimates of the onset of greenness in the spring and the onset of yellowing in the autumn in deciduous forests (RMSE≤one week). Phenological metrics identical to those provided with the MODIS Global Vegetation Phenology product (MDC12Q2) are less robust to data gaps, and they can be subject to large biases of approximately two weeks or more during the autumn phenological transitions. In the evergreen forests, in situ NDVI time series describe the phenology with high fidelity despite small temporal changes in the canopy foliage. However, MODIS is unable to provide consistent phenological patterns. In crops and savannah, MODIS NDVI time series reproduce the general temporal patterns of phenology, but significant discrepancies appear between MODIS and ground-based NDVI time series during very localized periods of time depending on the weather conditions and spatial heterogeneity within the MODIS pixel. In the rainforest, the temporal pattern exhibited by a MODIS 16-day composite NDVI time series is more likely due to a pattern of noise in the NDVI data structure according to both rainy and dry seasons rather than to phenological changes. More investigations are needed, but in all cases, this result leads us to conclude that MODIS time series in tropical rainforests should be interpreted with great caution.
Auteurs, date et publication :
Auteurs G. Hmimina , E. Dufrêne , J.-Y. Pontailler , N. Delpierre , M. Aubinet , B. Caquet , A. de Grandcourt , B. Burban , C. Flechard , A. Granier , P. Gross , B. Heinesch , B. Longdoz , C. Moureaux , J.-M. Ourcival , S. Rambal , L. Saint André , K. Soudani
Publication : Remote Sensing of Environment
Date : 2013
Volume : 132
Pages : 145–158
Catégorie(s)
#CIRAD #CNRS #FORET Paracou #FORET PuechabonRésumé
The ability of ant colonies to transport, store, and distribute food resources through trophallaxis is a key advantage of social life. Nonetheless, how the structure of the digestive system has adapted across the ant phylogeny to facilitate these abilities is still not well understood. The crop and proventriculus, structures in the ant foregut (stomodeum), have received most attention for their roles in trophallaxis. However, potential roles of the esophagus have not been as well studied. Here, we report for the first time the presence of an auxiliary thoracic crop in Pheidole aberrans and Pheidole deima using X-ray micro-computed tomography and 3D segmentation. Additionally, we describe morphological modifications involving the endo- and exoskeleton that are associated with the presence of the thoracic crop. Our results indicate that the presence of a thoracic crop in major workers suggests their potential role as repletes or live food reservoirs, expanding the possibilities of tasks assumed by these individuals in the colony. Our contribution emphasizes the utility of combining data from external and internal morphology to better understand functional and behavioral mechanisms.
Auteurs, date et publication :
Auteurs A. Casadei-Ferreira , G. Fischer , E.P. Economo
Publication : Arthropod Structure & Development
Date : 2020
Volume : 59
Pages : 100977
Catégorie(s)
#CNRS #FORET NouraguesRésumé
The hologenome concept considers the entity formed by a host and its microbiota, the holobiont, as new level of hierarchical organization subject to neutral and selective forces. We used grafted plants to evaluate the hologenome concept. If deterministic forces shape plant holobionts, then grafted plants will exhibit a particular signature in the root microbiota community, the holobiont composition. Reciprocally, if the microbiota of these chimeric plants is randomly assembled, the hologenome concept would be of limited importance for plants. We analyzed the root-endosphere microbiota of two independent model plant systems including ungrafted and reciprocal-grafting treatments. Consistent with the idea that co-evolution shapes at least in part host-microbiota combinations, grafted and ungrafted hosts harbor markedly different microbiota compositions. The results indicate a non-random assembly of bacterial communities inhabiting the root endosphere of chimeric plants with a stronger effect of the rootstock than scion on the recruitment of microorganisms. Because chimeric plants did not have a random microbiota, the null hypothesis that holobionts assemble randomly and hologenome concept is an intellectual construction only can be rejected. The study supports the relevance of hologenome as biological level of organization and opens new avenues for a better fundamental understanding of plants as holobionts.
Auteurs, date et publication :
Auteurs Marine Biget , Tingting Wang , Cendrine Mony , Qicheng Xu , Lucie Lecoq , Veronique Chable , Kevin R. Theis , Ning Ling , Philippe Vandenkoornhuyse
Date : 2022