Auteurs, date et publication :
Auteurs Tomáš Pavlíček , Csaba Csuzdi
Publication : Zoology in the Middle East
Date : 2025
Volume : 58
Issue : sup4
Pages : 107-110
Catégorie(s)
#CNRS #FORET NouraguesAuteurs, date et publication :
Auteurs Xu Pan , Mathieu Santonja , Pierre Emmanuel Courty , Olaf Butensch n , Matty Berg , Phil Murray , Benjamin Yguel , Daphn e Brul , Andreas Prinzing
Publication : Authorea
Date : 2020
Catégorie(s)
#CNRS #EcoGenO #Université de RennesRésumé
Ecological corridors promote species coexistence in fragmented habitats where dispersal limits species fluxes. The corridor concept was developed and investigated with macroorganisms in mind while microorganisms, the invisible majority of biodiversity, were disregarded. We analyzed the effect of corridors on the dynamics of endospheric fungal assemblages associated with plant roots at the scale of one meter over two years (i.e. at five time points) by combining an experimental corridor-mesocosm with high-throughput amplicon sequencing. We show that the plant root endospheric mycobiota was sensitive to corridor effects when the corridors were set up at a small spatial scale. The endospheric mycobiota of connected plants had higher species richness, lower beta-diversity, and more deterministic assembly than the mycobiota of isolated plants. These effects became more pronounced with the development of host plants. Biotic corridors composed of host plants may thus play a key role in the spatial dynamics of microbial communities and may influence microbial diversity and related ecological functions.
Auteurs, date et publication :
Auteurs Jie Hu , Philippe Vandenkoornhuyse , Fadwa Khalfallah , Romain Causse-Védrines , Cendrine Mony
Publication : New Phytologist
Date : 2025
Volume : n/a
Issue : n/a
Catégorie(s)
#CNRS #EcoGenO #Université de RennesRésumé
Alpine treelines globally may move upslope due to climatic warming. Such movement would need, as the first steps, seed germination and seedling establishment ab
Auteurs, date et publication :
Auteurs Hannah Loranger , Gerhard Zotz , Maaike Y. Bader
Publication : AoB PLANTS
Date : 2016
Volume : 8
Catégorie(s)
#CNRS #Lautaret #UGARésumé
Rock glaciers, usually preserved in periglacial environments of cold-climate high-relief regions, are useful (palaeo)climate indicators. In the European Alps, numerous studies have focused on describing these geomorphological features. However, very few have attempted directly dating them. This lack of measurement is particularly evident in the French Alps. To fill this gap, we performed Cosmic Ray Exposure (CRE) dating through beryllium-10 (10Be) on 10 granitic rock samples collected from two relict rock glaciers, hereafter referred as RG1 and RG2, located at col du Lautaret in the French Alps. This first CRE dating of rock glaciers in the French Alps yielded mean ages of 11.8 ± 0.5 kyrs and 11.6 ± 0.6 kyrs for RG1 and RG2, respectively. While RG2 is clearly a talus-derived rock glacier, the origin of RG1 is less clear. It could potentially be talus-derived, glacier-derived or of mixed origin. The 10Be ages indicate that both rock glaciers became inactive during the transition between the Younger Dryas and the onset of the Holocene, consistently with other studies in the Northern Hemisphere. Considering surface velocity measurements carried out since the 1980s on neighbouring rock glaciers, we hypothesise that the rock glaciers were formed either during the Younger Dryas or slightly earlier, between the Heinrich Stadial 1 and the Younger Dryas. During this period, we estimated temperatures ~3.6 °C lower than the 1980s and precipitation up to 30% lower than at present.
Auteurs, date et publication :
Auteurs Joanna Charton , Deborah Verfaillie , Vincent Jomelli , Bernard Francou
Publication : Geomorphology
Date : 2025
Volume : 394
Pages : 107962
Catégorie(s)
#CNRS #Lautaret #UGARésumé
Subalpine grassland ecosystems are important from biodiversity, agriculture, and touristic perspectives but their resilience to seasonally occurring climatic extremes is increasingly challenged with climate change, accelerating their vulnerability to tipping points. Microbial communities, which are central in ecosystem functioning, are usually considered as more resistant and highly resilient to such extreme events due to their functional redundancy and strong selection in residing habitats. To investigate this, we explored soil microbial responses upon recurrent summer droughts associated with early snowmelt in subalpine grasslands mesocosms set-up at the Lautaret Pass (French Alps). Potential respiration, nitrification and denitrification were monitored over a period of two growing seasons along with quantification of community gene abundances of total bacteria as well as (de)nitrifiers. Results revealed that droughts had a low and short-term adverse impact on bacterial total respiration supporting their hypothesized high resilience, i.e., resistance and ability to recover. Nitrification and abundances of the corresponding functional guilds showed relatively strong resistance to summer droughts but declined in response to early snowmelt. This triggered a cascading effect on denitrification but also on abundances of denitrifying communities which recovered from all climatic extremes except from the summer droughts where nitrifiers were collapsed. Denitrification and respective functional groups faced high impact of applied stresses with strong reduction in abundance and activity of this specialized community. Although, consequently lower microbial competition for nitrate may be positive for plant biomass production, warnings exist when considering the potential nitrogen leaching from these ecosystems as well as risks of greenhouses gases emission such as N2O.
Auteurs, date et publication :
Auteurs Farhan Hafeez , Lionel Bernard , Franck Poly , Jean-Christophe Clément , Thomas Pommier
Date : 2021
Pages : 2021.03.15.435477
Catégorie(s)
#CNRS #Lautaret #UGARésumé
Although parasite infection and pollution are common threats facing wild populations, the response of the gut microbiota to the joint impact of these stressors remains largely understudied. Here, we experimentally investigated the effects of exposure to Polycyclic Aromatic Hydrocarbons (PAHs) and infection by a common acanthocephalan intestinal parasite (Pomphorhynchus sp.) on the gut microbial flora of a freshwater fish, the European chub (Squalius cephalus). Naturally infected or uninfected individuals were exposed to PAHs at environmentally realistic concentrations over a five-week period. Characterization of the gut bacterial community through 16S rRNA gene amplicon sequencing revealed that parasitic infection was a more structuring factor of bacterial diversity and composition than PAH exposure. Specifically, chub infected by Pomphorhynchus sp. harbored significantly less evenly represented gut bacterial communities than the uninfected ones. In addition, substantial changes in sequence abundance were observed within the main bacterial phyla, including the Firmicutes, Fusobacteriota, Actinobacteriota, and Proteobacteria. Again, these compositional changes correlated with host infection with Pomphorhynchus sp., confirming its pivotal role in gut microbial assemblage. Overall, these results highlight the importance of defining the parasitic status of individuals when conducting microbial ecotoxicological analyses at the digestive tract level, as this should lead to better understanding of microbiota modulations and help to identify microbial markers specifically associated with chemicals.
Auteurs, date et publication :
Auteurs Yannick Colin , Noëlie Molbert , Thierry Berthe , Simon Agostini , Fabrice Alliot , Beatriz Decencière , Alexis Millot , Aurélie Goutte , Fabienne Petit
Publication : Scientific Reports
Date : 2022
Volume : 12
Issue : 1
Pages : 11084
Catégorie(s)
#CNRS #ENS #PLANAQUAAuteurs, date et publication :
Auteurs Marc Théry , Sylvain Pincebourde , François Feer
Publication : Behavioral Ecology
Date : 2025
Volume : 19
Issue : 3
Pages : 627-634
Catégorie(s)
#CNRS #FORET NouraguesRésumé
In the French Alps, Soldanella alpina (S. alpina) grow under shade and sun conditions during the vegetation period. This species was investigated as a model for the dynamic acclimation of shade leaves to the sun under natural alpine conditions, in terms of photosynthesis and leaf anatomy. Photosynthetic activity in sun leaves was only slightly higher than in shade leaves. The leaf thickness, the stomatal density and the epidermal flavonoid content were markedly higher, and the chlorophyll/flavonoid ratio was significantly lower in sun than in shade leaves. Sun leaves also had a more oxidised plastoquinone pool, their PSII efficiency in light was higher and their non-photochemical quenching (NPQ) capacity was higher than that of shade leaves. Shade-sun transferred leaves increased their leaf thickness, stomatal density and epidermal flavonoid content, while their photosynthetic activity and chlorophyll/flavonoid ratio declined compared to shade leaves. Parameters indicating protection against high light and oxidative stress, such as NPQ and ascorbate peroxidase, increased in shade-sun transferred leaves and leaf mortality increased. We conclude that the dynamic acclimation of S. alpina leaves to high light under alpine conditions mainly concerns anatomical features and epidermal flavonoid acclimation, as well as an increase in antioxidative protection. However, this increase is not large enough to prevent damage under stress conditions and to replace damaged leaves.
Auteurs, date et publication :
Auteurs Anne-Claire Talhouët , Sylvie Meyer , Xavier Baudin , Peter Streb
Publication : Physiologia Plantarum
Date : 2025
Volume : 168
Issue : 3
Pages : 563-575
Catégorie(s)
#CNRS #Lautaret #UGARésumé
1. Efficient extraction of soil water is essential for the productivity of plant communities. However, research on the complementary use of resources in mixed plant communities, and especially the impact of plant species richness on root water uptake, is limited. So far, these investigations have been hindered by a lack of methods allowing for the estimation of root water uptake profiles.
Auteurs, date et publication :
Auteurs Marcus Guderle , Dörte Bachmann , Alexandru Milcu , Annette Gockele , Marcel Bechmann , Christine Fischer , Christiane Roscher , Damien Landais , Olivier Ravel , Sébastien Devidal , Jacques Roy , Arthur Gessler , Nina Buchmann , Alexandra Weigelt , Anke Hildebrandt , Katie Field
Publication : Functional Ecology
Date : 2025
Volume : 32
Issue : 1
Pages : 214-227