Résumé
Seedling recruitment is a bottleneck for population dynamics and range shift. The vital rates linked to recruitment by seed are impacted by amplified drought induced by climate change. In the Mediterranean region, autumn and winter seedling emergence and mortality may have strong impact on the overall seedling recruitment. However, studies focusing on the temporal dynamic of recruitment during these seasons are rare. This study was performed in a deciduous Mediterranean oak forest located in southern France and quantifies the impact of amplified drought conditions on autumn and winter seedling emergence and seedling mortality rates of two herbaceous plant species with meso-Mediterranean and supra-Mediterranean distribution (respectively, Silene italica and Silene nutans). Seedlings were followed from October 2019 to May 2020 in both undisturbed and disturbed plots where the litter and the aboveground biomass have been removed to create open microsites. Amplified drought conditions reduced seedling emergence and increased seedling mortality for both Silene species but these negative effects were dependent on soil disturbance conditions. Emergence of S. italica decreased only in undisturbed plots (−7%) whereas emergence of S. nutans decreased only in disturbed plots (−10%) under amplified drought conditions. The seedling mortality rate of S. italica was 51% higher under amplified drought conditions in undisturbed plots while that of S. nutans was 38% higher in disturbed plots. Aridification due to lower precipitation in the Mediterranean region will negatively impact the seedling recruitment of these two Silene species. Climate change effects on early vital rates may likely have major negative impacts on the overall population dynamic.
Auteurs, date et publication :
Auteurs Suzon Garnier , Emma Giordanengo , Arne Saatkamp , Mathieu Santonja , Ilja M. Reiter , Jean‐Philippe Orts , Thierry Gauquelin , Eric Meineri
Publication : Ecology and Evolution
Date : 2025
Volume : 11
Issue : 22
Pages : 16143-16152
Catégorie(s)
#ANR-Citation #CNRS #FORET O3HPAuteurs, date et publication :
Auteurs Mario X Ruiz‐González , Jérémie Lauth , Céline Leroy , Alain Jauneau , Hervé Gryta , Patricia Jargeat , Alain Dejean , Jérôme Orivel
Publication : Journal of Basic Microbiology
Date : 2025
Volume : 53
Issue : 1
Pages : 98-100
Catégorie(s)
#CNRS #FORET NouraguesRésumé
Species interactions are central in predicting the impairment of biodiversity with climate change. Trophic interactions may be altered through climate-dependent changes in either predator food preferences or prey communities. Yet, climate change impacts on predator diet remain surprisingly poorly understood. We experimentally studied the consequences of 2°C warmer climatic conditions on the trophic niche of a generalist lizard predator. We used a system of semi-natural mesocosms housing a variety of invertebrate species and in which climatic conditions were manipulated. Lizards in warmer climatic conditions ate at a greater predatory to phytophagous invertebrate ratio and had smaller individual dietary breadths. These shifts mainly arose from direct impacts of climate on lizard diets rather than from changes in prey communities. Dietary changes were associated with negative changes in fitness-related traits (body condition, gut microbiota) and survival. We demonstrate that climate change alters trophic interactions through top-predator dietary shifts, which might disrupt eco-evolutionary dynamics.
Auteurs, date et publication :
Auteurs Elvire Bestion , Andrea Soriano-Redondo , Julien Cucherousset , Staffan Jacob , Joël White , Lucie Zinger , Lisa Fourtune , Lucie Di Gesu , Aimeric Teyssier , Julien Cote
Publication : Proceedings of the Royal Society B: Biological Sciences
Date : 2019
Volume : 286
Issue : 1914
Pages : 20192227
Catégorie(s)
#CNRS #Metatron terrestreRésumé
Mountain environments are marked by an altitudinal zonation of habitat types. They are home to a multitude of terrestrial green algae, who have to cope with abiotic conditions specific to high elevation, e.g., high UV irradiance, alternating desiccation, rain and snow precipitations, extreme diurnal variations in temperature and chronic scarceness of nutrients. Even though photosynthetic green algae are primary producers colonizing open areas and potential markers of climate change, their overall biodiversity in the Alps has been poorly studied so far, in particular in soil, where algae have been shown to be key components of microbial communities. Here, we investigated whether the spatial distribution of green algae followed the altitudinal zonation of the Alps, based on the assumption that algae settle in their preferred habitats under the pressure of parameters correlated with elevation. We did so by focusing on selected representative elevational gradients at distant locations in the French Alps, where soil samples were collected at different depths. Soil was considered as either a potential natural habitat or temporary reservoir of algae. We showed that algal DNA represented a relatively low proportion of the overall eukaryotic diversity as measured by a universal Eukaryote marker. We designed two novel green algae metabarcoding markers to amplify the Chlorophyta phylum and its Chlorophyceae class, respectively. Using our newly developed markers, we showed that elevation was a strong correlate of species and genus level distribution. Altitudinal zonation was thus determined for about fifty species, with proposed accessions in reference databases. In particular, Planophila laetevirens and Bracteococcus ruber related species as well as the snow alga Sanguina genus were only found in soil starting at 2,000 m above sea level. Analysis of environmental and bioclimatic factors highlighted the importance of pH and nitrogen/carbon ratios in the vertical distribution in soil. Capacity to grow heterotrophically may determine the Trebouxiophyceae over Chlorophyceae ratio. The intensity of freezing events (freezing degree days), proved also determinant in Chlorophyceae distribution. Guidelines are discussed for future, more robust and precise analyses of environmental algal DNA in mountain ecosystems and address green algae species distribution and dynamics in response to environmental changes.
Auteurs, date et publication :
Auteurs Adeline Stewart , Delphine Rioux , Fréderic Boyer , Ludovic Gielly , François Pompanon , Amélie Saillard , Wilfried Thuiller , Jean-Gabriel Valay , Eric Maréchal , Eric Coissac
Publication : Frontiers in Plant Science
Date : 2025
Volume : 12
Catégorie(s)
#ANR-Citation #CNRS #Lautaret #UGAAuteurs, date et publication :
Auteurs Erik H Poelman , René PA van Wijngaarden , Ciska E Raaijmakers
Publication : Evolutionary Ecology
Date : 2025
Volume : 27
Issue : 4
Pages : 661-674
Catégorie(s)
#CNRS #FORET NouraguesRésumé
Snowmelt in alpine ecosystems brings ample water, and together with above-freezing temperatures, initiates plant growth. In this scenario, rapid activation of photosynthesis is essential for a successful life-history strategy. But, strong solar radiation in late spring enhances the risk of photodamage, particularly before photosynthesis is fully functional. We compared the photoprotective strategy of five alpine forbs: one geophyte not particularly specialised in subnival life (Crocus albiflorus) and four wintergreens differing in their degree of adaptation to subnival life, from least to most specialised: Gentiana acaulis, Geum montanum, Homogyne alpina and Soldanella alpina. We used distance to the edge of snow patches as a proxy to study time-dependent changes after melting. We postulated that the photoprotective response of snowbed specialists would be stronger than of more-generalist alpine meadow species. Fv/Fm was relatively low across wintergreens and even lower in the geophyte C. albiflorus. This species also had the largest xanthophyll-cycle pool and lowest tocopherol and flavonoid glycoside contents. After snow melting, all the species progressively activated ETR, but particularly the intermediate snowbed species G. acaulis and G. montanum. The photoprotective responses after snowmelt were idiosyncratic: G. montanum rapidly accumulated xanthophyll-cycle pigments, tocopherol and flavonoid glycosides; while S. alpina showed the largest increase in plastochromanol-8 and chlorophyll contents and the greatest changes in optical properties. Climate warming scenarios might shift the snowmelt date and consequently alter the effectiveness of photoprotection mechanisms, potentially changing the fitness outcome of the different strategies adopted by alpine forbs.
Auteurs, date et publication :
Auteurs Beatriz Fernández-Marín , Ana Sáenz-Ceniceros , Twinkle Solanki , Thomas Matthew Robson , José Ignacio García-Plazaola
Publication : Physiologia Plantarum
Date : 2025
Volume : 172
Issue : 3
Pages : 1506-1517
Catégorie(s)
#CNRS #Lautaret #UGAAuteurs, date et publication :
Auteurs Y-N Ngo , D Ho Tong Minh , I Moussawi , L Villard , L Ferro-Famil , M Mariotti D'Alessandro , S Tebaldini , C Albinetv , K Scipal , T Le Toan
Date : 2025
Pages : 8675-8678
Catégorie(s)
#CNRS #FORET NouraguesRésumé
Many new taxons have been discovered in HautesAlpes (southern alps, France) since 1994, date of publishing of a botanical atlas over this territory (CHAS, 1994). New stations have also been discovered for noteworthy species in regard to their rarity or distribution. Consequently, 104 new taxons are mentioned for the first time in the studied zone. The majority of these new species (43%) has a ruderal strategy, and 18% of them are neophytes. Besides, 6 of these new mentions are due to taxonomics reviewing of local populations (Arum cylindraceum, Cynoglossum montanum, Fritillaria burnatii, Linaria vulgaris, Luzula alpina, Schoenoplectus lacustris). The reviewing of the local distribution of 98 taxons is also lead, taking intout acount the rarety of these species or the originality of the new data. Finally, 12 species escaped from the Lautaret alpine garden (2100 m) are presented in regard to their long term naturalization possibility.
Auteurs, date et publication :
Auteurs Cédric Dentant , Franck le Driant , Jérémie Van Es , Lionel Ferrus , Luc Garraud , Sylvain Abdulhak , Rolland Douzet
Publication : Le Monde des plantes
Date : 2025
Volume : 508
Pages : 3-26
Catégorie(s)
#CNRS #Lautaret #UGARésumé
Maternal effects can give newborns a head start in life by adjusting natal phenotypes to natal environments, yet their strength and adaptiveness are often difficult to investigate in natural populations. Here, we studied anticipatory maternal effects and their adaptiveness in common lizards in a seminatural experimental system. Specifically, we investigated how maternal environments (i.e., vegetation cover) and maternal phenotype (i.e., activity levels and body length) can shape offspring phenotype. We further studied whether such maternal effects influenced offspring survival in natal environments varying with respect to vegetation cover, conspecific density, and, consequently, maternal fitness. More active females from dense vegetation habitats produced bigger offspring than their less active counterparts, the contrary being true for sparse vegetation habitats. Moreover, females from dense vegetation habitats produced more active offspring and more active offspring survived better in dense vegetation habitats, resulting in greater maternal fitness through maternal effects. These results suggest adaptive anticipatory maternal effects, induced by vegetation structure and mediated by activity levels that may shape early-life prospects in natal environments.
Auteurs, date et publication :
Auteurs Elvire Bestion , Aimeric Teyssier , Marylin Rangassamy , Olivier Calvez , Olivier Guillaume , Murielle Richard , Amandine Braem , Felix Zajitschek , Susanne Zajitschek , Julien Cote
Publication : The American Naturalist
Date : 2022
Volume : 200
Issue : 6
Pages : 773-789
Catégorie(s)
#CNRS #Metatron terrestreRésumé
Aim To incorporate changes in alpine land cover (tree line shift, glacier retreat and primary succession) into species distribution model (SDM) predictions for a selection of 31 high-elevation plants.
Auteurs, date et publication :
Auteurs Bradley Z. Carlson , Damien Georges , Antoine Rabatel , Christophe F. Randin , Julien Renaud , Anne Delestrade , Niklaus E. Zimmermann , Philippe Choler , Wilfried Thuiller , Mathieu Rouget
Publication : Diversity and Distributions
Date : 2025
Volume : 20
Issue : 12
Pages : 1379-1391