Résumé
While soil ecosystems undergo important modifications due to global change, the effect of soil properties on plant distributions is still poorly understood. Plant growth is not only controlled by soil physico-chemistry but also by microbial activities through the decomposition of organic matter and the recycling of nutrients essential for plants. A growing body of evidence also suggests that plant functional traits modulate species’ response to environmental gradients. However, no study has yet contrasted the importance of soil physico-chemistry, microbial activities and climate on plant species distributions, while accounting for how plant functional traits can influence species-specific responses. Using hierarchical effects in a multi-species distribution model, we investigate how four functional traits related to resource acquisition (plant height, leaf carbon to nitrogen ratio, leaf dry matter content and specific leaf area) modulate the response of 44 plant species to climatic variables, soil physico-chemical properties and microbial decomposition activity (i.e. exoenzymatic activities) in the French Alps. Our hierarchical trait-based model allowed to predict well 41 species according to the TSS statistic. In addition to climate, the combination of soil C/N, as a measure of organic matter quality, and exoenzymatic activity, as a measure of microbial decomposition activity, strongly improved predictions of plant distributions. Plant traits played an important role. In particular, species with conservative traits performed better under limiting nutrient conditions but were outcompeted by exploitative plants in more favorable environments. We demonstrate tight associations between microbial decomposition activity, plant functional traits associated to different resource acquisition strategies and plant distributions. This highlights the importance of plant–soil linkages for mountain plant distributions. These results are crucial for biodiversity modelling in a world where both climatic and soil systems are undergoing profound and rapid transformations.
Auteurs, date et publication :
Auteurs Camille Martinez‐Almoyna , Gabin Piton , Sylvain Abdulhak , Louise Boulangeat , Philippe Choler , Thierry Delahaye , Cédric Dentant , Arnaud Foulquier , Jérôme Poulenard , Virgile Noble , Julien Renaud , Maxime Rome , Amélie Saillard , Wilfried Thuiller , Tamara Münkemüller
Publication : Ecography
Date : 2025
Volume : 43
Issue : 10
Pages : 1550-1559
Catégorie(s)
#CNRS #Lautaret #UGARésumé
The repetitive content of the plant genome (repeatome) often represents its largest fraction and is frequently correlated with its size. Transposable elements (TEs), the main component of the repeatome, are an important driver in the genome diversification due to their fast-evolving nature. Hybridization and polyploidization events are hypothesized to induce massive bursts of TEs resulting, among other effects, in an increase of copy number and genome size. Little is known about the repeatome dynamics following hybridization and polyploidization in plants that reproduce by apomixis (asexual reproduction via seeds). To address this, we analyzed the repeatomes of two diploid parental species, Hieracium intybaceum and H. prenanthoides (sexual), their diploid F1 synthetic and their natural triploid hybrids (H. pallidiflorum and H. picroides, apomictic). Using low-coverage next-generation sequencing (NGS) and a graph-based clustering approach, we detected high overall similarity across all major repeatome categories between the parental species, despite their large phylogenetic distance. Medium and highly abundant repetitive elements comprise ∼70% of Hieracium genomes; most prevalent were Ty3/Gypsy chromovirus Tekay and Ty1/Copia Maximus-SIRE elements. No TE bursts were detected, neither in synthetic nor in natural hybrids, as TE abundance generally followed theoretical expectations based on parental genome dosage. Slight over- and under-representation of TE cluster abundances reflected individual differences in genome size. However, in comparative analyses, apomicts displayed an overabundance of pararetrovirus clusters not observed in synthetic hybrids. Substantial deviations were detected in rDNAs and satellite repeats, but these patterns were sample specific. rDNA and satellite repeats (three of them were newly developed as cytogenetic markers) were localized on chromosomes by fluorescence in situ hybridization (FISH). In a few cases, low-abundant repeats (5S rDNA and certain satellites) showed some discrepancy between NGS data and FISH results, which is due partly to the bias of low-coverage sequencing and partly to low amounts of the satellite repeats or their sequence divergence. Overall, satellite DNA (including rDNA) was markedly affected by hybridization, but independent of the ploidy or reproductive mode of the progeny, whereas bursts of TEs did not play an important role in the evolutionary history of Hieracium.
Auteurs, date et publication :
Auteurs Danijela Zagorski , Matthias Hartmann , Yann J. K. Bertrand , Ladislava Paštová , Renata Slavíková , Jiřina Josefiová , Judith Fehrer
Publication : Frontiers in Plant Science
Date : 2020
Volume : 11
Catégorie(s)
#CNRS #Lautaret #UGAAuteurs, date et publication :
Auteurs Bruno Locatelli , Sandra Lavorel , Sean Sloan , Ulrike Tappeiner , Davide Geneletti
Publication : Frontiers in Ecology and the Environment
Date : 2025
Volume : 15
Issue : 3
Pages : 150-159
Catégorie(s)
#CNRS #Lautaret #UGARésumé
Cessation of traditional management threatens semi-natural grassland diversity through the colonisation or increase of competitive species adapted to nutrient-poor conditions. Regular mowing is one practice that controls their abundance. This study evaluated the ecophysiological mechanisms limiting short- and long-term recovery after mowing for Festuca paniculata, a competitive grass that takes over subalpine grasslands in the Alps following cessation of mowing. We quantified temporal variations in carbon (C) and nitrogen (N) content, starch, fructan and total soluble sugars in leaves, stem bases and roots of F. paniculata during one growth cycle in mown and unmown fields and related them to the dynamics of soil mineral N concentration and soil moisture. Short-term results suggest that the regrowth of F. paniculata following mowing might be N-limited, first because of N dilution by C increments in the plant tissue, and second, due to low soil mineral N and soil moisture at this time of year. However, despite short-term effects of mowing on plant growth, C and N content and concentration at the beginning of the following growing season were not affected. Nevertheless, total biomass accumulation at peak standing biomass was largely reduced compared to unmown fields. Moreover, lower C storage capacity at the end of the growing season impacted C allocation to vegetative reproduction during winter, thereby dramatically limiting the horizontal growth of F. paniculata tussocks in the long term. We conclude that mowing reduces the growth of F. paniculata tussocks through both C and N limitation. Such results will help understanding how plant responses to defoliation regulate competitive interactions within plant communities.
Auteurs, date et publication :
Auteurs F. Baptist , H. Secher-Fromell , F. Viard-Cretat , I. Aranjuelo , J.-C. Clement , A. Creme , M. Desclos , P. Laine , S. Nogues , S. Lavorel
Publication : Plant Biology
Date : 2025
Volume : 15
Issue : 2
Pages : 395-404
Catégorie(s)
#CNRS #Lautaret #UGARésumé
An important focus of community ecology, including invasion biology, is to investigate functional trait diversity patterns to disentangle the effects of environmental and biotic interactions. However, a notable limitation is that studies usually rely on a small and easy-to-measure set of functional traits, which might not immediately reflect ongoing ecological responses to changing abiotic or biotic conditions, including those that occur at a molecular or physiological level. We explored the potential of using the diversity of expressed genes—functional genomic diversity (FGD)—to understand ecological dynamics of a recent and ongoing alpine invasion. We quantified FGD based on transcriptomic data measured for 26 plant species occurring along adjacent invaded and pristine streambeds. We used an RNA-seq approach to summarize the overall number of expressed transcripts and their annotations to functional categories, and contrasted this with functional trait diversity (FTD) measured from a suite of characters that have been traditionally considered in plant ecology. We found greater FGD and FTD in the invaded community, independent of differences in species richness. However, the magnitude of functional dispersion was greater from the perspective of FGD than from FTD. Comparing FGD between congeneric alien–native species pairs, we did not find many significant differences in the proportion of genes whose annotations matched functional categories. Still, native species with a greater relative abundance in the invaded community compared with the pristine tended to express a greater fraction of genes at significant levels in the invaded community, suggesting that changes in FGD may relate to shifts in community composition. Comparisons of diversity patterns from the community to the species level offer complementary insights into processes and mechanisms driving invasion dynamics. FGD has the potential to illuminate cryptic changes in ecological diversity, and we foresee promising avenues for future extensions across taxonomic levels and macro-ecosystems.
Auteurs, date et publication :
Auteurs Hannah E. Marx , Marta Carboni , Rolland Douzet , Christophe Perrier , Franck Delbart , Wilfried Thuiller , Sébastien Lavergne , David C. Tank
Publication : Ecology and Evolution
Date : 2025
Volume : 11
Issue : 17
Pages : 12075-12091
Catégorie(s)
#ANR-Citation #CNRS #Lautaret #UGAAuteurs, date et publication :
Auteurs Isabelle Boulangeat , Damien Georges , Cédric Dentant , Richard Bonet , Jérémie Van Es , Sylvain Abdulhak , Niklaus E. Zimmermann , Wilfried Thuiller
Publication : Ecography
Date : 2025
Volume : 37
Issue : 12
Pages : 1230-1239
Catégorie(s)
#CNRS #Lautaret #UGARésumé
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 #UGARésumé
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 #UGARésumé
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
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