Résumé
Whether the success of alien species can be explained by their functional or phylogenetic characteristics remains unresolved because of data limitations, scale issues and weak quantifications of success. Using permanent grasslands across France (50 000 vegetation plots, 2000 species, 130 aliens) and building on the Rabinowitz’s classification to quantify spread, we showed that phylogenetic and functional similarities to natives were the most important correlates of invasion success compared to intrinsic functional characteristics and introduction history. Results contrasted between spatial scales and components of invasion success. Widespread and common aliens were similar to co-occurring natives at coarse scales (indicating environmental filtering), but dissimilar at finer scales (indicating local competition). In contrast, regionally widespread but locally rare aliens showed patterns of competitive exclusion already at coarse scale. Quantifying trait differences between aliens and natives and distinguishing the components of invasion success improved our ability to understand and potentially predict alien spread at multiple scales.
Auteurs, date et publication :
Auteurs Marta Carboni , Tamara Münkemüller , Sébastien Lavergne , Philippe Choler , Benjamin Borgy , Cyrille Violle , Franz Essl , Cristina Roquet , François Munoz , DivGrass Consortium , Wilfried Thuiller , Elsa Cleland
Publication : Ecology Letters
Date : 2025
Volume : 19
Issue : 3
Pages : 219-229
Catégorie(s)
#CNRS #Lautaret #UGARésumé
The topographical heterogeneity of mountain landscapes and the associated species turnover over short distances should prompt us to examine the relationships between climate and mountain plant distribution at a much finer scale than is commonly done. Here, I focused on the root zone temperature experienced by lowstature perennial-dominated plant communities of temperate mountains, which are seasonally covered by snow. Based on the analysis of multi-annual recordings of ground temperatures across a broad spectrum of plant communities, I propose a habitat template using Growing Degree Days (GDD) and Freezing Degree Days (FDD). These two indices summarize soil thermal conditions experienced during the favorable and the unfavorable period for growth. This heuristic framework allows refining our working hypotheses on the range shifts of mountain plants in response to recent and future climate change. Regional trends in climate variables controlling GDD and FDD indicate that the combination of earlier snow melt-out and higher summer temperatures have led to an overall increase in GDD over the last decades. However the persistence of cold episodes in spring and in fall along with the shorter snow coverage suggest that the positive effect of an extended growing season might be counteracted by the detrimental effects of increasing FDD. I thus hypothesize (i) a local-scale, downward shift of plant species along mesotopographical gradients, with marked species infilling in sparsely vegetated, longlasting snow patches that contain vacant niches and (ii) a watershed-scale upward shift of subalpine species inhabiting south-exposed grasslands and able to cope with moderate FDD. This perspective challenges the simplistic view of an overall range shift of mountain plants along elevational gradients and calls for the improvement of models of snow cover dynamics and root zone temperature to draw up realistic scenarios of mountain vegetation changes under a warmer climate.
Auteurs, date et publication :
Auteurs P. Choler
Publication : Perspectives in Plant Ecology, Evolution and Systematics
Date : 2025
Volume : 30
Pages : 6-15
Catégorie(s)
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Auteurs Adeline Francois , Juliette Rousset , Marie Didier , André Evette
Date : 2024
Catégorie(s)
#CNRS #Lautaret #UGAAuteurs, date et publication :
Auteurs Bradley Z. Carlson , Christophe F. Randin , Isabelle Boulangeat , Sébastien Lavergne , Wilfried Thuiller , Philippe Choler
Publication : Alpine Botany
Date : 2025
Volume : 123
Issue : 2
Pages : 41-53
Catégorie(s)
#CNRS #Lautaret #UGARésumé
Despite several studies on the Ajuga L. genus, the chemical composition of Ajuga pyramidalis, an alpine endemic species, is still largely unknown. The purpose of this study was to therefore deeper describe it, particularly from the phytochemistry and bioactivity perspectives. In that respect, A. pyramidalis was investigated and 95% of the extracted mass of the plant was characterized by chromatography and mass spectrometry. Apart from the already determined chemical compounds, namely, harpagide and 8-O-acetylharpagide, two iridoids, and neoajugapyrin A, a neo-clerodane diterpene, and three polyphenols (echinacoside, verbascoside and teupoloside) were identified for the first time in A. pyramidalis. Incidentally, the first RX structure of a harpagoside derivative is also described in this paper. The extracts and isolated compounds were then evaluated for various biochemical or biological activities; notably a targeted action on the renewal of the epidermis was highlighted with potential applications in the cosmetic field for anti-aging.
Auteurs, date et publication :
Auteurs Anthonin Gori , Benjamin Boucherle , Aurélien Rey , Maxime Rome , Caroline Barette , Emmanuelle Soleilhac , Christian Philouze , Marie-Odile Fauvarque , Nicola Fuzzati , Marine Peuchmaur
Publication : Metabolites
Date : 2023
Volume : 13
Issue : 1
Pages : 128
Catégorie(s)
#CNRS #Lautaret #UGARésumé
The species-richness of the flora in the European Alps results from complex interactions between geographical, climatic and environmental factors. In this study, we focus on a complex of closely related Alpine plants: Primula hirsuta, P. pedemontana and their relatives. Using a large DNA dataset of thousands of single-nucleotide polymorphisms sequenced across 149 individuals spanning all the western Alps, we refine phylogenetic relationships in this clade and explore the evolutionary origins of a mysterious lineage found in one valley of the Écrins range (France): the Valgaudemar. In particular, we demonstrate that this lineage did not originate from a simple allopatric divergence, but from an isolated lineage related to Primula pedemontana, which later got introgressed by P. hirsuta. This leads us to develop a phylogeographic scenario explaining the origins of the Valgaudemar lineage, and shed light on a potential glacial refugium in the south of the Écrins range. We believe this study takes part in the deep understanding of the origins of endemism in the European Alps and more generally of the maintaining of species diversity.
Auteurs, date et publication :
Auteurs Camille Voisin , Cédric Dentant , Delphine Rioux , Florian C. Boucher
Publication : Alpine Botany
Date : 2023
Volume : 133
Issue : 1
Pages : 21-33
Catégorie(s)
#CNRS #Lautaret #UGARésumé
Aim Two core assumptions of species distribution models (SDMs) do not hold when modelling invasive species. Invasives are not in equilibrium with their environment and niche quantification and transferability in space and time are limited. Here, we test whether combining global- and regional-scale data in a novel framework can overcome these limitations. Beyond simply improving regional niche modelling of non-native species, the framework also makes use of the violation of regional equilibrium assumptions, and aims at estimating the stage of invasion, range filling and risk of spread in the near future for 27 invasive species in the French Alps. Innovation For each invader we built three sets of SDMs using a committee averaging method: one global model and two regional models (a conventional model and one using the global model output to weight pseudo-absences). Model performances were compared using the area under the receiver operating characteristic curve, the true skill statistic, sensitivity and specificity scores. Then, we extracted the predictions for observed presences and compared them to global and regional models. This comparison made it possible to identify whether invasive species were observed within or outside of their regional and global niches. Main conclusions This study provides a novel methodological framework for improving the regional modelling of invasive species, where the use of a global model output to weight pseudo-absences in a regional model significantly improved the predictive performance of regional SDMs. Additionally, the comparison of the global and regional model outputs revealed distinct patterns of niche estimates and range filling among the species. These differences allowed us to draw conclusions about the stage of invasion and the risk of spread in the near future, which both correspond to experts' expectations. This framework can be easily applied to a large number of species and is therefore useful for control of biological invasions and eradication planning.
Auteurs, date et publication :
Auteurs Laure Gallien , Rolland Douzet , Steve Pratte , Niklaus E. Zimmermann , Wilfried Thuiller
Publication : Global Ecology and Biogeography
Date : 2025
Volume : 21
Issue : 11
Pages : 1126-1136
Catégorie(s)
#CNRS #Lautaret #UGARésumé
Rock glaciers are creeping bodies of ice and rock that account for an important part of the mountain cryosphere. In this study, we investigated long-term changes of the Laurichard rock glacier (French Alps), to understand how this rock glacier is responding to climate change. Using feature-tracking and photogrammetric measurements between 1952 and 2019, we quantified changes in thickness, flow velocities and from which we derived the ice/rock flux of the rock glacier at a decadal time scale. This is the first time that emergence velocity and surface mass balance changes have been reconstructed for a rock glacier. Our results reveal a very small surface mass balance ranging from −0.1 m a−1 to +0.05 m a−1, reflecting the role of debris in damping the melt rate of the underlying ice. Surprisingly, we found a more negative surface mass balance in the upper part than in the lower part of the rock glacier during the 1952–1971 cold period, likely due to a reduction in rock and snow mass accumulation. Our study shows that thickness changes are mainly driven by changes in surface mass balance except during the most recent period in the lower part of the rock glacier, which was also influenced by a compressive flow related to a protrusion that prevented the rock glacier from advancing. We conclude that the period 1994–2019 witnessed a marked acceleration in rock glacier flow, in agreement with the observations of other rock glaciers in the European Alps. This strong increase in surface speed is likely a consequence of changes in the basal conditions.
Auteurs, date et publication :
Auteurs Diego Cusicanqui , Antoine Rabatel , Christian Vincent , Xavier Bodin , Emmanuel Thibert , Bernard Francou
Publication : Journal of Geophysical Research: Earth Surface
Date : 2025
Volume : 126
Issue : 9
Pages : e2021JF006161
Catégorie(s)
#CNRS #Lautaret #UGARésumé
Annual plants usually flower and set seed once before senescence results in the death of the whole plant (monocarpic senescence). Leaf senescence also occurs in polycarpic perennials; even in “evergreen” species individual leaves senesce. In the annual model Arabidopsis thaliana sugars accumulate in the senescent leaves and senescence is accelerated by high sugar availability. Similar to A. thaliana, sugar contents increased with leaf age in the perennial Arabis alpina grown under warm conditions (22 ◦C day/18 night). At 5 ◦C, sugar contents in non-senescent leaves were higher than at a warm temperature, but dependent on the accession, either sugars did not accumulate or their contents decreased in old leaves. In A. alpina plants grown in their natural habitat in the Alps, sugar contents declined with leaf age. Growth at a cold temperature slightly delayed senescence in A. alpina. In both warm and cold conditions, an external glucose supply accelerated senescence, but natural variation was found in this response. In conclusion, sugar accumulation under warm conditions could accelerate leaf senescence in A. alpina plants, but genotype-specific responses and interactions with growth temperature are likely to influence senescence under natural conditions.
Auteurs, date et publication :
Auteurs Astrid Wingler , Emma Josefine Stangberg , Triambak Saxena , Rupal Mistry
Publication : Journal of Integrative Plant Biology
Date : 2025
Volume : 54
Issue : 8
Pages : 595-605
Catégorie(s)
#CNRS #Lautaret #UGARésumé
A growing body of work examines the direct and indirect effects of climate change on ecosystems, typically by using manipulative experiments at a single site or performing meta-analyses across many independent experiments. However, results from single-site studies tend to have limited generality. Although meta-analytic approaches can help overcome this by exploring trends across sites, the inherent limitations in combining disparate datasets from independent approaches remain a major challenge. In this paper, we present a globally distributed experimental network that can be used to disentangle the direct and indirect effects of climate change. We discuss how natural gradients, experimental approaches, and statistical techniques can be combined to best inform predictions about responses to climate change, and we present a globally distributed experiment that utilizes natural environmental gradients to better understand long-term community and ecosystem responses to environmental change. The warming and (species) removal in mountains (WaRM) network employs experimental warming and plant species removals at high- and low-elevation sites in a factorial design to examine the combined and relative effects of climatic warming and the loss of dominant species on community structure and ecosystem function, both above- and belowground. The experimental design of the network allows for increasingly common statistical approaches to further elucidate the direct and indirect effects of warming. We argue that combining ecological observations and experiments along gradients is a powerful approach to make stronger predictions of how ecosystems will function in a warming world as species are lost, or gained, in local communities.
Auteurs, date et publication :
Auteurs Case M. Prager , Aimee T. Classen , Maja K. Sundqvist , Maria Noelia Barrios-Garcia , Erin K. Cameron , Litong Chen , Chelsea Chisholm , Thomas W. Crowther , Julie R. Deslippe , Karl Grigulis , Jin-Sheng He , Jeremiah A. Henning , Mark Hovenden , Toke T. Thomas Høye , Xin Jing , Sandra Lavorel , Jennie R. McLaren , Daniel B. Metcalfe , Gregory S. Newman , Marie Louise Nielsen
Publication : Ecology and Evolution
Date : 2025
Volume : 12
Issue : 10
Pages : e9396