Résumé

In Mediterranean ecosystems, the projected rainfall reduction of up to 30% may alter plant–soil interactions, particularly litter decomposition and Home Field Advantage (HFA). We set up a litter transplant experiment in the three main forests encountered in the northern part of the Medi-terranean Basin (dominated by either Quercus ilex, Quercus pubescens, or Pinus halepensis) equipped with a rain exclusion device, allowing an increase in drought either throughout the year or concentrated in spring and summer. Senescent leaves and needles were collected under two precipitation treatments (natural and amplified drought plots) at their “home” forest and were left to decompose in the forest of origin and in other forests under both drought conditions. MS-based metabolomic analysis of litter extracts combined with multivariate data analysis enabled us to detect modifications in the composition of litter specialized metabolites, following amplified drought treatment. Amplified drought altered litter quality and metabolomes, directly slowed down litter decomposition, and induced a loss of home field (dis)advantage. No indirect effect mediated by a change in litter quality on decomposition was observed. These results may suggest major alterations of plant–soil interactions in Mediterranean forests under amplified drought conditions.

Auteurs, date et publication :

Auteurs Elodie Quer , Susana Pereira , Thomas Michel , Mathieu Santonja , Thierry Gauquelin , Guillaume Simioni , Jean-Marc Ourcival , Richard Joffre , Jean-Marc Limousin , Adriane Aupic-Samain , Caroline Lecareux , Sylvie Dupouyet , Jean-Philippe Orts , Anne Bousquet-Mélou , Raphaël Gros , Marketa Sagova-Mareckova , Jan Kopecky , Catherine Fernandez , Virginie Baldy

Publication : Plants

Date : 2025

Volume : 11

Issue : 19

Pages : 2582

Catégorie(s)

#ANR-Citation #CNRS #FORET Puechabon

Résumé

The intensification of summer drought expected with climate change can induce metabolism modifications in plants to face such constraints. In this experiment, we used both a targeted approach focused on flavonoids, as well as an untargeted approach, to study a broader fraction of the leaf metabolome of Quercus pubescens exposed to amplified drought. A forest site equipped with a rainfall exclusion device allowed reduction of natural rainfall by ~30% over the tree canopy. Leaves of natural drought (ND) and amplified drought (AD) plots were collected over three seasonal cycles (spring, summer, and autumn) in 2013 (the second year of rain exclusion), 2014, and 2015. As expected, Q. pubescens metabolome followed a seasonal course. In the summer of 2015, the leaf metabolome presented a shifted and early autumnal pattern because of harsher conditions during this year. Despite low metabolic modification at the global scale, our results demonstrated that 75% of Quercus metabolites were upregulated in springs when trees were exposed to AD, whereas 60 to 73% of metabolites (93% in summer 2015), such as kaempferols and quercetins, were downregulated in summers/autumns. Juglanin, a kaempferol pentoside, as well as rhododendrin derivatives, were upregulated throughout the year, suggesting an antioxidant ability of these metabolites. Those changes in terms of phenology and leaf chemistry could, in the end, affect the ecosystem functioning.

Auteurs, date et publication :

Auteurs Amélie Saunier , Stéphane Greff , James D. Blande , Caroline Lecareux , Virginie Baldy , Catherine Fernandez , Elena Ormeño

Publication : Metabolites

Date : 2022

Volume : 12

Issue : 4

Pages : 307

Catégorie(s)

#CNRS #FORET O3HP

Résumé

Mountain regions face substantial challenges and opportunities arising from global change. The capacity of mountain regions for (systemic) innovation will be determinant to the success of system transformations envisioned by social actors of mountain communities. By analysing the social networks of two regions in the Alps and relating them to desired future visions of sustainable regional development, we provide insights about innovative capacities in mountain regions and propose how to strengthen these capacities in order to support regional transformations. In particular, we analyse innovation systems’ collaboration networks to evaluate the innovative capacity of communities, co-construct visions with mountain stakeholders, and assess innovation requirements to meet these visions. Accordingly, we propose changes to the collaboration networks for addressing regional innovation system (RIS) capacities to help achieve visions through systemic innovation. Our analysis furthers the understanding on the type and magnitude of regional innovation system changes required to more effectively address desired transformative visions in mountain regions. We close by discussing implications of our approach for the assessment of innovative capacity and the transformation of mountain regions.

Auteurs, date et publication :

Auteurs Victor Blanco , Tobias Luthe , Enora Bruley , Adrienne Grêt-Regamey

Publication : Regional Environmental Change

Date : 2025

Volume : 23

Issue : 3

Pages : 102

Catégorie(s)

#CNRS #Lautaret #UGA

Résumé

Sanguina nivaloides is the main alga forming red snowfields in high mountains and Polar Regions. It is non-cultivable. Analysis of environmental samples by X-ray tomography, focused-ion-beam scanning-electron-microscopy, physicochemical and physiological characterization reveal adaptive traits accounting for algal capacity to reside in snow. Cysts populate liquid water at the periphery of ice, are photosynthetically active, can survive for months, and are sensitive to freezing. They harbor a wrinkled plasma membrane expanding the interface with environment. Ionomic analysis supports a cell efflux of K+, and assimilation of phosphorus. Glycerolipidomic analysis confirms a phosphate limitation. The chloroplast contains thylakoids oriented in all directions, fixes carbon in a central pyrenoid and produces starch in peripheral protuberances. Analysis of cells kept in the dark shows that starch is a short-term carbon storage. The biogenesis of cytosolic droplets shows that they are loaded with triacylglycerol and carotenoids for long-term carbon storage and protection against oxidative stress.

Auteurs, date et publication :

Auteurs Jade A. Ezzedine , Clarisse Uwizeye , Grégory Si Larbi , Gaelle Villain , Mathilde Louwagie , Marion Schilling , Pascal Hagenmuller , Benoît Gallet , Adeline Stewart , Dimitris Petroutsos , Fabienne Devime , Pascal Salze , Lucie Liger , Juliette Jouhet , Marie Dumont , Stéphane Ravanel , Alberto Amato , Jean-Gabriel Valay , Pierre-Henri Jouneau , Denis Falconet

Publication : Nature Communications

Date : 2023

Volume : 14

Issue : 1

Pages : 7500

Catégorie(s)

#CNRS #Lautaret #UGA

Résumé

Co-deployment of a portfolio of carbon removal technologies is anticipated in order to remove several gigatons of carbon dioxide from the atmosphere and meet climate targets. However, co-application effects between carbon removal technologies have rarely been examined, despite multiple recent perspectives suggesting potential synergies between basalt enhanced weathering and biochar application. To study the co-application effects of basalt for enhanced weathering and biochar on carbon sequestration, along with related co-benefits and risks, we conducted a fully replicated factorial mesocosm experiment with wheat. Basalt applied alone (74 t ha−1) resulted in an estimated carbon sequestration potential of 1.13 t of equivalent CO2 ha−1 over the course of approximately 6 months. Co-application with biochar (12 t ha−1) did not significantly increase estimated carbon sequestration potential. Total alkalinity fluxes and isotopic evidence indicated nearly exactly additive effects of basalt and biochar co-applied, with no significant interaction effect. Biochar carbon sequestration, approximately 32 t of equivalent CO2 ha−1 in our experiment, was unaffected by basalt addition during our experiment. Co-benefits of basalt and biochar on plant biomass as well as nutrient uptake and availability similarly mostly showed additive tendencies when co-applied. Nonetheless, a few synergistic tendencies were observed when co-applied for plant potassium and magnesium uptake as well as soil calcium availability. Soil calcium availability increased by 126% compared to expected effects based on separate application. Finally, we did not observe a reduction in the increased uptake of potentially harmful trace elements released from basalt when co-applied with biochar. Overall, our results support the co-application of basalt for enhanced weathering and biochar, with additive effects on carbon sequestration and additive, if not synergistic, effects on associated co-benefits.

Auteurs, date et publication :

Auteurs Nicolas Honvault , Marie-Laure Tiouchichine , Joana Sauze , Clément Piel , Damien Landais , Sébastien Devidal , Emmanuel Gritti , Delphine Bosch , Alexandru Milcu

Publication : Applied Geochemistry

Date : 2024

Volume : 169

Pages : 106054

Catégorie(s)

#CNRS #Ecotron de Montpellier #Ecotron IleDeFrance #ENS

Résumé

Biochar undergoes changes that start almost immediately after removal from the reactor and continue indefinitely after application to soil. Such changes affect the physical-chemical properties of the biochar including particle size distribution, elemental content, oxidation state, acidity, ion exchange capacities, aliphatic and aromatic contents, degree of aromatic condensation, surface and pore characteristics, loss of matter from the biomass body, and other properties. Known as aging or weathering, these changes can influence the interaction of particles with small molecules and ions, dissolved natural organic matter, metal oxides and ions, and cells. This chapter reviews advances in knowledge and understanding of aging processes and their impacts since a similar chapter in the previous edition of the book. It discusses experimental methods of aging and their merits and shortcomings; transport of biochar particles and colloids in the soil profile; short- and long-term alterations in the physical-chemical properties of biochars; redox behavior of biochars; the effects of aging on the sorption of organic compounds; and the effects of aging on the reactions and sorption of metals.

Auteurs, date et publication :

Auteurs Joseph J. Pignatello , Minori Uchimiya , Samuel Abiven

Date : 2025

Catégorie(s)

#CNRS #Ecotron de Montpellier #Ecotron IleDeFrance #ENS

Résumé

Flowering phenology is important in the adaptation of many plants to their local environment, but its adaptive value has not been extensively studied in herbaceous perennials. We used Arabis alpina as a model system to determine the importance of flowering phenology to fitness of a herbaceous perennial with a wide geographical range. Individual plants representative of local genetic diversity (accessions) were collected across Europe, including in Spain, the Alps and Scandinavia. The flowering behaviour of these accessions was documented in controlled conditions, in common-garden experiments at native sites and in situ in natural populations. Accessions from the Alps and Scandinavia varied in whether they required exposure to cold (vernalization) to induce flowering, and in the timing and duration of flowering. By contrast, all Spanish accessions obligately required vernalization and had a short duration of flowering. Using experimental gardens at native sites, we show that an obligate requirement for vernalization increases survival in Spain. Based on our analyses of genetic diversity and flowering behaviour across Europe, we propose that in the model herbaceous perennial A. alpina, an obligate requirement for vernalization, which is correlated with short duration of flowering, is favoured by selection in Spain where the plants experience a long growing season.

Auteurs, date et publication :

Auteurs Jörg Wunder , Andrea Fulgione , Per Toräng , Stefan Wötzel , Michel Herzog , José Ramón Obeso , Yiannis Kourmpetis , Roeland van Ham , Thomas Odong , Marco Bink , Ulla Kemi , Jon Ågren , George Coupland

Publication : Proceedings of the Royal Society B: Biological Sciences

Date : 2023

Volume : 290

Issue : 2011

Pages : 20231401

Catégorie(s)

#CNRS #Lautaret #UGA

Résumé

Freshwater ecosystems are increasingly exposed to pharmaceutical contamination, impacting non-target species. Concentrations can vary over time and location, allowing for potential acclimation or recovery effects. Additionally, parasites might interfere with the absorption and adverse outcomes pathways of pollutants. We examined the combined effects of paracetamol and parasite on the behavior and coloration of the European chub (Squalius cephalus), a ubiquitous fish species, from natural populations. Fish were exposed in mesocosms to acute doses of paracetamol (16 μg g−1 once a day over two days), followed by lower doses during a long-term exposure (1.6 μg g−1 once a week over three weeks), followed by a three-week recovery phase. Acute exposure induced marginal decreases in behavioral activity, and changes in dorsal brightness, hue and UV luminance. Interestingly, the long-term phase alone did not yield notable results on behavior and coloration. However, some effects of the acute exposure persisted during the long-term phase, highlighting that the expression of biological responses may be delayed in relation to past high exposure. Parasitism did not attenuate acute impacts, suggesting parasites may not help mitigate effects of paracetamol on behavior and coloration, but alone increased activity levels slightly. No effects of pollutant exposure, either of the acute or long-term phase, were observed after a recovery phase, indicating ability for recovery dynamics. Overall, our findings emphasize that pollutants effects can be highly transient, with rapid recovery when pollutant exposure ceased. Considering different exposure phases is crucial when assessing the ecological consequences of environmental contaminants.

Auteurs, date et publication :

Auteurs Léa Lorrain-Soligon , Alexis Golven , Simon Agostini , Alexis Millot , Alexandre Bauer , Thierry Rigaud , Beatriz Decencière , Carine Puppo , Aurélie Goutte

Publication : Chemosphere

Date : 2025

Volume : 374

Pages : 144225

Catégorie(s)

#ANR-Citation #CNRS #PLANAQUA

Résumé

Conventionally, the Bowen ratio method and eddy covariance are used to measure evapotranspiration (ET); however, they have limited accuracy. Inverse analysis (IA), a novel method presented here, can estimate evapotranspiration (ETa) using commonly measured climatic variables. However, because actual ET data are limited, the accuracy of IA remains uncertain. Recently, IA accuracy has been improved, thus, observed latent heat flux (lEobs) in FLUXNET2015 data, a global dataset, and estimated values can be compared. Herein, we aim to evaluate the accuracy of the IA method. Eight forest sites in the dataset during 2000–2014 were selected as test sites, and hourly, daily, monthly, and yearly comparisons of lEobs and ETa were conducted using regression analysis and root mean square error (RMSE) calculations. The results are as follows: ① Comparison of lEobs-hourly and ETa for all sites showed a similar pattern, with an average root mean square error (RMSE) of 0.0053 mm h−1. ② Comparison of lEobs-daily and ETa showed high correlation coefficients, with slopes ranging from 1.016–0.717 and an average RMSE of 1.08 mm h−1. ③ Comparison of lEobs-monthly and ETa showed similar patterns, with slopes ranging from 1.042–0.811 and an average RMSE of 17.9 mm m−1. ④ The slope of lEobs-yearly and ETa was 0.988 and the average RMSE was 71.0 mm year−1. ⑤ The average of lEobs-yearly and ETa showed a strong relationship, with a slope of 0.992. ⑥ The differences between the time steps of lEobs and ETa were evaluated qualitatively using RMSE/lEobs-yearly, with hourly–yearly differences of 8.4%, 70.2%, 40.4%, and 14.2%, respectively. The above results indicate that IA can be used for an accurate estimation of ET. The findings of this study contribute significantly to water management and a deeper understanding of the hydrologic cycle.

Auteurs, date et publication :

Auteurs Toshisuke Maruyama , Sanshiro Fujii

Publication : Hydrological Processes

Date : 2025

Volume : 36

Issue : 12

Pages : e14762

Catégorie(s)

#CNRS #FORET Puechabon

Résumé

The re-assembly of plant communities during climate warming depends on several concurrent processes. Here, we present a novel framework that integrates spatially explicit sampling, plant trait information and a warming experiment to quantify shifts in these assembly processes. By accounting for spatial distance between individuals, our framework allows separation of potential signals of environmental filtering from those of different types of competition. When applied to an elevational transplant experiment in the French Alps, we found common signals of environmental filtering and competition in all communities. Signals of environmental filtering were generally stronger in alpine than in subalpine control communities, and warming reduced this filter. Competition signals depended on treatments and traits: Symmetrical competition was dominant in control and warmed alpine communities, while hierarchical competition was present in subalpine communities. Our study highlights how distance-dependent frameworks can contribute to a better understanding of transient re-assembly dynamics during environmental change.

Auteurs, date et publication :

Auteurs Billur Bektaş , Wilfried Thuiller , Julien Renaud , Maya Guéguen , Irene Calderón-Sanou , Jean-Gabriel Valay , Marie-Pascale Colace , Tamara Münkemüller

Publication : Ecology Letters

Date : 2025

Volume : 26

Issue : 7

Pages : 1119-1131

Catégorie(s)

#CNRS #Lautaret #UGA