Résumé
Over the centuries, specific farming practices shaped permanent grasslands in mountains. With socioeconomic change, farming practices have changed and with them the landscape. Over time, food production has been increasingly decoupled from the preservation of permanent grassland, endangering the delivery of crucial ecosystem services. This contribution looks into the role of institutions – including normative, regulative and cultural-cognitive elements – in preserving current bundles of ecosystem services provided by mountain grasslands. In particular, we investigate how such institutions affect farmers’ management choices. Based on a review of scientific literature and empirical data from three case studies, we compare institutions in Austria, France and Norway. The cases represent different modes of multi-level governance (EU and non-EU), different grassland management practices, linked to different farming systems (dairy, breeding, rearing of heifers, suckler cow and sheep production) and different socio-economic conditions. The results underpin that ecological insights into the impact of farming practices on the ecology of grassland need to be combined with an understanding of the complex institutional interactions that affect farming practices, to ensure the resilience of mountain grasslands. If the design of regulatory measures considers both changing dynamics, it may enable farms to adapt and transform while maintaining traditional grassland management practices © 2015 Elsevier Ltd. All rights reserved.
Auteurs, date et publication :
Auteurs Markus Schermer , Ika Darnhofer , Karoline Daugstad , Marine Gabillet , Sandra Lavorel , Melanie Steinbacher
Publication : Land Use Policy
Date : 2025
Volume : 52
Pages : 382-391
Catégorie(s)
#CNRS #Lautaret #UGARésumé
Abstract. Light-absorbing particles (LAPs) such as black carbon or mineral dust are some of the main drivers of snow radiative transfer. Small amounts of LAPs significantly increase snowpack absorption in the visible wavelengths where ice absorption is particularly weak, impacting the surface energy budget of snow-covered areas. However, linking measurements of LAP concentration in snow to their actual radiative impact is a challenging issue which is not fully resolved. In the present paper, we point out a new method based on spectral irradiance profile (SIP) measurements which makes it possible to identify the radiative impact of LAPs on visible light extinction in homogeneous layers of the snowpack. From this impact on light extinction it is possible to infer LAP concentrations present in each layer using radiative transfer theory. This study relies on a unique dataset composed of 26 spectral irradiance profile measurements in the wavelength range 350–950 nm with concomitant profile measurements of snow physical properties and LAP concentrations, collected in the Alps over two snow seasons in winter and spring conditions. For 55 homogeneous snow layers identified in our dataset, the concentrations retrieved from SIP measurements are compared to chemical measurements of LAP concentrations. A good correlation is observed for measured concentrations higher than 5 ng g−1 (r2=0.81) despite a clear positive bias. The potential causes of this bias are discussed, underlining a strong sensitivity of our method to LAP optical properties and to the relationship between snow microstructure and snow optical properties used in the theory. Additional uncertainties such as artefacts in the measurement technique for SIP and chemical contents along with LAP absorption efficiency may explain part of this bias. In addition, spectral information on LAP absorption can be retrieved from SIP measurements. We show that for layers containing a unique absorber, this absorber can be identified in some cases (e.g. mineral dust vs. black carbon). We also observe an enhancement of light absorption between 350 and 650 nm in the presence of liquid water in the snowpack, which is discussed but not fully elucidated. A single SIP acquisition lasts approximately 1 min and is hence much faster than collecting a profile of chemical measurements. With the recent advances in modelling LAP–snow interactions, our method could become an attractive alternative to estimate vertical profiles of LAP concentrations in snow.
Auteurs, date et publication :
Auteurs Francois Tuzet , Marie Dumont , Laurent Arnaud , Didier Voisin , Maxim Lamare , Fanny Larue , Jesus Revuelto , Ghislain Picard
Publication : The Cryosphere
Date : 2019
Volume : 13
Issue : 8
Pages : 2169-2187
Catégorie(s)
#CNRS #Lautaret #UGARésumé
Although it is known that multiple interactions among plant functional traits, microbial properties, and abiotic soil parameters influence the nutrient turnover, the relative contribution of each of these groups of variables is poorly understood. We manipulated grassland plant functional composition and soil nitrogen (N) availability in a multisite mesocosm experiment to quantify their relative effects on soil N turnover. Overall, root traits, arbuscular mycorrhizal colonization, denitrification potential, as well as N availability and water availability, best explained the variation in measured ecosystem properties, especially the trade-off between nutrient sequestration and plant biomass production. Their relative contributions varied with soil N availability. In relatively N-p oor soils (10–20 μg·N·g−1 soil), N turnover was mainly controlled by microbial properties and abiotic soil parameters, whereas in the relatively N-rich soils (110–120 μg·N·g−1 soil), N turnover was mainly controlled by plant traits and microbial properties. This experiment is a strong demonstration of the importance of functional characteristics of both plants and soil microbes, and their interplay with soil N availability, for N turnover in grassland soils.
Auteurs, date et publication :
Auteurs Nicolas Legay , Sandra Lavorel , Catherine Baxendale , Ute Krainer , Michael Bahn , Marie-Noëlle Binet , Amélie A. M. Cantarel , Marie-Pascale Colace , Arnaud Foulquier , Eva-Maria Kastl , Karl Grigulis , Bello Mouhamadou , Franck Poly , Thomas Pommier , Michael Schloter , Jean-Christophe Clément , Richard D. Bardgett
Publication : Ecosphere
Date : 2025
Volume : 7
Issue : 11
Pages : e01448
Catégorie(s)
#CNRS #Lautaret #UGARésumé
Alpine plants like Soldanella alpina L. are subjected to high PAR and high UV radiation. Among the important photoprotective mechanisms that prevent photoinhibition under such conditions, passive optical barriers such as UV-absorbing compounds were investigated. In this study, temporal and spatial patterns of epidermal UV-A absorbance for S. alpina leaves were investigated with a combination of absorbance measurements at 375 nm and imaging methods. UV-A absorbance was highest in plants acclimated to full sunlight and was markedly stable during the leaves’ lifetime. UV-A absorbance was correlated with leaf structure (leaf mass per area ratio, density of epidermal cells and stomata) and biochemical features such as chlorophyll and carotenoid content and ratio, which are characteristics of light acclimation. UV-A-absorbing compounds were mainly localised in the epidermal vacuoles and trichomes. Leaves with low UV-A absorbance were significantly more photosensitive than leaves with high UV-A absorbance. However, the epidermal UV-A absorbance increased in low-absorbance leaves under full sunlight even in the absence of UV radiation. Results suggest that high epidermal UV-A absorbance protects S. alpina leaves from photoinactivation, which is especially important after snowmelt, when plants are suddenly exposed to full sunlight.
Auteurs, date et publication :
Auteurs Constance Laureau , Sylvie Meyer , Xavier Baudin , Christophe Huignard , Peter Streb
Publication : Functional Plant Biology
Date : 2025
Volume : 42
Issue : 7
Pages : 599
Catégorie(s)
#CNRS #Lautaret #UGARésumé
Abstract. From the micro- to the mesoscale, water and energy budgets of mountainous catchments are largely driven by topographic features such as terrain orientation, slope, steepness, and elevation, together with associated meteorological forcings such as precipitation, solar radiation, and wind speed. Those topographic features govern the snow deposition, melting, and transport, which further impacts the overall water cycle. However, this microscale variability is not well represented in Earth system models due to coarse resolutions. This study explores the impact of precipitation, shortwave radiation, and wind speed on the water budget distribution over a 15.28 ha small, mid-elevation (2000–2200 m) alpine catchment at Col du Lautaret (France). The grass-dominated catchment remains covered with snow for 5 to 6 months per year. The surface–subsurface coupled distributed hydrological model ParFlow-CLM is used at a very high resolution (10 m) to simulate the impacts on the water cycle of meteorological variability at very small spatial and temporal scales. These include 3D simulations of hydrological fluxes with spatially distributed forcing of precipitation, shortwave radiation, and wind speed compared to 3D simulations of hydrological fluxes with non-distributed forcing. Our precipitation distribution method encapsulates the spatial snow distribution along with snow transport. The model simulates the dynamics and spatial variability of snow cover using the Common Land Model (CLM) energy balance module and under different combinations of distributed forcing. The resulting subsurface and surface water transfers are computed by the ParFlow module. Distributed forcing leads to spatially heterogeneous snow cover simulation, which becomes patchy at the end of the melt season and shows a good agreement with the remote sensing images (mean bias error (MBE) = 0.22). This asynchronous melting results in a longer melting period compared to the non-distributed forcing, which does not generate any patchiness. Among the distributed meteorological forcings tested, precipitation distribution, including snow transport, has the greatest impact on spatial snow cover (MBE = 0.06) and runoff. Shortwave radiation distribution has an important impact, reducing evapotranspiration as a function of the slope orientation (decreasing the slope between observed and simulated evapotranspiration from 1.55 to 1.18). For the primarily east-facing catchment studied here, distributing shortwave radiation helps generate realistic timing and spatial heterogeneity in the snowmelt at the expense of an increase in the mean bias error (from 0.06 to 0.22) for all distributed forcing simulations compared to the simulation with only distributed precipitation. Distributing wind speed in the energy balance calculation has a more complex impact on our catchment, as it accelerates snowmelt when meteorological conditions are favorable but does not generate snow patches at the end of our test case. This shows that slope- and aspect-based meteorological distribution can improve the spatio-temporal representation of snow cover and evapotranspiration in complex mountain terrain.
Auteurs, date et publication :
Auteurs Aniket Gupta , Alix Reverdy , Jean-Martial Cohard , Basile Hector , Marc Descloitres , Jean-Pierre Vandervaere , Catherine Coulaud , Romain Biron , Lucie Liger , Reed Maxwell , Jean-Gabriel Valay , Didier Voisin
Publication : Hydrology and Earth System Sciences
Date : 2023
Volume : 27
Issue : 1
Pages : 191-212
Catégorie(s)
#CNRS #Lautaret #UGARésumé
This study analyzes the impact of droughts, compared with average climatic conditions, on the supporting ecosystem service water provision in sub-watersheds in managed alpine grasslands in two climatically different regions of the Alps, Lautaret (French Alps) and Stubai (Austrian Alps). Soil moisture was modelled in the range of 0–0.3 m. At both sites, current patterns showed that the mean seasonal soil moisture was (1) near field capacity for grasslands with low management intensity and (2) below field capacity for grasslands with higher land-use intensity. Soil moisture was significantly reduced by drought at both sites, with lower reductions at the drier Lautaret site. At the sub-watershed scale, soil moisture spatial heterogeneity was reduced by drought. Under drought conditions, the evapotranspiration to precipitation ratios at Stubai was slightly higher than those at Lautaret, indicating a dominant ‘water spending’ strategy of plant communities. Regarding catchment water balance, deep seepage was reduced by drought at Stubai more strongly than at Lautaret. Hence, the observed ‘water spending’ strategy at Stubai might have negative consequences for downstream water users. Assessing the water provision service for alpine grasslands provided evidence that, under drought conditions, evapotranspiration was influenced not only by abiotic factors but also by the water-use strategy of established vegetation. These results highlight the importance of ‘water-use’ strategies in existing plant communities as predictors of the impacts of drought on water provision services and related ecosystem services at both the field and catchment scale. © 2015 The Authors. Ecohydrology published by John Wiley & Sons, Ltd.
Auteurs, date et publication :
Auteurs Georg Leitinger , Romed Ruggenthaler , Albin Hammerle , Sandra Lavorel , Uta Schirpke , Jean-Christophe Clement , Pénélope Lamarque , Nikolaus Obojes , Ulrike Tappeiner
Publication : Ecohydrology
Date : 2025
Volume : 8
Issue : 8
Pages : 1600-1613
Catégorie(s)
#CNRS #Lautaret #UGARésumé
Climatic variation is a key driver of genetic differentiation and phenotypic traits evolution, and local adaptation to temperature is expected in widespread species. We investigated phenotypic and genomic changes in the native range of the Asian tiger mosquito, Aedes albopictus. We first refine the phylogeographic structure based on genome-wide regions (1,901 double-digest restriction-site associated DNA single nucleotide polymophisms [ddRAD SNPs]) from 41 populations. We then explore the patterns of cold adaptation using phenotypic traits measured in common garden (wing size and cold tolerance) and genotype-temperature associations at targeted candidate regions (51,706 exon-capture SNPs) from nine populations. We confirm the existence of three evolutionary lineages including clades A (Malaysia, Thailand, Cambodia, and Laos), B (China and Okinawa), and C (South Korea and Japan). We identified temperature-associated differentiation in 15 out of 221 candidate regions but none in ddRAD regions, supporting the role of directional selection in detected genes. These include genes involved in lipid metabolism and a circadian clock gene. Most outlier SNPs are differently fixed between clades A and C, whereas clade B has an intermediate pattern. Females are larger at higher latitude yet produce no more eggs, which might favor the storage of energetic reserves in colder climate. Nondiapausing eggs from temperate populations survive better to cold exposure than those from tropical populations, suggesting they are protected from freezing damages but this cold tolerance has a fitness cost in terms of egg viability. Altogether, our results provide strong evidence for the thermal adaptation of A. albopictus across its wide temperature range.
Auteurs, date et publication :
Auteurs Stephanie Sherpa , Jordan Tutagata , Thierry Gaude , Frederic Laporte , Shinji Kasai , Intan H. Ishak , Xiang Guo , Jiyeong Shin , Sebastien Boyer , Sebastien Marcombe , Theeraphap Chareonviriyaphap , Jean-Philippe David , Xiao-Guang Chen , Xiaohong Zhou , Laurence Despres
Publication : MOLECULAR BIOLOGY AND EVOLUTION
Date : 2022
Volume : 39
Issue : 5
Catégorie(s)
#ANR-Citation #CNRS #Lautaret #UGAAuteurs, date et publication :
Auteurs Sandra Lavorel , Karl Grigulis
Publication : Journal of Ecology
Date : 2025
Volume : 100
Issue : 1
Pages : 128-140
Catégorie(s)
#CNRS #Lautaret #UGAAuteurs, date et publication :
Auteurs Sébastien Ibanez , Fabien Arène , Sébastien Lavergne
Publication : Oecologia
Date : 2025
Volume : 180
Issue : 4
Pages : 989-1000
Catégorie(s)
#CNRS #Lautaret #UGARésumé
The ecosystem services (ES) concept has emerged and spread widely recently, to enhance the importance of preserving ecosystems through global change in order to maintain their benefits for human well-being. Numerous studies consider various dimensions of the interactions between ecosystems and land use via ES, but integrated research addressing the complete feedback loop between biodiversity, ES and land use has remained mostly theoretical. Few studies consider feedbacks from ecosystems to land use systems through ES, exploring how ES are taken into account in land management decisions. To fill this gap, we carried out a role-playing game to explore how ES cognition mediates feedbacks from environmental change on farmers’ behaviors in a mountain grassland system. On a close to real landscape game board, farmers were faced with changes in ES under climatic and socio-economic scenarios and prompted to plan for the future and to take land management decisions as they deemed necessary. The outcomes of role-playing game were complemented with additional agronomic and ecological data from interviews and fieldwork. The effects of changes in ES on decision were mainly direct, i.e. not affecting knowledge and values, when they constituted situations with which farmers were accustomed. For example, a reduction of forage quantity following droughts led farmers to shift from mowing to grazing. Sometimes, ES cognitions were affected by ES changes or by external factors, leading to an indirect feedback. This happened when fertilization was stopped after farmers learned that it was inefficient in a drought context. Farmers’ behaviors did not always reflect their attitudes towards ES because other factors including topographic constraints, social value of farming or farmer individual and household characteristics also influenced land-management decisions. Those results demonstrated the interest to take into account the complete feedback loop between ES and land management decisions to favor more sustainable ES management.
Auteurs, date et publication :
Auteurs Pénélope Lamarque , Patrick Meyfroidt , Baptiste Nettier , Sandra Lavorel , Kurt O. Reinhart
Publication : Plos One
Date : 2014
Volume : 9
Issue : 9
Pages : e107572