Auteurs, date et publication :
Auteurs Tony Robillard , Hannah M ter Hofstede , Jérôme Orivel , Natállia M Vicente
Publication : Bioacoustics
Date : 2025
Volume : 24
Issue : 2
Pages : 123-143
Catégorie(s)
#CNRS #FORET NouraguesAuteurs, date et publication :
Auteurs Jan Šobotník , Thomas Bourguignon , Tiago F Carrijo , Christian Bordereau , Alain Robert , Barbora Křížková , Joice P Constantini , Eliana M Cancello
Publication : Arthropod structure & development
Date : 2025
Volume : 44
Issue : 5
Pages : 401-406
Catégorie(s)
#CNRS #FORET NouraguesAuteurs, date et publication :
Auteurs Jae-Cheon Sohn , Donald R Davis , Carlos Lopez-Vaamonde
Publication : ZooKeys
Date : 2025
Issue : 494
Pages : 69
Catégorie(s)
#⛔ No DOI found #CNRS #FORET NouraguesRésumé
Mountain regions are key for humanity's water supply, and their water yield depends on climatic, soil and vegetation effects. Here we explore the effects of vegetation composition and structure on the water balance of high elevation grasslands with different climatic conditions across the Alps. Using a total of 220 deep seepage collectors with intact soil-vegetation monoliths in different types of mountain grasslands in the Austrian, French and Swiss Alps, we solved the water balance equation for evapotranspiration (ET) and related the results to biomass, the abundance of certain plant functional types and structural and functional vegetation properties. While daily mean ET during the growing season was similar at all sites, ET to precipitation ratios were significantly higher and ET to potential ET ratios significantly lower at the drier French sites than at the more humid Swiss and Austrian site. Large variability of ET, seepage and soil moisture within all sites pointed at a high influence of vegetation on the water balance. While ET increased significantly with biomass at all sites, the influence of other vegetation properties was site specific. At the more humid, subalpine Austrian site the effects of vegetation on ET were stronger and more diverse than at the higher elevation Swiss site and the drier French sites, where climatic drivers dominated ET. The potential to influence ET and water yield of mountain areas by manipulating the plant canopy with systematic land management is therefore higher in regions with good growing conditions than in areas with harsh climate. Copyright © 2014 John Wiley & Sons, Ltd.
Auteurs, date et publication :
Auteurs N. Obojes , M. Bahn , E. Tasser , J. Walde , N. Inauen , E. Hiltbrunner , P. Saccone , J. Lochet , J. C. Clément , S. Lavorel , U. Tappeiner , Ch Körner
Publication : Ecohydrology
Date : 2025
Volume : 8
Issue : 4
Pages : 552-569
Catégorie(s)
#CNRS #Lautaret #UGARésumé
Recent observations and geodetic measurements in the European Alps show that changes are occurring on rock glacier dynamics, ranging from moderate velocity variations to strong acceleration or even total collapse. These changes can be related to the ground temperature and to climate warming. In most cases, rock glaciers do not represent any serious hazard, except the instability of their surface and local rockfalls at the steep front. The surface movements, though moderate, can nevertheless cause damages to sensible infrastructures like cableways or buildings, if these are not designed to adapt to surface movements. The strong accelerations observed on some rock glaciers, however, induce a change of magnitude, and may threaten in some cases downslope areas. Thus, the presence of active or inactive rock glaciers with high ice content must be considered not only with regard to present conditions and dynamics, but with respect to possible evolutions due to climate change.
Auteurs, date et publication :
Auteurs Giorgio Lollino , Andrea Manconi , John Clague , Wei Shan , Marta Chiarle , P. Schoeneich , X. Bodin , T. Echelard , V. Kaufmann , A. Kellerer-Pirklbauer , J. -M. Krysiecki , G. K. Lieb
Date : 2025
Volume : 1
Pages : 223-227
Catégorie(s)
#CNRS #Lautaret #UGARésumé
It has long been recognized that plant species and soil microorganisms are tightly linked, but understanding how different species vary in their effects on soil is currently limited. In this study, we identified those plant characteristics (identity, specific functional traits, or resource acquisition strategy) that were the best predictors of nitrification and denitrification processes. Ten plant populations representing eight species collected from three European grassland sites were chosen for their contrasting plant trait values and resource acquisition strategies. For each individual plant, leaf and root traits and the associated potential microbial activities (i.e., potential denitrification rate [DEA], maximal nitrification rate [NEA], and NH4þ affinity of the microbial community [NHScom]) were measured at two fertilization levels under controlled growth conditions. Plant traits were powerful predictors of plant–microbe interactions, but relevant plant traits differed in relation to the microbial function studied. Whereas denitrification was linked to the relative growth rate of plants, nitrification was strongly correlated to root trait characteristics (specific root length, root nitrogen concentration, and plant affinity for NH4þ) linked to plant N cycling. The leaf economics spectrum (LES) that commonly serves as an indicator of resource acquisition strategies was not correlated to microbial activity. These results suggest that the LES alone is not a good predictor of microbial activity, whereas root traits appeared critical in understanding plant–microbe interactions.
Auteurs, date et publication :
Auteurs Amélie A. M. Cantarel , Thomas Pommier , Marie Desclos-Theveniau , Sylvain Diquélou , Maxime Dumont , Fabrice Grassein , Eva-Maria Kastl , Karl Grigulis , Philippe Laîné , Sandra Lavorel , Servane Lemauviel-Lavenant , Emmanuelle Personeni , Michael Schloter , Franck Poly
Publication : Ecology
Date : 2025
Volume : 96
Issue : 3
Pages : 788-799
Catégorie(s)
#CNRS #Lautaret #UGARésumé
Background and aims Rhizodeposition plays an important role in mediating soil nutrient availability in ecosystems. However, owing to methodological difficulties (i.e., narrow zone of soil around roots, rapid assimilation by soil microbes) fertility-induced changes in rhizodeposition remain mostly unknown.
Auteurs, date et publication :
Auteurs Florence Baptist , Iker Aranjuelo , Nicolas Legay , Luis Lopez-Sangil , Gemma Molero , Pere Rovira , Salvador Nogués
Publication : Plant and Soil
Date : 2025
Volume : 394
Issue : 1-2
Pages : 391-406
Catégorie(s)
#CNRS #Lautaret #UGARésumé
The full-scale avalanche test site at Lautaret Pass in the southern French Alps has been used by IRSTEA-Cemagref Research Institute since 1972. Over recent years, two avalanche paths have been used routinely to release avalanches and study avalanche dynamics and interactions between avalanches and obstacles. Avalanche flows are generally dense and dry, sometimes with a powder cloud on top. Main avalanche path no. 2 is dedicated to studies on avalanche dynamics. Within the flow of the avalanche, flow height and vertical profiles of pressure and velocity are measured along a 3.5 m tripod. The snow volume released in the release zone is quantified by differential analysis of laser scanning measurements performed before and after triggering. High-speed positioning of the avalanche front along the track is carried out by terrestrial oblique photogrammetry. Above the dense layer, the upper layer of the avalanche is characterized by particle and air flux measurements. Avalanche path no. 1 is smaller in size and particularly well-suited to experiments on structures exposed to small to medium-size avalanches (b1000 m3). A macroscopic sensor structure consisting of a one square-meter plate supported by a 3.5 m high steel cantilever beam is fixed in the ground, facing the avalanche. Impact pressures are reconstructed from the beam deformations and avalanche velocity is measured by optical sensors. For these experimental devices dedicated to improving our understanding of avalanche physics, a national and international partnership has been developed over the years, including INSA de Lyon, CNRS and Université Joseph Fourier (France), Aalto University (Finland), Nagoya University (Japan), Boku University (Austria) and IGEMA (Bolivia).
Auteurs, date et publication :
Auteurs Emmanuel Thibert , Hervé Bellot , Xavier Ravanat , Frédéric Ousset , Gaëtan Pulfer , Mohamed Naaim , Pascal Hagenmuller , Florence Naaim-Bouvet , Thierry Faug , Koichi Nishimura , Yoichi Ito , Djebar Baroudi , Alexander Prokop , Peter Schön , Alvaro Soruco , Christian Vincent , Ali Limam , Raphaële Héno
Publication : Cold Regions Science and Technology
Date : 2025
Volume : 115
Pages : 30-41
Catégorie(s)
#CNRS #Lautaret #UGARésumé
Abstract. We aimed at quantifying biogenic volatile organic compound (BVOC) emissions in June from three Mediterranean species located at the O3HP site (southern France): Quercus pubescens, Acer monspessulanum and C. coggygria (for isoprene only). As Q. pubescens was shown to be the main BVOC emitter with isoprene representing ≈ 99% of the carbon emitted as BVOC, we mainly focused on this species. C. coggygria was found to be a non-isoprene emitter (no other BVOCs were investigated).
To fully understand both the canopy effect on Q. pubescens isoprene emissions and the inter-individual variability (tree to tree and within canopy), diurnal variations of isoprene were investigated from nine branches (seven branches located to the top of canopy at ≈ 4 m above ground level (a.g.l.), and two inside the canopy at ≈ 2 m a.g.l.).
The Q. pubescens daily mean isoprene emission rate (ERd) fluctuated between 23 and 98 μgC gDM−1 h−1. Q. pubescens daily mean net assimilation (Pn) ranged between 5.4 and 13.8, and 2.8 and 6.4 μmol CO2 m−2 s−1 for sunlit and shaded branches respectively. Both ERd and isoprene emission factors (Is), assessed according to Guenther et al. (1993) algorithm, varied by a factor of 4.3 among the sunlit branches. While sunlit branches ERd was clearly higher than for shaded branches, there was a non-significant variability of Is (59 to 77 μgC gDM−1 h−1). Diurnal variations of isoprene emission rates (ERs) for sunlit branches were also investigated. ERs were detected at dawn 2 h after Pn became positive and were mostly exponentially dependent on Pn. Diurnal variations of ERs were not equally well described throughout the day by temperature (CT) and light (CL) parameters according to G93 algorithm. Temperature had more impact than photosynthetically active radiation (PAR) on the morning emissions increase, and ER was no longer correlated to CL × CT between solar noon (maximum ER) and mid-afternoon, possibly due to thermal stress of the plant. A comparison between measured and calculated emissions using two isoprene algorithms (G93 and MEGAN – Model of Emissions of Gases and Aerosols from Nature) highlighted the importance of isoprene emission factor Is value used, and some weakness in assessing isoprene emissions under Mediterranean climate conditions (drought) with current isoprene models.
Auteurs, date et publication :
Auteurs A.-C. Genard-Zielinski , C. Boissard , C. Fernandez , C. Kalogridis , J. Lathière , V. Gros , N. Bonnaire , E. Ormeño
Publication : Atmospheric Chemistry and Physics
Date : 2015
Volume : 15
Issue : 1
Pages : 431-446
Catégorie(s)
#CNRS #FORET O3HPRésumé
The Moderate Resolution Imaging Spectroradiometer (MODIS) yields global operational estimates of terrestrial gross primary production (GPP). In this study, we compared MOD17A2 GPP with tower eddy flux-based estimates of GPP from 2001 to 2010 over an evergreen broad-leaf Mediterranean forest in Southern France with a significant summer drought period. The MOD17A2 GPP shows seasonal variations that are inconsistent with the tower GPP, with close-to-accurate winter estimates and significant discrepancies for summer estimates which are the least accurate. The analysis indicated that the MOD17A2 GPP has high bias relative to tower GPP during severe summer drought which we hypothesized caused by soil water limitation. Our investigation showed that there was a significant correlation (R2 = 0.77, p < 0.0001) between the relative soil water content and the relative error of MOD17A2 GPP. Therefore, the relationship between the error and the measured relative soil water content could explain anomalies in MOD17A2 GPP. The results of this study indicate that careful consideration of the water conditions input to the MOD17A2 GPP algorithm on remote sensing is required in order to provide accurate predictions of GPP. Still, continued efforts are necessary to ascertain the most appropriate index, which characterizes soil water limitation in water-limited environments using remote sensing.
Auteurs, date et publication :
Auteurs Jia Liu , Serge Rambal , Florent Mouillot
Publication : Remote Sensing
Date : 2015
Volume : 7
Issue : 1
Pages : 1154-1180