Résumé
Man-made sounds are now recognized as a pervasive pollutant, and impacts on wildlife have been researched for many years. However, less knowledge is available on certain species, particularly small freshwater invertebrates, which are abundant, highly diversified, and occupy key positions in food webs. Also, it is not clear whether the responses to noise observed at the level of individuals have consequences on communities. A mesocosm investigation was performed to assess the response of a freshwater planktonic community to chronic motorboat noise. Noise was expected to disturb trophic links within the community and particularly the consumption of cladocerans by dipteran larvae. To test this hypothesis, the functional response of Chaoborus larvae feeding on Daphnia was derived, and their behavior during the foraging process was recorded in microcosms (aquariums). Although noise did not induce obvious alteration in the community composition, a significant increase in the abundance of cladocerans was found that was not supported by the results of the microcosm investigation, showing no difference in Chaoborus functional response or behavior between the noisy and noiseless conditions. The results of this chapter suggest that the composition of freshwater zooplankton and particularly cladocerans is likely to be altered by chronic noise, with further investigations needed to understand the mechanisms. They also illustrate how scaling up the effects of noise from individual responses to community remains difficult.
Auteurs, date et publication :
Auteurs Emilie Rojas , Camille Desjonquères , Simon Agostini , Sarah Fiorini , Béatriz Decencière , Michael Danger , Vincent Felten , Vincent Médoc , Arthur N. Popper , Joseph Sisneros , Anthony D. Hawkins , Frank Thomsen
Date : 2025
Pages : 1-17
Catégorie(s)
#CNRS #ENS #PLANAQUARésumé
According to theories on cave adaptation, cave organisms are expected to develop a lower metabolic rate compared to surface organisms as an adaptation to food scarcity in the subterranean environments. To test this hypothesis, we compared the oxygen consumption rates of the surface and subterranean populations of a surface-dwelling species, the newt Calotriton asper, occasionally found in caves. In this study, we designed a new experimental setup in which animals with free movement were monitored for several days in a respirometer. First, we measured the metabolic rates of individuals from the surface and subterranean populations, both maintained for eight years in captivity in a natural cave. We then tested individuals from these populations immediately after they were caught and one year later while being maintained in the cave. We found that the surface individuals that acclimated to the cave significantly reduced their oxygen consumption, whereas individuals from the subterranean population maintained in the cave under a light/dark cycle did not significantly modify their metabolic rates. Second, we compared these metabolic rates to those of an obligate subterranean salamander (Proteus anguinus), a surface aquatic Urodel (Ambystoma mexicanum), and a fish species (Gobio occitaniae) as references for surface organisms from different phyla. As predicted, we found differences between the subterranean and surface species, and the metabolic rates of surface and subterranean C. asper populations were between those of the obligate subterranean and surface species. These results suggest that the plasticity of the metabolism observed in surface C. asper was neither directly due to food availability in our experiments nor the light/dark conditions, but due to static temperatures. Moreover, we suggest that this adjustment of the metabolic level at a temperature close to the thermal optimum may further allow individual species to cope with the food limitations of the subterranean environment.
Auteurs, date et publication :
Auteurs Olivier Guillaume , Marine Deluen , Allan Raffard , Olivier Calvez , Audrey Trochet
Publication : Ecology and Evolution
Date : 2025
Volume : 10
Issue : 23
Pages : 12983-12989
Catégorie(s)
#CNRS #Ecotron IleDeFrance #ENS #PLANAQUARésumé
Emerging organic micropollutants (OMPs) are ubiquitous in waterbodies and not fully eliminated by wastewater treatment plants (WWTP). A proposed WWTP upgrade includes OMPs sorption by biochar rather than activated carbon (AC). Activated biochar (AB) and non-activated biochar (NAB) sorption performance towards 4 target OMPs (benzotriazole, sulfamethoxazole, carbamazepine, diclofenac) were evaluated in real-wastewater. Sorption processes are discussed in light of sorption mechanisms that depend both on OMP and on biochar physico-chemical properties. AB and AC have similar average sorption efficiency (45%), while NABs are much less efficient (<19%). OMPs sorption significantly correlates to SSA, inversely to H/C (indicating hydrophobic interaction with graphene-like structures) and to CEC or ash content (indicating H-bond or ternary surface complexation sorption mechanisms). This highlights the need to mix AB sources with different physico-chemical characteristics to sorb a large OMP spectrum within WWTPs. Production and use of ABs alleviate the negative environmental impact of ACs.
Auteurs, date et publication :
Auteurs Fabienne Favre , Ana Slijepcevic , Umberto Piantini , Urban Frey , Samuel Abiven , Hans-Peter Schmidt , Laurent Charlet
Publication : Bioresource Technology Reports
Date : 2025
Volume : 17
Pages : 100966
Catégorie(s)
#CNRS #Ecotron IleDeFrance #ENSRésumé
Species dispersal and resource spatial flows greatly affect the dynamics of connected ecosystems. So far, research on meta-ecosystems has mainly focused on the quantitative effect of subsidy flows. Yet, resource exchanges at heterotrophic-autotrophic (e.g., aquatic-terrestrial) ecotones display a stoichiometric asymmetry that likely matters for functioning. Here, we joined ecological stoichiometry and the meta-ecosystem framework to understand how subsidy stoichiometry mediates the response of the meta-ecosystem to subsidy flows. Our model results demonstrate that resource flows between ecosystems can induce a positive spatial feedback loop, leading to higher production at the meta-ecosystem scale by relaxing local ecosystem limitations (“spatial complementarity”). Furthermore, we show that spatial flows can also have an unexpected negative impact on production when accentuating the stoichiometric mismatch between local resources and basal species needs. This study paves the way for studies on the interdependancy of ecosystems at the landscape extent.
Data: The code and the data, as well as a small tutorial to run the model are available on Github via Zenodo: https://doi.org/10.5281/zenodo.7733880
Auteurs, date et publication :
Auteurs Benôıt Pichon , Elisa Thébault , Gérard Lacroix , Isabelle Gounand
Date : 2023
Catégorie(s)
#CNRS #ENS #PLANAQUARésumé
When assessing the carbon storage potential of a crop, it is useful to 1) quantify the inputs that return to the soil, such as roots, rhizodeposition and sometimes aboveground biomass, and 2) estimate the carbon gains or losses attributed to the priming effect. This allows to draw up a balance of inputs and outputs at the end of the growing season. While the quantity of carbon supplied by roots and aboveground biomass is relatively easy to measure, the quantity of rhizodeposition and the priming effect are not.To establish such a balance, 12 intercropping plant species from 3 plant families (brassicaceae, fabaceae and poaceae) were grown for two months in mesocosms (15 liters) under controlled conditions simulating a temperate summer climate in real time in an ecotron. Multi-pulse atmospheric labeling with 13CO2 99% was used to trace photosynthesized carbon and thus quantify aboveground and root biomass, rhizodeposition and variations in carbon stock due to the priming effect.The results show that rhizodeposition represents a significant carbon input (around a quarter of root biomass), positively correlated with root biomass. Root biomass is therefore one of the main traits to be considered for increasing inputs. At the same time, 10 out of 12 plants accelerated the mineralization of soil organic matter (positive priming effect), resulting in a cumulative carbon loss over the course of the plant's growth that can be of the same order of magnitude as the biomass input.This priming effect is highly heterogeneous and difficult to explain by plant traits, but seems quantitatively more important for brassicaceae. We propose that this variability is due both to the spatial heterogeneity inducing these processes, but also to the great variability of processes that can occur in the rhizosphere, processes that can simultaneously lead to an acceleration and/or deceleration of the decomposition of native soil organic matter.
Auteurs, date et publication :
Auteurs Baptiste Hulin , Simon Chollet , Folrent Massol , Samuel Abiven
Date : 2024
Pages : 5143
Catégorie(s)
#CNRS #Ecotron IleDeFrance #ENSRésumé
Soil respiration influences regional carbon dynamics, yet our limited
understanding of drivers of soil respiration currently constrains robust
modeling of soil CO2 efflux. There is evidence that soil respiration
does not follow the standard Arrhenius relationship with soil
temperature at the daily scale, as used in many ecosystem models, but
demonstrates a hysteretic response. The understanding of this hysteretic
response is critical to soil carbon and greenhouse gas emission
modeling. Why soil respiration deviates from monotonic temperature
dependence may depend on lag effects and antecedent features of abiotic
and biotic drivers associated with above- and belowground process
linkages. We set up a 6 months long experiment to determine the biotic
and abiotic drivers of the hysteretic relationship between soil
respiration and soil temperature. The experiment took place at Ecotron
IleDeFrance (France) using replicated closed environmental facilities
allowing the simultaneous control of environmental conditions and
on-line measurement of ecosystem processes. We reproduced semi-arid
ecosystems using basalt soil mesocosms planted with two functional
groups of plants (shrubs and grasses) in monocultures and in a mixture.
We independently controlled above- and belowground temperatures and
rainfall intensity. The split-plot, repeated-measures design allowed for
diel aboveground and temperature cycle treatments to mimic natural
conditions or for diel cycle aboveground temperature and constant soil
temperature treatments to constrain vertical soil temperature gradients,
yet mimic natural aboveground conditions. Soil CO2 concentrations were
measured under mild and heavy precipitations conditions that represent
current and project conditions. We calculated the soil respiration every
30 minutes using the gradient method and conducted additional plant
photosynthesis measurements to better target the role of biotic factors.
Our data show that abiotic and biotic treatments affect the total soil
respiration but also diel patterns and the strength of the hysteretic
effect. This demonstrates the power of experimental approaches to
disentangle physical and biological drivers of soil respiration and
better predict future CO2 efflux from soils.
Auteurs, date et publication :
Auteurs Yann Dusza , Sabrina Juarez , Simon Chollet , Régis Ferrière , Amandine Hansart , Florent Massol , Mathieu Llavata , Jean-François Le Galliard , Enrique Pérez Sánchez-Cañete , Greg Barron-Gafford
Date : 2018
Volume : 20
Pages : 8461
Catégorie(s)
#CNRS #Ecotron IleDeFrance #ENSAuteurs, date et publication :
Auteurs Simon P. K. Bowring , Matthew W. Jones , Philippe Ciais , Bertrand Guenet , Samuel Abiven
Publication : Nature Geoscience
Date : 2025
Volume : 15
Issue : 2
Pages : 135-142
Catégorie(s)
#CNRS #Ecotron IleDeFrance #ENSAuteurs, date et publication :
Auteurs Johanne Lebrun Thauront , Christian Walter , Philippa Ascough , Pierre Barre , Samuel Abiven
Date : 2023
Catégorie(s)
#CNRS #Ecotron IleDeFrance #ENSAuteurs, date et publication :
Auteurs Johanne Lebrun Thauront , Severin Luca Bellè , Marcus Schiedung , Amicie Delahaie , Marija Stojanova , François Baudin , Pierre Barré , Samuel Abiven
Date : 2024
Catégorie(s)
#CNRS #Ecotron IleDeFrance #ENSRésumé
Pyrogenic carbon (PyC) is a continuum of aromatic and condensed organic molecules. It represents about 15 % of organic carbon in soils and sediments1. However, there is a discrepancy in the literature regarding quantification of PyC: different methods that are currently considered as reference differ largely in their results1,2. Indeed, most methods used to quantify PyC are based on different operational principles (e.g. chemical, thermal or physical stability of PyC, molecular markers) and consequently, they do not cover the same range of the PyC continuum2. In addition, most of them are expensive and/or time consuming. Here, we propose a new PyC quantification method based on Rock-Eval® thermal analysis, thought to be rapid, inexpensive and comparable to the previous methods toolbox. Rock-Eval® thermal analysis has been successfully introduced to the field of soil carbon analysis in the last two decades and allowed to distinguish between various pools of soil carbon (inorganic carbon, stable and active organic carbon) using a single analysis of combined pyrolysis and thermal oxidation3,4. In this study, we formulate the hypothesis that Rock-Eval® thermal analysis in combination with predictive modelling is suitable to quantify PyC in soil matrices.To build and validate such a model, we chose soil samples originating from contrasting climate zones and parent material and with varying properties including clay content and mineralogy, iron oxide speciation and content, pH, cation-exchange capacity and organic carbon content. We measured PyC using a set of established methods (i.e. CTO-375, BPCA and HyPy) and acquired Rock-Eval® thermograms. Then, we identified the relevant features for PyC quantification in the thermograms by applying several machine-learning approaches. This work adds a new soil carbon pool to the ones already accessible from Rock-Eval® thermal analysis and allows an efficient and rapid quantification of PyC in soils, which is needed for large-scale studies of soil carbon pools.(1) Reisser, M.; Purves, R. S.; Schmidt, M. W. I.; Abiven, S. Pyrogenic Carbon in Soils: A Literature-Based Inventory and a Global Estimation of Its Content in Soil Organic Carbon and Stocks. Front. Earth Sci. 2016, 4 (August), 1-14. https://doi.org/10.3389/feart.2016.00080.(2) Hammes, K.; Smernik, R. J.; Skjemstad, J. O.; Schmidt, M. W. I. Characterisation and Evaluation of Reference Materials for Black Carbon Analysis Using Elemental Composition, Colour, BET Surface Area and 13C NMR Spectroscopy. Appl. Geochemistry 2008, 23 (8), 2113-2122. https://doi.org/10.1016/j.apgeochem.2008.04.023.(3) Disnar, J. R.; Guillet, B.; Keravis, D.; Di-Giovanni, C.; Sebag, D. Soil Organic Matter (SOM) Characterization by Rock-Eval Pyrolysis: Scope and Limitations. Org. Geochem. 2003, 34 (3), 327-343. https://doi.org/10.1016/S0146-6380(02)00239-5.(4) Cécillon, L.; Baudin, F.; Chenu, C.; Houot, S.; Jolivet, R.; Kätterer, T.; Lutfalla, S.; Macdonald, A.; Van Oort, F.; Plante, A. F.; Savignac, F.; Soucémarianadin, L. N.; Barré, P. A Model Based on Rock-Eval Thermal Analysis to Quantify the Size of the Centennially Persistent Organic Carbon Pool in Temperate Soils. Biogeosciences 2018, 15 (9), 2835-2849. https://doi.org/10.5194/bg-15-2835-2018.
Auteurs, date et publication :
Auteurs Johanne Lebrun Thauront , Severin Luca Bellè , Marcus Schiedung , Amicie Delahaie , Marija Stojanova , François Baudin , Pierre Barré , Samuel Abiven
Date : 2024
Pages : 16551