Résumé
A new monotypic genus in the ‘Archeuptychia clade’ Xikrin Barbosa, Freitas, Siewert & Marín gen. nov. (Nymphalidae: Satyrinae: Euptychiina) is described to accommodate a new species, Xikrin ueharapradoi Freitas & Barbosa gen. et sp. nov., in the highly diverse Satyrinae subtribe Euptychiina, based mainly on molecular data. To date, this species is known only from the region of Carajas, in the eastern Amazon rainforest. The phylogenetic relationship and taxonomy of this new taxon are discussed.
Auteurs, date et publication :
Auteurs Eduardo P. Barbosa , Ricardo R. Siewert , Mario A. Marín , Patrícia A. Machado , Isabela F. Oliveira , José A. C. Filho , André V. L. Freitas
Publication : Austral Entomology
Date : 2025
Volume : 62
Issue : 3
Pages : 310-322
Catégorie(s)
#CNRS #FORET NouraguesRésumé
The detection of solar induced chlorophyll fluorescence (SIF) in the field with spectrometers is based on the depth of the solar Fraunhofer or oxygen absorption lines in the upwelling radiance compared to that in the downwelling irradiance. This relative depth enables the differentiation of SIF from the reflected radiation. Recent studies have shown that if oxygen bands are used to retrieve SIF from tower-based measurements, then atmospheric correction is required. This study presents a band shape fitting (BSF) approach to retrieve both the relative optical path length (deepening) and SIF (infilling) from field measurements at the same time, using information in the measured spectral shape of the O2 feature. This approach is an alternative to using radiative transfer process models for estimating atmospheric transmittance. The method was applied to measurements taken from 100 m elevation above a forest, yielding plausible results for SIF in the O2A and O2B bands. The sensitivity to combined atmospheric and instrument characteristics prohibits application at much greater distances from the surface.
Auteurs, date et publication :
Auteurs Christiaan van der Tol , Tommaso Julitta , Peiqi Yang , Neus Sabater , Ilja Reiter , Marin Tudoroiu , Dirk Schuettemeyer , Matthias Drusch
Publication : Remote Sensing of Environment
Date : 2023
Volume : 284
Pages : 113304
Catégorie(s)
#CNRS #FORET O3HPRésumé
Abstract
Biogeochemical niche (BN) hypothesis aims to relate species/genotype elemental composition with its niche based on the fact that different elements are involved differentially in distinct plant functions. We here test the BN hypothesis through the analysis of the 10 foliar elemental concentrations and 20 functional‐morphological of 60 tree species in a French Guiana tropical forest. We observed strong legacy (phylogenic + species) signals in the species‐specific foliar elemental composition (elementome) and, for the first time, provide empirical evidence for a relationship between species‐specific foliar elementome and functional traits. Our study thus supports the BN hypothesis and confirms the general niche segregation process through which the species‐specific use of bio‐elements drives the high levels of α‐diversity in this tropical forest. We show that the simple analysis of foliar elementomes may be used to test for BNs of co‐occurring species in highly diverse ecosystems, such as tropical rainforests. Although cause and effect mechanisms of leaf functional and morphological traits in species‐specific use of bio‐elements require confirmation, we posit the hypothesis that divergences in functional‐morphological niches and species‐specific biogeochemical use are likely to have co‐evolved.
Auteurs, date et publication :
Auteurs Jordi Sardans , Joan Llusià , Romà Ogaya , Helen Vallicrosa , Iolanda Filella , Albert Gargallo‐Garriga , Guille Peguero , Leandro Van Langenhove , Lore T. Verryckt , Clément Stahl , Elodie A. Courtois , Laëtitia M. Bréchet , Akash Tariq , Fanjiang Zeng , Abdulwahed Fahad Alrefaei , Weiqi Wang , Ivan A. Janssens , Josep Peñuelas
Publication : Ecology
Date : 2025
Volume : 104
Issue : 11
Pages : e4118
Catégorie(s)
#CIRAD #CNRS #FORET Nouragues #FORET ParacouRésumé
Guide méthodologique construit dans le cadre d’une réflexion collective sur les services AnaEE France n’engageant pas les organismes tutelles de l’infrastructure. Ce document propose une méthodologie et des principes de tarification pour les services de l'infrastructure nationale AnaEE-France. Nous rappelons que ces services couvrent l’accès aux plateformes expérimentales, la production d’analyses pour caractériser les écosystèmes, la mise à disposition d’instruments et d’échantillons, et l’accès aux plateformes de modélisation.
Auteurs, date et publication :
Auteurs Marion Bousquet , Alyssa Clavreul , Jean-Gabriel Valay
Date : 2023
Catégorie(s)
#CNRS #Coordination AnaEE #INRAERésumé
Neonatal maturity depends on the maternal capacity to provide nutrients for foetal growth. This study aimed to investigate the effects of systemic administration of recombinant porcine somatotropin (pST), one of the main regulators of growth and metabolism, to pregnant gilts during late gestation on circulating nutrients and expression levels of genes in liver and skeletal muscle of their 110-day-old foetuses. Gilts received either daily injections of sterile water (control [CTL] group, n = 15) or of 5 mg of pST (pST group, n = 17) from days 90 to 109 of gestation. At day 110 postconceptus, pairs of foetuses (one of small and one of average size within a litter) were selected. Circulating fructose concentrations were greater, but circulating concentrations of urea were lower in pST than in CTL foetuses. Expression levels of genes involved in carbohydrate and lipid metabolism were more affected by pST treatment in liver than in muscle. Hepatic molecular changes suggest an inhibition of energy-consuming processes (glycogen and lipid biosynthesis) and the activation of energy-producing pathway (mitochondrial oxidation) in pST compared to CTL foetuses. Expression levels of some genes involved in intracellular degradation of proteins were greater in the liver of pST foetuses, and combined with lower uremia, this suggests a higher utilisation of protein sources in pST foetuses than in CTL foetuses. In muscle, molecular changes were mainly observed in the IGF-insulin axis. Altogether, pST-treated gilts seem to have a greater ability to support foetal liver development by the reorientation of energy and protein metabolism.
Auteurs, date et publication :
Auteurs F. Gondret , I. Louveau , P. Langendjik , C. Farmer
Publication : animal
Date : 2023
Volume : 17
Issue : 1
Pages : 100691
Catégorie(s)
#CNRS #EcoGenO #Université de RennesRésumé
Mountain grasslands contain large stocks of soil organic carbon (SOC), of which a good part is in labile particulate form. This labile SOC may be protected by cold climate that limits microbial activity. Strong climate change in mountain regions threatens to destabilize these SOC stocks. However, so far the climate response of SOC stocks in mountain grasslands remains highly uncertain, under either warming or cooling conditions. To overcome this knowledge gap, we studied the effect of pedoclimatic regime changes on topsoil (0–10 cm) SOC in two complementary experiments: 3 °C of warming or cooling by reciprocal transplanting to an alpine (2450 m a.s.l.) and a subalpine (1950 m a.s.l.) grassland and 1 °C of warming by open-top chambers in the same grasslands. Topsoil SOC stocks were higher at the alpine site than at the subalpine site, and the biogeochemical signature of the soil organic matter (SOM) also differed between the two study sites. SOM was O-enriched, H-depleted, and more thermally stable at the warmer subalpine site. After three years, abrupt warming by transplanting tended to decrease topsoil SOC content. The remaining SOC was characterized by a more thermostable signature. This result suggests the preferential depletion of labile SOC upon experimental topsoil warming. Cooling did not modify overall SOC content but uphill transplanted topsoils showed a more thermolabile biogeochemical signature. In contrast, open-top chamber warming of alpine and subalpine topsoils caused limited changes to SOC stocks and SOM biogeochemical signature, possibly because the induced pedoclimatic change was more limited and more gradual compared to the warming by transplantating which reduced the annual snow cover period by around 60 days and increased cumulative degree days by a factor of ten as compared to the OTC-induced warming. Gradual temperature changes may take longer to become effective than a shock transplant treatment. We conclude that SOC in mountain grassland topsoils can be highly reactive to climate shocks.
Auteurs, date et publication :
Auteurs Khedim Norine , Poulenard Jérôme , Cecillon Lauric , Baudin François , Barre Pierre , Saillard Amélie , Billur Bektaş , Grigulis Karl , Lavorel Sandra , Münkemüller Tamara , Choler Philippe
Publication : Geoderma
Date : 2023
Volume : 429
Pages : 116238
Catégorie(s)
#ANR-Citation #CNRS #Lautaret #UGARésumé
Estimating consistent large-scale tropical forest height using remote sensing is essential for understanding forest-related carbon cycles. The Global Ecosystem Dynamics Investigation (GEDI) light detection and ranging (LiDAR) instrument employed on the International Space Station has collected unique vegetation structure data since April 2019. Our study shows the potential value of using remote-sensing (RS) data (i.e., optical Sentinel-2, radar Sentinel-1, and radar PALSAR-2) to extrapolate GEDI footprint-level forest canopy height model (CHM) measurements. We show that selected RS features can estimate vegetation heights with high precision by analyzing RS data, spaceborne GEDI LiDAR, and airborne LiDAR at four tropical forest sites in South America and Africa. We found that the GEDI relative height (RH) metric is the best at 98% (RH98), filtered by full-power shots with a sensitivity greater than 98%. We found that the optical Sentinel-2 indices are dominant with respect to radar from 77 possible features. We proposed the nine essential optical Sentinel-2 and the radar cross-polarization HV PALSAR-2 features in CHM estimation. Using only ten optimal indices for the regression problems can avoid unimportant features and reduce the computational effort. The predicted CHM was compared to the available airborne LiDAR data, resulting in an error of around 5 m. Finally, we tested cross-validation error values between South America and Africa, including around 40% from validation data in training to obtain a similar performance. We recommend that GEDI data be extracted from all continents to maintain consistent performance on a global scale. Combining GEDI and RS data is a promising method to advance our capability in mapping CHM values.
Auteurs, date et publication :
Auteurs Yen-Nhi Ngo , Dinh Ho Tong Minh , Nicolas Baghdadi , Ibrahim Fayad
Publication : Remote Sensing
Date : 2023
Volume : 15
Issue : 4
Pages : 975
Catégorie(s)
#CIRAD #CNRS #FORET Nouragues #FORET ParacouRésumé
Seed morphological description is traditionally based on adjectives, which originated from the comparison with other shapes, including geometric figures. Nevertheless, descriptions based on this feature are not quantitative and measurements giving the percentage of similarity of seeds with reference figures are not available in the literature. Lateral views of Silene seeds resemble the cardioid and cardioid-derived figures. Dorsal views, nonetheless, resemble ellipses and derivatives, allowing seed shape quantification by comparison with defined geometric figures. In this work, we apply already-described models as well as new models to the morphological analysis of 51 Silene species. Our data revealed the existence of a link between lateral and dorsal models. Lateral models closed in the hilum region (models LM2 and LM4) were associated with those convex models of the dorsal seed views (DM1-DM4, DM10). Lateral models more open around the hilum region adjusted to seeds characterized as dorso canaliculata type better, i.e., to those geometric models with partial concavities in their dorsal views. The relationship between lateral and dorsal models, as well as between the models to their utility in taxonomy, is discussed.
Auteurs, date et publication :
Auteurs José Javier Martín-Gómez , José Luis Rodríguez-Lorenzo , Bohuslav Janoušek , Ana Juan , Emilio Cervantes
Publication : Taxonomy
Date : 2023
Volume : 3
Issue : 1
Pages : 109-132
Catégorie(s)
#CNRS #Lautaret #UGARésumé
Introduction
Primary Sjögren’s syndrome (pSS) is a systemic autoimmune disease characterized by exocrine gland dysfunction. No therapeutic strategy is sufficient on its own for the management of dry mouth and therapeutic innovations are required.
Methods
This Predelfi study was a single-center, prospective, comparative, randomized, double-blind, cross-over controlled study with the primary objective of assessing the tolerance to and effectiveness of two adhesive biofilms (containing prebiotics and, sodium alginate, respectively) in patients with pSS and hyposialia (#NCT04206826 in ClinicalTrials.gov). Secondary objectives were to obtain initial data regarding the clinical effectiveness of such biofilms in the improvement of signs and symptoms related to dry mouth and potential changes in the oral microbiota. Ten pSS patients with pSS were included (9 females and 1 male) with a mean age of 58.1 ± 14.0 years.
Results and discussion
Tolerance to the prebiotic and sodium alginate biofilms was assessed by the patients (visual analog scale [VAS] score 66.7 and 87.6, respectively) and the practitioner (90 and 100, respectively). The absolute changes in the VAS scores at the start and end of each treatment period highlighted an improvement in mouth dryness for the sodium alginate versus the prebiotic biofilm. The VAS scores for other parameters (mouth burning sensation; taste alteration; chewing; swallowing and speech difficulties) remained globally comparable between the two groups. Unstimulated salivary flow showed no changes regardless of the biofilm used. Regarding the oral microbiota, the sodium alginate biofilm increased the abundance of the Treponema genus, whereas the use of the prebiotic biofilm as the first treatment increased the abundance of the genera Veillonella and Prevotella. Nevertheless, the prebiotic biofilm appeared to stimulate “milder” genera with regard to periodontal infections. Furthermore, pre-treatment with the prebiotic biofilm prevented the emergence of the Treponema genus induced by subsequent treatment with the sodium alginate biofilm, suggesting a potential protective effect.
Auteurs, date et publication :
Auteurs Marie Orliaguet , Shao Bing Fong , Laëtitia Le Pottier , Vincent Meuric , Sylvie Boisramé , Martine Bonnaure-Mallet , Jacques-Olivier Pers
Publication : Frontiers in Microbiology
Date : 2023
Volume : 14
Pages : 1071683
Catégorie(s)
#CNRS #EcoGenO #Université de RennesRésumé
Pyrogenic organic matter (PyOM) is a product of incomplete combustion during wildfires and an important pool of soil organic carbon (SOC). The dynamics of PyOM and SOC in boreal and permafrost-affected soils are largely unknown, while storing large amounts of global carbon and being vulnerable to climate change. Here, we traced the vertical mobility, allocation in soil fractions and decomposition losses of highly 13C-labeled PyOM and its precursor ryegrass organic matter (grass OM) after two years of in-situ incubation in soil cores installed in the upper 10 cm of continuous (northern sites) and discontinuous to sporadic (southern sites) permafrost-affected forest soils in Northern Canada. At the northern sites, up to three times more PyOM was lost by decomposition (39% of initial) compared to the southern sites (11% of initial). Losses of grass OM were substantial (69–84% of initial) and larger in southern soils. The vertical incorporation was limited and >90% of recovered PyOM and grass OM were found at the applied depth (0–3 cm). The PyOM strongly interacted with mineral surfaces, as indicated by around 40% recovered in the mineral-associated heavy density fractions (<63 μm). Microscale analyses by SEM and NanoSIMS showed that PyOM was mainly allocated towards the fine fraction in a particulate and aggregated form, highlighting the importance of abiotic processes for the incorporation of PyOM in permafrost-affected soils. The grass OM was mainly recovered in the mineral fractions at southern soils with enhanced allocation towards mineral surfaces as well as increased distribution at the microscale after initial decomposition, while it remained as particulate OM in northern soils. Our results highlight that permafrost-affected boreal forest soils are sensitive to fresh PyOM and OM inputs with substantial losses. Especially PyOM persistence depended on site and soil specific properties and not solely on its physico-chemical persistence. The responses are decoupled for PyOM and non-pyrolyzed OM and require a better understanding to evaluate carbon feedbacks of high-latitude soils with global warming and associated shifts in vegetation and wildfire regimes.
Auteurs, date et publication :
Auteurs Marcus Schiedung , Severin-Luca Bellè , Carmen Hoeschen , Steffen A. Schweizer , Samuel Abiven
Publication : Soil Biology and Biochemistry
Date : 2023
Volume : 178
Pages : 108959