Résumé
Aim We investigate the spatiotemporal context of the diversification ofAllobates, a widespread genus of Amazonian frogs with high species diversity particularly in western Amazonia. We tested if that diversity originated in situ or through repeated dispersals from other Amazonian areas and if this diversification took place during or after the Pebas system, a vast lacustrine system occupying most western Amazonia between 23 and 10 million years ago (Mya). Location Amazonia. Taxon Allobates(Anura: Aromobatidae). Methods We gathered a spatially and taxonomically extensive sampling of mitochondrial DNA sequences from 932Allobatesspecimens to delimit Operational Taxonomic Units (OTUs). Complete mitogenomes of these OTUs were assembled to reconstruct a time-calibrated phylogeny used to infer the historical and spatial origin of the AmazonianAllobateslineages. Results Phylogenetic analyses and ancestral area reconstruction suggested that most of the western Amazonian lineages resulted from in situ diversification and that these events occurred between the inferred origin of the genus (25 Mya) and 10 Mya, with a possible peak between 14 and 10 Mya. Dispersal among areas mostly occurred from western Amazonia towards the Brazilian and the Guiana Shields. Closely relatedAllobatesOTUs display an allopatric pattern of distribution, matching interfluves delimited by modern Amazonian rivers. Main Conclusions In western Amazonia, diversification ofAllobatesappears to have been simultaneous with the last stages of the Pebas system (14-10 Mya). Subsequently (within the last 10 Mya), modern Amazonian river courses shaped the distribution pattern ofAllobatesspecies and possibly promoted allopatric speciation.
Auteurs, date et publication :
Auteurs Alexandre Rejaud , Miguel T. Rodrigues , Andrew J. Crawford , Santiago Castroviejo-Fisher , Andres F. Jaramillo , Juan C. Chaparro , Frank Glaw , Giussepe Gagliardi-Urrutia , Jiri Moravec , Ignacio J. De la Riva , Pedro Perez , Albertina P. Lima , Fernanda P. Werneck , Tomas Hrbek , Santiago R. Ron , Raffael Ernst , Philippe J. R. Kok , Amy Driskell , Jerome Chave , Antoine Fouquet
Publication : JOURNAL OF BIOGEOGRAPHY
Date : 2020
Volume : 47
Issue : 11
Pages : 2472-2482
Catégorie(s)
#ANR-Citation #CNRS #FORET NouraguesRésumé
Resorption is the active withdrawal of nutrients before leaf abscission. This mechanism represents an important strategy to maintain efficient nutrient cycling; however, resorption is poorly characterized in old-growth tropical forests growing in nutrient-poor soils. We investigated nutrient resorption from leaves in 39 tree species in two tropical forests on the Guiana Shield, French Guiana, to investigate whether resorption efficiencies varied with soil nutrient, seasonality, and species traits. The stocks of P in leaves, litter, and soil were low at both sites, indicating potential P limitation of the forests. Accordingly, mean resorption efficiencies were higher for P (35.9%) and potassium (K; 44.6%) than for nitrogen (N; 10.3%). K resorption was higher in the wet (70.2%) than in the dry (41.7%) season. P resorption increased slightly with decreasing total soil P; and N and P resorptions were positively related to their foliar concentrations. We conclude that nutrient resorption is a key plant nutrition strategy in these old-growth tropical forests, that trees with high foliar nutrient concentration reabsorb more nutrient, and that nutrients resorption in leaves, except P, are quite decoupled from nutrients in the soil. Seasonality and biochemical limitation played a role in the resorption of nutrients in leaves, but species-specific requirements obscured general tendencies at stand and ecosystem level.
Auteurs, date et publication :
Auteurs Ifigenia Urbina , Oriol Grau , Jordi Sardans , Olga Margalef , Guillermo Peguero , Dolores Asensio , Joan LLusia , Roma Ogaya , Albert Gargallo-Garriga , Leandro Van Langenhove , Lore T. Verryckt , Elodie A. Courtois , Clement Stahl , Jennifer L. Soong , Jerome Chave , Bruno Herault , Ivan A. Janssens , Emma Sayer , Josep Penuelas
Publication : ECOLOGY AND EVOLUTION
Date : 2021
Volume : 11
Issue : 13
Pages : 8969-8982
Catégorie(s)
#ANR-Citation #CNRS #FORET NouraguesRésumé
Abstract
Heatwaves and soil droughts are increasing in frequency and intensity, leading many tree species to exceed their thermal thresholds, and driving wide‐scale forest mortality. Therefore, investigating heat tolerance and canopy temperature regulation mechanisms is essential to understanding and predicting tree vulnerability to hot droughts. We measured the diurnal and seasonal variation in leaf water potential (Ψ), gas exchange (photosynthesis
A
net
and stomatal conductance
g
s
), canopy temperature (
T
can
), and heat tolerance (leaf critical temperature
T
crit
and thermal safety margins TSM, i.e., the difference between maximum
T
can
and
T
crit
) in three oak species in forests along a latitudinal gradient (
Quercus petraea
in Switzerland,
Quercus ilex
in France, and
Quercus coccifera
in Spain) throughout the growing season. Gas exchange and Ψ of all species were strongly reduced by increased air temperature (
T
air
) and soil drying, resulting in stomatal closure and inhibition of photosynthesis in
Q. ilex
and
Q. coccifera
when
T
air
surpassed 30°C and soil moisture dropped below 14%. Across all seasons,
T
can
was mainly above
T
air
but increased strongly (up to 10°C >
T
air
) when
A
net
was null or negative. Although trees endured extreme
T
air
(up to 42°C), positive TSM were maintained during the growing season due to high
T
crit
in all species (average
T
crit
of 54.7°C) and possibly stomatal decoupling (i.e.,
A
net
≤0 while
g
s
>0). Indeed,
Q. ilex
and
Q. coccifera
trees maintained low but positive
g
s
(despite null
A
net
), decreasing Ψ passed embolism thresholds. This may have prevented
T
can
from rising above
T
crit
during extreme heat. Overall, our work highlighted that the mechanisms behind heat tolerance and leaf temperature regulation in oak trees include a combination of high evaporative cooling, large heat tolerance limits, and stomatal decoupling. These processes must be considered to accurately predict plant damages, survival, and mortality during extreme heatwaves.
Auteurs, date et publication :
Auteurs Alice Gauthey , Ansgar Kahmen , Jean‐Marc Limousin , Alberto Vilagrosa , Margaux Didion‐Gency , Eugénie Mas , Arianna Milano , Alex Tunas , Charlotte Grossiord
Publication : Global Change Biology
Date : 2025
Volume : 30
Issue : 8
Pages : e17439
Catégorie(s)
#CNRS #FORET PuechabonAuteurs, date et publication :
Auteurs L. Zinger
Date : 1970
Catégorie(s)
#CNRS #eDNARésumé
Parental decisions in animals are often context-dependent and shaped by fitness trade-offs between parents and offspring. For example, the selection of breeding habitats can considerably impact the fitness of both offspring and parents, and therefore, parents should carefully weigh the costs and benefits of available options for their current and future reproductive success. Here, we show that resource-use preferences are shaped by a trade-off between parental effort and offspring safety in a tadpole-transporting frog. In a large-scale in situ experiment, we investigated decision strategies across an entire population of poison frogs that distribute their tadpoles across multiple water bodies. Pool use followed a dynamic and sequential selection process, and transportation became more efficient over time. Our results point to a complex suite of environmental variables that are considered during offspring deposition, which necessitates a highly dynamic and flexible decision-making process in tadpole-transporting frogs.
Auteurs, date et publication :
Auteurs Eva Ringler , Georgine Szipl , Ryan J. Harrigan , Perta Bartl-Binder , Rosanna Mangione , Max Ringler
Publication : MOLECULAR ECOLOGY
Date : 2018
Volume : 27
Issue : 9
Pages : 2289-2301
Catégorie(s)
#ANR-Citation #CNRS #FORET NouraguesRésumé
The extraction of crude oil and gold has substantially increased heavy metal contamination in the environment, yet the study of wildlife exposure and biological response to this pollution remains nascent even in the most biodiverse places in the world. We present a survey of heavy metal exposure in the feathers of wedge‐billed woodcreepers (Glyphorynchus spirurus), a resident neotropical bird found within protected regions of the Amazon near oil and gold extraction sites. Our results show elevated heavy metal contamination in samples collected from protected areas proximate to known oil and gold extraction. Surprisingly, several samples from remote reference sites also displayed elevated levels of various heavy metals, suggesting a background of natural deposition or complex heavy metal contamination in the environment from anthropogenic sources. These results highlight the need to understand the ecological and biological impacts of increased heavy metal exposure on wildlife across space and time, including remote regions of the world purportedly untouched by these humanmediated stressors. Toward this goal, historical and contemporary data from native bird populations may provide crucial indicators for heavy metal contamination and exposure in wildlife and human communities. Environ Toxicol Chem 2024; 43:2601–2607. © 2024 The Author(s). Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.
Auteurs, date et publication :
Auteurs Yeraldi Loera , Cristian Gruppi , Kelly Swing , Shane C. Campbell-Staton , Borja Milá , Thomas B. Smith
Publication : Environmental Toxicology and Chemistry
Date : 2024
Volume : 43
Issue : 12
Pages : 2601-2607
Catégorie(s)
#CNRS #FORET NouraguesRésumé
We conducted an analysis of global forest cover to reveal that 70% of remaining forest is within 1 km of the forest's edge, subject to the degrading effects of fragmentation. A synthesis of fragmentation experiments spanning multiple biomes and scales, five continents, and 35 years demonstrates that habitat fragmentation reduces biodiversity by 13 to 75% and impairs key ecosystem functions by decreasing biomass and altering nutrient cycles. Effects are greatest in the smallest and most isolated fragments, and they magnify with the passage of time. These findings indicate an urgent need for conservation and restoration measures to improve landscape connectivity, which will reduce extinction rates and help maintain ecosystem services.
Auteurs, date et publication :
Auteurs Nick M. Haddad , Lars A. Brudvig , Jean Clobert , Kendi F. Davies , Andrew Gonzalez , Robert D. Holt , Thomas E. Lovejoy , Joseph O. Sexton , Mike P. Austin , Cathy D. Collins , William M. Cook , Ellen I. Damschen , Robert M. Ewers , Bryan L. Foster , Clinton N. Jenkins , Andrew J. King , William F. Laurance , Douglas J. Levey , Chris R. Margules , Brett A. Melbourne
Publication : SCIENCE ADVANCES
Date : 2015
Volume : 1
Issue : 2
Catégorie(s)
#ANR-Citation #CNRS #Metatron terrestreRésumé
Spatial heterogeneity in the distribution of phenotypes among populations is of major importance for species evolution and ecosystem functioning. Dispersal has long been assumed to homogenise populations in structured landscapes by generating maladapted gene flows, making spatial heterogeneity of phenotypes traditionally considered resulting from local adaptation or plasticity. However, there is accumulating evidence that individuals, instead of dispersing randomly in the landscapes, adjust their dispersal decisions according to their phenotype and the environmental conditions. Specifically, individuals might move in the landscape to find and settle in the environmental conditions that best match their phenotype, therefore maximizing their fitness, a hypothesis named habitat matching. Although habitat matching and associated non-random gene flows can produce spatial phenotypic heterogeneity, their potential consequences for metapopulation and metacommunity functioning are still poorly understood. Here, we discuss evidence for intra and interspecific drivers of habitat matching, and highlight the potential consequences of this process for metapopulation and metacommunity functioning. We conclude that habitat matching might deeply affect the eco-evolutionary dynamics of meta-systems, pointing out the need for further empirical and theoretical research on its incidence and implications for species and communities evolution under environmental changes.
Auteurs, date et publication :
Auteurs Staffan Jacob , Elvire Bestion , Delphine Legrand , Jean Clobert , Julien Cote
Publication : EVOLUTIONARY ECOLOGY
Date : 2015
Volume : 29
Issue : 6, SI
Pages : 851-871
Catégorie(s)
#ANR-Citation #CNRS #Metatron terrestreRésumé
Abstract
Globe-LFMC 2.0, an updated version of Globe-LFMC, is a comprehensive dataset of over 280,000 Live Fuel Moisture Content (LFMC) measurements. These measurements were gathered through field campaigns conducted in 15 countries spanning 47 years. In contrast to its prior version, Globe-LFMC 2.0 incorporates over 120,000 additional data entries, introduces more than 800 new sampling sites, and comprises LFMC values obtained from samples collected until the calendar year 2023. Each entry within the dataset provides essential information, including date, geographical coordinates, plant species, functional type, and, where available, topographical details. Moreover, the dataset encompasses insights into the sampling and weighing procedures, as well as information about land cover type and meteorological conditions at the time and location of each sampling event. Globe-LFMC 2.0 can facilitate advanced LFMC research, supporting studies on wildfire behaviour, physiological traits, ecological dynamics, and land surface modelling, whether remote sensing-based or otherwise. This dataset represents a valuable resource for researchers exploring the diverse LFMC aspects, contributing to the broader field of environmental and ecological research.
Auteurs, date et publication :
Auteurs Marta Yebra , Gianluca Scortechini , Karine Adeline , Nursema Aktepe , Turkia Almoustafa , Avi Bar-Massada , María Eugenia Beget , Matthias Boer , Ross Bradstock , Tegan Brown , Francesc Xavier Castro , Rui Chen , Emilio Chuvieco , Mark Danson , Cihan Ünal Değirmenci , Ruth Delgado-Dávila , Philip Dennison , Carlos Di Bella , Oriol Domenech , Jean-Baptiste Féret
Publication : Scientific Data
Date : 2024
Volume : 11
Issue : 1
Pages : 332
Catégorie(s)
#CNRS #FORET PuechabonRésumé
Genome size varies greatly across the tree of life and transposable elements are an important contributor to this variation. Among vertebrates, amphibians display the greatest variation in genome size, making them ideal models to explore the causes and consequences of genome size variation. However, high-quality genome assemblies for amphibians have, until recently, been rare. Here, we generate a high-quality genome assembly for the dyeing poison frog, Dendrobates tinctorius. We compare this assembly to publicly available frog genomes and find evidence for both large-scale conserved synteny and widespread rearrangements between frog lineages. Comparing conserved orthologs annotated in these genomes revealed a strong correlation between genome size and gene size. To explore the cause of gene-size variation, we quantified the location of transposable elements relative to gene features and find that the accumulation of transposable elements in introns has played an important role in the evolution of gene size in D. tinctorius, while estimates of insertion times suggest that many insertion events are recent and species-specific. Finally, we carry out population-scale mobile-element sequencing and show that the diversity and abundance of transposable elements in poison frog genomes can complicate genotyping from repetitive element sequence anchors. Our results show that transposable elements have clearly played an important role in the evolution of large genome size in D. tinctorius. Future studies are needed to fully understand the dynamics of transposable element evolution and to optimize primer or bait design for cost-effective population-level genotyping in species with large, repetitive genomes.
Auteurs, date et publication :
Auteurs Carolin Dittrich , Franz Hoelzl , Steve Smith , Chloe A Fouilloux , Darren J Parker , Lauren A O’Connell , Lucy S Knowles , Margaret Hughes , Ade Fewings , Rhys Morgan , Bibiana Rojas , Aaron A Comeault
Publication : Genome Biology and Evolution
Date : 2024
Volume : 16
Issue : 6
Pages : evae109