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Shifting trait coordination along a soil‐moisture‐nutrient gradient in tropical forests
No full textInternational audienceSoil nutrients and water availability are strong drivers of tropical tree species distribution across scales. However, the physiological mechanisms underlying environmental filtering along these gradients remain incompletely understood. Previous studies mostly focused on univariate variation in structural traits, but a more integrative approach combining multiple physiological traits is needed to fully portray species functional strategies. We measured nine leaf functional traits related to trees' resource capture and hydraulic strategies for 552 individuals belonging to 21 tropical tree species across an environmental gradient in Amazonian forests. Our sampling included generalist and specialist species from terra firme (TF) and seasonally flooded (SF) forests. We tested the influence of the topographic wetness index, a proxy for soil moisture and nutrient gradients, on each trait separately and on the trait integration through multivariate indices computed from the eigenvalues of a principal component analysis on the traits of the species. Finally, we evaluated intraspecific trait variability (ITV) for generalists and specialists by calculating the coefficient of variation for each trait. Results showed that (1) the environment had a greater influence on trait syndromes than single trait variation. Moreover, (2) SF specialist species expressed a stronger leaf trait coordination than TF specialist species. Furthermore, (3) the ability of generalist species to occupy a broader range of environments was not reflected by a larger ITV than specialist species but by the capacity to change trait coordination across environments. Our work highlights the need to investigate functional strategies as multidimensional syndromes in physiological trait space to fully understand and predict species distribution along environmental gradients. Read the free Plain Language Summary for this article on the Journal blog.Les nutriments du sol et la disponibilité de l'eau sont des facteurs importants de la distribution des espèces d'arbres tropicaux à différentes échelles. Cependant, les mécanismes physiologiques à l'origine du filtrage environnemental le long de ces gradients restent mal compris. Les études précédentes se sont principalement concentrées sur la variation des traits de façon individuelle. Cependant, pour décrire pleinement les stratégies fonctionnelles des espèces, une approche plus intégrative, qui combine un ensemble de traits physiologiques (syndrome de trait) est nécessaire. Dans cette étude, nous avons mesuré neuf traits fonctionnels foliaires liés à l'acquisition des ressources et à la gestion de l'eau des arbres, sur 552 individus appartenant à 21 espèces d'arbres tropicaux, le long d'un gradient environnemental. L'échantillonnage comprend des espèces généralistes et spécialistes des forêts de terra firme et des forêts de bas‐fond en Guyane française. Nous avons utilisé un indice d'humidité topographique (TWI) comme indicateur de l'humidité et de l'accumulation des nutriments du sol. Nous avons testé l'influence de TWI sur chacun des traits séparément et de façon conjointe. Nous avons comparé la coordination des traits pour les espèces généralistes et spécialistes en fonction du TWI, grâce à des indices multivariés, obtenus en utilisant la gamme des valeurs propres d'une analyse en composantes principales sur les traits de l'espèce. Enfin, nous avons évalué la variabilité intraspécifique des traits (ITV) pour les généralistes et les spécialistes en calculant le coefficient de variation pour chaque trait. Les résultats illustrent que (1) l'environnement a une plus grande influence sur le syndrome de traits que sur la variation des traits pris un par un. De plus, (2) les espèces spécialistes des bas‐fond ont une plus forte coordination entre les traits que les spécialistes de terra firme. Enfin, (3) la capacité des espèces généralistes à occuper une plus large gamme d'environnements se traduit par leur capacité à changer la coordination de leurs traits à travers différents environnements plutôt que par une ITV plus importante que celle des espèces spécialistes. Notre travail plaide en faveur de l'utilisation de syndromes de traits pour étudier les stratégies fonctionnelles et comprendre les mécanismes de distribution des espèces le long des gradients environnementaux
New fossiliferous sites from the mid-Cretaceous Tendrara dome (High Plateaus, Morocco): biostratigraphical, paleoenvironmental and paleogeographical implications
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Vegetation and climate change during MIS 35-19 (~1.2 - 0.75 Ma) in Western Mediterranean (Alboran Sea): new insights to understand the late hominin occupation in Western Europe?
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Contrasted climate patterns during the Holocene in the central Mediterranean inferred from pollen data.
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Schémas climatique contrasté de la Méditerrannée centrale durant l'Holocène à partir de données pollinique.
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Painting the diversity of a world's favorite fruit: A next generation catalog of cultivated bananas
No full textThe sequencing reads were deposited in the NCBI SRA associated with the BioProject PRJNA450532. SNP datasets were recorded in a database (dbname: Catalogue_Musa_Mosaic) browsable via a web application https://gigwa.cgiar.org/gigwa (Rouard et al., 2022; Sempéré et al., 2019).This work is dedicated to two eminent banana scientists who passed away during the preparation of this manuscript. Professor Edmond De Langhe devoted his life and passion to bananas until the end and leaves an unvaluable contribution to our understanding of this crop. Dr. Hughes Tezenas du Montcel, a renowned expert in banana research, significantly enriched the field through his extensive collection of banana plants and laid the groundwork for the Musa Germplasm Information System. This work could not have been possible without their dedication to banana germplasm collection and conservation.International audienceSocietal Impact Statement: Bananas are nutritious fruits of major importance worldwide. Characterizing their diversity is essential to ensure their conservation and use. A catalog showcasing cultivated bananas genomic diversity was compiled and is to be used as a tool to support the classification of banana cultivars. This research revealed that cultivated banana groups are not all made of identical clones. Materials from recent collecting missions indicated that more banana diversity is expected to be found as the exploration of the banana gene pool continues. These discoveries will drive dynamic conservation strategies for banana genetic resources and should increase their use.Summary: . Banana is an important food crop cultivated in many tropical and subtropical regions around the world. Because banana cultivars often have low fertility, they are typically propagated clonally, which maintains desirable traits across generations. However, different factors, such as synonymy, incomplete passport data, and environmental effects, complicate the morphological-based assignment of banana cultivars to specific clones or cultivar groups.. In this study, we applied a previously developed genomic-based tool for fine-scale characterization of banana ancestry, known as in silico chromosome painting, to high-throughput genotyping data from 317 banana accessions. This dataset covers most of the globally conserved, studied, and cultivated cultivar groups and includes both genebanks and new, uncharacterized materials.. By comparing curated morphological assignation to the genomic patterns resulting from in silico chromosome painting, we compiled a diversity catalog referencing curated passport data, pictures, and chromosome painting patterns of the cultivar groups.. Examining the genomic patterns obtained, intra-cultivar group variability was discovered. In some cultivar groups, mitotic recombination or deletions accumulated clonally. In addition, at least four cultivar groups encompassed cultivars from distinct sexual events co-existing, notably Pisang Awak with five distinct patterns across two ploidy levels. Finally, additional patterns were discovered in the newest materials of the set, showing that a wider diversity of clones still exists on farm
A regressive analysis of the main environmental risk factors of human echinococcosis in 370 counties in China
No full textInternational audienceBackground Echinococcosis is a natural focal, highly prevalent disease in China. Factors influencing the spread of echinococcosis are not only related to personal exposure but also closely related to the environment itself. The purpose of this study was to explore the influence of environmental factors on the prevalence of human echinococcosis and to provide a reference for prevention and control of echinococcosis in the future. Methods Data were collected from 370 endemic counties in China in 2018. By downloading Modis, DEM and other remote-sensing images in 2018. Data on environmental factors, i . e ., elevation, land surface temperature (LST) and normalized difference vegetation index (NDVI) were collected. Rank correlation analysis was conducted between each environmental factor and the prevalence of echinococcosis at the county level. Negative binomial regression was used to analyze the impact of environmental factors on the prevalence of human echinococcosis at the county level. Results According to rank correlation analysis, the prevalence of human echinococcosis in each county was positively correlated with elevation, negatively correlated with LST, and negatively correlated with NDVI in May, June and July. Negative binomial regression showed that the prevalence of human echinococcosis was negatively correlated with annual LST and summer NDVI, and positively correlated with average elevation and dog infection rate. The prevalence of human cystic echinococcosis was inversely correlated with the annual average LST, and positively correlated with both the average elevation and the prevalence rate of domestic animals. The prevalence of human alveolar echinococcosis was positively correlated with both NDVI in autumn and average elevation, and negatively correlated with NDVI in winter. Conclusion The prevalence of echinococcosis in the population is affected by environmental factors. Environmental risk assessment and prediction can be conducted in order to rationally allocate health resources and improve both prevention and control efficiency of echinococcosis
Abattage des bovins : contrôle de l’état de conscience et fluidité industrielle
No full textInternational audienceThis article examines how the control of animal consciousness, prescribed by EC regulation no. 1099/2009 on animal welfare, fits in with the objective of industrial fluidity in cattle slaughterhouses. Based on observations made in 12 slaughterhouses and a corpus of 30 interviews with industrialists and state officials in charge of animal welfare inspections, the article outlines the difficulties posed by the implementation of this requirement, and reports on the strategies developed by actors in an attempt to reconcile production continuity with regulatory compliance. The article shows that the monitoring of animals’ state of consciousness enters into tension with the objective of industrial fluidity because it introduces uncertainty into the slaughtering process, particularly in the case of ritual practices carried out without stunning. Highlighting these standardization difficulties leads us to discuss this prescription for monitoring of cattle end-of-life from the angle of a paradoxical injunction.L’article interroge la manière dont le contrôle de l’état de conscience des animaux, prescrit par le règlement de protection animale CE n°1099/2009, s’articule avec l’objectif de fluidité industrielle en abattoirs de bovins. À l’appui d’observations menées dans 12 abattoirs et d’un corpus de 30 entretiens réalisés auprès d’industriels et d’agents de l’État en charge des inspections de protection animale, il expose les difficultés posées par la mise en œuvre de cette prescription et rend compte des stratégies élaborées par les acteurs pour tenter de concilier continuité productive et conformité réglementaire. L’article montre que le contrôle de l’état de conscience des animaux entre en tension avec l’objectif de fluidité industrielle parce qu’il introduit de l’incertitude dans le processus d’abattage, en particulier dans le cas des pratiques rituelles effectuées sans étourdissement. La mise en lumière de ces difficultés de normalisation amène à discuter cette prescription de surveillance-contrôle de la fin de vie des bovins sous l’angle d’une injonction paradoxale
Promouvoir les filières résilientes à fort impact sur le développement territorial oasien au Maghreb
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Plant-to-plant defence induction in cotton is mediated by delayed release of volatiles upon herbivory
No full textInternational audienceCaterpillar feeding immediately triggers the release of volatile compounds stored in the leaves of cotton plants. Additionally, after 1 d of herbivory, the leaves release other newly synthesised volatiles. We investigated whether these volatiles affect chemical defences in neighbouring plants and whether such temporal shifts in emissions matter for signalling between plants.Undamaged receiver plants were exposed to volatiles from plants infested with Spodoptera caterpillars. For receiver plants, we measured changes in defence-related traits such as volatile emissions, secondary metabolites, phytohormones, gene expression, and caterpillar feeding preference. Then, we compared the effects of volatiles emitted before and after 24 h of damage on neighbouring plant defences.Genes that were upregulated in receiver plants following exposure to volatiles from damaged plants were the same as those activated directly by herbivory on a plant. Only volatiles emitted after 24 h of damage, including newly produced volatiles, were found to increase phytohormone levels, upregulate defence genes, and enhance resistance to caterpillars.These results indicate that the defence induction by volatiles is a specific response to de novo synthesised volatiles, suggesting that these compounds are honest signals of herbivore attack. These findings point to an adaptive origin of airborne signalling between plants.</p