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We are in a climate and ecological emergency, where climate change and direct anthropogenic interference with the biosphere are risking abrupt and/or irreversible changes that threaten our life-support systems. Efforts are underway to increase the resilience of some ecosystems that are under threat, yet collective awareness and action are modest at best. Here, we highlight the potential for a biosphere resilience sensing system to make it easier to see where things are going wrong, and to see whether deliberate efforts to make things better are working. We focus on global resilience sensing of the terrestrial biosphere at high spatial and temporal resolution through satellite remote sensing, utilizing the generic mathematical behaviour of complex systems—loss of resilience corresponds to slower recovery from perturbations, gain of resilience equates to faster recovery. We consider what subset of biosphere resilience remote sensing can monitor, critically reviewing existing studies. Then we present illustrative, global results for vegetation resilience and trends in resilience over the last 20 years, from both satellite data and model simulations. We close by discussing how resilience sensing nested across global, biome-ecoregion, and local ecosystem scales could aid management and governance at these different scales, and identify priorities for further work. This article is part of the theme issue ‘Ecological complexity and the biosphere: the next 30 years’.

Contemporary climate change affects population dynamics, but its influence varies with landscape structure. It is still unclear whether landscape fragmentation buffers or amplifies the effects of climate on population size and the age and body size of individuals composing these populations. This study aims to investigate the impacts of warm climates on lizard life-history traits and population dynamics in habitats that vary in their connectivity. We monitored common lizard Zootoca vivipara populations for 3 years in an experimental system in which both climatic conditions and connectivity among habitats were simultaneously manipulated. We considered two climatic treatments (i.e. present-day climate and warm climate [+1.4°C than present-day climate]) and two connectivity treatments (i.e. a connected treatment in which individuals could move from one climate to the other and an isolated treatment in which movement between climates was not possible). We monitored survival, reproduction, growth, dispersal, age and body size of each individual in the system as well as population density through time. We found that the influence of warm climates on life-history traits and population dynamics depended on connectivity among thermal habitats. Populations in warm climates were (i) composed of younger individuals only when isolated; (ii) larger in population size only in connected habitats and (iii) composed of larger age-specific individuals independently of the landscape configuration. The connectivity among habitats altered population responses to climate warming likely through asymmetries in the flow and phenotype of dispersers between thermal habitats. Our results demonstrate that landscape fragmentation can drastically change the dynamics and persistence of populations facing climate change.Le changement climatique actuel impacte la dynamique des populations, mais son influence varie avec la structure du paysage. A ce jour, il est difficile de prédire si la fragmentation du paysage réduit ou augmente les effets du réchauffement climatique sur la taille des populations, ainsi que sur l'âge et la taille corporelle des individus qui composent ces populations. Cette étude s'intéresse aux impacts d'un climat plus chaud sur les traits d'histoire de vie et la dynamique de populations vivant dans des habitats qui diffèrent quant à leur niveau de connectivité. Pendant trois ans, nous avons suivi des populations de lézards vivipares Zootoca vivipara au sein d'un dispositif expérimental qui permet de manipuler simultanément les conditions climatiques et le niveau de connectivité entre habitats. Nous avons considéré deux traitements climatiques [i.e., climat actuel et climat chaud (+1.4°C plus chaud que le climat actuel)] et deux traitements de connectivité (i.e., un traitement connecté au sein duquel les individus pouvaient se déplacer d'un climat à un autre, et un traitement isolé au sein duquel les déplacements entre climats n'étaient pas permis). Tout au long de l'expérience, nous avons mesuré la survie, la reproduction, la croissance, la dispersion, l'âge et la taille corporelle de chaque individu ainsi que la densité des populations. Nous avons observé que l'influence du climat chaud sur les traits d'histoire de vie et la dynamique de population dépendait du niveau de connectivité entre habitats. Les populations en climat chaud étaient composées (i) d'individus plus jeunes seulement en habitat isolé, (ii) de plus d'individus uniquement en habitat connecté et (iii) d'individus plus grands à âge égal et ce indépendamment de la configuration du paysage. Nos résultats montrent que le niveau de connectivité entre habitats altère les réponses des populations au réchauffement climatique via une asymétrie dans le flux et le phénotype des dispersants entre climats. Nos résultats démontrent que la fragmentation du paysage peut influencer de façon drastique la dynamique et la persistance des populations face au changement climatique.

Peri-urban areas support a broad range of multifunctional demands for public goods. In northwest Europe, peri-urban areas tend to overlap with intensive agricultural land, resulting in conflicts between agricultural use and the public good demands of residents. Sustainable intensification (SI) of agriculture might help reconcile agricultural and well-being goals, but it is unclear how the mix of actors in a peri-urban setting can trigger or restrain SI. In a Dutch case study, we explored how SI of agriculture can contribute to making peri-urban areas more sustainable, and which actors are key enabling factors for implementing SI. We used interviews, surveys, workshops, and empirical analysis to obtain insight into the stakeholder’s vision of a sustainable future for the case study area, the farming system and actor network. We integrated these insights in a Bayesian Belief Network, where we linked the actor network to implementation of three SI measures (farm-level efficiency measures, small landscape elements, and direct sales), and used sensitivity analysis to model effects of support for implementation by different groups of actors. The case study has a dense stakeholder network, where, dependent on the SI measure, farmers are triggered by all actors to implement SI, or have a stronger role in uptake themselves. The sensitivity analysis suggested that the future preferred by the stakeholders requires broad support of all actors involved, with local actors without a formal role being essential for uptake. Overall, trade-offs among public goods are almost inevitable when taking up SI measures.

International audience; Humans have built ports on all the coasts of the world, allowing people to travel, exploit the sea, and develop trade. The proliferation of these artificial habitats and the associated maritime traffic are not predicted to fade in the coming decades. Ports share common characteristics: species find themselves in novel singular environments, with particular abiotic properties-e.g., pollutants, shading, protection from wave action-within novel communities in a melting-pot of invasive and native taxa. Here we discuss how this drives evolution, including setting-up of new connectivity hubs and gateways, adaptive responses to exposure to new chemicals or new biotic communities, and hybridization between lineages that would have never come into contact naturally. There are still important knowledge gaps however, such as the lack of experimental tests to distinguish adaptation from acclimation processes, the lack of studies to understand the putative threats of port lineages to natural populations, or to better understand the outcomes and fitness effects of anthropogenic hybridization. We thus call for further research examining "biological portuarization", defined as the repeated evolution of marine species in port-ecosystems under human-altered selective pressures. Furthermore, we argue that ports act as giant mesocosms often isolated from the open sea by seawalls and locks, and so provide replicated life-size evolutionary experiments essential to support predictive evolutionary sciences.

Forest ecosystems depend on their capacity to withstand and recover from natural and anthropogenic perturbations (that is, their resilience)1. Experimental evidence of sudden increases in tree mortality is raising concerns about variation in forest resilience2, yet little is known about how it is evolving in response to climate change. Here we integrate satellite-based vegetation indices with machine learning to show how forest resilience, quantified in terms of critical slowing down indicators3–5, has changed during the period 2000–2020. We show that tropical, arid and temperate forests are experiencing a significant decline in resilience, probably related to increased water limitations and climate variability. By contrast, boreal forests show divergent local patterns with an average increasing trend in resilience, probably benefiting from warming and CO2 fertilization, which may outweigh the adverse effects of climate change. These patterns emerge consistently in both managed and intact forests, corroborating the existence of common large-scale climate drivers. Reductions in resilience are statistically linked to abrupt declines in forest primary productivity, occurring in response to slow drifting towards a critical resilience threshold. Approximately 23% of intact undisturbed forests, corresponding to 3.32 Pg C of gross primary productivity, have already reached a critical threshold and are experiencing a further degradation in resilience. Together, these signals reveal a widespread decline in the capacity of forests to withstand perturbation that should be accounted for in the design of land-based mitigation and adaptation plans.

All data & code generated during this study have been deposited in the INRAE dataverse: https://entrepot.recherche.data.gouv.fr/dataset.xhtml?persistentId=doi:10.57745/G4D3PG. The shiny application enabling the exploration and analysis of our complete dataset (PCA, GLM/Elastic Net and associated visualizations) is available here: https://fruitfliesmetabo.shinyapps.io/shiny.; International audience; Most phytophagous insect species exhibit a limited diet breadth and specialize on a few or a single host plant. In contrast, some species display a remarkably large diet breadth, with host plants spanning several families and many species. It is unclear, however, whether this phylogenetic generalism is supported by a generic metabolic use of common host chemical compounds ('metabolic generalism') or alternatively by distinct uses of diet-specific compounds ('multi-host metabolic specialism')? Here, we simultaneously investigated the metabolomes of fruit diets and of individuals of a generalist phytophagous species, Drosophila suzukii, that developed on them. The direct comparison of metabolomes of diets and consumers enabled us to disentangle the metabolic fate of common and rarer dietary compounds. We showed that the consumption of biochemically dissimilar diets resulted in a canalized, generic response from generalist individuals, consistent with the metabolic generalism hypothesis. We also showed that many diet-specific metabolites, such as those related to the particular color, odor, or taste of diets, were not metabolized, and rather accumulated in consumer individuals, even when probably detrimental to fitness. As a result, while individuals were mostly similar across diets, the detection of their particular diet was straightforward. Our study thus supports the view that dietary generalism may emerge from a passive, opportunistic use of various resources, contrary to more widespread views of an active role of adaptation in this process. Such a passive stance towards dietary chemicals, probably costly in the short term, might favor the later evolution of new diet specializations.

Determining how sibling interactions alter the fitness outcomes of dispersal is pivotal for the understanding of family living, but such studies are currently scarce. Using a large demographic dataset on pre-industrial humans from Finland, we studied dispersal consequences on different indicators of lifetime reproductive success according to sex-specific birth rank (a strong determinant of dispersal in our population). Contrary to the predictions of the leading hypotheses, we found no support for differential fitness benefits of dispersal for either males or females undergoing low vs. high sibling competition. Our results are inconsistent with both hypotheses that family members could have different fitness maximizing strategies depending on birth rank, and that dispersal could be mainly driven by indirect fitness benefits for philopatric family members. Our study stresses the need for studying the relative outcomes of dispersal at the family level in order to understand the evolution of family living and dispersal behaviour.

International audience; A large part of the soil protist diversity is missed in metabarcoding studies based on 0.25 g of soil environmental DNA (eDNA) and universal primers due to ca. 80% co-amplification of non-target plants, animals and fungi. To overcome this problem, enrichment of the substrate used for eDNA extraction is an easily implemented option but its effect has not yet been tested. In this study, we evaluated the effect of a 150 μm mesh size filtration and sedimentation method to improve the recovery of protist eDNA, while reducing the co-extraction of plant, animal and fungal eDNA, using a set of contrasted forest and alpine soils from La Réunion, Japan, Spain and Switzerland. Total eukaryotic diversity was estimated by V4 18S rRNA metabarcoding and classical amplicon sequence variant calling. A 2- to 3- fold enrichment in shelled protists (Euglyphida, Arcellinida and Chrysophyceae) was observed at the sample level with the proposed method, with, at the same time, a 2-fold depletion of Fungi and a 3- fold depletion of Embryophyceae. Protist alpha diversity was slightly lower in filtered samples due to reduced coverage in Variosea and Sarcomonadea, but significant differences were observed in only one region. Beta diversity varied mostly between regions and habitats, which explained the same proportion of variance in bulk soil and filtered samples. The increased resolution in soil protist diversity estimates provided by the filtration-sedimentation method is a strong argument in favour of including it in the standard protocol for soil protist eDNA metabarcoding studies

The uncontrolled colonization of benthic organisms on submerged surfaces, also called biofouling, causes severe damage in the shipping and aquaculture industries. Biofouling starts with a benthic biofilm composed of a complex assemblage of microbes, bacteria and benthic diatoms, called microfouling, on which macrofouling invertebrate species settle and grow. Invertebrate larvae may use natural soundscapes to orientate inshore and choose their optimal habitat. Recent studies have demonstrated that ship sounds enhance the larval settlement and growth of several invertebrate species, such as mussels, associated with biofouling. Among invertebrates, effects of sound generated by offshore human activities are still poorly studied. This study aims to assess the effect of pile driving, drilling and vessel sounds on model species associated with micro and macrofouling. First, the biofilm development of Navicula pelliculosa and Amphora coffeaeformis was assessed, then, the larval development of the blue mussel (Mytilus edulis) was evaluated from the D-veliger to the postlarval stage. Mussel larvae and microalgae were exposed 12 h each day in tanks (Larvosonic) adapted to sound experiments under controlled conditions. All anthropogenic sounds induced a thinner N. pelliculosa biofilm coupled with a lower microalgae concentration. The drilling sound had a stronger effect on the biofilm thickness. The drilling sound significantly reduced the pediveliger settlement and the postlarvae clearance rate by 70.4% and tended to diminish settler sizes compared to control sound. Contrary to our expectation, pile driving tended to enhance larval recruitment by 22% (P=0.077) and the boat sound did not stimulate larval settlements or recruitment. Drilling sound generated a stressful acoustic environment for pediveliger settlements and postlarvae seem to maintain their shell valves closed to preserve energy. We identify potential causes and mechanisms involved in these impacts of anthropophony on larval ecology and microfouling dynamics.

Plasmodium falciparum, the most virulent agent of human malaria, spread from Africa to all continents following the out-of-Africa human migrations. During the transatlantic slave trade between the 16thand 19thcenturies, it was introduced twice independently to the Americas where it adapted to new environmental conditions (new human populations and mosquito species). Here, we analyzed the genome-wide polymorphisms of 2,635 isolates across the currentP. falciparumdistribution range in Africa, Asia, Oceania, and the Americas to investigate its genetic structure, invasion history, and selective pressures associated with its adaptation to the American environment. We confirmed that American populations originated from Africa with at least two independent introductions that led to two genetically distinct clusters, one in the North (Haiti and Columbia) and one in the South (French Guiana and Brazil), and the admixed Peruvian group. Genome scans revealed recent and more ancient signals of positive selection in the American populations. Particularly, we detected positive selection signals in genes involved in interactions with host (human and mosquito) cells and in genes involved in resistance to malaria drugs in both clusters. We found that some genes were under selection in both clusters. Analyses suggested that for five genes, adaptive introgression between clusters or selection on standing variation was at the origin of this repeated evolution. This study provides new genetic evidence onP. falciparumcolonization history and on its local adaptation in the Americas.

International audience

1. Aggregated species occurrence and abundance data from disparate sources are increasingly accessible to ecologists for the analysis of temporal trends in biodiversity. However, sampling biases relevant to any given research question are often poorly explored and infrequently reported; this can undermine statistical inference. In other disciplines, it is common for researchers to complete “risk-of-bias” assessments to expose and document the potential for biases to undermine conclusions. The huge growth in available data, and recent controversies surrounding their use to infer temporal trends, indicate that similar assessments are urgently needed in ecology. 2. We introduce ROBITT, a structured tool for assessing the “Risk-Of-Bias In studies of Temporal Trends in ecology”. ROBITT has a similar format to its counterparts in other disciplines: it comprises signalling questions designed to elicit information on the potential for bias in key study domains. In answering these, users will define study inferential goal(s) and relevant statistical target populations. This information is used to assess potential sampling biases across domains relevant to the research question (e.g. geography, taxonomy, environment), and how these vary through time. If assessments indicate biases, then usersmust clearly describe them and/or explain what mitigating action will be taken.3. Everything that users need to complete a ROBITT assessment is provided: the tool,a guidance document,and a worked example. Following other disciplines, the tool and guidance document were developed through a consensus-forming process across experts working in relevant areas of ecology and evidence synthesis.4. We propose that researchers should be strongly encouraged to include a ROBITT assessment when publishing studies of biodiversitytrends, especially when usingaggregated data. This will help researchers to structure their thinking, clearly acknowledge potential sampling issues,highlight where expert consultation is required, and provides an opportunity to describe data checks that might gounreported. ROBITT will also enable reviewers, editors, and readers to establish how well research conclusions are supported given a dataset combined with some analytical approach. In turn, itshouldstrengthen evidence-based policy and practice, reduce differing interpretations of data, and provide a clearer picture of the uncertainties associated with our understanding of reality. risk-of-bias; speciesoccurrence data; temporal trends; Essential Biodiversity Variables; indicators; uncertainty; insect declines

This first book volume collects country reports produced by the AE4EU Horizon 2020 project and the European Association Agroecology Europe which involved a large number of organisations, as well as more than 25 "mappers" who conducted the work in different European countries. Among them were many members of the Agroecology Europe Youth Network (AEEUYN). The different volumes of the book series offer an illustrative state of the art of agroecology in Europe by synthesizing and providing key information on the common understanding of agroecology, as well as its development at the European level. To scale up agroecology, this first book volume provides critical information and analysis of the development of agroecology in different contexts, which is very much needed as a necessary step to attain larger insights about the state of the art of agroecology, as well as to support its expansion and use at the policymaker level. Documenting the development of agroecology in 13 European countries (Albania, Austria, Bosnia, Bulgaria, Croatia, Germany, Greece, Italy, Kosovo, Malta, Montenegro, North Macedonia, and Romania), this volume describes 112 initiatives, examples, cases, and programmes linked to agroecology, and the development of agroecology in these European countries as well as the diversity of use of the concept.

Within the set of risk factors that compromise the conservation of marine biodiversity, one of the least understood concerns is the noise produced by human operations at sea and from land. Many aspects of how noise and other forms of energy may impact the natural balance of the oceans are still unstudied. Substantial attention has been devoted in the last decades to determine the sensitivity to noise of marine mammals—especially cetaceans and pinnipeds—and fish because they are known to possess hearing organs. Recent studies have revealed that a wide diversity of invertebrates are also sensitive to sounds, especially via sensory organs whose original function is to allow maintaining equilibrium in the water column and to sense gravity. Marine invertebrates not only represent the largest proportion of marine biomass and are indicators of ocean health but many species also have important socio-economic values. This review presents the current scientific knowledge on invertebrate bioacoustics (sound production, reception, sensitivity), as well as on how marine invertebrates are affected by anthropogenic noises. It also critically revisits the literature to identify gaps that will frame future research investigating the tolerance to noise of marine ecosystems.

Aquaculture can represent an alternative means of economic yield and food security. Despite this fact, consumers still have a more negative perception of farmed fish when compared with wild fish, including its sustainability. Understanding how consumers perceive sustainability is essential in building an effective strategy to encourage sustainable fish consumption. A survey with 2145 consumers was conducted in five European countries (France, Germany, Italy, Poland, and Spain) to inquire into consumers’ beliefs about the main pillars of the sustainability (environmental, social, and economic) when farmed and wild fish are compared, as well as to identify segments of consumers with similar beliefs about fish sustainability. Overall, results showed that European consumers perceived farmed fish as being more sustainable, locally obtained, providing environmental benefits, generating employment, improving human living conditions, generating rural development, and ensuring more fair fish prices than wild fish. Conversely, wild fish was perceived as ensuring animal welfare and being more organic but causing more environmental damage than farmed fish. Additionally, it seems that to effectively communicate aquaculture sustainability, it would be better to focus on single aspects of sustainability (beliefs) rather than focusing on the whole concept of sustainability. Finally, four segments of consumers were identified according to consumers’ beliefs, which were labelled accordingly: ambivalent, pro aquaculture, pro wild fish, and impartial. Results obtained may be helpful to provide each segment with tailored marketing strategies to stimulate farmed fish consumption and improve the overall image of the aquaculture sector to foster its full development in Europe. Objectius de Desenvolupament Sostenible::14 - Vida Submarina Objectius de Desenvolupament Sostenible::14 - Vida Submarina::14.2 - Per al 2020, gestionar i protegir de manera sostenible dels ecosistemes marins i costaners amb vista a evitar efectes nocius importants, fins i tot mitjançant l'enfortiment de la seva resiliència, i adoptar mesures de restauració a fi de restablir la salut i la productivitat dels oceans Objectius de Desenvolupament Sostenible::14 - Vida Submarina::14.5 - Per al 2020, conservar almenys el 10% de les zones costaneres i marines, de conformitat amb les lleis nacionals i el dret internacional i sobre la base de la millor informació científica disponible Objectius de Desenvolupament Sostenible::14 - Vida Submarina::14.a - Augmentar els coneixements científics, desenvolupar la capacitat de recerca i transferir la tecnologia marina, tenint en compte els criteris i directrius per a la transferència de tecnologia marina de la Comissió Oceanogràfica Intergovernamental, a fi de millorar la salut dels oceans i potenciar la contribució de la biodiversitat marina al desenvolupament dels països en desenvolupament, en particular els petits Estats insulars en desenvolupament i els països menys avançats Objectius de Desenvolupament Sostenible::14 - Vida Submarina::14.c - Millorar la conservació i l'ús sostenible dels oceans i els seus recursos aplicant el dret internacional reflectit en la Convenció de les Nacions Unides sobre el Dret del Mar, que proporciona el marc jurídic per a la conservació i la utilització sostenible dels oceans i els seus recursos, com es recorda en el paràgraf 158 del document "El futur que volem" Objectius de Desenvolupament Sostenible::2 - Fam zero

Organisms throughout their lives constantly modify their surrounding environment; such activities are often termed niche construction. An important property of niche construction is that its consequences can persist for a long period of time and several subsequent generations can be affected. This phenomenon is described as a time lag in niche construction, or ecological inheritance.Studies have suggested that time lag in niche construction can help avoiding the tragedy of the commons. In other words, it can lead to evolution of contribution to a common good, which is associated with positive niche construction, or to the limitation of a common bad, which is associated with negative niche construction.In this article, we will study the evolutionary consequences of incorporating time lags in a negative niche construction process: waste production. We consider a population that extrudes waste into its environment as it consumes resources to grow and reproduce. Higher consumption rates can lead to higher waste production. Individuals that adopt this selfish strategy are expected to be selected as toxic effects are equally shared among all individuals.We show that indeed this tragedy of the commons persists in many cases and selfish strategies evolve in general. When evolution is rapid and intragenerational time lag is incorporated, however, selfish strategies are no longer favoured and strategies resulting in less waste production can be selected. Importantly, heavy pollution results in smaller population sizes, so that drift becomes more important than natural selection and limits the evolution of higher waste production.

Parasites are omnipresent, and their eco-evolutionary significance has aroused much interest from scientists. Parasites may affect their hosts in many ways by altering host density, vulnerability to predation, and energy content, thus modifying profitability within the optimal foraging framework. Consequently, parasites could impact predator diet and trophic links through food webs. Here, we investigate the consequences of the iridovirus Daphnia iridescent virus 1 (DIV-1) infection on the reproductive success, mortality, appearance, mobility, and biochemical composition of water fleas (Daphnia magna), a widespread freshwater crustacean. We compare search time between infected and uninfectedDaphniapreyed by a common aquatic insect (Notonectasp.) as well as the handling time and feeding preference ofNotonectasp. Our findings show that infection does not change fecundity but reduces lifespan and thereby constrains fitness. InfectedDaphniashow reduced mobility and increased color reflectance in the UV and visible domains, which potentially affects their visibility and thus catchability. Infection increases body size and the amount of proteins but does not affect carbohydrate and lipid contents. Although infectedDaphniahad a longer handling time, they are preferred over uninfected individuals by aquatic insects. Taken together, our findings show that DIV-1 infection could makeDaphniamore profitable to predators (21% energy increase), a positive effect that should be balanced with density reductions due to higher mortalities. We also highlight that exposure to infection in asymptomatic individuals leads to ecological characteristics that differ from both healthy and symptomatic infected individuals.

Viruses are key players in marine ecosystems where they infect abundant marine microbes. RNA viruses are emerging as key members of the marine virosphere. They have recently been identified as a potential source of mortality in diatoms, a group of microalgae that accounts for roughly 40% of the primary production in the ocean. Despite their likely importance, their impacts on host populations and ecosystems remain difficult to assess. In this study, we introduce an innovative approach that combines automated 3D confocal microscopy with quantitative image analysis and physiological measurements to expand our understanding of viral infection. We followed different stages of infection of the bloom-forming diatom Guinardia delicatula by the RNA virus GdelRNAV-04 until the complete lysis of the host. From 20h after infection, we observed quantifiable changes in subcellular host morphology and biomass. Our microscopy monitoring also showed that viral infection of G. delicatula induced the formation of auxospores as a probable defense strategy against viruses. Our method enables the detection of discriminative morphological features on the subcellular scale and at high throughput for comparing populations, making it a promising approach for the quantification of viral infections in the field in the future.

International audience; Aim: Species-level traits, such as body and range sizes, are important correlates of extinction risk. However, both are often related and are driven by environmental factors. Here, we elucidated links between environmental factors, body size, range size and susceptibility to extinction, across the whole order of rodents. Location: Global. Time period: Current. Major taxa studied: Rodents (order Rodentia). Methods: We compiled an unprecedentedly large database of rodent morphology, phylogeny, range size, conservation status, global climate and normalized difference vegetation index (NDVI), comprising >86% of all described species. Using phylogenetic regressions, we initially explored the environmental factors driving body size. Next, we modelled the relationship between body size and range size. From this relationship, we computed and mapped (at the assemblage level) an index of relative range size, corresponding to the deviation from the expected range size of each species, given its body size. Finally, we tested whether relative range was correlated with the risk of extinction of the species derived from an assessment by the International Union for Conservation of Nature. Results: We found that, contrary to the expectations of Bergmann's rule, the body size of rodents was mostly influenced by variation in NDVI (rather than latitude/temperature). Body size, in turn, imposed a constraint on species range size, as evidenced by a triangular relationship that was segmented at the lower bound. The relative species range size derived from this relationship highlighted four geographical regions where rodents with small relative range were concentrated globally. We demonstrated that lower relative range size was associated with increased risk of extinction. Main conclusions: Species that, given their body size, are distributed across ranges that are smaller than expected have elevated extinction risk. Therefore, investigating the relationships between environmental drivers, body size and range size might help to detect species that could become threatened in the near future.

International audience; While the exploitation of aquatic fauna and flora has been documented in several primate species to date, the evolutionary contexts and mechanisms behind the emergence of this behavior in both human and non-human primates remain largely overlooked. Yet, this issue is particularly important for our understanding of human evolution, as hominins represent not only the primate group with the highest degree of adaptedness to aquatic environments, but also the only group in which true coastal and maritime adaptations have evolved. As such, in the present study we review the available literature on primate foraging strategies related to the exploitation of aquatic resources and their putative associated cognitive operations. We propose that aquatic resource consumption in extant primates can be interpreted as a highly site-specific behavioral expression of a generic adaptive foraging decision-making process, emerging in sites at which the local cost-benefit trade-offs contextually favor aquatic over terrestrial foods. Within this framework, we discuss the potential impacts that the unique intensification of this behavior in hominins may have had on the evolution of the human brain and spatial ecology.

On the climate-health issue, studies have already attempted to understand the influence of climate change on the transmission of malaria. Extreme weather events such as floods, droughts, or heat waves can alter the course and distribution of malaria. This study aims to understand the impact of future climate change on malaria transmission using, for the first time in Senegal, the ICTP's community-based vector-borne disease model, TRIeste (VECTRI). This biological model is a dynamic mathematical model for the study of malaria transmission that considers the impact of climate and population variability. A new approach for VECTRI input parameters was also used. A bias correction technique, the cumulative distribution function transform (CDF-t) method, was applied to climate simulations to remove systematic biases in the Coupled Model Intercomparison Project Phase 5 (CMIP5) global climate models (GCMs) that could alter impact predictions. Beforehand, we use reference data for validation such as CPC global unified gauge-based analysis of daily precipitation (CPC for Climate Prediction Center), ERA5-land reanalysis, Climate Hazards InfraRed Precipitation with Station data (CHIRPS), and African Rainfall Climatology 2.0 (ARC2). The results were analyzed for two CMIP5 scenarios for the different time periods: assessment: 1983-2005; near future: 2006-2028; medium term: 2030-2052; and far future: 2077-2099). The validation results show that the models reproduce the annual cycle well. Except for the IPSL-CM5B model, which gives a peak in August, all the other models (ACCESS1-3, CanESM2, CSIRO, CMCC-CM, CMCC-CMS, CNRM-CM5, GFDL-CM3, GFDL-ESM2G, GFDL-ESM2M, inmcm4, and IPSL-CM5B) agree with the validation data on a maximum peak in September with a period of strong transmission in August-October. With spatial variation, the CMIP5 model simulations show more of a difference in the number of malaria cases between the south and the north. Malaria transmission is much higher in the south than in the north. However, the results predicted by the models on the occurrence of malaria by 2100 show differences between the RCP8.5 scenario, considered a high emission scenario, and the RCP4.5 scenario, considered an intermediate mitigation scenario. The CanESM2, CMCC-CM, MCC-CMS, inmcm4, and IPSL-CM5B models predict decreases with the RCP4.5 scenario. However, ACCESS1-3, CSIRO, NRCM-CM5, GFDL-CM3, GFDL-ESM2G, and GFDL-ESM2M predict increases in malaria under all scenarios (RCP4.5 and RCP8.5). The projected decrease in malaria in the future with these models is much more visible in the RCP8.5 scenario. The results of this study are of paramount importance in the climate-health field. These results will assist in decision-making and will allow for the establishment of preventive surveillance systems for local climate-sensitive diseases, including malaria, in the targeted regions of Senegal.

International audience; Contrasting views of ecosystem services in seasonal wetlands of Gharb, Morocco.Submerged in winter, the seasonal wetlands (merjas) of the Gharb plain in Morocco were traditionally usedfor grazing in summer, alongside other productive uses. Yet, merjas were considered by the colonialadministration as unhealthy and unproductive environments, despite their abundance in natural resources.During the 20th century, the plain, including the merjas, was drained and irrigated to contribute to thenational objectives of food security and export of agricultural products. This article examines how local andinstitutional stakeholders view the merjas and the benefits they provide, through an analysis of ecosystemservices. While State institutions consider them as virgin lands to be developed and as potential flood controlbuffer zones to protect irrigated areas and cities, riverside communities consider them as productive lands,disadvantaged by occasional floods. The study shows contrasting views of ecosystem services, where eachstakeholder has a utilitarian vision of merjas. Despite the international debate on biodiversity and carbonstorage in wetlands, the ecological dimensions are rarely mentioned. The ecosystem services approachreveals the antagonisms between stakeholders, but can be a means of negotiating the future of merjas in aterritorial vision.; Immergés en hiver, les marais saisonniers (merjas) de la plaine du Gharb au Maroc étaient traditionnellement exploités pour le pâturage en été, à côté d'autres usages productifs. Pourtant, ils étaient considérés par l'administration coloniale comme des milieux insalubres et peu valorisés, malgré leur abondance en ressources naturelles. Au cours du XX e siècle, la plaine a fait l'objet d'un aménagement hydro-agricole, incorporant les merjas, pour contribuer aux objectifs nationaux de sécurité alimentaire et d'exportation de produits agricoles. Cet article interroge le regard porté par les acteurs locaux et institutionnels sur les merjas et les bénéfices qu'elles procurent, à travers une analyse des services écosystémiques. Si les institutions les considèrent comme des terres vierges à aménager et des zones tampon de régulation des crues pour protéger les secteurs aménagés et les villes, les collectivités riveraines les considèrent comme des espaces productifs, défavorisés par les crues. L'étude montre des visions contrastées des services écosystémiques, où chaque acteur a une vision utilitariste des merjas. Malgré le débat international sur la biodiversité et le stockage de carbone dans les zones humides, les dimensions écologiques sont peu citées. L'approche par les services écosystémiques dévoile les antagonismes entre acteurs, mais peut être un moyen de négociation sur le devenir des merjas dans une vision territoriale. Mots clés : zones humides temporaires / services écosystémiques / collectivité riveraine / acteurs institutionnels / Maroc

International audience; French rivers are subject to winter floods. The northern pike (Esox lucius) needs these, as it performs lateral migrations for breeding. On the contrary, the allochthonous European catfish (Silurus glanis) is known to be less active in winter. however, very few studies have focused on the behaviour of these two predatory fishes during winter floods. Thus, we propose to characterize their respective responses to high waters, using a radio telemetry approach: thirty northern pikes and seven European catfish were tagged with radio transmitters in the aisne river (northern France) and monitored between october 2020 and May 2021. as a result, some northern pikes and at least one catfish were recorded in the major bed, in various habitats, during two major floods. A "preferential zone" was identified for the northern pike and defined from the pre-flood positions; three types of behaviour were identified: "sedentary" pikes never left these zones, "returned" pikes left during floods but returned when the water level dropped, and "departed" pikes did not come back at all. Individuals from the departed group were significantly larger than those from the other two groups (5% threshold), and those in the sedentary group significantly smaller (10% threshold), suggesting a greater exploration capacity in experienced northern pikes. Meanwhile, the supposed winter quiescence of the European catfish can be questioned, as our observations highlight an adaptability to various conditions. These results also underline the importance of taking the major bed into account in riverine management policies. Résumé.-Comportement de deux poissons prédateurs Esox lucius linnaeus, 1758 et Silurus glanis linnaeus, 1758 lors de deux crues successives dans l'Aisne (France).; Les rivières françaises sont sujettes aux crues hivernales, et ces périodes d’inondation sont des événements importants pour le comportement du brochet commun (Esox lucius), qui effectue des migrations latérales pour se reproduire. Le silure glane (Silurus glanis), allochtone, est quant à lui connu pour être plutôt moins actif pendant l’hiver. Cependant, peu d’études ont été réalisées sur le comportement de ces deux poissons prédateurs lors des crues hivernales. Nous avons donc cherché à caractériser leurs réponses respectives à la montée des eaux à l’aide d’une approche de radio télémétrie. Trente brochets communs et sept silures glanes ont été marqués à l’aide d’émetteurs radio dans la rivière Aisne (Nord de la France), et suivis entre octobre 2020 et mai 2021. Un nombre important de brochets ainsi qu’au moins un silure ont été enregistrés dans le lit majeur, dans divers habitats inondés, lors des deux crues les plus importantes. Concernant les brochets, une “zone préférentielle” a été identifiée, et définie à partir des positions des individus avant les inondations. Trois types de comportements principaux ont été identifiés : les brochets “sédentaires” ne quittaient jamais ces zones, les brochets “explorateurs” les quittaient mais revenaient à la décrue, et les brochets “délaisseurs” n’y revenaient pas du tout. Les individus du groupe des délaisseurs étaient significativement plus gros que ceux des deux autres groupes au seuil de 5 %, et ceux du groupe des sédentaires significativement plus petits au seuil de 10 %. Ceci suggère une plus grande capacité d’exploration chez les brochets plus expérimentés. Concernant le silure glane, nos observations remettent en cause sa supposée quiescence et mettent en évidence l’adaptabilité de l’espèce à diverses conditions. Ces résultats soulignent l’importance de la prise en compte du lit majeur dans les politiques de gestion fluviale.

International audience; 1. The increase in heatwave intensity and duration is challenging microalgal photosynthesis in shallow waters. In particular, the extent of photosynthesis impairment or limitation due to short extreme heat stress events occurring during a heatwave remains unknown.2. In this study, we investigated the importance of microalgal diversity and thermal history in the response of phototrophic biofilms to severe heat stress. We exposed isolated microalgal strains, synthetic communities previously acclimated at three temperatures, and natural phototrophic biofilms sampled at different seasons to several temperature/duration pairs (from 31 to 44 °C for 30, 60, 120 or 180 min). Microalgal photosynthetic activity (FV/FM) was measured after each heat stress and was shown to be a function of thermal dose, defined as the product of time and an exponential function of temperature.3. It appeared that the thermal history plays an important role in tolerance to heat stress, with synthetic communities acclimated at highest temperature being more tolerant. However, the responsiveness (i.e., the strength of the response) to heat stress was driven by the microalgal diversity of the community.4. Synthesis: Our analysis showed that although photosynthetic activity was negatively impacted by heat stress, gross primary productivity was even more strongly and rapidly impacted, highlighting the fact that in situ, even moderate heat stress can significantly impair primary productivity in shallow waters.

International audience; Unmanned aerial vehicles (UAVs) are widely used to assess the vegetation of an ecosystem. This report presents three data sets from UAVs used on a savannah-type ecosystem in Senegal. Two data sets contain an orthomosaic and a surface and terrain digital model (UAV outputs), along with associated field measurements on the tree and herbaceous layers, while the third data set contains an orthomosaic and digital surface model, along with field measurements on the herbaceous layers. One data set was compiled over the entire rainy season on the same plot (plot dataset). One was compiled across a landscape at the 7000 ha Dahra Djoloff research center (CRZ-dahra Centre de recherche zootechnique de Dahra). The third data set was compiled across Senegal from the North to the Southeast of the country with wide variability in climate and soil conditions. All the data sets are in Open Access in the Zenodo repository. These data sets could be used in many different studies: calibration between field measurements and UAV outputs on a large scale, or used as an intermediate step between field and satellite images.

In insects such as Drosophila melanogaster, flight guidance is based upon converging sensory information provided by several modalities including chemoperception. Drosophila flies are particularly attracted by complex odours combining volatile molecules from yeast, pheromones and microbe-metabolized food. Based on a recent study revealing that adult male courtship behaviour can be affected by early preimaginal exposure to maternally-transmitted egg factors, we wondered whether a similar exposure could affect free-flight odour tracking in flies of both sexes? Our main experiment consisted to test, in a wind tunnel, flies differently conditioned during preimaginal development. Each fly was presented to a dual choice of food labelled by groups of D. melanogaster or D. simulans flies of each sex. The combined effect of food with the cis-vaccenyl acetate pheromone (cVA), involved in aggregation behaviour, was also measured. In parallel, using the head-space method, we determined the "odorant" identity of the different labelled food tested. We also measured the antennal electrophysiological response to cVA in females and males resulting of the different preimaginal conditioning procedures. Our data indicate that flies differently modulated their flight response (take off, flight duration, food landing and preference), according to sex, conditioning and food choice. Our head-space analysis revealed that many food-derived volatile molecules diverged between sexes and species. Antennal responses to cVA showed a clear sex specific variation for conditioned flies, but not for control flies. In summary, our study indicates that preimaginal conditioning can affect Drosophila free flight behaviour in a sex specific manner.

International audience; Reproductive seasonality is the norm in mammals from temperate regions but less common at lower latitudes, where a broad diversity of reproductive phenology strategies is observed. Our knowledge of the evolutionary determinants shaping this diversity remains fragmentary and may reflect high phenotypic plasticity in individual strategies. Here we investigated the ecological determinants and fitness consequences of variation in birth timing across the annual cycle in a social primate endemic to the Congo basin, the mandrill, Mandrillus sphinx, which breeds seasonally. We further examined traits that modulate this variation within and across individuals. We used 9 years of ecological, life history and behavioural data from a natural population to characterize patterns of environmental and reproductive seasonality. We then investigated the consequences of variation in birth timing for pre- and postnatal offspring survival and maternal interbirth intervals. Finally, we studied the influence of within- (reproductive history and age) and between-individual (social rank) traits on variation in birth timing. We found that mandrills’ daily foraging time varied seasonally, with greater fluctuations for subordinate than dominant females. Birth timing was plastic, as females gave birth year round without detectable consequences for postnatal offspring survival. Giving birth within the birth peak, however, decreased interbirth intervals and probability of miscarriage. Finally, reproductive history and social rank mediated within- and between-individual variation in birth timing, respectively. Specifically, females that experienced a previous reproductive failure gave birth early in the next birthing season and dominant females bred less seasonally than subordinates, which may reflect their more even access to resources across the year. Overall, the selective pressures shaping mandrill reproductive seasonality differed from a classical scenario of seasonal fluctuations in resources limiting offspring survival. A complex interplay between social and ecological factors may thus determine within- and between-individual variation in phenology strategies of tropical and gregarious mammals.

Estuaries are key reactive ecosystems along the land–ocean aquatic continuum, with significant ecological and economic value. However, they have been facing strong morphological management changes and increased nutrient and contaminant inputs, possibly leading to ecological problems such as coastal eutrophication. Therefore, it is necessary to quantify the import and export fluxes of the estuaries, their retention capacity, and estuarine eutrophication potential. The 1-D Carbon-Generic Estuary Model (C-GEM) was used to simulate the transient hydrodynamics, transport, and biogeochemistry for estuaries with different sizes and morphologies along the French Atlantic coast during the period 2014–2016 using readily available geometric, hydraulic, and biogeochemical data. These simulations allowed us to evaluate the budgets of the main nutrients (phosphorus – P; nitrogen – N; silica – Si) and total organic carbon (TOC), and their imbalance, providing insights into their eutrophication potential. Cumulated average annual fluxes to the Atlantic coast from the seven estuaries studied were 9.6 kt P yr−1, 259 kt N yr−1, 304 kt Si yr−1, and 145 kt C yr−1. Retention rates varied depending on the estuarine residence times, ranging from 0 %–27 % and 0 %–34 % to 2 %–39 % and 8 %–96 % for total phosphorus (TP), total nitrogen (TN), dissolved silica (DSi), and TOC, respectively. Large-scale estuaries had higher retention rates than medium and small estuaries, which we interpreted in terms of estuarine residence times. As shown by the indicator of eutrophication potential (ICEP), there might be a risk of coastal eutrophication, i.e., the development of non-siliceous algae that is potentially harmful to the systems studied due to the excess TN over DSi. This study also demonstrates the ability of our model to be applied with a similar setup to several estuarine systems characterized by different sizes, geometries, and riverine loads.

International audience; We propose an original approach to optimize the TRISHNA instrument spectral configuration for the Split-Window (SW) method. First, we consider as input of end-to-end simulations an emissivity dataset that accounts for cavity effect within vegetation canopy. Second, we propose a bi-dimensional approach where both locations of TRISHNA SW channels, namely λ T IR3 c and λ T IR4 c , can slide within predefined spectral intervals. We report a large sensitivity to channel positions, with variations of RMSE on retrieved land surface temperature up to 3 K. Our bi-dimensional approach shows that this sensitivity is consistent with the underlying assumptions of the SW method. Indeed, two regions are observed in the (λ T IR3 c , λ T IR4 c) space: (1) an unfavorable region corresponding to λ T IR3 c ≤ 10.0 µm, where large RMSE values are ascribed to large differences between emissivities in both SW channels, and (2) a favorable region corresponding to λ T IR3 c ≥ 10.3 µm, where differences between emissivities in both SW channels are small, and where RMSE values are driven by the differences between atmospheric transmittance in both SW channels. Overall, it is necessary to better account for the difference in surface emissivities between the two SW channels, whereas disregarding the cavity effect within vegetation canopy is not critical. Eventually, our bidimensional approach permits to define an optimal position for λ T IR3 c at 10.6 µm, which induces a larger robustness to uncertainties on channel positions. By applying our study on two structurally different SW formulations and addressing impacts of uncertainties on land surface emissivity and atmospheric water vapor content, we show that these results can be generalized to other SW formulations.

We explored a 320-km transect in the Tumucumaque mountain range along the border between southern French Guiana and Brazil, sampling all trees and lianas with DBH >= 10 cm in seven 25 x 25-m plots installed near seven boundary milestones. We isolated DNA from cambium tissue and sequenced two DNA barcodes (rbcLa and matK) to aid in species identification. We also collected fertile herbarium specimens from other species (trees/shrubs/herbs) inside and outside the plots. The selected DNA barcodes were useful at the family level but failed to identify specimens at the species level. Based on DNA barcoding identification, the most abundant families in the plots were Burseraceae, Fabaceae, Meliaceae, Moraceae, Myristicaceae and Sapotaceae. One third of the images of sampled plants posted on the iNaturalist website were identified by the community to species level. New approaches, including the sequencing of the ITS region and fast evolving DNA plastid regions, remain to be tested for their utility in the identification of specimens at lower taxonomic levels in floristic inventories in the Amazon region., Um transecto de 320 km foi explorado na Serra do Tumucumaque, ao longo da fronteira entre o sul da Guiana Francesa e o Brasil por meio da amostragem de todas as arvores e lianas com DAP . 10 cm em sete parcelas de 25 x 25 m instaladas perto de sete marcos fronteiricos. Isolamos DNA de tecido cambial e sequenciamos dois codigos de barra de DNA (rbcLa e matK) para auxiliar na identificacao das especies. Tambem coletamos especimes de herbario ferteis de outras especies (arvores/ arbustos/ervas) dentro e fora das parcelas. Os codigos de barra de DNA selecionados foram uteis em nivel de familia, mas nao conseguiram identificar especimes em nivel de especie. Com base na identificacao de DNA barcoding, as familias mais abundantes nas parcelas foram Burseraceae, Fabaceae, Meliaceae, Moraceae, Myristicaceae e Sapotaceae. Um terco das imagens de plantas amostradas postadas no website iNaturalist foram identificadas em nivel de especie. Novas abordagens, incluindo o sequenciamento da regiao ITS e regioes de DNA plastidial de rapida evolucao, ainda precisam ser testadas quanto a sua utilidade na identificacao de especimes ate niveis taxonomicos mais baixos em inventarios floristicos na regiao amazonica. PALAVRAS-CHAVE: codigo de barras de DNA, fronteira Guiana Francesa-Brasil, inventario de arvores, matK, rbcLa, Tumucumaque

This paper focuses on the environment of Ethiopia, a country highly sensitive to droughts severely affecting vegetation. Vegetation monitoring of Ethiopian Highlands requires visualization of environmental parameters to assess droughts negatively influencing agricultural sustainable management of crops. Therefore, this study presented mapping of several climate and environmental variables including Palmer Drought Severity Index (PDSI). The data were visualized and interpreted alongside the topographic data to evaluate the environmental conditions for vegetation. The datasets included WorldClim and GEBCO and Digital Chart of the World (DCW). Research has threefold objectives: i) environmental mapping; ii) technical cartographic scripting; iii) data processing. Following variables were visualized on seven new maps: 1) topography; 2) soil moisture; 3) T °C minimum; 4) T °C maximum; 5) Wind speed; 6) Precipitation; 7) Palmer Drought Severity Index (PDSI). New high-resolution thematic environmental maps are presented and the utility of GMT for mapping multi-source datasets is described. With varying degrees of soil moisture (mean value of 15.0), min T°C (−1.8°C to 24°C), max T°C (14.4°C to 40.2°C) and wind speed (0.1 to 6.1 m/s), the maps demonstrate the variability of the PDSI fields over the country area (from −11.7 to 2.3) induced by the complex sum of these variables and intensified by the topographic effects notable over the Ethiopian Highlands which can be used for vegetation analysis. The paper presents seven new maps and contributes to the environmental studies of Ethiopia.

Some cancers have evolved the ability to spread from host to host by transmission of cancerous cells. These rare biological entities can be considered parasites with a host-related genome. Still, we know little about their specific adaptation to a parasitic lifestyle. MtrBTN2 is one of the few lineages of transmissible cancers known in the animal kingdom. Reported worldwide, MtrBTN2 infects marine mussels. We isolated MtrBTN2 cells circulating in the hemolymph of cancerous mussels and investigated their phenotypic traits. We found that MtrBTN2 cells had remarkable survival capacities in seawater, much higher than normal hemocytes. With almost 100% cell survival over three days, they increase significantly their chances to infect neighboring hosts. MtrBTN2 also triggered an aggressive cancerous process: proliferation in mussels was ~ 17 times higher than normal hemocytes (mean doubling time of ~ 3 days), thereby favoring a rapid increase of intra-host population size. MtrBTN2 appears to induce host castration, thereby favoring resources re-allocation to the parasites and increasing the host carrying capacity. Altogether, our results highlight a series of traits of MtrBTN2 consistent with a marine parasitic lifestyle that may have contributed to the success of its persistence and dissemination in different mussel populations across the globe.

Since 1950 humans have introduced 8300 teragrams (Tg, 1012 g, millions of metric tons) of plastic polymers into the Earth’s surface environment. Accounting for the dispersal and fate of produced plastics and fragmented microplastics in the environment has been challenging. Recent studies have fueled debate on the global river budget for plastic transport to oceans, the sinking and beaching of marine plastics and the emission and deposition of atmospheric microplastics. Here we define a global plastics cycle and budget, and develop a box model of plastics cycling, including the fragmentation and transport of large and small microplastics (LMP, SMP) within coupled terrestrial, oceanic and atmospheric reservoirs. We force the model with historical plastics production and waste data, and explore how macroplastics, LMP and SMP propagate through the reservoirs from 1950 to 2015 and beyond. We find that considerable amounts of plastics reside most likely in the deep ocean (82 Tg), in shelf sediments (116 Tg), on beaches (1.8 Tg) and, as a result of marine emissions, in the remote terrestrial surface pool (28 Tg). Business as usual or maximum feasible reduction and discard scenarios show similar, 4-fold increases in atmospheric and aquatic ecosystem SMP exposure by 2050, because future plastics mobilization is controlled by releases from the large terrestrial discarded plastics reservoir (3500 Tg). Zero-release from 2025 onwards illustrates recovery of P and LMP reservoirs on centennial time scales, while SMP continue to cycle in air, soil, and surface ocean for millennia. Limiting dramatic future dispersal of plastics requires, in addition to reducing use and waste, remediation of the large terrestrial legacy plastics pool.

International audience

Key message Different components of water balance and temperature reduce density and height growth of saplings of Picea abies (L.) H. Karst (Norway spruce), Abies alba Mill. (silver fir) and Fagus sylvatica L. (European beech) in mixed uneven-aged forests in the French Alps and Jura mountains. Ungulate browsing is an additional pressure on fir and beech that could jeopardise the renewal of these species in the future. Context The uncertainty in tree recruitment rates raises questions about the factors affecting regeneration processes in forests. Factors such as climate, light, competition and ungulate browsing pressure may play an important role in determining regeneration, forest structures and thus future forest composition. Aims The objective of this study was to quantify sapling densities and height increments of spruce, fir and beech and to identify dominant environmental variables influencing them in mixed uneven-aged forests in the French Alps and Jura mountains. Methods Sapling height increment and density were recorded in 152 plots, and non-linear mixed models were obtained to establish relations between them and environmental factors known to affect regeneration, namely altitude, slope, aspect, canopy openness, soil characteristics, temperature, precipitation and ungulate browsing. Results Regeneration density, varying from 0 to 7 saplings per m 2, decreased with sapling height and was also negatively affected for spruce by PET, but positively for fir by precipitation and for beech by mean annual soil water content. Height increment reached up to 50 cm annually, increasing with sapling height and canopy openness and decreasing under high maximum summer temperatures for spruce and beech. The statistical effect of different environmental variables varied slightly among species but trends were quite similar. Additionally, ungulate browsing was high, with fir being the most intensely browsed, followed closely by beech, while spruce was rarely browsed. Conclusions All these results suggest that more temperature warming and a decrease in water availability could negatively impact sapling growth and density in the three species, with possible reduction of forest renewal fluxes. The observed increase of ungulate populations leading to increased browsing could be particularly detrimental to fir saplings.

International audience; CONTEXTSo far, digital technology development in agriculture has mainly dealt with precision agriculture, often associated with conventional large-scale systems. The emergence of digital agriculture - based on the triptych of “new data sources / new processing methods / new inter-connection capacities (internet)” - opens up prospects for mobilizing digital technologies to accelerate the deployment of other forms of agriculture, such as agroecology. A specific research agenda must therefore be built to redirect researchers specialized in digital technologies towards these new issues. This construction is significant because digital technology and agroecology are disruptive innovations that shake up the actors' practices, agricultural innovation ecosystems, and value chains.OBJECTIVEAn interdisciplinary group of INRAE researchers (covering 10 scientific departments) was mandated to carry out this reflection, with the objective of developing a research agenda to better couple digitalization and agroecology, in order to pave the way for responsible digital farming. The group used the framework of responsible research and innovation.METHODOver 18 months, the group met monthly by video-conference, to overcome the interdisciplinarity barrier, and at three face-to-face seminars, where creative design exercises were carried out (based on a world café format, and “remember the future” method). This work gave rise to three prospective lines of research aimed at putting digitalization at the service of agroecology and local food systems. These topics prioritize research that fosters innovations in digital technology, as well as organisations and policies that (1) accelerate the agroecological transition on the farm and in the territories, (2) manage the territories as commons, (3) empower farmers and consumers. Then, the group examined these three prospective lines of research from an RRI perspective as well as three current research topics on digital agriculture (digital soil mapping, precision agriculture, technologies for food wastage reduction).RESULTS AND CONCLUSIONSThis work allowed us to highlight the gaps between current research on digital agriculture and the RRI expectations, and the tensions (between rationalization and diversity of farming systems, between complexity of agroecological systems and the need for simplification of models, and finally between data speculation and frugality). We were also able to refine the specific scientific questions of each prospective line of research and finally to draw attention to the key levers that will have to be integrated if these research efforts are to be approached from an RRI perspective.SIGNIFICANCEThis contribution shows RRI can be used not only to reflect on research practices but also as a framework to build a research agenda paving the way for responsible digital agriculture.

International audience; Summary In French law, the principle of ecological solidarity is intended to be implementedwhen a decision taken by a public authority would have a significant impact on the environment.That is, when the impact has not yet occurred. This interpretation immediately reduces its scopeand suggests that it would only apply to areas that have not yet been degraded. Taking theopposite view of the principle, this article demonstrates that the concept of ecological solidaritywould also be a driving force in the implementation of measures for the ecological restoration ofdegraded environments and in particular soils. In doing so, it draws on a field study located inthe heart of the Calanques National Park (SynTerCalM project, 2014-2016) to highlight how theinaction toward a degradation that can be invisible, soil contamination, undermines theconservation and restoration objectives of the environments with which it is related.; En droit français, le principe de solidarité écologique a vocation à être mis en oeuvre lorsqu’unedécision prise par une autorité publique aurait une incidence notable sur l’environnement. C’està-dire lorsque l’incidence n’aurait pas encore eu lieu. Cette interprétation réduit d’emblée sonchamp d’application et laisse entendre qu’elle ne s’appliquerait qu’aux espaces non encoredégradés. Prenant le contrepied du principe, cet article démontre que le concept de solidaritéécologique pourrait être un élément moteur dans la mise en oeuvre de mesures de restaurationécologique des milieux dégradés et en particulier des sols. Ce faisant, il se fonde sur une étude deterrain située dans le coeur du Parc national des Calanques (projet SynTerCalM, 2014-2016) poursouligner comment l’inaction face à une dégradation parfois invisible, en l’occurrence lacontamination des sols, nuit aux objectifs de conservation et de restauration des milieux aveclesquels il est en relation.

International audience; For more than a decade, high-throughput sequencing has transformed the study of marine planktonic communities and has highlighted the extent of protist diversity in these ecosystems. Nevertheless, little is known relative to their genomic diversity at the species-scale as well as their major speciation mechanisms. An increasing number of data obtained from global scale sampling campaigns is becoming publicly available, and we postulate that metagenomic data could contribute to deciphering the processes shaping protist genomic differentiation in the marine realm. As a proof of concept, we developed a findable, accessible, interoperable and reusable (FAIR) pipeline and focused on the Mediterranean Sea to study three a priori abundant protist species: Bathycoccus prasinos, Pelagomonas calceolata and Phaeocystis cordata. We compared the genomic differentiation of each species in light of geographic, environmental and oceanographic distances. We highlighted that isolation-byenvironment shapes the genomic differentiation of B. prasinos, whereas P. cordata is impacted by geographic distance (i.e. isolation-by-distance). At present time, the use of metagenomics to accurately estimate the genomic differentiation of protists remains challenging since coverages are lower compared to traditional population surveys. However, our approach sheds light on ecological and evolutionary processes occurring within natural marine populations and paves the way for future protist population metagenomic studies.

Many virological studies have tested the persistence of enveloped RNA viruses in various environmental and laboratory conditions and shown their short-term persistence. In this article, we analyzed Toscana virus (TOSV) infectivity, a pathogenic sandfly-borne phlebovirus, in two different conditions: in the sugar meal and blood meal of sand flies. Our results showed that TOSV RNA was detectable up to 15 days in sugar solution at 26 °C and up to 6 h in blood at 37 °C. Moreover, TOSV remains infective for 7 days in sugar solution and for minimum 6 h in rabbit blood. TOSV has shown persistent infectivity/viability under different conditions, which may have important epidemiological consequences. These results strengthen new hypotheses about the TOSV natural cycle, such as the possibility of horizontal transmission between sand flies through infected sugar meal.

Effects of climate change can be handled by means of mitigation and adaptation. In the biological sciences, adaptations are evolved solutions of engineering problems where organisms need to match an ecological challenge. Based on Adaptive Dynamics theory, a definition is proposed of adapted states and adaptational lags which is applicable during periods with environmental change of any speed and to any character. Adaptation can thus be studied even when it emerges from complex eco-evolutionary processes and targets for adaptation are not defined or known a priori. The approach is exemplified with a model for delayed germination (germination probability) in an annual plant, which is the classic life history example for adaptation to uncertain environments. Plasticity and maternal effects are added to the model to investigate lags in these modes of trait determination which are often presumed to be adaptive. In the example, adaptational lags are not converging to an equilibrium and change sign. For the model version with plasticity and maternal effect weights, the presence of a lag in these trait components can temporarily change the direction of selection on the genotypic weight. Adaptational lag is related to the establishment probability of mutants in the model example. It could therefore have practical relevance. A first general classification is proposed of model structures that include both adaptive control and evolutionary adaptation.

Wild bees are declining, mainly due to the expansion of urban habitats that have led to land-use changes. Effects of urbanization on wild bee communities are still unclear, as shown by contrasting reports on their species and functional diversities in urban habitats. To address this current controversy, we built a large dataset, merging 16 surveys carried out in 3 countries of Western Europe during the past decades, and tested whether urbanization influences local wild bee taxonomic and functional community composition. These surveys encompassed a range of urbanization levels, that were quantified using two complementary metrics: the proportion of impervious surfaces and the human population density. Urban expansion, when measured as a proportion of impervious surfaces, but not as human population density, was significantly and negatively correlated with wild bee community species richness. Taxonomic dissimilarity of the bee community was independent of both urbanization metrics. However, occurrence rates of functional traits revealed significant differences between lightly and highly urbanized communities, for both urbanization metrics. With higher human population density, probabilities of occurrence of above-ground nesters, generalist and small species increased. With higher soil sealing, probabilities of occurrence of above-ground nesters, generalists and social bees increased as well. Overall, these results, based on a large European dataset, suggest that urbanization can have negative impacts on wild bee diversity. They further identify some traits favored in urban environments, showing that several wild bee species can thrive in cities.

SummaryNatural quantitative variation in developmental processes must be driven by allelic variation. Yet, the genotype-phenotype relationships underlying developmental system variation are understudied due to their inherent complexity. Taking advantage of the simpleCaenorhabditis elegansgermline stem cell system, we characterized natural differences in the germ stem cell niche activity of two distinct wild isolates—measured as differences in germline progenitor zone (PZ) size. Through quantitative trait locus (QTL) analysis, we detected multiple candidate causal loci, including two large-effect QTL on chromosomes II and V. Resolving the chromosome V QTL, we show that the isolate with a smaller PZ exhibits a unique 148 bp deletion in the promoter region of the Notch ligand,lag-2, a central signal promoting germ stem cell fate and proliferation. As predicted, introducing this deletion into the isolate with a large PZ resulted in a smaller PZ. Unexpectedly, re-introducing the deleted ancestral sequence in the isolate with a smaller PZ further reduced PZ size. Using allelic replacement lines, we show that these contradictory phenotypic effects are due to epistatic interactions among thelag-2promoter, the chromosome II QTL, and additional loci in the genome. Although thelag-2deletion appeared to explain natural variation in germ stem cell niche activity, its effects across multiple genetic backgrounds were unpredictable due to higher-order epistasis. Studying the genetic architecture of quantitative developmental systems without taking into account its natural variation may be misleading, emphasizing the need for a better integration of developmental and quantitative genetics.

The limited amount of ecological data covering offshore parts of the ocean impedes our ability to understand and anticipate the impact of anthropogenic stressors on pelagic marine ecosystems. Isoscapes, i.e., spatial models of the distribution of stable isotope ratios, have been employed in the recent years to investigate spatio-temporal patterns in biogeochemical process and ecological responses. Development of isoscapes on the scale of ocean basins is hampered by access to suitable reference samples. Here we draw on archived material from long-running plankton survey initiatives, to build temporally explicit isoscape models for the North Atlantic Ocean (> 40°N). A total of 570 zooplankton samples were retrieved from Continuous Plankton Recorder archives and analysed for δ13C and δ15N values. Bayesian generalised additive models were developed to (1) model the relations between isotopic values and a set of predictors and (2) predict isotopic values for the whole of the study area. We produced yearly and seasonal isoscape models for the period 1998–2020. These are the first observation-based time-resolved C and N isoscapes developed at the scale of the North Atlantic Ocean. Drawing on the Stable Isotope Trajectory Analysis framework, we identify five isotopically distinct regions. We discuss the hydro-biogeochemical processes that likely explain theses modes, the differences in temporal dynamics (stability and cycles) and compare our results with previous bioregionalization efforts. Finally, we lay down the basis for using the isoscapes as a tool to define predator distributions and their interactions with the trophic environment. The isoscapes developed in this study have the potential to update our knowledge of marine predator ecology and therefore our capacity to improve their conservation in the future.

International audience; Many insect species harbour heritable bacterial endosymbionts. Some facultative endosymbionts provide benefits to their hosts under certain environmental conditions. Facultative endosymbionts are expected to impose additional energetic expenditures to their host, reducing host fitness. While there is accumulating evidence in plant sucking insects that facultative endosymbionts reduce the fitness of their host under permissive conditions, no direct energy costs associated with facultative endosymbionts have been identified. Using the standard metabolic rate (SMR) as a measure of the energy cost of self-maintenance, we investigated whether two common facultative endosymbionts Hamiltonella defensa or Regiella insecticola increase the maintenance cost of the pea aphid Acyrthosiphon pisum which could translate into host fitness reduction ('compensation hypothesis'). In addition, we tested if there was a link between SMR and the aphid fitness and whether it depended on endosymbiont density and aphid energetic reserves. Finally, we measured SMR at different temperatures to assess the impact of suboptimal thermal conditions on physiological cost of endosymbionts. In the presence of facultative endosymbionts, aphids expressed generally a lower fitness and a higher SMR compared to uninfected ones, in accordance with the 'compensation hypothesis'. However, the SMR difference between infected and uninfected aphids tended to decrease with increasing temperature. Complex host genotype-by-symbiont genotype-by-temperature interactions on SMR were also revealed. Energetic budget of adult aphids appeared weakly influenced by the aphid genotype and endosymbiont species, suggesting that facultative endosymbionts primarily impact the consumption of energy resources rather than their acquisition. Density of facultative endosymbionts varied largely among aphid lines but was not associated with the fitness nor metabolic rate of aphids. This work supports the energy basis of facultative endosymbiont associated fitness costs and raises new questions about the effect of facultative endosymbionts on the energy metabolism of their host. Read the free Plain Language Summary for this article on the Journal blog.

International audience; Groundwater irrigation is essential to sustain food production, and aquifer depletion represents a major sustainability challenge for humanity. There is a need for adequate modelling tools to assess the impacts of farming practices on groundwater resources with policy-makers and farmers in different contexts, especially in the case of smallholder farms in the tropics. We introduce the NIRAVARI model, which was designed to represent the Indian farming and water resource context. NIRAVARI is a parsimonious model integrating biophysical and decisional processes dealing with the farming system and the water table processes. A specific focus is given to how to irrigate with multiple water resources. Its formalisms include equations from well-tested published models for soil moisture and plant water stress simulations. The programming and graphic user interface is based on Excel VBA. We illustrate the ability of NIRAVARI to simulate a broad range of farmer adaptation strategies using four scenarios of cropping systems and water resources policies, and therefore, its interest for participatory scenario design and assessment with stakeholders.

International audience; Large carnivores play a pivotal regulating role in maintaining healthy and balanced ecosystems; however, most of them are rare and elusive, and knowledge about their resource consumption is scarce. Traditional methods based on morphological identification of undigested remains are labor intensive and often not sufficiently accurate, leading to errors and biased ecological inferences. Here, we developed a multi-marker DNA metabarcoding approach to analyze the dietary diversity of giant otters (Pteronura brasiliensis) from fecal DNA while controlling predator species identity. We combined two mitochondrial markers, 12S rRNA and cytochrome c oxidase 1 (COI) gene, that target the full range of potential vertebrate and invertebrate prey. We compiled a local reference database of DNA barcodes for most potentially ingested fish, which were used to evaluate the specificity of the metabarcoding primers in silico. Most prey are identified at the species level (>90%) and the dietary profiles provided independently by the two markers are highly similar, whether in terms of list of prey or frequency of occurrences, hence validating the approach. We detected a higher number of rare fish prey with the 12S primers that amplified solely Teleost species while the degenerate COI primers revealed non-fish prey (e.g., amphibians, snakes, birds, and earthworms) and confirmed predator species identity. This study demonstrated that scat DNA metabarcoding is particularly useful to provide in-depth information on elusive carnivorous dietary profile. Our methodology opens up new opportunities to understand how top carnivores diet cope with the effects of anthropogenic alteration of ecosystems and identify conflicts with humans and livestock.

L'écopastoralisme est une pratique de gestion écologique en plein essor, dont les bienfaits pour le maintien ou la restauration des milieux naturels ont été largement démontrés. Mais cette solution alternative de gestion obtient-elle les mêmes résultats sur des milieux fortement anthropisés et artificialisés ? Une étude menée sur les digues artificielles du Rhône de la réserve de chasse de Donzère-Mondragon s'est intéressée aux impacts des différents troupeaux sur les communautés végétales d’écosystèmes récents. Grâce à un suivi botanique sur plusieurs années, les scientifiques ont pu démontrer que la gestion par les herbivores s'avérait efficace pour maintenir l'ouverture des milieux et augmenter significativement le nombre et la diversité des espèces par rapport à l’absence de gestion ou aux interventions mécaniques.

Primary forests, defined here as forests where the signs of human impacts, if any, are strongly blurred due to decades without forest management, are scarce in Europe and continue to disappear. Despite these losses, we know little about where these forests occur. Here, we present a comprehensive geodatabase and map of Europe’s known primary forests. Our geodatabase harmonizes 48 different, mostly field-based datasets of primary forests, and contains 18,411 individual patches (41.1 Mha) spread across 33 countries. When available, we provide information on each patch (name, location, naturalness, extent and dominant tree species) and the surrounding landscape (biogeographical regions, protection status, potential natural vegetation, current forest extent). Using Landsat satellite-image time series (1985–2018) we checked each patch for possible disturbance events since primary forests were identified, resulting in 94% of patches free of significant disturbances in the last 30 years. Although knowledge gaps remain, ours is the most comprehensive dataset on primary forests in Europe, and will be useful for ecological studies, and conservation planning to safeguard these unique forests., Measurement(s)Geographic DistributionTechnology Type(s)digital curationFactor Type(s)countrySample Characteristic - Environmentprimary forestSample Characteristic - LocationEurope Machine-accessible metadata file describing the reported data: 10.6084/m9.figshare.14540625

International audience; Amazonian rainforests, once thought to be pristine wilderness, are increasingly known to have been widely inhabited, modified, and managed prior to European arrival, by human populations with diverse cultural backgrounds. Amazonian Dark Earths (ADEs) are fertile soils found throughout the Amazon Basin, created by pre-Columbian societies with sedentary habits. Much is known about the chemistry of these soils, yet their zoology has been neglected. Hence, we characterized soil fertility, macroinvertebrate communities, and their activity at nine archeological sites in three Amazonian regions in ADEs and adjacent reference soils under native forest (young and old) and agricultural systems. We found 673 morphospecies and, despite similar richness in ADEs (385 spp.) and reference soils (399 spp.), we identified a tenacious pre-Columbian footprint, with 49% of morphospecies found exclusively in ADEs. Termite and total macroinvertebrate abundance were higher in reference soils, while soil fertility and macroinvertebrate activity were higher in the ADEs, and associated with larger earthworm quantities and biomass. We show that ADE habitats have a unique pool of species, but that modern land use of ADEs decreases their populations, diversity, and contributions to soil functioning. These findings support the idea that humans created and sustained high-fertility ecosystems that persist today, altering biodiversity patterns in Amazonia.

Context Evidence for effects of habitat loss and fragmentation on the viability of temperate forest herb populations in agricultural landscapes is so far based on population genetic studies of single species in single landscapes. However, forest herbs differ in their life histories, and landscapes have different environments, structures and histories, making generalizations difficult. Objectives We compare the response of three slow-colonizing forest herbs to habitat loss and fragmentation and set this in relation to differences in life-history traits, in particular their mating system and associated pollinators. Methods We analysed the herbs’ landscape-scale population genetic structure based on microsatellite markers from replicate forest fragments across seven European agricultural landscapes. Results All species responded to reductions in population size with a decrease in allelic richness and an increase in genetic differentiation among populations. Genetic differentiation also increased with enhanced spatial isolation. In addition, each species showed unique responses. Heterozygosity in the self-compatible Oxalis acetosella was reduced in smaller populations. The genetic diversity of Anemone nemorosa, whose main pollinators are less mobile, decreased with increasing spatial isolation, but not that of the bumblebee-pollinated Polygonatum multiflorum. Conclusions Our study indicates that habitat loss and fragmentation compromise the long-term viability of slow-colonizing forest herbs despite their ability to persist for many decades by clonal propagation. The distinct responses of the three species studied within the same landscapes confirm the need of multi-species approaches. The mobility of associated pollinators should be considered an important determinant of forest herbs’ sensitivity to habitat loss and fragmentation.