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International audience; Context : Flower-visiting insects depend on floral resource availability from both cultivated and semi-natural habitats in agricultural landscapes. Landscape studies exploring insect abundance mainly focus on land cover maps without considering plant species within. Highlighting the functional role of landscapes through the potential floral resources they provide is an overlooked innovative approach. Objectives : We aimed to identify traits of floral communities that are important, across several spatial scales, for explaining the abundance of flower-visiting insects. Mapping and quantifying potential floral resources according to their attractivity, accessibility and profitability in both crop and non-crop habitats was performed to gain insights into flower-vising insect requirements. Methods : We translated land-cover maps of 39 landscapes of 250 m, 500 m and 1000 m radius into potential floral resource maps, using pre-existing vegetation surveys and floral traits databases. In the centres of the landscapes, the abundance of flower-visiting insect groups (domestic and wild bees, bumblebees and hoverflies) were recorded in organic winter cereal fields. We then fitted Generalized Linear Models (GLMs) to investigate the effects of flower trait variables (pre-selected with conditional random forests) at both field and landscape scales on the abundance of each flower-visiting insect group. Results : Floral resource maps explained the abundances of flower-visiting insect groups. Small wild bees (< 1 cm) responded positively to the relative amount of attractive and accessible floral resources at 250 m. The abundance of domestic bees and bumblebees was positively correlated with the relative amount of high nectar producing plants at 1000 m. The abundance of hoverflies was positively influenced by the relative amount of actinomorphic flowers (i.e., those with radial symmetry), at 1000 m.Conclusion : Resource maps could explain flower-visiting insect abundances, identify which category of floral resources organisms require, and determine in which habitat types these resources prevail. These results open a new research area related to managing the environment by optimising floral resources for flower-visiting insect conservation and pollination maintenance.

International audience; Since 2008, there has been a major decrease in the numbers of old and large sardines in the Gulf of Lions, which has had a major effect on regional fisheries. A bottom-up process involving a shift in diet towards smaller planktonic prey has been suggested as the main driver of this development. Yet, the reproductive capacities of the sardines have not changed, suggesting potential modifications in energy allocation trade-offs. Whether this could also affect maintenance, in particular at the end of the winter reproductive period, and explain the lower adult survival and the disappearance of older individuals remains unclear. We therefore experimentally investigated the consequences of seasonal food availability (summer vs. winter) on life-history traits and energy allocation trade-offs at the individual and population levels. Our results indicate that food resources during summer had a major effect on energy reserves and growth, limiting the maximum size and body condition reached at the end of reproduction. In addition, food restrictions during growth and/or reproduction periods led to physiological costs mediated by increased oxidative damage. Mediterranean sardines did not show any ability for compensatory growth and did not appear to be capital breeders. Instead, they displayed individual differences in coping with physiological constraints and displayed various life-history strategies regardless of food availability. We highlighted 3 main individual energy allocation strategies: (1) preferential allocation to body condition or (2) to growth, or (3) simultaneous allocation to reproduction and growth. These issues are key, as climate change is expected to favour smaller phytoplankton, which might amplify the deterioration in the condition of pelagic fish.

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.

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’.

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.

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

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; Although animal dispersal is known to play key roles in ecological and evolutionary processes such as colonization, population extinction and local adaptation, little is known about its genetic basis, particularly in vertebrates. Untapping the genetic basis of dispersal should deepen our understanding of how dispersal behaviour evolves, the molecular mechanisms that regulate it and link it to other phenotypic aspects in order to form the so-called dispersal syndromes. Here, we comprehensively combined quantitative genetics, genome-wide sequencing and transcriptome sequencing to investigate the genetic basis of natal dispersal in a known ecological and evolutionary model of vertebrate dispersal: the common lizard, Zootoca vivipara. Our study supports the heritability of dispersal in semi-natural populations, with less variation attributable to maternal and natal environment effects. In addition, we found an association between natal dispersal and both variation in the carbonic anhydrase (CA10) gene, and in the expression of several genes (TGFB2, SLC6A4, NOS1) involved in central nervous system functioning. These findings suggest that neurotransmitters (serotonin and nitric oxide) are involved in the regulation of dispersal and shaping dispersal syndromes. Several genes from the circadian clock (CRY2, KCTD21) were also differentially expressed between disperser and resident lizards, supporting that the circadian rhythm, known to be involved in long-distance migration in other taxa, might affect dispersal as well. Since neuronal and circadian pathways are relatively well conserved across vertebrates, our results are likely to be generalisable, and we therefore encourage future studies to further investigate the role of these pathways in shaping dispersal in vertebrates.

The survival of animals depends, among other things, on their ability to identify threats in their surrounding environment. Senses such as olfaction, vision and taste play an essential role in sampling their living environment, including microorganisms, some of which are potentially pathogenic. This study focuses on the mechanisms of detection of bacteria by theDrosophilagustatory system. We demonstrate that the peptidoglycan (PGN) that forms the cell wall of bacteria triggers an immediate feeding aversive response when detected by the gustatory system of adult flies. Although we identify ppk23+ and Gr66a+ gustatory neurons as necessary to transduce fly response to PGN, we demonstrate that they play very different roles in the process. Time-controlled functional inactivation andin vivocalcium imaging demonstrate that while ppk23+ neurons are required in the adult flies to directly transduce PGN signal, Gr66a+ neurons must be functional in larvae to allow future adults to become PGN sensitive. Furthermore, the ability of adult flies to respond to bacterial PGN is lost when they hatch from larvae reared under axenic conditions. Recolonization of axenic larvae, but not adults, with a single bacterial species,Lactobacillus brevis,is sufficient to restore the ability of adults to respond to PGN. Our data demonstrate that the genetic and environmental characteristics of the larvae are essential to make the future adults competent to respond to certain sensory stimuli such as PGN.

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

International audience; Aster Like Nanoparticles (ALNs) are femtoentities, recently discovered in different aquatic environments, whose intrinsic nature and ecological features remain to be determined. In this study, we investigate the in-situ temporal dynamics of ALNs during one year in 3 different lakes, in relation with the physico-chemical and biological environment. ALN abundances in investigated lakes showed a marked seasonal dynamic (from no detectable to 4.28 ± 0.75 x 10 6 ALNs.mL-1), with characteristic peaks in spring. We recorded correlation between ALNs and some prokaryotic phyla suggesting a broad and non-specific relationship. From their seasonal dynamics and potential link with prokaryotes, we conclude that ALNs represent an important ecological actor in the functioning of aquatic ecosystems.

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.

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

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.

International audience; Combined effects of multiple, climate change-associated stressors are of mounting concern, especially in Arctic ecosystems. Elevated mercury (Hg) exposure in Arctic animals could affect behavioral responses to changes in foraging landscapes caused by climate change, generating interactive effects on behavior and population resilience. We investigated this hypothesis in little auks (Alle alle), a keystone Arctic seabird. We compiled behavioral data for 44 birds across 5 years using accelerometers while also quantifying blood Hg and environmental conditions. Warm sea surface temperature (SST) and low sea ice coverage reshaped time activity budgets (TABs) and diving patterns, causing decreased resting, increased flight, and longer dives. Mercury contamination was not associated with TABs. However, highly contaminated birds lengthened interdive breaks when making long dives, suggesting Hg-induced physiological limitations. As dive durations increased with warm SST, subtle toxicological effects threaten to increasingly constrain diving and foraging efficiency as climate change progresses, with ecosystem-wide repercussions.

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.

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

International audience

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.

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.

Strengthening of feed security in the Sahel is urgently needed given the climate change and growing human population. A prerequisite to this is sustainable use of rangeland forage resources for livestock. Many studies have focused on the assessment of rangeland resources during the rainy season, while only a few have focused on the dry season which is the longest and most demanding period for livestock in Sahelian rangelands. The objective of this study is to develop remote sensing-based models for estimating dry season forage vegetation mass. To that end, 29 vegetation indices calculated from each of the MODIS-MCD43A4 (500 m), Landsat-8 (30 m), and Sentinel-2 (10 m) satellite products were used and tested against in situ data collected during three field-measurement campaigns in 2021 at eleven monitoring sites across Senegalese rangelands. Four statistical models were tested, namely, random forest, gradient boosting machines, and simple linear and multiple linear regressions. The two main vegetation mass variables modeled from remote sensing imagery were the standing herbaceous and litter dry mass (BH) and total forage dry mass (BT) with a dry mass of woody plant leaves added to BH. Overall, Sentinel-2 data provided the best performance for the assessment of BH with multiple linear regression (R2 = 0.74; RMSE = 378 kg DM/ha) using NDI5 (Normalized Difference Index5), GRCI (Green Residue Cover Index), SRI (Simple Ratio Index), TCARI (Transformed Chlorophyll Absorption in Reflectance Index), and DFI (Dead Fuel Index) indices. For BT, the best model was also obtained from Sentinel-2 data, including RVI3 (Ratio Vegetation Index3) (R2 = 0.78; RMSE = 496 kg DM/ha). Results showed the suitability of combining the red, green, blue, NIR, SWIR1, and SWIR2 bands in monitoring forage availability during the dry season. Our study revealed that the spectral richness of the optical sensor systems Sentinel-2, Landsat-8, and MODIS-MCD43A4 allowed for accurate assessments of dry-season forage mass of semi-arid rangelands. Adding to this, the high spatial and temporal resolution of Sentinel-2 satellite imagery makes this a promising data source for timely monitoring. These findings can support the monitoring of the animal feed balance in Sahelian countries and contribute to enhancing the resilience of pastoralism toward feed shortage through early warning systems.

Background Understanding how behavioural dynamics, inter-individual variability and individual interactions scale-up to shape the spatial spread and dispersal of animal populations is a major challenge in ecology. For biocontrol agents, such as the microscopic Trichogramma parasitic wasps, an understanding of movement strategies is also critical to predict pest-suppression performance in the field. Methods We experimentally studied the spatial propagation of groups of parasitoids and their patterns of parasitism. We investigated whether population spread is density-dependent, how it is affected by the presence of hosts, and whether the spatial distribution of parasitism (dispersal kernel) can be predicted from the observed spread of individuals. Using a novel experimental device and high-throughput imaging techniques, we continuously tracked the spatial spread of groups of parasitoids over large temporal and spatial scales (8 h; and 6 m, ca. 12,000 body lengths). We could thus study how population density, the presence of hosts and their spatial distribution impacted the rate of population spread, the spatial distribution of individuals during population expansion, the overall rate of parasitism and the dispersal kernel (position of parasitism events). Results Higher population density accelerated population spread, but only transiently: the rate of spread reverted to low values after 4 h, in a “tortoise-hare” effect. Interestingly, the presence of hosts suppressed this transiency and permitted a sustained high rate of population spread. Importantly, we found that population spread did not obey classical diffusion, but involved dynamical switches between resident and explorer movement modes. Population distribution was therefore not Gaussian, though surprisingly the distribution of parasitism (dispersal kernel) was. Conclusions Even homogenous asexual groups of insects develop behavioural heterogeneities over a few hours, and the latter control patterns of population spread. Behavioural switching between resident and explorer states determined population distribution, density-dependence and dispersal. A simple Gaussian dispersal kernel did not reflect classical diffusion, but rather the interplay of several non-linearities at individual level. These results highlight the need to take into account behaviour and inter-individual heterogeneity to understand population spread in animals.

Background To encourage Covid-19 vaccination, France introduced during the Summer 2021 a ‘Sanitary Pass’, which morphed into a ‘Vaccine Pass’ in early 2022. While the sanitary pass led to an increase in Covid-19 vaccination rates, spatial heterogeneities in vaccination rates remained. To identify potential determinants of these heterogeneities and evaluate the French sanitary and vaccine passes’ efficacies in reducing them, we used a data-driven approach on exhaustive nationwide data, gathering 141 socio-economic, political and geographic indicators. Methods We considered the association between vaccination rates and each indicator at different time points: before the sanitary pass announcement (week 2021-W27), before the sanitary pass came into force (week 2021-W31) and 1 month after (week 2021-W35) and the equivalent dates for the vaccine pass (weeks 2021-W49, 2022-W03 and 2022-W07). Results The indicators most associated with vaccination rates were the share of local income coming from unemployment benefits, overcrowded households rate, immigrants rate and vote for an ‘anti-establishment’ candidate at the 2017 Presidential election. These associations increase over time. Consequently, living in a district below the median of such indicator decreases the probability to be vaccinated by about 30% at the end of the studied period, and this probability gradually decreases by deciles of these indicators. Conclusions Our analysis reveals that factors related to poverty, immigration and trust in the government are strong determinants of vaccination rate, and that vaccination inequities tended to increase after the introduction of the French sanitary and vaccination passes.

International audience; Holopelagic Sargassum blooms in the tropical North Atlantic since 2011 are composed of two species, Sargassum natans and S. fluitans, and three morphotypes: S. natans VIII, S. natans I and S. fluitans III. The distinct morphology and the variations in space and time of the proportion of these three morphotypes suggest that they may have different physiology. For the first time, we have quantified the growth rates of these three morphotypes through in situ 9-day experiments on the coast of Martinique Island (French West Indies). Despite the non-optimal conditions for growth for these pelagic species and the short time of the experiment, we have observed that Sargassum fluitans III was growing faster (approximately twice as fast) than S. natans VIII and S. natans I. Sargassum natans I exhibited the slowest growth. The differences in tissue composition (CNP and CN natural isotopes) of morphotypes point to a greater benefit for S. fluitans III from the coastal localization of our experiment than for the two S. natans morphotypes, and suggest that S. natans I had achieved its last growth further offshore before our experiment. These contrasting growth performances are consistent with the dominance of S. fluitans III in recent observations in the Caribbean region and along the path from the Sargassum belt. This also makes this last morphotype the best candidate for cultivation. Making the distinction between the growth performances of morphotypes may improve the current predictive models about dispersal of these species.

International audience; A risk assessment for disasters is usually composed of hazard, vulnerability and exposure variables, which are hardly studied and modeled simultaneously. In volcanology, it remains ambitious to anticipate risk trajectories of pre- and post-eruption regimes. The interdependencies and feedback loops of the system's components, between geological, ecological, social and economic ones, give rise to trade-offs and synergies that should be disentangled for supporting decision-makers and helping local communities to face the risks. We developed here an innovative discrete-event and possibilistic model based on a dynamical network representation to assess volcanological multi-risk and long term post-eruption impacts of such a multifactorial system. We illustrated our method with the region around Mount Meru (Northern Tanzania), a strato-volcano with various eruption styles, located in a growing economic and touristic region (>1 M.inh.). We used qualitative and rule-based Petri nets, largely unused in environmental sciences, for an integrated assessment of the overall system dynamics and associated risks. As a central result, we showed that the region could recover from a blast eruption, irrespective of the timescale. Our study highlights the fact that agriculture and pastoralism remain key activities to favour the recovery of this region. Yet, as soon as subsidies from governmental and non-governmental organizations are lacking, the modeled region remains isolated from national and international activities and shifts to rural dynamics. Our case study can equip environmental risk assessment with innovative models, new dynamical indices (e.g. desirable and non-desirable trajectories), and rigorous reasoning for an ultimate integrated management of social-ecological systems at stake.

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.

International audience; The intensification of biological processes coping with salt stress became a major issue to mitigate land degradation. The Sine-Saloum Delta in Senegal is characterized by salt-affected soils with vegetation dominated by salt-tolerant grass Sporobolus robustus and shrubs like Prosopis juliflora. Plant experiments in controlled conditions suggested that arbuscular mycorrhizal (AM) fungi might be the key actors of facilitation process observed between S. robustus and P. juliflora, but the AM fungal community determinants are largely unknown. The current field-based study aimed at (1) characterizing the environmental drivers (rhizosphere physico-chemical properties, plant type and season) of the AM fungal community along an environmental gradient and (2) identifying the AM fungal taxa that might explain the S. robustus-mediated benefits to P. juliflora. Glomeraceae predominated in the two plants, but a higher richness was observed for S. robustus. The pH and salinity were the main drivers of AM fungal community associated with the two plants, negatively impacting richness and diversity. However, while a negative impact was also observed on mycorrhizal colonization for S. robustus, P. juliflora showed opposite colonization patterns. Furthermore, no change was observed in terms of AM fungal community dissimilarity between the two plants along the environmental gradient as would be expected according to the stress-gradient and complementary hypotheses when a facilitation process occurs. However, changes in intraspecific diversity of shared AM fungal community between the two plants were observed, highlighting 23 AM fungal OTUs associated with both plants and the highest salinity levels. Consequently, the increase of their abundance and frequency along the environmental gradient might suggest their potential role in the facilitation process that can take place between the two plants. Their use in ecological engineering could also represent promising avenues for improving vegetation restoration in saline Senegalese's lands.

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.

International audience; The traditional view of sex roles and sexual selection emphasises the evolution of male ornaments as a result of female mate choice and male-male competition. Female ornaments are now receiving more attention, although their roles in mating decisions are still less well understood, especially considering cases in which colourful ornaments are expressed by both sexes. In this study, we analysed whether female skin coloration (luminance and redness of the face and hindquarters) influenced male mate choice and sexual behaviours in relation to intracycle (cycle phase), inter-cycle (number of consecutive cycles, conceptive nature of the cycle), and inter-individual (age, social rank, weight, and parity) variation in a captive social group of Japanese macaques (Macaca fuscata). Males did not preferentially choose darker/redder females. Moreover, males did not appear to use female skin coloration to apportion their mating efforts on the fertile phase of the menstrual cycle or during cycles that lead to conception, or to discriminate between females. Collectively, our results suggest that female skin coloration may not have been sexually selected in this species and that males mated regardless of such variation across females. To our knowledge, our study is among the few to report a lack of male choice for female coloration in a species where both sexes display ornamentation. Our findings provide novel insights on the role and evolution of female coloration in sexual signalling and mating decisions.

International audience; Harvesting may drive body downsizing along with population declines and decreased harvesting yields. These changes are commonly construed as consequences of direct harvest selection, where small-bodied, early-reproducing individuals are immediately favoured. However, together with directly selecting against a large body size, harvesting and body downsizing alter many ecological features, such as competitive and trophic interactions, and thus also indirectly reshape natural selection acting back on body sizes through eco-evolutionary feedback loops (EEFLs). We sketch plausible scenarios of simple EEFLs in which one-dimensional, density-dependent natural selection acts either antagonistically or synergistically with direct harvest selection on body size. Antagonistic feedbacks favour body-size stasis but erode genetic variability and associated body-size evolvability, and may ultimately impair population persistence and recovery. In contrast, synergistic feedbacks drive fast evolution towards smaller body sizes and favour population resilience, but may have far-reaching bottom–up or top–down effects. We illustrate the further complexities resulting from multiple environmental feedbacks using a co-evolving predator–prey pair, in which case outcomes from EEFLs depend not only on population densities, but also on whether prey sit above or below the optimal predator/prey body-size ratio, and whether prey are more or less evolvable than their predators. EEFLs improve our ability to understand and predict nature's response to harvesting, but their integration into the research agenda will require a full consideration of the effects and dynamics of natural selection.

International audience; Aim Mountains host complex ecosystems whose wide range of ecological conditions over small geographical distances makes them biodiversity hotspots. To ensure their long-term conservation, a better understanding of the interaction between climate change and modifications in land use is necessary. Most studies have focused on only one of these factors at a time, leading to incomplete predictions. In this study, we explored the relative contribution of both recreative activities and climate change on the population dynamics of the black grouse (Tetrao tetrix), an emblematic cold-adapted species of the Alps.Methods We used data from a network of 47 monitoring sites dispersed around the French Alps and surveyed since the 1980s or 1990s. We estimated black grouse population growth rates using state-space models and tested for effects of biotic and abiotic pressures on both long-term trends and inter-annual variations in these rates.Results Population trajectories were strongly heterogeneous in space; nevertheless, a general decline at the edge of the black grouse distribution area was revealed in the southern pre-Alps. We found very little influence of hunting and new ski lift cables installation on inter-annual variability in population growth rate. In contrast, our results suggest strong impact of climatic conditions and phenology. While temperature positively influenced growth rate, precipitation had a negative effect. Early snowmelt and vegetation season were correlated with high positive values of annual population growth rates.Main conclusions Birds in mountain habitats may be drastically affected by ongoing climate change, perhaps to a greater extent than by an increase in recreational activities. However, other human activities in the mountains (such as animal grazing or forest exploitation) that were not taken into consideration in this study might also have a strong impact on habitat structure and indirectly affect populations' growth.

Biogeographical studies have traditionally focused on readily visible organisms, but recent technological advances are enabling analyses of the large-scale distribution of microscopic organisms, whose biogeographical patterns have long been debated. Here we assessed the global structure of plankton geography and its relation to the biological, chemical, and physical context of the ocean (the ‘seascape’) by analyzing metagenomes of plankton communities sampled across oceans during the Tara Oceans expedition, in light of environmental data and ocean current transport. Using a consistent approach across organismal sizes that provides unprecedented resolution to measure changes in genomic composition between communities, we report a pan-ocean, size-dependent plankton biogeography overlying regional heterogeneity. We found robust evidence for a basin-scale impact of transport by ocean currents on plankton biogeography, and on a characteristic timescale of community dynamics going beyond simple seasonality or life history transitions of plankton., We thank the commitment of the following people and sponsors who made this expedition possible: CNRS (in particular Groupement de Recherche GDR3280), European Molecular Biology Laboratory (EMBL), Genoscope/CEA, Fund for Scientific Research – Flanders, VIB, Stazione Zoologica Anton Dohrn, UNIMIB, Paris Sciences et Lettres (PSL) Research University (ANR-11-IDEX-0001–02), the French Government ANR (projects FRANCE GENOMIQUE/ANR-10-INBS-09, MEMO LIFE/ANR-10-LABX-54, POSEIDON/ANR-09-BLAN-0348, PROMETHEUS/ANR-09-PCS-GENM-217, MAPPI/ANR-2010-COSI-004, TARA-GIRUS/ANR-09-PCS-GENM-218), US NSF grant DEB-1031049, FWO, BIO5, Biosphere 2, Agnès b., the Veolia Environment Foundation, Région Bretagne, World Courier, Illumina, Cap L’Orient, the EDF Foundation EDF Diversiterre, FRB, the Prince Albert II de Monaco Foundation, Etienne Bourgois, the Tara schooner and its captain and crew. We thank MERCATOR-CORIOLIS and ACRI-ST for providing daily satellite data during the expedition. The bulk of genomic computations were performed using the Airain HPC machine provided through GENCI- [TGCC/CINES/IDRIS] (grants t2011076389, t2012076389, t2013036389, t2014036389, t2015036389 and t2016036389). We are also grateful to the French Ministry of Foreign Affairs for supporting the expedition and to the countries who granted us sampling permissions.

Increasing evidence indicates that sexual coercion is widespread. While some coercive strategies are conspicuous, such as forced copulation or sexual harassment, less is known about the ecology and evolution of intimidation, where repeated male aggression promotes future rather than immediate mating success with targeted females. Although known in humans, intimidation was recently reported in chimpanzees (Pan troglodytes) and chacma baboons (Papio ursinus), where males are regularly violent against females. Here, we investigate the nature of male coercive strategies in wild mandrills (Mandrillus sphinx), a primate living in large polygynandrous groups where severe male aggression towards females is rare and females can form coalitions against males. Yet, we found support for all three predictions of the sexual coercion hypothesis, namely that male aggression (1) specifically targets sexually receptive females, (2) inflicts costs to these females, and (3) increases male mating success in the long-term. These results hold true when considering only non-physical threats, or only severe aggression. Finally, we show that high-ranking females are most targeted by males, probably because of their higher reproductive performances, while high-ranking males are most coercive. These results indicate that sexual intimidation is widespread in sexually dimorphic and group-living mammals, and that males and females vary in their propensities to use, and to be exposed to sexual coercion, respectively.

Background The Black Soldier Fly (BSF) Hermetia illucens is a cosmopolitan fly massively used by industrial companies to reduce biowaste and produce protein and fat for poultry and aquaculture feed. However, the natural history and the genetic diversity of the BSF are poorly known. Here, we present a comprehensive phylogeny and time tree based on a large dataset of complete mitochondrial genomes better to understand the evolution and timing of the BSF. Results In this study, we analyzed 677 CO1 sequences derived from samples found all over the five continents, leading us to discover 52 haplotypes, including ten major haplotypes. This worldwide cryptic genetic and genomic diversity is mirrored at a local scale in France, in which we found five major haplotypes sometimes in sympatry. Phylogenetic analyses of 60 complete mitochondrial genomes robustly resolved the phylogeny of the major BSF haplotypes. We estimate the separation events of the different haplotypes at more than 2 million years for the oldest branches characterizing the ancestral split between present North American lineages and the other highly diverse south-central American clades, possibly the following radiation beyond the isthmus of Panama northwards. Our data confirm that this North American lineage ultimately gave birth to almost all commercial BSF stocks that participated in the worldwide BSF dissemination through farm escapements. Conclusions Our data resolve the phylogenetic relationships between the major lineages and give insights into the BSF’s short and long-term evolution. Our results indicate that commercial BSF stock’s genetic and genomic diversity is very low. These results call for a better understanding of the genomic diversity of the BSF to unravel possible specific adaptations of the different lineages for industrial needs and to initiate the selection process.

4 páginas.- 14 referencias.- Free Access, Soil can be seen as an important and delicate interfacebetween the biosphere, hydrosphere, atmosphere andlithosphere. Biogeochemical processes occurring at thisinterface are crucial for maintaining soil ecosystem func-tion, plant productivity and water quality. Aside fromcontrolling the fate of pollutants, this interface plays akey role in the biogeochemical cycles and thus has a rolein soils acting as a source or sink of greenhouse gases.With this in mind, we decided to organize the 8thInternational Symposium on Interactions of Soil Mineralswith Organic Components and Microorganisms (ISMOM2019), with the focus on “Understanding Soil Interfacial Reactions for Sustainable Soil Management and Climatic Change Mitigation”. This meeting took place in Seville,Spain, during 23–28 June 2019, and was organized by Heike Knicker and Francisco J. González-Vila from the IRNAS-CSIC, Seville, as a part of the interCongress series of international symposia of Commission 2.5 (Soil chemical, physical and biological interfacial reactions) of theInternational Union of Soil Sciences (IUSS).During the meeting, we had the pleasure of presenting the contributions of 170 participants from 33 countries. In total, 185 abstracts were submitted, of which 157 were finally presented as plenary (two), keynote (five) or oral (54) talks along with 96 posters. The number, diversity and quality of the submitted abstracts, as well as the excellent work of the scientific committee, provided an interesting and well‐balanced scientific programme. The contributions were presented during the following six sessions. Soil as a C and N sink: Who is the major player – soil minerals, soil organic matter quality, microbial activity or their interplay? New physical, chemical and biological analytical approaches: How can they lead us to a better understanding of soil interfaces? Ecological disturbances: How do mismanagement of soils (overgrazing, erosion, etc.) and natural disasters (fire, flooding, etc.) affect the interplay between soil minerals, SOM and microorganisms? Dynamics of pollutants at soil interfaces: What is new and how can environmental biotechnology be beneficial for soil restoration and bioremediation? Soil amendments (biochar, composts and digestates): How do they affect interactions at soil interfaces? Nutrient availability in soils: Can our knowledge on soil interfaces improve biotechnological approaches or soil management to decrease the need for artificial fertilizers? In order to increase the visibility of posters, a part of the time for the poster session was dedicated to a “pico‐session” during which poster presenters had a maximum of 2 min to advertise their work. This offer was well appreciated both by presenters, in particular by young researchers, and interested participants and greatly stimulated the following discussions at the poster boards. Considerable time for discussion and remaining questions was also provided after each session, an offer that was also well accepted by the audience. A special highlight was the Dr P.M. Huang Prize awarded to Dr. Rota Wagai from the National Institute for Agro‐Environmental Sciences, NIAES, Japan, for his outstanding and unique contributions to our understanding of the interaction of organic matter, minerals and microorganisms in the soil. Generous sponsorship from the IUSS Stimulus Fund, Commission 2.5 of the IUSS, the International Humic Substance Society (IHSS) and the University of Seville allowed travel grants to be awarded to young scientists and scientists from under‐funded countries, in addition to keynote speakers. The support by the IRNAS‐CSIC, as well as the sponsoring by Agrana AG, Bruker BioSpin GmbH, Analisis Vinicos, Abogase Legal SI and AMC Chemical & TRICHODEX, contributed to successfully providing this international platform for fruitful discussions between scientists and students from soil sciences, chemistry, biology, biochemistry, physics, ecology or environmental sciences., The papers collected together in this special issue of the European Journal of Soil Science reflect the diversity of communications at the conference. The following special issue contains a small collection of 14 papers based on presentations made at the meeting. As part of the section Soil as a C and N sink, the contribution of Briedis et al. (2021) describes a study dealing with the effects of land‐use types (native vegetation [NV] vs. no‐till system [NT]) on organic carbon (OC) stocks and on the chemical composition of organic matter (OM), seeking a better understanding of the OC build‐up in no‐till areas and the mechanisms that govern OC protection in highly weathered soils in Brazil. Applying solid‐state 13C nuclear magnetic resonance (NMR) spectroscopic analyses in soils fractionated into coarse and fine fractions by sieving, they concluded that “maintaining continuous NT is a sine qua non condition” to improve SOM contents. They confirmed further that the interactions of labile compounds with soil minerals can be seen as the driving factor for OM protection in soil. The article by Cissé, van Oort, Chenu, Essi, and Staunton (2021) shifts the focus to the soil organic nitrogen fraction and investigates the relative enrichment of SOM in the operationally defined fraction, glomalin‐related soil protein. This study relied on the “42‐Plots” long‐term bare fallow trial in Versailles, France, and challenged hypotheses on the fungal origin and intrinsic stability of this fraction. It was concluded that GRSP is continually produced by the recycling of soil organic matter, with no evidence that it is of predominantly arbuscular fungal origin. Soil pH and availability of sources of N contributed to the complex balance between protein synthesis and accumulation. The work by Le Bayon et al. (2021) introduced the use of X‐ray microcomputed tomography for characterizing earthworm‐derived belowground soil aggregates. It was presented in the section dedicated to New physical, chemical and biological analytical approaches. The calculation of density and size (down to 30 μm) allowed the authors to distinguish mineral and light organic and void spaces, and to compare pore size distribution in soils after the action of different earthworms. This major advance opens exciting possibilities for the study of organo‐mineral interfaces. A more pedogenesis‐related approach is presented by Pospíšilová and her coworkers (Pospíšilová et al., 2021). Applying X‐ray diffraction (XRD) on the fine earth and clay fractions of soils from the Litovelské Pomoraví (Czech Republic), they identified hydroxy‐interlayered vermiculites (HIV). Such minerals appear not to have been found in Bohemian and Moravian loess before. Based on their findings, they concluded that HIV and even vermiculite are pedogenic clay minerals. The paper by Wu, Wu, Huang, and Cai (2021) demonstrates how the interaction with mineral or organo‐mineral surfaces may have an important impact on molecular reactions. This study reports that one mineral in particular, birnessite, facilitates the conjugate transfer of plasmids and may initiate the formation of intracellular reactive oxygen species. Clay minerals may contribute to the global dissemination of antimicrobial resistance. The goal of the session Ecological disturbances was to present some new insights on the impact of (mis)management of soils or natural disasters and how they affect the interplay between soil minerals, SOM and microorganisms. Towards this goal, Escobar Ortega, Aguilar Vásquez, Ávila Alba, and García de Salamone (2021) evaluated the impact on the rhizosphere microbial communities of inclusion of cover crops in succession with soybean and plant growth‐promoting rhizobacteria (PGPR) inoculation. The underlying assumption of this work is that the inclusion of cover crops adds, through the input of crop residues to the soil, to the preservation of soil quality. However, using glyphosate to interrupt the growth of the cover crop is supposed to have a negative impact on the microbial rhizosphere communities that should be better understood. Therefore, they assessed whether the inoculation of two cover crops with A. brasilense and P. fluorescens, their growth interruption with glyphosate and the fertilization of cover crops at sowing, modify the functional and structural diversity of rhizosphere microbial communities. The study of the response of the microbial communities to changing management practices was also the objective of the work by Navas, Martín‐Lammerding, Hontoria, Ulcuango, and Mariscal‐Sancho (2021). They hypothesized that tillage type affects the abundance and size of macroaggregates, which in turn changes the microenvironment and the total abundances of fungi and bacteria within them. Evaluating the total abundance of bacteria (based on 16S rRNA analysis) and fungi (based on internal transcribed spacer analysis) inhabiting each aggregate fraction, they found that bacteria and fungi respond differently to changes in the distribution of aggregates induced by management practices. They further observed that in contrast to the fungal abundance, the distribution of bacteria in the aggregates was closely related to C and N concentrations. Another paper from Navas, Pérez‐Esteban, Torres, Hontoria, and Moliner (2021) investigated microbial communities along a gradient of metal contamination in a former copper mining area. Their underlying objective is to identify and exploit the metal resistance properties of microorganisms to use as biofertilizers to improve the efficiency of phytoremediation. Marked differences in abundances of species were observed along the contamination gradient and metal‐resistant genes were identified. Contaminated soils may be an important reservoir for useful microorganisms, notably Bradyrhizobium diazoefficiens and Pseudomonas aeruginosa, capable of both resisting large metal contents and also improving nutrient availability. Studying the fate of pollutants in soils is strongly associated with the study and understanding of their sorption behaviour. In line with this and within the fourth session Dynamics of pollutants at soil interfaces, Mikhail Borisover (2021) introduced a new approach to quantify sorption–desorption hysteresis using single‐point desorption isotherms in liquid‐phase sorption experiments in terms of the Gibbs free energy of non‐relaxed states. The study by Evans and Jacobs (2021) investigates the complexity of tertiary anion exchange reactions in soils from different horizons of alpine tundra soils in order to assess their impact on aluminium biogeochemistry. A combination of batch and column experimental approaches was used to follow oxalate/hydroxide/fluoride exchange along with aluminium solubilization. In recent years, concerns about the application of glyphosate have considerably increased. As a consequence, the behaviour of this widely used herbicide in soils has also been an issue discussed at the ISMOM after the presentation of Galicia‐Andrés, Tunega, Gerzabek, and Oostenbrink (2021), who investigate the molecular basis of the interactions between glyphosate and kaolinite, a clay mineral with high abundances in subtropical and tropical soils. Applying force‐field molecular dynamics simulation together with first principle calculations using a density functional theory‐based approach, they were in particular interested in the role of H‐bond formation as the precursor stage. They confirmed that kaolinite has an important contribution to the overall adsorption capacity of soils for glyphosate, specifically in its anionic form. Another study of an agrochemical was presented in the session dedicated to Soil amendments; the contribution of Aldana, Hazlerigg, Lopez‐Capel, and Werner (2021) presents results of batch studies in which the sorption and retention of atrazine, diuron, enrofloxacin, oxytetracycline and biochar applied in different doses to tropical soils with different texture was investigated. They identified rice husk biochar as an amendment that can efficiently reduce the leaching of the selected agrochemicals. However, because changes in soil properties due to the amendment may inadvertently lead to increased leaching, the authors conclude that the implementation of this approach should be conducted carefully and that field studies evaluating the long‐term effects of biochar‐amended soils on the fate of agrochemicals are still needed. Leiva‐Suárez et al. (2021) suggested the use of biochar, rich in nitrogen, as a slow‐release fertilizer, and studied the long‐term availability of N and P in sewage sludge‐derived hydrochars and pyrochars during a second cropping period. They prepared a soil that was previously amended with 13C‐ and 15N‐enriched hydrochars and pyrochars and was subjected to a first cropping period. After a second cropping period with Lolium perenne, the distribution of the isotopic labels between crop and soil was monitored. Hydrochars were identified as good candidates for long‐term fertilization and all amendments were reported to have comparable turnover rates in the long term, independently of their aromaticity and the native SOM. In another work presented in the session Nutrient availability in soils, Liu et al. (2021) tested the hypothesis that the efficiency of nitrification inhibitors can be increased by enhancing the nitrogen application rate. To test the hypothesis, field experiments with different N fertilization rates and the addition of nitrification inhibitor 3,4‐dimethylpyrazole phosphate (DMPP) were conducted and the respective efficacy of DMPP addition in reducing soil N2O emissions was determined. They suggest that ammonia‐oxidizing bacteria could be the dominant N2O emission contributors in nitrogen‐treated soils. They further reported that DMPP was more efficient at high nitrogen rates and concluded that DMPP application can be an efficient strategy to mitigate environmental risks related to N2O emissions from soils. We would like to thank EJSS for providing the opportunity for this special issue and acknowledge the great help and support of the Editor in Chief Professor Jennifer Dungait and the EJSS publication staff. Finally, we wish to thank the contributing authors and offer our sincere gratitude to all the reviewers, without whom this special issue could not have been completed. Last but not least, we thank all the participants of the 8th ISMOM for their activity, which turned the meeting into a lively and successful event. We are looking forward to continuing the discussions and interactions initiated at this meeting at the 9th ISMOM in 2024.

1. Reliable phenological observations are needed to quantify the impact of climate change on tree phenology. Ground observations remain a prime source of phenological data, but their accuracy and precision have not been systematically quantified. The high subjectivity of ground phenological observations affects their accuracy, and the high within-population variability of tree phenology affects their precision. The magnitude of those effects is unknown to date. 2. We first explored the inter-observer variability in the timing of bud development and leaf senescence in trees using a unique dataset of seven observer inter-calibration sessions. Then, using tree phenological data collected in three European forests (n= 2346 observations for budburst, n= 539 for leaf senescence), we quantified how the 'observer uncertainty' (accuracy of the observations) and the 'population sampling uncertainty' (precision of the observations) combine to affect the estimates of the budburst and the leaf senescence dates. 3. The median observer uncertainty was 8 days for budburst (BBCH=7) and 15 days for leaf senescence (BBCH=95). As expected, the population sampling uncertainty decreased with increasing sample size, and was about 6 days for budburst and 10 days for leaf senescence for a sample of 10 individuals monitored per population (corresponding to the median sample size in the phenological literature). As a whole, the overall uncertainty of phenological observations could reach up to two weeks for budburst and one month for leaf senescence. 4. Synthesis. This paper quantifies for the first time the accuracy and precision of ground phenological observations in forest trees and as such offers tables to estimate the uncertainty of phenological data. We show that reliable estimates of budburst and leaf senescence require three times (n= 30) to two times (n= 20) larger sample sizes as compared to sample sizes usually considered in phenological studies. We further call for an increased effort of observer inter-calibration, required to increase the accuracy of phenological observations. These recommendations reduce the uncertainty of phenological data, thereby improving the estimation of phenological trends over time, the response of phenology to temperature or the inference of phenological model parameters.

B.J.-A. was funded by the Marie Curie Clarín-COFUND program of the Principality of Asturias-EU (ACB17-26) and the Spanish Research Agency (AEI/10.13039/501100011033)., Testolin, R., Attorre, F., Borchardt, P., Brand, R.F., Bruelheide, H., Chytrý, M., De Sanctis, M., Dolezal, J., Finckh, M., Haider, S., Hemp, A., Jandt, U., Kessler, M., Korolyuk, A.Y., Lenoir, J., Makunina, N., Malanson, G.P., Montesinos-Tubée, D.B., Noroozi, J., Nowak, A., Peet, R.K., Peyre, G., Sabatini, F.M., Šibík, J., Sklenář, P., Sylvester, S.P., Vassilev, K., Virtanen, R., Willner, W., Wiser, S.K., Zibzeev, E.G., Jiménez-Alfaro, B.

Organisms can gain information about predation risks from their parents, their own personal experience, and their conspecifics and adjust their behavior to alleviate these risks. These different sources of information can, however, provide conflicting information due to spatial and temporal variation of the environment. This raises the question of how these cues are integrated to produce adaptive antipredator behavior. We investigated how common lizards (Zootoca vivipara) adjust the use of conspecific cues about predation risk depending on whether the information is maternally or personally acquired. We experimentally manipulated the presence of predator scent in gestating mothers and their offspring in a full-crossed design. We then tested the consequences for social information use by monitoring offspring social response to conspecifics previously exposed to predator cues or not. Lizards were more attracted to the scent of conspecifics having experienced predation cues when they had themselves no personal information about predation risk. In contrast, they were more repulsed by conspecific scent when they had personally obtained information about predation risk. However, the addition of maternal information about predation risk canceled out this interactive effect between personal and social information: lizards were slightly more attracted to conspecific scent when these two sources of information about predation risk were in agreement. A chemical analysis of lizard scent revealed that exposure to predator cues modified the chemical composition of lizard scents, a change that might underlie lizards’ use of social information. Our results highlight the importance of considering multiple sources of information while studying antipredator defenses., L.W. was supported by the Fyssen Foundation Post-Doctoral Fellowship and J.C. by an ANR-12-JSV7-0004-01. This work was supported by an “Investissements d’avenir” programme from the Agence Nationale de la Recherche number ANR-11- INBS-0001 Ana EE-Services.

Current agricultural practices facilitate emergence and spread of plant diseases through the wide use of monocultures. Host mixtures are a promising alternative for sustainable plant disease control. Their effectiveness can be partly explained by priming-induced cross-protection among plants. Priming occurs when plants are challenged with non-infective pathogen genotypes, resulting in increased resistance to subsequent infections by infective pathogen genotypes. We developed an epidemiological model to explore how mixing two distinct resistant varieties can reduce disease prevalence. We considered a pathogen population composed of three genotypes infecting either one or both varieties. We found that host mixtures should not contain an equal proportion of resistant plants, but a biased ratio (e.g. 80 : 20) to minimize disease prevalence. Counter-intuitively, the optimal ratio of resistant varieties should contain a lower proportion of the costliest resistance for the pathogen to break. This benefit is amplified by priming. This strategy also prevents the invasion of pathogens breaking all resistances.

International audience; Cats Felis catus, in all their forms (domestic, free-roaming/stray and feral), have been identified as a major global threat to biodiversity, especially birds and small mammals. However, there has been little previous consideration of the extent and impact of predation of bats by cats, or of whether specific characteristics make certain species of bats particularly vulnerable to predation by cats. We reviewed the impact of cats on bats, based on a collation of scientific literature and the International Union for Conservation of Nature (IUCN) Red List database. Our aim was to produce a synthesis of the extent to which cats prey upon and threaten bats. We also collated available data on cat diet, which provide information on predation rates of bats by cats. Few studies (n = 44) have identified bat species preyed upon or threatened by cats, with a disproportionate number of studies from islands. In these studies, 86 bat species (about 7% of the global extant tally) are reported as preyed upon or threatened by cats, and about one quarter of these species are listed as Near Threatened or threatened (IUCN categories Critically Endangered, Endangered, or Vulnerable). In IUCN Red List assessments, cats are more frequently mentioned as a threat to threatened or Near Threatened bat species than to non-threatened species (IUCN category Least Concern). In studies reporting on the incidence of bats in cat dietary samples (scats, stomachs and guts), the frequency of occurrence of bats in samples averaged 0.7 ± 2.1% (mean ± standard deviation; n = 102). Many studies had sample sizes that were too small to be likely to detect bats. All forms of cat are reported to kill bats, and such predation has been reported in all major terrestrial habitats. We conclude that predation by cats is an under-appreciated threat to the world’s bat species.

International audience; Invasive alien aquatic plant species (IAAPs) cause serious ecological and economic impact and are a major driver of changes in aquatic plant communities. Their invasive success is influenced by both abiotic and biotic factors. Here, we summarize the existing knowledge on the biology of 21 IAAPs (four free-floating species, eight sediment-rooted, emerged or floating-leaved species, and nine sediment-rooted, submerged species) to highlight traits that are linked to their invasive success. We focus on those traits which were documented as closely linked to plant invasions, including dispersal and growth patterns, allelopathy and herbivore defence. The traits are generally specific to the different growth forms of IAAPs. In general, the species show effective dispersal and spread mechanisms, even though sexual and vegetative spread differs strongly between species. Moreover, IAAPs show varying strategies to cope with the environment. The presented overview of traits of IAAPs will help to identify potential invasive alien aquatic plants. Further, the information provided is of interest for developing species-specific management strategies and effective prevention measures.

International audience; Passive Acoustic Monitoring offers promising opportunities for biodiversity assessments and species conservation and is still in development. The robustness of community metrics depends on sampling effort and acoustic surveys should be adjusted for cost-effectiveness. Using a large-scale acoustic survey of bat assemblages conducted along 5487 survey nights across France, we assessed the effect of sampling duration on the level of confidence of four community metrics (total bat activity, species of conservation concern activity, species richness, and community specialisation index). We further investigated whether this effect varied across habitats and seasons. Overall, a high level of confidence (i.e., 95% similarity between cumulated survey nights) was reached after 2 to >20 sampling nights, depending on the community metric, the habitat and the season considered. CSI required the lowest sampling duration. A higher sampling duration was required in three-dimensionally structured habitats (e.g., forests) and habitats unfavourable to bats (e.g., intensive farmlands), while a high degree of confidence was reached earlier in more favourable habitats and non-intensive farmlands, and during the season of higher activity. Beyond providing recommendations for the design of context-dependent minimum sampling duration in acoustic surveys, we show that weighted community indices such as the CSI are efficient summary measures, and advocate for their use when monitoring resources are limited.

Transfer efficiency is the proportion of energy passed between nodes in food webs. It is an emergent, unitless property that is difficult to measure, and responds dynamically to environmental and ecosystem changes. Because the consequences of changes in transfer efficiency compound through ecosystems, slight variations can have large effects on food availability for top predators. Here, we review the processes controlling transfer efficiency, approaches to estimate it, and known variations across ocean biomes. Both process-level analysis and observed macroscale variations suggest that ecosystem-scale transfer efficiency is highly variable, impacted by fishing, and will decline with climate change. It is important that we more fully resolve the processes controlling transfer efficiency in models to effectively anticipate changes in marine ecosystems and fisheries resources.