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International audience; From the 1980's, Indonesian shrimp production has continuously increased through a large expansion of culturedareas and an intensification of the production. As consequences of diseases and environmental degradations linkedto this development, there are currently 250,000 ha of abandoned ponds in Indonesia. To implement effectiveprocedure to undertake appropriate aquaculture ecosystem assessment and monitoring, an integrated indicatorbased on four criteria using very high spatial optical satellite images, has been developed to discriminate activefrom abandoned ponds. These criteria were: presence of water, aerator, feeding bridge and vegetation. Thisindicator has then been applied to the Perancak estuary, a production area in decline, to highlight the abandonmentdynamic between 2001 and 2015. Two risk factors that could contribute to explain dynamics of abandonmentwereidentified: climate conditions and pond locations within the estuary, suggesting that a spatial approach should beintegrated in planning processes to operationalize pond rehabilitation.

International audience; Diagenesis has been recognized for decades to significantly alter the trace elements biogenic signatures in fossil tooth enamel and bone that are routinely used for paleobiological and paleoenvironmental reconstructions. This signature is modified during diagenesis according to a complex continuum between two main processes, addition and substitution. For an additive-like, or early diagenesis, the trace elements biogenic profiles can be restored by leaching secondary minerals, but this technique is inefficient for a substitutive-like, or extensive diagenesis for which secondary trace elements are incorporated into the biogenic mineral. This scheme is however unclear for Ca, the major cation in tooth enamel and bone hydroxylapatite, whose stable isotope composition (δ44/42Ca) also conveys biological and environmental information. We present a suite of leaching experiments for monitoring δ44/42Ca values in artificial and natural fossil enamel and bone from different settings. The results show that enamel δ44/42Ca values are insensitive to an additive-like diagenesis that involves the formation of secondary Ca-carbonate mineral phases, while bone shows a consistent offset toward 44Ca-enriched values, that can be restored to the biogenic baseline by a leaching procedure. In the context of a substitutive-like diagenesis, bone exhibits constant δ44/42Ca values, insensitive to leaching, and shows a REE pattern symptomatic of extensive diagenesis. Such a REE pattern can be observed in fossil enamel for which δ44/42Ca values are still fluctuating and follow a trophic pattern. We conclude that Ca isotopes in fossil enamel are probably not prone to extensive diagenesis and argue that this immunity is due to the very low porosity of enamel that cannot accommodate enough secondary minerals to significantly modify the isotopic composition of the enamel Ca pool.

International audience; The effect of biodiversity on ecosystem functioning has been widely acknowledged, and the importance of the functional roles of species, as well as their diversity, in the control of ecosystem processes has been emphasised recently. However, bridging biodiversity and ecosystem science to address issues at a biogeographic scale is still in its infancy. Bridging this gap is the primary goal of the emerging field of functional biogeography. While the rise of Big Data has catalysed functional biogeography studies in recent years, comprehensive evidence remains scarce. Here, we present the rationale and the first results of a country-wide initiative focused on the C-3 permanent grasslands. We aimed to collate, integrate and process large databases of vegetation releves, plant traits and environmental layers to provide a country-wide assessment of ecosystem properties and services which can be used to improve regional models of climate and land use changes. We outline the theoretical background, data availability, and ecoinformatics challenges associated with the approach and its feasibility. We provide a case study of upscaling of leaf drymatter content averaged at ecosystemlevel and country-wide predictions of forage digestibility. Our framework sets milestones for further hypothesis testing in functional biogeography and earth system modelling. (C) 2015 Elsevier B.V. All rights reserved.

International audience; The surface area of mangrove ecosystems in Senegal have fluctuated substantially over several decades. Satellite data at 10 to 30-m resolution, which has been available since the 1980s, has allowed the mapping and quantification of these dynamics. However, the plant formations have reorganized internally; this has not been well-documented, possibly because there is no established method for detecting zonation of the Senegalese mangrove. This paper proposes a two-step method for mapping the zonation of the Saloum Delta mangrove. First, mangrove surfaces were detected using machine learning methods from an object-based time series. Finally, a typology was developed through object-based clustering using time-series metrics derived from the harmonic regression modeling of the vegetation fraction. A comparison with field data allowed us to determine the number of classes and discriminating variables. The results showed that the selected method resulted in an overall accuracy of 97.55% (Kappa = 95.42) for the land cover at 4 classes (Water, Mangrove, Salt flats, Other land covers), with an F1-Score of 98.91% for the mangroves. Second, our results suggest that the annual trend of the vegetation fraction at the object scale is effective in differentiating mangrove zonation into three classes based on canopy density and stand height (HM: High mangrove; LDM: Low and dense mangrove; LOM: Low and open mangrove). Finally, the temporal stability of the classes and uncertainty around the magnitudes of the plant fraction values per class were assessed by Bayesian inference. An overall accuracy of 85.5% can be expected to identify the zonation typology on an inter-annual scale. This mapping technique can be used to characterize the rate of change in zonation in response to environmental changes and to guide management strategies.

International audience; The embeddedness of entrepreneurs in a network of social relations has been largely documented by the literature since the seminal work of Granovetter. In different contexts, it has been shown that the entrepreneurial network plays a central role in the creation of their business and provides a variety of resources. Few studies, however, seek to understand the motivations of entrepreneurs when they mobilize a tie, and the effects of these mobilizations on the content and quality of this relationship. From a fieldwork undertaken in Morocco, we implement a “quantified narratives” method which codes each sequence of access to a resource in the course of the start-up in order to map the network of relationships of young innovative entrepreneurs. We go further than previous studies using this method in that we develop a multivariate model that enables us to build hypotheses from qualitative material analysis and to test them econometrically. This case study highlights more generally the interest of mixed methods in analyzing complex mechanisms like network mobilization and their motivations. We analyze the different logics which led entrepreneurs to the mobilization of the network at the time of the creation of their business. The main result that emerges is that the family is sidelined in obtaining funding. This original result is indicative of the tension faced by these young Moroccan entrepreneurs: the need to grow their business is sometimes in contradiction with the desire to create through it a space of autonomy gained on the family.

International audience; This work reports the development of a perfect antireflective coating designed to operate over the 3.7-4.8 mu m MWIR region, in order to improve the optics used in thermal detection systems. A simulated stack with 99.97% average transmittance is designed for a silicon support using an effective refractive index approach. This structure made of two layers is deposited by electron beam evaporation to achieve an optical transmittance as high as 99.21% and a 98.56% average. These performances are similar to that reported for the best MWIR interferential antireflective systems, but rely on a much simpler design. The first layer is fabricated by oblique angle deposition to obtain Ge nanocolumns that are then coated with a dense MgF2 capping film. Because environmental pollution can cause light absorption in the infrared region, different techniques are combined to provide key insights about the nanostructure and the related optical properties: ellipsometry, spectrophotometry and scanning-transmission electron microscopy combined with energy-dispersive X-ray spectrometry. With this approach, essential chemical aspects like oxidation, water adsorption in the Ge layer and intermixing at the Ge/MgF2 interface are evidenced. Advanced models based on effective medium approximation, considering this set of information, are addressed here to gain a better description of the optical response of the surface. In a context of performance optimization of this almost perfect antireflective bilayer, new routes and perspectives to limit or reduce these compositional issues are proposed.

International audience; A 5 m long core from Uttarangudi in the distal plain of Cauvery delta in South India provides evidences of vegetation, climate and anthropogenic activities during the late Pleistocene and Holocene. The pollen catchment area for this region is the localised sources, including the adjoining Tertiary upland plateau. The recorded variation in pollen assemblages and sediments indicates that the environmental conditions have changed over time from aerial oxidising to lacustrine or ponded environment. The lack of pollen records from 17,802 cal BP until 11,535 cal BP suggests severe drier conditions and an extremely patchy, species-poor Tropical Dry Evergreen Forest (TDEF) vegetation community associated with an arid climate. Between 11,535 and 8487 cal BP, partial climatic amelioration appears to have occurred, and the trend become humid until 7034 cal BP characterised by the expansion of the TDEF vegetation and strengthening of the monsoon precipitation. The period from 7034–3553 cal yr BP recorded a regressive transition of the forest taxa influenced by a weakened monsoon precipitation and enhanced anthropogenic activity. The subsequent increase of disturbance signals post 3553 cal yr BP is in agreement with independent archaeological evidences obtained from this region.

International audience; Teeth are usually targeted for dating archaeological sites because they are less prone to dissolution, in comparison with bones. However, despite this apparent resistance, teeth do undergo diagenesis, which needs to be accounted for in order to obtain accurate ages. In particular, the uptake of trace elements such as uranium in dental tissues needs to be considered for dose rate determination when dated using electron spin resonance(ESR). Characterising the mineralogy and structural integrity of samples prior to dating may thus provide important information related to their state of preservation, especially in the case of teeth whose U content can significantly affect the dose rate. In this study, we dated five teeth of small-sized bovids using combined ESR/U-series dating. They were collected at the Middle Stone Age site of Lovedale, located in the central interior of South Africa. Micromorphology provided sedimentary context to the samples, which were recovered from a layer of gravel rich in faunal remains. Using cathodoluminescence, laser-induced fluorescence, Fourier transform infrared spectroscopy and Raman micro-spectroscopy we assessed the degree of preservation of the enamel. Results reveal that carbonate hydroxyapatite underwent post-depositional alteration, based on its molecular structure and elemental composition. Although the teeth all originate from the same layer and were sampled in the same 1-m square and at asimilar elevation, U-content in the enamel differs highly from one tooth to the other, with values ranging from 1.7 to 29.6 ppm. These values are correlated with equivalent doses (De) from 228 to 923 Gy and are consistent with variations in crystallinity determined with vibrational spectroscopy. We also investigated the possible saturation of the ESR signal, by repeating measurements with microwave power values from 1 to 20 mW.Despite such diversity in U-content, the ages calculated assuming an early uptake of U all fall within the same range, from 63 ± 8 ka to 68 ± 15 ka and may only represent a minimum estimate.

International audience; During the mid-to-late Pliocene (ca. 4–3 Ma), several hominin species were present in central Sahel, eastern andsouthern Africa. The potential for the discovery of hominin remains from this interval is limited by the availabilityof exposed Pliocene deposits and the ability to investigate them. As a result, most discoveries have beenmade in the Afar region of Ethiopia and in the Lake Turkana basin, thus unveiling only a portion of Pliocenehominins' probable geographical presence. In this study we provide a continental view of geographic areaspotentially accessible to these hominins. To do so, we estimate the climatic envelope suitable for mid-to-latePliocene hominin presence, using the earth system model IPSL-CM5A and the Maxent habitat suitability algorithm.Our analysis reveals high habitat suitability for these hominin species in semi-arid regions where annualthermal amplitude and mean annual precipitation are moderate, mostly corresponding to tropical xerophyticshrublands. Our habitat model estimates geographically continuous, suitable climatic conditions for homininsbetween central Sahel and northeastern Africa, but not between eastern and southern Africa. This discontinuitysuggests that southern African and eastern African hominins were separated by an environmental barrier thatcould only be crossed during particularly favourable periods or by undertaking long-range dispersal overclimatically hostile habitats. Under climate conditions of northern hemisphere summer at perihelion this climaticbarrier is not present. In contrast, the Turkana basin, the Laetoli region, and a large part of southern Africaremain suitable for all precession angles, suggesting that these areas may have functioned as refugia. The constantpresence of these stable areas combined with the periodic establishment of corridors for dispersion canpotentially explain hominin diversity in eastern Africa.

This special issue of the Journal of Pragmatics concerns the activity of inviting and responding to invitations in authentic telephone calls in six different languages. Using Conversational Analysis to investigate telephone calls that were audio- recorded in family homes, and in one case, in a bank office, the papers focus on invitations to friends, famiily members, acquaintances and other casual recipients in ordinary and institutional conversations.

International audience; The Altiplano and more specifically the Titicaca circum-lake sector have recorded several major landscape transformations. In particular, changes in the lake water level lead to a significant vulnerability and contributed to the development of flexible and diverse agropastoral activities of the pre-Columbian and current populations to climate change. The Tiwanaku River, particularly because of the presence of the pre-Columbian Tiwanaku site, has been the subject of several research studies aimed at characterizing the environment of the archaeological site. Here we propose a new synthesis of the geomorphology of the Tiwanaku River watershed based on an interdisciplinary approach (Historical geography and remote sensing, cross combined with field survey). Our results show that the general organization of the drainage system is influenced by lake level and climatic changes. However several watercourses of the Tiwanaku River might be related to pre-Columbian agricultural or protourban structures. Our work allowed to estimate the regressive pattern of the coastline of Lake Titicaca and to identify major changes of the terminal and medium watercourse of the Tiwanaku River over the last 70 years.

International audience; Tropical forests play a fundamental role in mitigating climate change through storage of carbon in above- and below- ground biomass. Their mitigation potential is, however, affected by significant greenhouse gas emissions through tropical deforestation or forest degradation. Mitigating degradation caused by conventional logging is therefore an important challenge for silvicultural management, and various reduced impact logging techniques seek to reduce biomass loss and other logging impacts during forest logging activities.Little knowledge exists about the potential of sustainable management for maintaining and restoring the climate change mitigation capacity of tropical forests. Our research contributes to knowledge about this potential, as our aim is to evaluate the above-ground biomass (AGB) stock of tropical forests managed for sustainable timber production and compare it with that of intact primary forests. We also determine the environmental and spatial factors that influence AGB.We estimated the AGB of 141 permanent sampling plots in Costa Rican tropical forests (71 plots set up in areas managed for timber production forests and 70 plots set up in areas with intact primary forests) using data for the 2000–2015 period. We compared the AGB of timber production forests with that of primary forest using linear mixed models and examined the relationship between forest AGB and climate, soil fertility and spatial variables (PCNM eigenvalues) using variation partitioning (VARPART) and multiple linear regression in the mixed model framework.Mean AGB was higher in forest plots set up in areas managed for timber production than in plots set up in areas with intact primary forests. In VARPART, spatial variables had the strongest effect on AGB with a small but significant effect of soil fertility. Regression showed potassium levels in the soil to be positively related to AGB. There was no significant effect of climate, probably because of the short temperature and precipitation gradients.Sustainable forest management in these Costa Rican forests managed for timber production has enabled them to store as much carbon in biomass as primary forests, due to the low intensity logging and sustainability criteria stipulated by the country’s forestry legislation. As a result, sustainable forest management, in addition to providing a sustainable timber ecosystem service, is also a natural climate solution, maintaining the mitigation potential of Costa Rica’s tropical forests in the current climate context.

The coast of Oaxaca, along the southern Mexican Pacific coastline, is home to diverse ecosystems, which undergoes significant erosion and accretion due to natural and anthropogenic influences. This study aims in analysing the historical shoreline variations and predicting the future changes for better coastal management plans. In order to study the long-term variations in shoreline, Landsat time-series satellite imageries between 1973 and 2020 were evaluated. Overall, the results indicate that the coast is highly dominated by accretion (74%) process, with the most significant changes occurring at the estuarine areas and beaches. Linear Regression Rate (LRR) and Weighted Linear Regression (WLR) methods showed mean variations at rates of 1.2 ± 2.5 and 0.4 ± 2.5 m/yr for the long-term period. The analysis of seven short-term periods (for every 5 years between 1986–2020) identified the maximum mean erosion of −20.6 m during 2005–2010 and accretion of 18.7 m during 2000–2005. However, the forecasted rate of change for the period 2030 and 2040 using End Point Rate (EPR) statistics revealed that the northern region would continue to move seaward at a rate of + 0 . 26 m/yr and the coastline of southern region would move landward at a possible rate of − 0 . 45 m/yr. The natural factors such as rainfall, river discharge, hurricane, and wave dynamics are the main drivers of shoreline changes along the estuarine and wetland areas. Contrarily, the anthropogenic factors such as breakwaters and urbanization are responsible for coastline dynamics along the beaches and ports. Henceforth, the estuarine region, lagoon openings, and tourist beaches require utmost attention as the sediment flow in these regions are not monitored constantly.

Understanding how science, technology and innovation can best help to accelerate progress in achieving sustainable development remains a grand challenge for researchers and practitioners. In the context of the global consultation process for preparing a post-2015 Sustainable Development Agenda, various science-based actor networks have emerged, aiming to translate research into political decision-making and to inform transformations towards sustainability. Over the last years, these networks seem to have taken an ever-growing role in structuring the science-policy interface in global sustainability governance. The question arises, however, how they understand and organize ‘scientific knowledge integration’ in sustainability politics. This study offers a structured comparison of twelve global science-based actor networks engaged in the implementation of the Sustainable Development Goals. It shows that these networks use two types of strategies to foster scientific knowledge integration in sustainability governance. A new framework emerges, in which each strategy corresponds to two main approaches of scientific knowledge integration: The entrepreneurial strategy generally seeks to advance advice-oriented and solution-oriented knowledge processes, while assessment-oriented and learning-oriented processes in scientific knowledge integration are mainly promoted through a mediating strategy.

Ni-zeolites (ZSM-11 and USY) were prepared for application in carbon dioxide hydrogenation. Structure, physical properties and texture were analyzed by XRD, N 2 sorptiometry, SEM and TEM images. The zeolites nickel reducibility (determined by in-situ TPR-MS) was directly related to the catalytic activity of zeolites. Glow-discharge plasma-assisted CO 2 hydrogenation was carried out under partial vacuum using a packed-bed catalytic reactor under two different configurations: In-Plasma Catalysis (IPC) and Post-Plasma Catalysis (PPC). CO 2 hydrogenation into CO (CO 2 + H 2 → CO + H 2 O) and CO 2 methanation (CO 2 + 4 H 2 → CH 4 + 2 H 2 O) reactions were more efficient when the reaction was assisted by plasma using the IPC mode. In IPC mode, a novel phenomenon was observed: a considerable amount of methane was released from the catalyst after plasma extinction. This phenomenon was explained combining the operando IR plasma technique and the analysis of the carbon balance during the plasma-assisted CO 2 hydrogenation reaction. Both configurations (IPC and PPC) were studied under different volumetric flow rates and the minimum lifetime of excited species generated within the plasma discharge for methane production was determined. The lifetime of the more active species which are responsible for methane production was lower than 67 ms. Under the operation conditions used in this work, methane production was only possible when CO 2 hydrogenation was performed in IPC mode. CO 2 hydrogenation was found to be more energy efficient when the reaction was carried out under plasma assistance compared to conventional heating. Higher CO 2 conversions, CO and CH 4 yields were achieved with respect to conventional heating at lower temperatures when plasma assistance was used.

The fieldweek associated with the 4th Asian Dendrochronological Association Conference was an excellent opportunity for education, networking, and research. The participants and group leaders worked together for five days in an area that was new to some of the group leaders and new to some of the participants which enabled us to learn about forest ecology around Kathmandu and Nagarkot, Nepal. The fieldweek was an excellent networking opportunity and the group leaders and participants bonded which strengthened international research in dendrochronology and continues to foster new research collaborations. All of the group leaders and participants had the opportunity to learn about tree-ring formation in Pinus roxburghii at 1500 masl elevation, to explore its wood anatomy, and to examine specific research questions in our field area. In the end we developed a better understanding of the stand-age structure of a stand of trees in Nagarkot, explored the erosion history from exposed roots, and investigated tree health issues on closely related sites. We found that P. roxburghii poses some dating issues with false and micro rings at this elevation, but we were still able to develop a tree-ring chronology from this species and make preliminary assessments of stand dynamics and health.

International audience; This study aims at improving dietary discrimination among primates through a new analytic approach of dental microwear texture analysis integrating a surface sampling on facets of both phase I and II of mastication. The surface sampling is applied on these two types of molar facets on 104 specimens belonging to four extant cercopithecids, and on 207 Plio-Pleistocene specimens representing four taxa from the Shungura Formation, Ethiopia. The extant species, including Colobus guereza, Theropithecus gelada, Papio hamadryas, Chlorocebus aethiops, compose a model covering a wide range of feeding ecology from leaf-eating through grass-eating habits to opportunistic habits.A principal component analysis built with a selection of the most discriminant variables and extant species as a model displays that the two facets contribute equally to the dispersion of individuals and to the between-species differences. Also, most contributing variables along the components are not central values of texture parameters (mean and median of the parameters measured on subsurfaces or a single value for the whole surface) but rather statistics of their dispersion (percentiles) and distribution (kurtosis, skewness).Once the fossil specimens are inserted into the extant species model, the two large-bodied colobines, Paracolobus and Rhinocolobus, are found to differ from the extant Colobus guereza, one of the most leaf-eating colobines. This highlights ecological diversity among early African colobines. Besides, the analysis tracks between-genus as well as temporal differences between the extinct species of papionins, attesting of a low ecological overlapping between Theropithecus and non-theropith papionins, notably after 2.4 Ma. No significant difference was found between T. brumpti, T. oswaldi, Theropithecus sp. supporting similar feeding habits with the present-day gelada, at least from 2.9 Ma onwards.

International audience; Farmers worldwide regularly plant trees to obtain provisioning and other ecosystem services. This practice has come under scrutiny by conservationists who perceive a reduction of biodiversity due to preferential planting of exotic trees. In order to reverse this preference for exotic trees it is necessary to identify the key drivers of exotic species planting and propose alternative species of interest to farmers. We examined this question in a coffee agroforestry landscape of the Western Ghats, India, a global biodiversity hotspot. We interviewed farmers regarding tree planting behaviour, preferences and constraints, and assessed the relative performance and value of native versus exotic species. Multivariateanalyses were used with six species-level characteristics and four farm-level characteristics, to reveal the most significant predictors of planting frequency.The exotic species Grevillea robusta was planted 5.4 times more often than native trees. Individual species’ planting frequencies were most strongly related to their realised economic values, which was highest for G. robusta. Native trees with greater multipurpose utility value and stature were also more likely to be planted. Farm-level characteristics related to increased planting efforts were increasing climatic dryness, increased land area with native tree tenurial rights and farm size. However, farmers with a greater proportion of land under secure tree tenure planted fewer trees.We conclude that although native trees had higher multipurpose utility and potential economic value than the exotic G. robusta, the latter is grown more often due to existing legal frameworks that restrict private ownership and realising monetary value from native species. If current laws were amended to increase the economic benefits obtained from native trees, they are likely to be planted more often by farmers. We propose that our results can help in implementation of the recent National Agroforestry Policy of India, as well as inform agroforestry policies and practice elsewhere.

International audience; Late Holocene depositional environments of the Lake Coatetelco, with a volcaniclastic watershed, were evaluatedwith respect to cultural transitions in the nearby archeological site at Xochicalco in order to explore therelationship between hydroclimate and evolution of one of the important Mesoamerican cultures in centralsouthernMexico. Several high-energy runoff events between ca. 2576 and 2232 cal yr BP (627–283 BCE) representedunstable watershed in an overall humid hydroclimate during the Pre-Classic Period. More silt and clayof ca. 1258–1006 cal yr BP (665–944 CE) were contemporary with flourishing of religious and political center onthe Xochicalco Hills during the Epiclassic Period. Anthropogenic perturbations over this interval led to depositionalhiatus and caused alterations in sediment composition and chronology. Deposition of authigeniccalcite between ca. 1006 and 854 cal yr BP (944–1096 CE) suggested droughts over earlier part of the Post-Classic Period, and aeolian activity of this interval possibly transported fine sand into the lake. Our observationof dry conditions, coeval with abandonment at Xochicalco, contributes additional data during the demise of avital pre-Columbian center in Mesoamerica. This arid hydroclimate occurred simultaneously as the ENSO becamestronger, and the conditions improved post ca. 854 cal yr BP (> 1096 CE) with an unstable paleohydrologyduring the latter part of the Post-Classic Period.

We studied the ecological resilience of salt marshes by deriving sea level rise (SLR) thresholds in two estuaries with contrasting upland hydrological inputs in the north-central Gulf of Mexico: Grand Bay National Estuarine Research Reserve (NERR) with limited upland input, and the Pascagoula River delta drained by the Pascagoula River, the largest undammed river in the continental United States. We applied a mechanistic model to account for vegetation responses and hydrodynamics to predict salt marsh distributions under future SLR scenarios. We further investigated the potential mechanisms that contribute to salt marsh resilience to SLR. The modeling results show that salt marshes in the riverine dominated estuary are more resilient to SLR than in the marine dominated estuary with SLR thresholds of 10.3 mm/yr and 7.2 mm/yr respectively. This difference of >3 mm/yr is mainly contributed by larger quantities of riverine-borne mineral sediments in the Pascagoula River. In both systems, sediment trapping by the above-ground vegetation appears to contribute more to marsh platform accretion than organic matter from below-ground biomass based on the medians of the accretion rates. However, below-ground biomass could contribute up to 90% of accretion in the marine dominated estuary compared to only 60% of accretion in the riverine dominated estuary. SLR thresholds of salt marshes are more sensitive to vegetation biomass in the marine dominated estuary while biomass and sediment similarly affect SLR thresholds of salt marshes in the riverine dominated estuary. This research will likely help facilitate more informed decisions on conservation/restoration policies for these two types of systems in the near-term needed to minimize future catastrophic loss of these coastal marsh habitats once SLR thresholds are exceeded.

Background Improved understanding of the processes shaping the assembly of tropical tree communities is crucial for gaining insights into the evolution of forest communities and biological diversity. The climate is thought to be the first order determinant of abundance and distribution patterns of tree species with contrasting traits such as evergreen and deciduous leaf phenology. However, the relative role of neutral, and niche-based processes in the evolution of these patterns remain poorly understood. Methods Here, we perform an integrated analysis of the data on tree species abundance, functional traits and community phylogeny from a network of 96 forest plots, each 1 ha in size, distributed along a broad environmental gradient in the central Western Ghats, India. Then, we determine the relative importance of various process in assembly and structuring of tropical forest communities with evergreen and deciduous leaf phenology. Results The deciduous leaf phenological trait has repeatedly evolved among multiple distantly related lineages. Tree communities in dry deciduous forests were phylogenetically clustered and showed a low range and variance of functional traits related to light harvesting, reproduction, and growth suggesting niche-based processes such as environmental filtering play a vital role in the assembly of tree communities in these forests. The external factors such as human-mediated disturbance also significantly, but to a lesser extent, influences the species and phylogenetic turnover. Conclusions These findings revealed that the environmental filtering plays a significant role in assembly of tree communities in the biologically diverse tropical forests in the Western Ghats biodiversity hotspot.

International audience; In recent decades, many studies have documented local declines of orchid species due to environmental changes. However, few data are available about the changes of orchid species distributions at large spatial and temporal scales. We aimed to characterize the recent dynamics of orchid distributions in Western Europe, in regard to (i) climate and land use changes and (ii) species’ ecology (i.e. biogeographic and open/closed habitat preferences). We analyzed data from a large-scale survey of 134 orchid species over 20 years in France, Belgium and Luxembourg. We designed null models to assess the nature and significance of recorded changes within each administrative unit and for each orchid species. We found sharp decline of most orchids in the northern part of the study area (i.e. northern France, Belgium and Luxembourg) resulting in an overall shift to the Mediterranean area in the south. We found more frequent decline of heliophilous species than of sciaphilous species, possibly due to the open habitat loss in relation to strong urbanization and changes in agricultural practices in the northern part of the study area. No significant differences in appearance or disappearance were detected between Mediterranean and Euro-Siberian species, thus suggesting that climate change is not a primary constraint of distribution changes over the period considered. Conversely, land use changes seem to affect in a higher extent the distribution of western European orchids. Observed distribution reduction of orchid species in the southern Mediterranean area will exacerbate the already existing contrast in species richness and related conservation priorities between the north and south of the study area

National audience; Accessing hospital care is a privilege for a growing proportion of the population in situations of economic and social precarity. It is therefore important that caregivers understand these difficulties in order to adapt their nursing approach.; L’hôpital est la porte d’entrée privilégiée d’une partie grandissante de la population en situation de précarité économique et socialeC’est pourquoi il est important que les soignants comprennent ces difficultés afin d’optimiser leurs interventions.

One of the most challenging aspects of turbulent combustion research is the development of reduced-order combustion models which can accurately reproduce the physics of real systems. The identification and utilization of the low dimensional manifolds in these system is paramount to understand and develop robust models which can account for turbulence–chemistry interactions. Recently, principal components analysis (PCA) has been given notable attention in its analysis of reacting systems, and its potential in reducing the number of dimensions with minimum reconstruction error. The present work provides a methodology which has the ability of exploiting the information obtained from PCA. Two formulations of the approach are shown: Manifold Generated from PCA (MG-PCA), based on a global analysis, and Manifold Generated from Local PCA (MG-L-PCA), based on performing the PCA analysis locally. The models are created using the co-variance matrix of a data-set which is representative of the system of interest. The reduced models are then used as a predictive tool for the reacting system of interest by transporting only a subset of the original state-space variables on the computational grid and using the PCA basis to reconstruct the non-transported variables. The present study first looks into the optimal selection of the subset of transported variables and analyzes the effect of this selection on the approximation of the state space and chemical species source terms. Then, a demonstration of various a posteriori cases is presented.

International audience; Neutral models (NMs) are built to test null hypotheses and to detect properties at work in an object or a system. While several studies in geomorphology have used NMs without explicitly mentioning them or describing how they were built, it must be recognized that neutral models more often concerned theoretical explorations that drove such use. In this paper, we propose a panel of NMs of river (channel) networks based on a well-established relationship between observed and simulated sinuosity properties. We first simulated new instances of river networks with a (one-parameter) neutral model based on optimal channel networks (OCN) and leading to homogeneous sinuosity watersheds. We then proposed a "less neutral" model able to generate a variety of river networks accounting for the spatial heterogeneity of observed properties such as elevation. These models, providing confidence levels, allowed us to certify that some properties played a role in the generation of the observed network. Finally, we demonstrated and illustrated both models on the Bidasoa watershed (Spain-France frontier), with a new dedicated software (called SSM). NMs in geomorphology ensure to progressively help to identify the process operating in an observed object, and to ultimately improve our understanding of it (i.e. intrinsic need). But they also provide simulated samples statistically "similar" to an observed one, thus offering new alternatives to every process carried by the observed object (i.e. extrinsic need). Artificial river networks studied here would be of great value to environmental sciences studying geomorphology and freshwater-related processes.

Most rare and endangered large carnivores such as tiger ( Panthera tigris ) exist in human-dominated landscapes as small, fragmented and isolated populations across their range. Connectivity between the remaining populations in the habitat fragments is essential for their long-term persistence and focus of management initiatives. We describe an individual-based, spatially explicit model of tiger movement behavior based on previously developed habitat models to (i) quantify inter-patch connectivity among major (protected) habitat patches in the Terai Arc Landscape of India and Nepal and (ii) investigate the effect of potential management initiatives, e.g. restoring corridors, on enhancing connectivity among fragmented protected habitats. Connectivity was not solely a function of distance between patches, but an outcome of the interplay between movement behavior and landscape composition, with asymmetric connectivity explained by canalizing or diffusing effects of the landscape, and depending on the landscape context of the starting patch. Patch connectivity was mostly determined by autocorrelation in tiger movement, the daily movement capacity, landscape structure, and the amount of matrix habitat. Several habitat patches were likely to be island-like and already effectively isolated. However, simulating scenarios of corridor restoration showed that most habitat patches in India and between India and Nepal could recover connectivity, which may mitigate negative genetic consequences of small population size and effective isolation on tiger populations in this landscape. Combining habitat models with individual-based models is a powerful and robust approach that could be widely applied to delineate dispersal corridors of large carnivores and quantify patch connectivity even if data are scarce.

We investigated the potential use of intra-tooth variations of stable carbon and oxygen isotopes in hippopotamid canines to retrieve signals of seasonality in continental contexts. A high-resolution serial isotope analysis of enamel was performed on both lower and upper canines of one extant common hippopotamus from the Sarh region (Chad). We discussed three methodological points: canine growth rates, optimal sampling resolution, and record of seasonality within hippopotamid canine enamel. In this 21-year old specimen, growth rates of 39.1 mm/year and 31 mm/year were established for the lateral part of lower and upper canines respectively. Our results suggest that the optimal sampling resolution to capture the seasonality is ca. 1–3 mm. Seasonal changes were observed in both δ13C and δ18O values, indicating an important C3 component in the diet during the rainy seasons (up to 50%) and a diet dominated by C4 grasses during the dry seasons (around 70%). Next, we performed a similar test on two fossils from the Shungura Formation (south-western Ethiopia). Seasonal variations in δ13C of the diet were also observed in the fossil specimens and the palaeoenvironmental implications are discussed. Preliminary conclusions from the δ18O and δ13C sequences seem consistent with a rise of seasonality during the Pliocene, synchronous with the global aridification and opening of the environments.

International audience