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The paper has the aim of reflect on the current situation of the Lake Chad Basin, characterized by the increasing Humanitarian Situation , determined not more only from the water crisis, but from the progressive presence of terrorist militias of the fundamentalist group Boko Haram. Indeed, today, environmental and social degradation of forests, increasingly advanced, the increasing salinization of soils, the proliferation of aquatic vegetation, the high concentration of population around the lake and wetlands exacerbate exploitation of resources and stir up the anarchist social conflicts. Scholars therefore speak of climate refugees, who face not only climate change, but also international terrorism . In the realization of the paper we will use the Human Development Index ( HDI ), the Human Poverty Index ( HPI ) and the Global Hunger Index referring to countries bordering Lake Chad, in order to better understand the phenomena under investigation

International audience; Ungulate populations exhibiting partial migration present a unique opportunity to explore the causes of the general phenomenon of migration. The European roe deer Capreolus capreolus is particularly suited for such studies due to a wide distribution range and a high level of ecological plasticity. In this study we undertook a comparative analysis of roe deer GPS location data from a representative set of European ecosystems available within the EURODEER collaborative project. We aimed at evaluating the ecological factors affecting migration tactic (i.e. occurrence) and pattern (i.e. timing, residence time, number of migratory trips). Migration occurrence varied between and within populations and depended on winter severity and topographic variability. Spring migrations were highly synchronous, while the timing of autumn migrations varied widely between regions, individuals and sexes. Overall, roe deer were faithful to their summer ranges, especially males. In the absence of extreme and predictable winter conditions, roe deer seemed to migrate opportunistically, in response to a tradeoff between the costs of residence in spatially separated ranges and the costs of migratory movements. Animals performed numerous trips between winter and summer ranges which depended on factors influencing the costs of movement such as between-range distance, slope and habitat openness. Our results support the idea that migration encompasses a behavioural continuum, with one-trip migration and residence as its end points, while commuting and multi-trip migration with short residence times in seasonal ranges are intermediate tactics. We believe that a full understanding of the variation in tactics of temporal separation in habitat use will provide important insights on migration and the factors that influence its prevalence.

Background Deforestation and land use change is widespread in Madagascar, altering local ecosystems and creating opportunities for disease vectors, such as the Anopheles mosquito, to proliferate and more easily reach vulnerable, rural populations. Knowledge of risk factors associated with malaria infections is growing globally, but these associations remain understudied across Madagascar’s diverse ecosystems experiencing rapid environmental change. This study aims to uncover socioeconomic, demographic, and ecological risk factors for malaria infection across regions through analysis of a large, cross-sectional dataset. Methods The objectives were to assess (1) the ecological correlates of malaria vector breeding through larval surveys, and (2) the socioeconomic, demographic, and ecological risk factors for malaria infection in four ecologically distinct regions of rural Madagascar. Risk factors were determined using multilevel models for the four regions included in the study. Results The presence of aquatic agriculture (both within and surrounding communities) is the strongest predictive factor of habitats containing Anopheles larvae across all regions. Ecological and socioeconomic risk factors for malaria infection vary dramatically across study regions and range in their complexity. Conclusions Risk factors for malaria transmission differ dramatically across regions of Madagascar. These results may help stratifying current malaria control efforts in Madagascar beyond the scope of existing interventions.

Wildfire is the main disturbance in forested ecosystems of southern Europe and is due to complex interactions between climate-weather, fuels and people. Warmer and drier conditions projected in this region are expected to profoundly affect wildfires, which will impact ecosystems and humans. We review the scientific literature addressing the assessment of climate change impacts on wildfires in southern Europe, with a twofold objective: (i) report the trends in wildfire danger and activity projected under warming climate in southern Europe and (ii) discuss the limitations of wildfire projections under the specific biogeographical context of southern Europe.We identified 22 projection studies that examined future wildfire danger or wildfire activity at local, regional or continental scale. Under the scenario with the highest greenhouse gas emissions, we found that projections studies estimate an increase in future fire danger and burnt areas varying, on average, from 2 to 4 % and from 15 to 25 % per decade, respectively. Fire-prone area expansion to the north and to Mediterranean mountains is a concern, while climate-induced burnt area increase might be limited by fuel availability in the most arid areas. While all studies agreed on the direction of changes, further comparisons on the magnitude of increase remained challenging because of heterogeneous methodological choices between projections studies (climate models, projection period, spatial scale and fire metrics). We then described three main sources of uncertainty that may affect the reliability of wildfire projections: climate projections, climate-fire models, and the influences of fuel load/structure and human related factors on the climate-fire relationships. We finally suggest research directions to address some of these issues for the purpose of refining fire danger and fire activity projections in southern Europe.

Forest production efficiency (FPE) metric describes how efficiently the assimilated carbon is partitioned into plants organs (biomass production, BP) or—more generally—for the production of organic matter (net primary production, NPP). We present a global analysis of the relationship of FPE to stand-age and climate, based on a large compilation of data on gross primary production and either BP or NPP. FPE is important for both forest production and atmospheric carbon dioxide uptake. We find that FPE increases with absolute latitude, precipitation and (all else equal) with temperature. Earlier findings—FPE declining with age—are also supported by this analysis. However, the temperature effect is opposite to what would be expected based on the short-term physiological response of respiration rates to temperature, implying a top-down regulation of carbon loss, perhaps reflecting the higher carbon costs of nutrient acquisition in colder climates. Current ecosystem models do not reproduce this phenomenon. They consistently predict lower FPE in warmer climates, and are therefore likely to overestimate carbon losses in a warming climate., Many models assume a universal carbon use efficiency across forest biomes, in contrast to assumptions of other process-based models. Here the authors analyse forest production efficiency across a wide range of climates to show a positive relationship with annual temperature and precipitation, indicating that ecosystem models are overestimating forest carbon losses under warming.

A complèter : pagination et WOS; International audience; Large wood (LW, or pieces of dead wood longer than 1 m and thicker than 10 cm in diameter) is a key element in forested streams, but its abundance has decreased worldwide as a result of snagging and clearing of riparian forests. Therefore, many restoration projects introduce LW into stream channels to enhance geomorphology, biotic communities, and ecosystem functioning. Because LW enhances the retention of organic matter and sediments, its restoration can reduce siltation in receiving reservoirs, although so far little information on this subject is available. We studied the effects of restoring the natural loading of LW in four streams in the Aiako Harria Natural Park (the Basque Country, Spain) in pool abundance, channel form, and storage of organic matter and sediments. In all reaches log jams induced the formation of new geomorphic features and changes in physical habitat, especially an increase in the number and size of pools and in the formation of gravel bars and organic deposits. The storage of organic matter increased 5- to 88-fold and streambed level rose 7 ± 4 to 21 ± 4 cm on average, resulting in the storage of 35.2 ± 19.7 to 711 ± 375 m3 (733–1400 m3 ha− 1 y− 1) of sediment per reach. Extrapolation of these results to the entire drainage basin suggests that basinwide restoration of LW loading would enhance the retention potential of stream channels by 66,817 ± 27,804 m3 (1075 m3 ha− 1 y− 1) of sediment and by 361 t (5.32 T ha− 1 y− 1) of organic matter, which represents 60% of the estimated annual inputs of sediments to the downstream Añarbe Reservoir and almost twice as much as the annual input of organic matter to the entire river network. Therefore, basinwide restoration of LW loading is a potentially important tool to manage catchments that feed reservoirs, where retention of sediments and organic matter can be considered important ecosystem services as they reduce reservoir siltation.

Ciprofloxacin (CIP), tamoxifen (TAM) and cyclophosphamide (CP) which are often used in anticancer treatment are released in hospital effluent and into the environment. Although the concentrations are low (from ng/L to μg/L), no data exist concerning their ecotoxicological impact. In this study two biomarkers of early effect were performed on hepatic cells (HepG2): cell viability and genotoxicity (DNA breaks) using cell proliferative assay and comet assay, respectively. These data were compared with two standardized ecotoxicological tests: algaltoxkit F™ and microtox®. Cells were exposed to an increasing amount of an individual drug or in a mixture for 24, 48 or 72 h. The time-exposure of bacteria and algae ranged between 5 and 30 min and 72 h, respectively. A non-monotonic dose–response on cell viability was observed when HepG2 cells were exposed to TAM alone or in the presence of CIP. The same scheme was observed with microtox® when the bacteria were exposed to the mixtures. On the other side, an individual drug does not induce any DNA breaks on hepatic cells, whereas a mixture leads to a dose dependent increase of DNA breaks. Similarly a positive response was observed with algaltoxkit F™ only with mixtures. Synergistic effects observed when drugs are in a mixture highlight the importance of investigating the ecotoxicological effects of contaminants at low concentrations and in mixtures. Keywords: Ciprofloxacin, Tamoxifen, Cyclophosphamide, Wastewater, Hormesis, Bioassays

During the last decades, an increasing number of predators were found to use specific prey pheromones as chemical cues. Beyond its ecological relevance, this knowledge has practical applications on insect conservation and pest control. In this study, we present first evidence that two species of the family Dasytidae (Coleoptera)Aplocnemus brevisRosenhauer andA. raymondiSainte-Claire Deville use the sex pheromone of the pine bast scaleMatsucoccus feytaudiDucasse (Hemiptera: Matsucoccidae) as kairomone to locate this prey. The feeding habits and biology ofAplocnemusspecies are practically unknown. In the laboratory, the adults ofAplocnemussp. acceptedM. feytaudiegg masses as food source as well as other diets. Females represented more than 90% ofAplocnemussp. attracted to the pheromone lures. We believe that females use this olfactory cue to locate suitable places for oviposition and that larvae are the predators ofMatsucoccus. This study further demonstrates that the response to the kairomone elicited short prey searching times, about 23% of the individuals appeared less than 12 min after lure exposure, being consistent with the hypothesis of prey specialization. Habitat and geographical distribution predict an ancestral association ofA. breviswithM. feytaudiand ofA. raymondiwithM. pini. Nevertheless, a recent prey shift ofA. raymondito the invasiveM. feytaudiin Corsica is in progress.