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Dans les grandes plaines de culture, les bordures de champs, lorsqu’elles sont bien aménagées, sont des refuges ou corridors pour la flore naturelle et de nombreux invertébrés, et une source de nourritures et d’abris pour la petite faune. Cependant, les pratiques agricoles des dernières décennies ont altéré leur composition floristique. Quels moyens mettre en œuvre pour valoriser les bordures extérieures dégradées? Le semis de fleurs sauvages peut-il favoriser la restauration écologique des bordures en limitant la dispersion d’adventices des cultures? Dans la Beauce, une expérimentation, portée par l’association Hommes et Territoires et menée de 2012 à 2018, livre ses premiers résultats.

Du fait de leurs bonnes connaissances des espèces et des milieux et de la mise en place de protocoles de suivi à grande échelle et sur le long terme, les réseaux associatifs naturalistes disposent de bases de données fiables, précieuses pour les scientifiques. Ainsi, dans cette étude, la valorisation d’une importante base de données de présence d’amphibiens via la modélisation de leur niche écologique a permis d’établir des cartes de répartition potentielle de quatre espèces protégées en France : le crapaud calamite, le triton crêté, la rainette arboricole et la rainette méridionale dans six départements français. Les résultats acquis permettront non seulement de mieux comprendre la biologie et l’écologie des espèces mais aussi d’aider à l’élaboration de plans d’actions de conservation dans les territoires concernés.

Mieux comprendre les fonctions des zones humides permet aux techniciens et gestionnaires une meilleure mise en œuvre de la séquence éviter-réduire-compenser sur ces zones. Cet article présente la méthode nationale d’évaluation des fonctions des zones humides qui constitue une avancée opérationnelle pour évaluer la compensation écologique des impacts sur les fonctions des zones humides. Simple à mettre en œuvre, articulée avec les principes de la compensation écologique édictés dans le Code de l’environnement, basée sur des connaissances scientifiques, elle fournit aux bureaux d’études, maîtres d’ouvrage, services de l’État, services instructeurs… des éléments partagés pour évaluer les fonctions des zones humides et le résultat des mesures de compensation écologique.

Species may respond to climate change by redistributing their distribution areas, but because they do not share the same climatic affinities, they should not respond in the same way. Consequently, distribution shifts of species that are currently found in sympatry may change the extent of the area of sympatry and therefore interspecific interactions at the local scale. In Western Europe, the green lizards Lacerta agilis and Lacerta bilineata live in partial sympatry, share morphological similarities, and can locally compete for resources. In this study, we used a correlative species distribution model (SDM), Maxent, to explore the effects of climate change on the distribution of suitable areas for each species and also within their sympatric area under future scenarios. Our simulations showed that all L. agilis subspecies are more likely to lose suitable habitats throughout their distribution areas whatever the scenario. Conversely, even if L. bilineata should lose less suitable areas, gains may be more restricted. In addition, when looking within the areas both reachable for L. a. agilis and L. bilineata to identify where sympatric areas will occur, we find that they should be spatially restricted. Climatic refugia potentially shared for both lizards may therefore be limited. Consequently, competitive exclusion expected in areas suitable for both species (i.e., the potential area of sympatry) could decrease in the future as climate changes likely lead L. agilis subspecies and L. bilineata to follow different species range shifts trajectories over the 21st century.

Climate and land use/land cover (LULC) change are two major global change factors driving shifts in the location of suitable areas for many species. Here, we assessed if a low‐vagility newt, Triturus marmoratus, can track displacement of suitable areas by 2100, and tested whether climate or LULC changes are primary drivers of the species' future distribution. We combined niche modelling with the process‐based model simRShift to improve biological relevance and simulate species dispersal by 2100 under scenarios of climate and LULC changes at high spatial resolution. Our results show that T. marmoratus could lose a significant part of its current French range in the coming decades, and that the range loss will primarily be driven by climate change, with LULC change playing a secondary role. The species seems unlikely to be able to track the northern shift of its suitable habitat as rapidly as required given the rate of climate warming during the 21st century. This is due to insufficient dispersal ability, which is compounded by the magnitude of habitat fragmentation in the human‐dominated landscape. We highlight the need to assess vulnerability and anticipate threats arising from global change even for species that are not currently considered endangered. We identified areas where the species is most likely to occur and be extinct in the future, which can serve as a guide for population monitoring. Our framework can support conservation strategy development by defining ecological corridors that would assist species to track their required habitats in the face of global change. [ABSTRACT FROM AUTHOR]

Dry grasslands of the Northwestern Mediterranean Basin are seminatural species‐rich ecosystems, composed of many annual species and some structuring perennial species. As these grasslands have been used as rangelands for centuries, human management (grazing; fire regimes) is one of their main ecological and evolutionary drivers, along with the Mediterranean climate. Despite EU conservation policy, damage to such grasslands still occurs and efficient ecological restoration is needed. This article reviews restoration constraints, effective techniques, and research perspectives for restoring them in the light of their ecological characteristics. Major restoration constraints specifically include (1) a poor contribution of the internal (seed bank) and external (seed rain) species pools, and (2) low establishment of some perennial species. The latter may be the result of the low seed quantity or quality of perennial species, stochastic or extended droughts, high soil nutrient content that may lead to competition (e.g. between weed and target species), inappropriate grazing management or fire regimes leading to shrub encroachment, or the death of target species seedlings in early stages of restoration. Successful restoration techniques include seeding, transplanting, hay transfer, and timely soil transfer, all of which have to be adapted to regional plant phenology and to local Mediterranean climate. They must be combined with appropriate grazing or fire management. Their success may depend on years with particular rainfall amounts or patterns or on particular target plant species. We discuss research perspectives contributing to a better understanding of seed dispersal, seedling recruitment, and soil processes and suggest the benefits of using ecosystem engineer species. [ABSTRACT FROM AUTHOR]

Aim: When modelling future or past geographic distributions of a species, attention should be paid to the possible differentiated responses to climate changes between lineages. Dispersal also plays an important role in the capacity of species to track suitable climate, which is particularly relevant for amphibians with limited dispersal ability. In this study, we included different lineages and dispersal distances into species distribution models to make them more biologically relevant in face of climate change scenarios. Location: Europe. Taxa: Bombina variegata and its lineages. Methods: Using MaxEnt, we fitted correlative niche models for B. variegata lineages and also for the species level (B. variegata sensu lato) that we projected under Last Glacial Maximum (LGM) and future climate scenarios (RCP2.6, RCP8.5). A comparison of projections was conducted considering both unlimited and limited dispersal abilities. Results: We found that the B. variegata lineages differed in their bioclimatic niches. In general, models run without discriminating the lineages showed reduced suitable areas compared to models run at each lineage, especially those for B. variegata pachypus and B. variegata scabra (southern lineages). Suitable areas identified for the LGM match with the climatic refugia identified in phylogeographic studies. Projections for the mid‐Holocene showed the increase of suitable areas for the lineages B. variegata variegata "Carpathians" and "Western" while they decreased for the southern lineages. In the future (2040–2080), only models under limited dispersal predict the extinction of the Carpathian lineage and a reduction in suitable areas for the other lineages, regardless of periods and scenarios. Main conclusions: We demonstrated important shifts in habitat suitability in Europe suggesting range‐shifts about hundreds of kilometres in response to past climate changes. However, rapid and unprecedented changes in suitability are expected in the future due to the accelerated climate warming during the 21st. According to their limited dispersal abilities, the persistence of all B. variegata lineages over time appears uncertain. We further recommend to integrate the intraspecific levels, when available, in modelling process to catch local variations and obtain more accurate results. [ABSTRACT FROM AUTHOR]

The white‐clawed crayfish (Austropotamobius pallipes) is globally endangered due to the impacts of habitat modification and fragmentation, water pollution, climate change, and invasive species, particularly the signal crayfish (Pacifastacus leniusculus). These pressures have caused the decline of A. pallipes populations in Europe, demonstrating the importance of predicting the species' potential distribution under current and future conditions. Focusing on the watercourses of mainland France, we aimed to identify suitable areas for A. pallipes to guide the conservation of current populations and future introduction actions or protection measures.We applied ecological niche modelling to model the potential distribution of both A. pallipes and P. leniusculus and identified locations suitable for A. pallipes only. We also assessed the potential distribution of the species under two representative concentration pathway (RCP) scenarios: RCP 2.6 and RCP 8.5, respectively describing low‐warming and high‐warming conditions.We found that A. pallipes and P. leniusculus exploit equivalent niches in France. Despite this, under current conditions, about 5% of the study area simultaneously records a high suitability for A. pallipes and a low suitability for P. leniusculus and is therefore of significant conservation interest. This percentage remains relatively stable under RCP 2.6 for 2050 and 2100, but decreases to 2% under RCP 8.5 for 2100.Ecological niche modelling can supply crucial guidance for conservation actions aimed at protecting endangered species at a national scale by identifying sites most suitable for protection and sites where climate change and invasive species constitute a threat. [ABSTRACT FROM AUTHOR]

Whereas the effects of climate change on the potential range shifts of amphibians have been modeled at various scales, exploring the future impacts of land-use changes has rarely been considered. We modeled the potential distribution of Bombina variegata, Hyla arborea, Hyla meridionalis, and Triturus cristatus using ecological niche modeling, in the French administrative region Nouvelle-Aquitaine. The species are all at range margin in the study area which makes them interesting model species to study range shifts because of their potential local adaptations to their marginal habitat. We used Dyna-CLUE modeling framework to produce land-use change scenarios and combined them with RCP 2.6 and RCP 8.5 climate change scenarios to predict their impact on local amphibian distributions. B. variegata, H. arborea, and T. cristatus were predicted to shift eastward and northward. H. meridionalis was predicted to increase its probability of presence in the study area. The effect of climate determined the general pattern of distribution and was modulated depending on the scenarios of land-use change. [ABSTRACT FROM AUTHOR]