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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]

Abstract: The transport phase of the animal‐mediated plant dispersal process is critical to dispersal effectiveness as it determines the spatial distribution of the diaspores released and their chance for further recruitment. Assessing this specific phase of the dispersal process generally requires combining diaspore retention times with the associated distances covered. Here, we specifically tested the effect of grooming behavior, interindividual contacts and ungulate fur on diaspore retention times and associated dispersal distances for the hooked diaspores of Xanthium strumarium L. experimentally attached to tamed individuals of three ungulate species. We used a comparative approach based on differing fur quality on different body zones of these three ungulates. During 6‐hr sessions, we monitored for grooming and social interactions that may induce intended or inadvertent diaspore detachment. Additionally, we proposed innovative approaches to directly assessing diaspore dispersal distances by red deer in situ. Fat‐tailed functions fitted diaspore retention time, highlighting the potential for long‐distance dispersal events. The longer the hair, the higher the retention capacity of diaspores in the animal's fur. As predicted, donkey retained diaspores longer than red deer and dwarf goat; and we also confirmed that diaspores attached to the short hair of the head fell off more quickly than did those on the other body zones. Dwarf goat groomed more often than both red deer and donkey, but also when it carried diaspores. Up to 14% of the diaspores detached from animal fur after specific grooming behavior. We observed, in controlled conditions, for the first time and for each ungulate species, interindividual transfers of diaspores, representing 5% of the diaspores attached to animals’ fur. Our results militate for incorporating animal behavior into plant dispersal modeling approaches. [ABSTRACT FROM AUTHOR]

Individual marking has become essential for studying population dynamics and ecological requirements. However, marking small-bodied species such as amphibians is becoming a challenge in the last decades. Amphibian surveys may require to mark manually individuals, using toe clipping, polymers and pigments, or passive integrated transponders (PIT-tags). Even if ethics committees have recently recommend avoiding toe clipping in amphibians, the use of PIT-tags led to controversial results because low tag retention reported in some studies. Here, we describe a protocol of potentially life-long PIT-tag marking in a protected species, the marbled newt Triturus marmoratus. In addition, we also detailed a second procedure of surgery for the implantation of transmitters needed in radio-tracking surveys. During both procedures, we found that the newt phase (either aquatic or terrestrial) strongly affected the anesthesia duration. Indeed, newts in aquatic phase were more quickly anesthetized than newts under terrestrial phase. We then recommend to pay attention of this physiological particularity when performing this kind of procedure. Improving our knowledge on ecological requirements and population dynamics of this species is crucial for management and conservation plans, and could be extended to other large newts. [ABSTRACT FROM AUTHOR]

Abstract: It has proved difficult to efficiently restore vegetation of alpine ski trails. Main causes are seed runoff and the lack of soil seed banks and microsites for plant recruitment. A previous study conducted on ski trails in the French Alps gave rise to the effect of vegetation cover and artificial hoof prints in soil to decrease the seed runoff. In this study, we hypothesized that this effect leads to the formation of soil seed bank. Soil samples have been collected in different microtopographies: mounds at the upslope side of plant growing on ski slope, cows’ hoof prints, and also in the bare soil at the periphery. The seed bank composition was determined by a germination method, then the number of germinable seeds was put in relation to the microtopographies. Results showed that both seedling and species number were twice as high in these microtopographies as in adjacent bare soil. As indicated by high similarity values, species that formed the seed bank were mostly recruited from the standing vegetation of ski trails. The analyses of dispersal characteristics of the species revealed that the flattest seeds remained on slope, whereas the roundest were almost found in the mounds. We discussed the engineering role of plants and the disturbance by cows in aiding seeding success. [Copyright &y& Elsevier]

Abstract: Ski resorts in the French Alps greatly affect alpine ecosystems through the construction of ski pistes. In this harsh climate and on steep slopes, important seed runoff hinders the revegetation process. This study aims at understanding how vegetation and grazing interacts with seed runoff. Seed movement after dispersal was investigated with three contrasting types of seeds in different vegetation covers, two steep slopes (25° and 35°) and artificial hoof prints in soil. After 3 months, seeds showed notable post-dispersal movement. The results are illustrated by dispersal curves at the soil surface. As vegetation cover increased from 15% to 60%, dispersal curves showed clumpy distributions of seeds. Hoof prints strongly reduced the traveled distance of post-dispersed seeds. Seed shape, measured by the flatness index, seems to be a key factor in post-dispersal movement, indicating that the flatter the seeds were, the more seeds remained on the slope. These results emphasize the engineering role of established vegetation and cow in aiding seeding success. The positive effects of hoof prints pointed out the utility of grazers in ski trail restoration. Additionally, the knowledge of seed shape will be helpful in predicting post-dispersal seeding patterns and subsequently in establishing both sown species and native species. [Copyright &y& Elsevier]

Delaying the first date of mowing of road verges is frequently practised as a way of preserving or enhancing biodiversity. Although the effects of this management practice on plant species richness remains controversial, it has been demonstrated that it allows more species to set seed. While an integrated management of the weed flora is currently promoted in arable fields adjacent to road verges, delaying the mowing of these field boundaries can be questioned, especially because seed dispersal from road verges to arable fields through field margins can be increased. In this context, the study aimed to assess the potential influence of delaying the first date of mowing of berms on (1) the species richness of berm standing vegetation (BSV), (2) the number of seeds and (3) the composition of seed rains in road verges and adjacent arable fields. To this end, we surveyed the standing vegetation and seed rain in four areas, i.e. in the berm, embankment, crop edge and field margin from a total of 252 sampling points. First, we analysed the effect of the mowing period (i.e. early or late summer) on species richness of both BSV and berm seed rain. Then, at each sample point in the four areas, we studied the variation in (i) seed abundance (i.e. number of seeds), (ii) contribution of BSV to each seed rain (i.e. Sorensen⿿s similarity and Bray-Curtis⿿ dissimilarity indices between the BSV and each sample point) and (iii) seed abundance of the most frequent species recorded in BSV. Our findings showed that delaying the first mowing to late summer for four years had no impact on the species richness of BSV, while it increased species number and abundance of seeds in the berm seed rain. We also demonstrated that BSV of the late mown berms contributed more to the berm seed rain, than that of early mown berms. Moreover, our results suggest that compared to early mowing, only Dactylis glomerata dispersed more seeds from the late mown berms to field margins. Regarding the most frequent weed species observed in the BSV, for example Elytrigia repens , Arrhenatherum elatius and Convolvulus arvensis , the number of seeds trapped in field margins was low except for A. elatius . Finally, under our conditions, late mowing remained inefficient in promoting plant species richness on berms, but did not represent a particular factor of weed risk in field margins. [ABSTRACT FROM AUTHOR]

Frequent drying of ponded water, and support of unique, highly specialized assemblages of often rare species, characterize temporary wetlands, such as vernal pools, gilgais, and prairie potholes. As small aquatic features embedded in a terrestrial landscape, temporary wetlands enhance biodiversity and provide aesthetic, biogeochemical, and hydrologic functions. Challenges to conserving temporary wetlands include the need to: (1) integrate freshwater and terrestrial biodiversity priorities; (2) conserve entire ‘pondscapes’ defined by connections to other aquatic and terrestrial systems; (3) maintain natural heterogeneity in environmental gradients across and within wetlands, especially gradients in hydroperiod; (4) address economic impact on landowners and developers; (5) act without complete inventories of these wetlands; and (6) work within limited or non-existent regulatory protections. Because temporary wetlands function as integral landscape components, not singly as isolated entities, their cumulative loss is ecologically detrimental yet not currently part of the conservation calculus. We highlight approaches that use strategies for conserving temporary wetlands in increasingly human-dominated landscapes that integrate top-down management and bottom-up collaborative approaches. Diverse conservation activities (including education, inventory, protection, sustainable management, and restoration) that reduce landowner and manager costs while achieving desired ecological objectives will have the greatest probability of success in meeting conservation goals. [ABSTRACT FROM AUTHOR]