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Abstract: A noticeable increase in mean temperature has already been observed in Switzerland and summer temperatures up to 4.8K warmer are expected by 2090. This article reviews the observed impacts of climate change on biodiversity and considers some perspectives for the future at the national level. The following impacts are already evident for all considered taxonomic groups: elevation shifts of distribution towards mountain summits, spread of thermophilous species, colonisation by new species from warmer areas and phenological shifts. Additionally, in the driest areas, increasing droughts are affecting tree survival and fish species are suffering from warm temperatures in lowland regions. These observations are coherent with model projections, and future changes will probably follow the current trends. These changes will likely cause extinctions for alpine species (competition, loss of habitat) and lowland species (temperature or drought stress). In the very urbanised Swiss landscape, the high fragmentation of the natural ecosystems will hinder the dispersal of many species towards mountains. Moreover, disruptions in species interactions caused by individual migration rates or phenological shifts are likely to have consequences for biodiversity. Conversely, the inertia of the ecosystems (species longevity, restricted dispersal) and the local persistence of populations will probably result in lower extinction rates than expected with some models, at least in 21st century. It is thus very difficult to estimate the impact of climate change in terms of species extinctions. A greater recognition by society of the intrinsic value of biodiversity and of its importance for our existence will be essential to put in place effective mitigation measures and to safeguard a maximum number of native species. [Copyright &y& Elsevier]

Land-use change is a major driver for changes in biodiversity. In this study, we investigated how the objectives of two conservation strategies (large-scale conservation of species richness versus conservation of diversity hotspots) can be achieved for grasshopper diversity under different scenarios of environmental change (land-use and climate change). Based on surveys of 95 grasshopper species from 2001 to 2004 recorded by the Swiss Centre for Faunal Cartography, we modelled the actual richness pattern as a function of different environmental variables. The impact of potential future environmental change on species richness was evaluated by applying four land-use scenarios (‘liberalization’, ‘business as usual’, ‘lowered agricultural production’, and ‘complete conversion of intensive open land’) and one climate change scenario. The effects of the scenarios were assessed at the national scale, as well as on small-scale hotspots. Environmental change has considerable effect on grasshopper species richness. At the national scale, the number of grasshopper species decreased under the ‘liberalization’ scenario (−0.24 species per 1ha pixel) and increased under a climate change scenario (+0.63 species per 1ha pixel). For most environmental change scenarios, species richness in small-scale hotspots was more negatively affected than on average on the national scale. The response of species richness to the scenarios did not differ significantly between hotspots of endangered and the hotspots of common grasshopper species. We conclude that conservation efforts at the national scale and small-scale hotspot conservation programs should be combined to conserve species richness most successfully. For the long-term conservation of species richness, common species as well as the combined effects of land-use and climate change have to be considered. [Copyright &y& Elsevier]

Butterfly monitoring and Red List programs in Switzerland rely on a combination of observations and collection records to document changes in species distributions through time. While most butterflies can be identified using morphology, some taxa remain challenging, making it difficult to accurately map their distributions and develop appropriate conservation measures. In this paper, we explore the use of the DNA barcode (a fragment of the mitochondrial gene COI) as a tool for the identification of Swiss butterflies and forester moths (Rhopalocera and Zygaenidae). We present a national DNA barcode reference library including 868 sequences representing 217 out of 224 resident species, or 96.9% of Swiss fauna. DNA barcodes were diagnostic for nearly 90% of Swiss species. The remaining 10% represent cases of para- and polyphyly likely involving introgression or incomplete lineage sorting among closely related taxa. We demonstrate that integrative taxonomic methods incorporating a combination of morphological and genetic techniques result in a rate of species identification of over 96% in females and over 98% in males, higher than either morphology or DNA barcodes alone. We explore the use of the DNA barcode for exploring boundaries among taxa, understanding the geographical distribution of cryptic diversity and evaluating the status of purportedly endemic taxa. Finally, we discuss how DNA barcodes may be used to improve field practices and ultimately enhance conservation strategies., Competing Interests: The authors declare that no competing interests exist. Affiliation with Hintermann & Weber AG does not alter our adherence to PLOS ONE policies on sharing data and materials.

Background: One of the major public health challenges in the field of communicable diseases consists of being able to predict where and when a population is at risk of being infected by a pathogen. In the case of vector-borne diseases, such predictions often require strong ecological knowledge of the vector life-cycle and the environmental conditions promoting or preventing its establishment and maintenance. In this study, we analyse how climatic factors influence the abundance and phenology of the Lyme borreliosis vector Ixodes ricinus in a Swiss temperate forest, based on a long-term monthly observation over a period of 15 years (2000 and 2014)., Results: Our results show that questing nymph density significantly decreased during the study period in the sampling area. Although the analyses of climatic variables point out the relative importance of air temperature, relative humidity and saturation deficit on nymph questing activity, the global trends followed by these variables over the study period failed to fully explain the observed decline. However, nymph phenology was additionally explained by the presence of climatic thresholds that limit the questing behaviours of ticks. Most notably, we found that the presumed upper threshold of air saturation deficit, which strongly limits the increase of questing nymph density and is typically reached in the middle of spring, was reached significantly earlier and earlier over years., Conclusions: In addition to phenology per se, the use of climatic thresholds may help to predict the presence and abundance of questing ticks in Lyme borreliosis endemic areas. Tick sensitivity to temperature or saturation deficit thresholds also suggests that extreme climatic events more than global trends may affect tick population dynamics. These two points may be of high importance in epidemiological short-term as well as long-term predictions. However, the highly unexplained variability in nymph density underlines the need for further studies that include other factors such as tick host abundance or tick microhabitats, two potentially influent factors that were not assessed in the present study.