Climate change has major impacts on viticultural ecosystems worldwide, affecting wine production. Apart from direct impacts, the increase in temperature during the development season is likely to favour insect species, including polyvoltine ones, leading potentially to more damage in the vineyards. In this study, we examined the extent to which changes in mean temperature over the development season (March through September) can potentially increase the voltinism change the phenology and influence the reproduction of pest species in the vineyard area of Neuchatel (Switzerland). We first analysed long-term daily mean temperature data from 1970 to 2022 at the meteorological station of Neuchâtel. Then we used two climate scenarios (RCP4.5 and RCP8.5) to analyse daily mean temperature during the period 2023–2099. For both of these periods, we computed the number of growing degree days (GDDs) above 10 °C, as it is the base development temperature for many polyvoltine pest species. We then used specific bioclimatic models for two major pest species, namely the European grapevine moth (Lobesia botrana) and the American grapevine leafhopper (Scaphoideus titanus) to compare the current and future suitability of these two species to the air temperature conditions in Neuchâtel. Our results show an increase of about 425 GDDs since 1970 (+85 GDDs per decade). According to our models, values will continue to rise during the next decades, with a trend ranging from +28 GDDs per decade (RCP4.5) to +100 GDDs per decade (RCP8.5). This could lead to additional generations of polyvoltine pest species. A third annual generation can be expected in one year out of four for the European grapevine moth by the middle of the 21st century. While temperature conditions are currently moderately favourable for the American grapevine leafhopper, they are predicted to become highly favourable by the middle and the end of the century under both scenarios. These trends mean that climate change is likely to increase pest damage risks in the vineyards of Neuchatel in the future. Pest regulation will remain crucial in limiting major impacts on wine production.

Climate change has major impacts on viticultural ecosystems worldwide, affecting wine production. Apart from direct impacts, the increase in temperature during the development season is likely to favour insect species, including polyvoltine ones, leading potentially to more damage in the vineyards. In this study, we examined the extent to which changes in mean temperature over the development season (March through September) can potentially increase the voltinism change the phenology and influence the reproduction of pest species in the vineyard area of Neuchatel (Switzerland). We first analysed long-term daily mean temperature data from 1970 to 2022 at the meteorological station of Neuchatel. Then we used two climate scenarios (RCP4.5 and RCP8.5) to analyse daily mean temperature during the period 2023-2099. For both of these periods, we computed the number of growing degree days (GDDs) above 10 degrees C, as it is the base development temperature for many polyvoltine pest species. We then used specific bioclimatic models for two major pest species, namely the European grapevine moth (Lobesia botrana) and the American grapevine leafhopper (Scaphoideus titanus) to compare the current and future suitability of these two species to the air temperature conditions in Neuchatel. Our results show an increase of about 425 GDDs since 1970 (+85 GDDs per decade). According to our models, values will continue to rise during the next decades, with a trend ranging from +28 GDDs per decade (RCP4.5) to +100 GDDs per decade (RCP8.5). This could lead to additional generations of polyvoltine pest species. A third annual generation can be expected in one year out of four for the European grapevine moth by the middle of the 21st century. While temperature conditions are currently moderately favourable for the American grapevine leafhopper, they are predicted to become highly favourable by the middle and the end of the century under both scenarios. These trends mean that climate change is likely to increase pest damage risks in the vineyards of Neuchatel in the future. Pest regulation will remain crucial in limiting major impacts on wine production.

Rural populations are particularly exposed to increasing weather variability, notably through agriculture. In this paper, we exploit longitudinal data for Turkish provinces from 2008 to 2018 together with precipitation records over more than 30 years to quantify how variability in a standardized precipitation index (SPI) affects out-migration as an adaptation mechanism. Doing so, we document the role of three potential causal channels: per capita income, agricultural output, and local conflicts. Our results show that negative SPI shocks (droughts) are associated with higher out-migration in rural provinces. A mediated-moderator approach further suggests that changes in per capita income account for more than one quarter of the direct effect of droughts on out-migration, whereas agricultural output is only relevant for provinces in the upper quartile of crop production. Finally, we find evidence that local conflict fatalities increase with drought and trigger out-migration, although this channel is distinct from the direct effect of SPI shocks on out-migration.

In Switzerland, as elsewhere in the world, climate change is challenging viticulture. Knowledge of the potential impacts is essential for preparing adaptation measures. Two aspects directly impacted by increasing temperatures are the choice of grapevine varieties and the location of vineyards. To help address these impacts, we analysed future trends in two bioclimatic indices, average growing season temperature (GST) and Huglin’s heliothermal index (HI), in the Swiss canton of Neuchâtel. We conducted our analysis based on regional climate change scenarios referring to the emission pathways RCP4.5 and RCP8.5. Under the assumption of RCP8.5, trends in GST and HI indicate that the climate in this region will become too hot for most grapevine varieties currently cultivated, especially Pinot noir. Moreover, adaptation problems under RCP8.5 are expected to originate from an increase in climate extremes in both temperature and precipitation. Results based on RCP4.5 indicate a broader scope for adaptation, as the climate will remain suitable for a larger number of grapevine varieties within the current altitudinal limits of the Neuchâtel vineyards. In theory, an altitudinal shift of Pinot noir would also be possible under this emission pathway. In practice, however, the possibility of establishing vineyards above 600 m would be limited by the presence of protected forests and rocky areas. Our results highlight that vineyards in this region will need important adaptation measures if anthropic greenhouse gas emissions do not decrease rapidly and considerably, limiting the global temperature increase to < 1.5 °C.

With global warming, the mean temperature during the insect development season has been increasing in Switzerland over the last decades, and this trend is predicted to continue. As a result, the annual number of generations could increase for polyvoltine insect species. Some pest species, such as the box tree moth (Cydalima perspectalis), the grapevine moth (Lobesia botrana), the codling moth (Cydia pomonella), and the Comstock mealybug (Pseudococcus comstocki), are therefore likely to produce more generations in the future, leading to more damage to forests, vineyards and crops. These species all have a base development temperature (tb) of around 10 degrees C. In this study, we examined the extent to which changes in daily mean temperature (Tmean) averaged over the development season (April through September) could potentially increase the voltinism of these species in various regions of Switzerland. We analysed long-term daily Tmean data from the period 1980-2021 at 67 meteorological stations covering an elevation range from 203 to 2283 m a.s.l. We then used two climate scenarios (RCP2.6 and RCP8.5) to analyse daily Tmean during the period 2022-2099. We computed growing degree days (GDDs) above tb = 10 degrees C and looked at the trends across elevation. Our results show that daily Tmean averaged across the development season increased more than the daily Tmean averaged over the entire year over the last 40 years. There was an average increase of 60 GDDs per decade during this period, with larger increases occurring at lower elevations. Our results indicate that by the end of the 21st century there could be more GDDs on the Swiss Plateau than currently occur at lower elevations on the southern side of the Alps and that the number of GDDs currently occurring on the Swiss Plateau could be found at middle elevations (800-1400 m a.s.l.). Future temperature conditions can thus be expected to favour additional generations of pests annually at lower elevations and to allow them to complete a full single cycle per year at higher elevations.

Climate change has various and complex effects on crop pests worldwide. In this review, we detail the role of the main climatic parameters related to temperature and precipitation changes that might have direct or indirect impacts on pest species. Changes in these parameters are likely to favour or to limit pest species, depending on their ecological context. On a global scale, crop pests are expected to benefit from current and future climate change. However, substantial differences appear across biomes and species. Temperate regions are generally more likely to face an increase in pest attacks compared with tropical regions. Therefore, climate change effects should be studied in the context of local climate and local ecological interactions across biomes.

Mountain areas are biodiversity hotspots and provide a multitude of ecosystem services of irreplaceable socio-economic value. In the European Alps, air temperature has increased at a rate of about 0.36°C decade-1 since 1970, leading to glacier retreat and significant snowpack reduction. Due to these rapid environmental changes, this mountainous region is undergoing marked changes in spring phenology and elevational distribution of animals, plants and fungi. Long-term monitoring in the European Alps offers an excellent natural laboratory to synthetize climate-related changes in spring phenology and elevational distribution for a large array of taxonomic groups. This review assesses the climatic changes that have occurred across the European Alps during recent decades, spring phenological changes and upslope shifts of plants, animals and fungi from evidence in published papers and previously unpublished data. Our review provides evidence that spring phenology has been shifting earlier during the past four decades and distribution ranges show an upwards trend for most of the taxonomic groups for which there are sufficient data. The first observed activity of reptiles and terrestrial insects (e.g. butterflies) in spring has shifted significantly earlier, at an average rate of -5.7 and -6.0 days decade-1 , respectively. By contrast, the first observed spring activity of semi-aquatic insects (e.g. dragonflies and damselflies) and amphibians, as well as the singing activity or laying dates of resident birds, show smaller non-significant trends ranging from -1.0 to +1.3 days decade-1 . Leaf-out and flowering of woody and herbaceous plants showed intermediate trends with mean values of -2.4 and -2.8 days decade-1 , respectively. Regarding species distribution, plants, animals and fungi (N = 2133 species) shifted the elevation of maximum abundance (optimum elevation) upslope at a similar pace (on average between +18 and +25 m decade-1 ) but with substantial differences among taxa. For example, the optimum elevation shifted upward by +36.2 m decade-1 for terrestrial insects and +32.7 m decade-1 for woody plants, whereas it was estimated to range between -1.0 and +11 m decade-1 for semi-aquatic insects, ferns, birds and wood-decaying fungi. The upper range limit (leading edge) of most species also shifted upslope with a rate clearly higher for animals (from +47 to +91 m decade-1 ) than for plants (from +17 to +40 m decade-1 ), except for semi-aquatic insects (-4.7 m decade-1 ). Although regional land-use changes could partly explain some trends, the consistent upward shift found in almost all taxa all over the Alps is likely reflecting the strong warming and the receding of snow cover that has taken place across the European Alps over recent decades. However, with the possible exception of terrestrial insects, the upward shift of organisms seems currently too slow to track the pace of isotherm shifts induced by climate warming, estimated at about +62 to +71 m decade-1 since 1970. In the light of these results, species interactions are likely to change over multiple trophic levels through phenological and spatial mismatches. This nascent research field deserves greater attention to allow us to anticipate structural and functional changes better at the ecosystem level.

With global warming, recent winters in Switzerland have been milder than in previous decades, and this trend is predicted to continue. Survival during the cold season could increase for insect species sensitive to winter cold events. Forest pests, such as the pine processionary moth (Thaumetopoea pityocampa) and green spruce aphid (Elatobium abietinum), as well as some crop pests, such as the southern green stink bug (Nezara viridula), could overwinter more easily. These species are affected by temperatures below -12 degrees C or below -8 degrees C. In this study, we examined whether changes in winter minimum temperatures (Tmin) could potentially favour the winter survival of these pest species in various places in Switzerland. We analysed long-term daily Tmin data from the period 1980-2019 at 67 locations. We then used two climatic scenarios (RCP2.6 and RCP8.5) to analyse daily Tmin in 2020-2099. We determined the number of days with Tmin below -8 degrees C or -12 degrees C and the frequency of years with at least one day below these thresholds. Our results show that the frequency of cold days has decreased over the last 40 years, even though winter Tmin has increased less than yearly Tmin. However, the -8 degrees C threshold was still reached in most years, except on the Southern side of the Alps. The -12 degrees C threshold was reached almost every year above 800 m, but infrequently at lower elevations. Our results indicate that, by the end of the 21st century, temperatures below -12 degrees C will occur only infrequently up to 1700 m in Switzerland, and years with occurrences of temperatures below -8 degrees C will become rare at lower elevations. Future temperature conditions can thus be expected to favour some crop pests, by enabling them to overwinter more easily on the Swiss Plateau, as well as some forest pests, which will likely reach higher elevations.

Global warming increases the need for local climatic studies in wine-producing areas. Winegrowers have to develop strategies to adapt their activities to new climatic conditions and to their various effects on vine culture. Among them, distribution and population dynamics of pest species are likely to change. New species could reach the temperate regions, and some native species could create more damages than previously in the vineyards. In Western Europe, the distribution of the American grapevine leafhopper Scaphoideus titanus has been observed to shift northwards during the last decades (Boudon and Maixner 2007). Plurivoltin species such as the European grapevine moth Lobesia botrana could produce more generations per year (Gutierrez et al. 2018), creating potentially more damages on grapes. To help winegrowers, it is crucial to lead research at local scale, taking into account microclimatic specificities of the vineyards (Mozell and Thach 2014).In this study, we examine temperature trends during the growing season in the region of Neuchatel and their potential impacts on major vine pest species. We focus on the American grapevine leafhopper and on the European grapevine moth. The American grapevine leafhopper is already established in the Lake Geneva area and could soon reach the Neuchatel area, while the European grapevine moth is already present in the Neuchatel vineyard. We use temperature data over the last 40 years (1980-2019) and two climatic scenarios to assess present suitability for pest development and the perspectives for the next decades.REFERENCESBoudon, E. & M. Maixner. 2007. Potential effects of climate change on distribution and activity of insect vectors of grapevine pathogens. In International and multi-disciplinary" Global warming, which potential impacts on the vineyards?".Gutierrez, A. P., L. Ponti, G. Gilioli & J. Baumgärtner (2018) Climate warming effects on grape and grapevine moth (Lobesia botrana) in the Palearctic region. Agricultural and Forest Entomology, 20, 255-271.Mozell, M. R. & L. Thach (2014) The impact of climate change on the global wine industry: Challenges & solutions. Wine Economics and Policy, 3, 81-89.

TALKS: 18.1 Brönnimann S.: Atmospheric Contribution to Multidecadal Flood Variability in Europe 18.2 Buchmann M., Brönnimann S., Begert M., Marty C.: Evaluating the seasonal robustness of snow climate indicators using a unique set of parallel snow data 18.3 Burgdorf A.-M., Arblaster J.: Precipitation response to ozone depletion in the Southern Hemisphere 18.4 Comte V., Schneider L., Rebetez M.: Trends in bioclimatic indices for the coming decades in the Neuchatel vineyard 18.5 Gudmundsson L., Gädeke A., Grant L., Kirchner J., Padron R., Thiery W., Seneviratne S.I.: Detecting and attributing climate change impacts in terrestrial systems 18.6 Scheen J., Pöppelmeier F., Lippold J., Stocker T.F.: Reconstructing AMOC strength by simulating the transport of Pa/Th isotopes in the ocean 18.7 Valler V., Franke J., Brugnara Y., Brönnimann S.: A monthly paleo-reanalysis of the atmosphere between 16032005 18.8 Zeder J., Fischer E.M.: Towards a conditional representation of heat wave probability in large ensemble climate model data

Foresters from many countries are seeking for tree species or provenances able to cope with expected climate change. While it becomes clear that some temperate tree species will increasingly suffer from climate warming, the fate of the ecologically and economically important silver fir (Abies alba Mill.) remains uncertain and debated because the ecological requirements of this species, as well as its resilience to drought, are still unclear. On the one hand, paleoecological studies reveal that this species was widely distributed under much warmer climate, suggesting a high potential to cope with ongoing and future climate warming. On the other hand, species distribution models generally predict a strong decline of its climatic suitability in the future. This paper aims to clarify the potential of this species to thrive in central and western Europe under predicted climate warming by reviewing the knowledge gained from different fields. Based on insight from different fields, we argue that silver fir has a great potential to thrive under warmer conditions in western and central Europe provided sufficient rainfall, as forecasted by climate models for most regions by 2100. For instance, dendroecological studies demonstrate that silver fir is more resistant and resilient to drought compared to co-occurring species such as Norway spruce, European beech and larch. The most prominent obstacle for increasing the proportion of fir in mixed forests nowadays is ungulate browsing that often prevents its upgrowth.

Winters and early springs are predicted to become warmer in temperate climates under continued global warming, which in turn is expected to promote earlier plant development. By contrast, there is no consensus about the changes in the occurrence and severity of late spring frosts. If the frequency and severity of late spring frosts remain unchanged in the future or change less than spring phenology of plants does, vulnerable plant organs (dehardened buds, young leaves, flowers or young fruits) may be more exposed to frost damage. Here we analyzed long-term temperature data from the period 1975-2016 in 50 locations in Switzerland and used different phenological models calibrated with long-term series of the flowering and leaf-out timing of two fruit trees (apple and cherry) and two forest trees (Norway spruce and European beech) to test whether the risk of frost damage has increased during this period. Overall, despite the substantial increase in temperature during the study period, the risk of frost damage was not reduced because spring phenology has advanced at a faster rate than the date of the last spring frost. In contrast, we found that the risk of frost exposure and subsequent potential damage has increased for all four species at the vast majority of stations located at elevations higher than 800 m while remaining unchanged at lower elevations. The different trends between lower and higher elevations are due to the date of the last spring frost moving less at higher altitudes than at lower altitudes, combined with stronger phonological shifts at higher elevations. This latter trend likely results from a stronger warming during late compared to earlier spring and from the increasing role of other limiting factors at lower elevations (chilling and photoperiod). Our results suggest that frost risk needs to be considered carefully when promoting the introduction of new varieties of fruit trees or exotic forest tree species adapted to warmer and drier climates or when considering new plantations at higher elevations.

This paper describes meteorological measurements collected since 1997 at 16 ICP Forests Level II sites across the complex topography of Switzerland, both under the canopy and in the open-field nearby.The data offer detailed comparisons of deciduous, mixed, and coniferous forest microclimatic conditions with standard meteorological conditions in the open-field.Contrary to the open-field stations, those under the canopy do not fully correspond to the WMO criteria.

What future for silver fir in Switzerland under ongoing climate change? Foresters in many countries are currently seeking for the most suitable forest species or provenances for facing the future climate, which will be much warmer than today with more extreme summer droughts. While it is clear that some tree species will increasingly suffer from climate warming, the fate of silver fir (Abies alba Mill.) remains very uncertain because contradictory results have been published about the suitability of this species to cope with climate warming. On the one hand, species distribution models predict a strong decline of its climatic niche in the future. On the other hand, paleoecological studies reveal that this species was widely distributed under much warmer and probably drier climate, suggesting a high potential to face future climate warming. This literature survey shows that this species could actually grow under warmer conditions provided that precipitation remains sufficient, which seems to be the case for most regions of Switzerland according to climatic model predictions for the end of the century. In addition, dendroecological studies have shown a higher resistance and resilience of silver fir to drought compared to Norway spruce, suggesting that silver fir could be promoted by foresters. Nowadays, the greatest threat to silver fir is undoubtedly the browsing pressure by ungulates which can jeopardize its regeneration and must therefore be properly regulated to increase the proportion of silver fir in Swiss mixed forests.

The length of the snow-free season is a key factor regulating plant phenology and shaping plant community composition in cold regions. While global warming has significantly advanced the time of snowmelt and the growth period at all elevations in the Swiss Alps, it remains unclear if it has altered the likelihood of frost risk for alpine plants. Here, we analyzed the influence of the snowmelt timing on the risk of frost exposure for subalpine and alpine plants shortly after snowmelt, i.e., during their most vulnerable period to frost at the beginning of their growth period. Furthermore, we tested whether recent climate warming has changed the risk of exposure of plants to frost after snowmelt. We analyzed snow and air temperature data in the Swiss Alps using six weather stations covering the period 1970-2016 and 77 weather stations covering the period 1998-2016, spanning elevations from 1418 to 2950 m asl. When analyzed across all years within each station, our results showed strong negative relationships between the time of snowmelt and the frequency and intensity of frost during the most vulnerable period to frost for subalpine and alpine plants, indicating a higher frost risk damage for plants during years with earlier snowmelt. However, over the last 46 years, the time of snowmelt and the last spring frost date have advanced at similar rates, so that the frequency and intensity of frost during the vulnerable period for plants remained unchanged.

Spring frosts are feared by farmers, fruit growers, and wine growers as they can cause significant damage to crops when they occur during the development of the plants. In the second half of April 2017, following a very warm period that had caused premature vegetation growth, a cold air mass from the Arctic penetrated central and western Europe, causing severe damage to natural and cultivated vegetation over broad areas. Here, we analyze how exceptional this event was in Switzerland and Germany in relation to the accumulated growing degree days (GDD), used as a proxy for plant phenology advancement. Although this damaging frost was not the latest on record in terms of calendar days, our results show that it was, in some regions, unprecedented in relation to the accumulated warmth during the preceding period, at least since the beginning of instrumental temperature records (1864). Our results also highlight how global warming has considerably increased the number of days with mean temperature above 5 °C in late winter and early spring, especially since 1970 (+ 16.8 ± 4.7 °C days decade −1 ). However, in spite of earlier spring phenology due to climate warming, our results suggest that the risk of damaging frost events to vegetation has remained unchanged over the last 150 years in lowlands of Switzerland and Germany, due to the concurring earlier occurrence of the last potentially damaging frosts (about − 20 days since 1864). Our analyses reveal therefore that the April 2017 damaging frost was a true outlier in terms of risk of frost damage to plants.

Over the last 40 years, warmer temperatures have caused a considerable decrease in snow cover on glaciers and high rates of glacial melt, particularly in tropical mountains. In the Bolivian Andes, the Chacaltaya glacier (5400 masl) had been a tourist destination known as the highest ski slope in the world since 1939. As a result of climate change, skiing has not been possible after 1987 and the glacier definitely disappeared in 2009. However, since 2005, the place has become a new attraction for tourists. Travel agencies in La Paz now offer day trips to the Chacaltaya site. In order to understand the present attraction of the site and its potential for reproduction elsewhere, 25 semi-structured interviews were conducted with various categories of stakeholders involved in the tourism industry in La Paz, and archives and images were analysed. Our results show that the multifunctional character of this tourist site, including easy access to a summit, beautiful views, acclimatisation to altitude and opportunity to experience snow, are key factors in its renewed attraction for visitors, together with, to a lesser extent, the incentive of being able to watch a famous and evident full disappearance of a glacier and former ski slope. The stakeholders' groups share general views and perceptions about environmental changes and about the qualities of the site, but they also differ in terms of projects and evaluation of potential attractiveness. In particular, the development of the visibility of climate change impacts on mountain environment is valued by experts or by members of the Andean Club, but not by travel agencies. The example of Chacaltaya shows that multifunctional tourist sites may still be attractive in the future.