Climate change impact on biodiversity in Switzerland: a review. Journal for Nature Conservation

A noticeable increase in mean temperature has already been observed in Switzerland and summer temperatures up to 4.8 K warmer are expected by 2090. This article reviews the observed impacts of climate change on biodiversity and consider some perspectives for the future at the national level. The following impacts are already evident for all considered taxonomic groups: elevation shifts of distribution toward 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.

Phylogenetic alpha and beta diversities of butterfly communities correlate with climate in the western Swiss Alps

The observation of non-random phylogenetic distribution of traits in communities provides evidence for niche-based community assembly. Environment may influence the phylogenetic structure of communities because traits determining how species respond to prevailing conditions can be phylogenetically conserved. In this study, we investigate the variation of butterfly species richness and of phylogenetic - and -diversities along temperature and plant species richness gradients. Our study indicates that butterfly richness is independently positively correlated to temperature and plant species richness in the study area. However, the variation of phylogenetic - and -diversities is only correlated to temperature. The significant phylogenetic clustering at high elevation suggests that cold temperature filters butterfly lineages, leading to communities mostly composed of closely related species adapted to those climatic conditions. These results suggest that in colder and more severe conditions at high elevations deterministic processes and not purely stochastic events drive the assemblage of butterfly communities.

Early Cretaceous life, climate and anoxia

Early Cretaceous life and the environment were strongly influenced by the accelerated break up of Pangaea, which was associated with the formation of a multitude of rift basins, intensified spreading, and important volcanic activity on land and in the sea. These processes likely interacted with greenhouse conditions, and Early Cretaceous climate oscillated between "normal" greenhouse, predominantly arid conditions, and intensified greenhouse, predominantly humid conditions. Arid conditions were important during the latest Jurassic and early Berriasian, the late Barremian, and partly also during the late Aptian. Humid conditions were particularly intense and widespread during shorter episodes of environmental change (EECs): the Valanginian Weissert, the latest Hauterivian Faraoni, the latest Barremian earliest Aptian Taxy, the early Aptian Selli, the early late Aptian Fallot and the late Aptian-early Albian Paquier episodes. Arid conditions were associated with evaporation, low biogeochemical weathering rates, low nutrient fluxes, and partly stratified oceans, leading to oxygen depletion and enhanced preservation of laminated, organic-rich mud (LOM). Humid conditions enabled elevated biogeochemical weathering rates and nutrient fluxes, important runoff and the buildup of freshwater lids in proximal basins, intensified oceanic and atmospheric circulation, widespread upwelling and phosphogenesis, important primary productivity and enhanced preservation of LOM in expanded oxygen-minimum zones. The transition of arid to humid climates may have been associated with the net transfer of water to the continent owing to the infill of dried-out groundwater reservoirs in internally drained inland basins. This resulted in shorter-term sea-level fall, which was followed by sea-level rise. These sea-level changes and the influx of freshwater into the ocean may have influenced oxygen-isotope signatures. Climate change preceding and during the Early Cretaceous EECs may have been rapid, but in general, the EECs had a "pre"-history, during which the stage was set for environmental change. Negative feedback on the climate through increased marine LOM preservation was unlikely, because of the low overall organic-carbon accumulation rates during these episodes. Life and climate co-evolved during the Early Cretaceous. Arid conditions may have affected continental life, such as across the Tithonian/Berriasian boundary. Humid conditions and the corresponding tendency to develop dys- to anaerobic conditions in deeper ocean waters led to phases of accelerated extinction in oceans, but may have led to more luxuriant vegetation cover on continents, such as during the Valanginian, to the benefit of herbivores. During Early Cretaceous EECs, reef systems and carbonate platforms in general were particularly vulnerable. They were the first to disappear and the last to recover, often only after several million years. (C) 2011 Elsevier Ltd. All rights reserved.

Melanin-based colour polymorphism responding to climate change.

Climate warming leads to a decrease in biodiversity. Organisms can deal with the new prevailing environmental conditions by one of two main routes, namely evolving new genetic adaptations or through phenotypic plasticity to modify behaviour and physiology. Melanin-based colouration has important functions in animals including a role in camouflage and thermoregulation, protection against UV-radiation and pathogens and, furthermore, genes involved in melanogenesis can pleiotropically regulate behaviour and physiology. In this article, I review the current evidence that differently coloured individuals are differentially sensitive to climate change. Predicting which of dark or pale colour variants (or morphs) will be more penalized by climate change will depend on the adaptive function of melanism in each species as well as how the degree of colouration covaries with behaviour and physiology. For instance, because climate change leads to a rise in temperature and UV-radiation and dark colouration plays a role in UV-protection, dark individuals may be less affected from global warming, if this phenomenon implies more solar radiation particularly in habitats of pale individuals. In contrast, as desertification increases, pale colouration may expand in those regions, whereas dark colourations may expand in regions where humidity is predicted to increase. Dark colouration may be also indirectly selected by climate warming because genes involved in the production of melanin pigments confer resistance to a number of stressful factors including those associated with climate warming. Furthermore, darker melanic individuals are commonly more aggressive than paler conspecifics, and hence they may better cope with competitive interactions due to invading species that expand their range in northern latitudes and at higher altitudes. To conclude, melanin may be a major component involved in adaptation to climate warming, and hence in animal populations melanin-based colouration is likely to change as an evolutionary or plastic response to climate warming.

Adapting global conservation strategies to climate change at the European scale: the otter as a flagship species

Climate change has created the need for new strategies in conservation planning that account for the dynamics of factors threatening endangered species. Here we assessed climate change threat to the European otter, a flagship species for freshwater ecosystems, considering how current conservation areas will perform in preserving the species in a climatically changed future. We used an ensemble forecasting approach considering six modelling techniques applied to eleven subsets of otter occurrences across Europe. We performed a pseudo-independent and an internal evaluation of predictions. Future projections of species distribution were made considering the A2 and B2 scenarios for 2080 across three climate models: CCCMA-CGCM2, CSIRO-MK2 and HCCPR HAD-CM3. The current and the predicted otter distributions were used to identify priority areas for the conservation of the species, and overlapped to existing network of protected areas. Our projections show that climate change may profoundly reshuffle the otter's potential distribution in Europe, with important differences between the two scenarios we considered. Overall, the priority areas for conservation of the otter in Europe appear to be unevenly covered by the existing network of protected areas, with the current conservation efforts being insufficient in most cases. For a better conservation, the existing protected areas should be integrated within a more general conservation and management strategy incorporating climate change projections. Due to the important role that the otter plays for freshwater habitats, our study further highlights the potential sensitivity of freshwater habitats in Europe to climate change.

How robust are global conservation priorities to climate change?

International conservation organisations have identified priority areas for biodiversity conservation. These global-scale prioritisations affect the distribution of funds for conservation interventions. As each organisation has a different focus, each prioritisation scheme is determined by different decision criteria and the resultant priority areas vary considerably. However, little is known about how the priority areas will respond to the impacts of climate change. In this paper, we examined the robustness of eight global-scale prioritisations to climate change under various climate predictions from seven global circulation models. We developed a novel metric of the climate stability for 803 ecoregions based on a recently introduced method to estimate the overlap of climate envelopes. The relationships between the decision criteria and the robustness of the global prioritisation schemes were statistically examined. We found that decision criteria related to level of endemism and landscape fragmentation were strongly correlated with areas predicted to be robust to a changing climate. Hence, policies that prioritise intact areas due to the likely cost efficiency, and assumptions related to the potential to mitigate the impacts of climate change, require further examination. Our findings will help determine where additional management is required to enable biodiversity to adapt to the impacts of climate change

Climate change, anthropogenic disturbance and the northward range expansion of Lactuca serriola (Asteraceae)

The distribution range of Lactuca serriola, a species native to the summer-dry mediterranean climate, has expanded northwards during the last 250 years. This paper assesses the influence of climate on the range expansion of this species and highlights the importance of anthropogenic disturbance to its spread. Location Central and Northern Europe. Methods Data on the geographic distribution of L. serriola were assembled through a literature search as well as through floristic and herbarium surveys. Maps of the spread of L. serriola in Central and Northern Europe were prepared based on herbarium data. The spread was assessed more precisely in Germany, Austria and Great Britain by pooling herbarium and literature data. We modelled the bioclimatic niche of the species using occurrence and climatic data covering the last century to generate projections of suitable habitats under the climatic conditions of five time periods. We tested whether the observed distribution of L. serriola could be explained for each time period, assuming that the climatic niche of the species was conserved across time. Results The species has spread northwards since the beginning of the 19th century. We show that climate warming in Europe increased the number of sites suitable for the species at northern latitudes. Until the late 1970s, the distribution of the species corresponded to the climatically suitable sites available. For the last two decades, however, we could not show any significant relationship between the increase in suitable sites and the distributional range change of L. serriola. However, we highlight potential areas the species could spread to in the future (Great Britain, southern Scandinavia and the Swedish coast). It is predominantly non-climatic influences of global change that have contributed to its rapid spread. Main conclusions The observation that colonizing species are not filling their climatically suitable range might imply that, potentially, other ruderal species could expand far beyond their current range. Our work highlights the importance of historical floristic and herbarium data for understanding the expansion of a species. Such historical distributional data can provide valuable information for those planning the management of contemporary environmental problems, such as species responses to environmental change.

Tree line shifts in the Swiss Alps: Climate change or land abandonment?

Questions: Did the forest area in the Swiss Alps increase between 1985 and 1997? Does the forest expansion near the tree line represent an invasion into abandoned grasslands (ingrowth) or a true upward shift of the local tree line? What land cover / land use classes did primarily regenerate to forest, and what forest structural types did primarily regenerate? And, what are possible drivers of forest regeneration in the tree line ecotone, climate and/or land use change? Location: Swiss Alps. Methods: Forest expansion was quantified using data from the repeated Swiss land use statistics GEOSTAT. A moving window algorithm was developed to distinguish between forest ingrowth and upward shift. To test a possible climate change influence, the resulting upward shifts were compared to a potential regional tree line. Results: A significant increase of forest cover was found between 1650 to and 2450 m. Above 1650 m, 10% of the new forest areas were identified as true upward shifts whereas 90% represented ingrowth, and we identified both land use and climate change as likely drivers. Most upward shift activities were found to occur within a band of 300 m below the potential regional tree line, indicating land use as the most likely driver. Only 4% of the upward shifts were identified to rise above the potential regional tree line, thus indicating climate change. Conclusions: Land abandonment was the most dominant driver for the establishment of new forest areas, even at the tree line ecotone. However, a small fraction of upwards shift can be attributed to the recent climate warming, a fraction that is likely to increase further if climate continues to warm, and with a longer time-span between warming and measurement of forest cover.

An alternative socio-ecological strategy? International Trade Unions' engagement with climate change

In the context of a global ecological crisis, it is an important move when trade unions turn to environmentalism. Yet, the form that this environmentalism takes is often overlooked. This is especially the case with international trade unions. Based on an empirical study of international trade unions' engagement with the climate change issue, this article argues that international trade unions follow three different (and partially conflicting) strategies. I label these strategies as 'deliberative', 'collaborative growth' and 'socialist', and I examine each in turn. I argue that such analysis is important if we want to identify the potential for transforming the social relations of production that are at the root of the current climate crisis, and for identifying an alternative socio-ecological strategy.

21st century climate change: where has all the geomorphology gone?

This Commentary draws together recently published work relating to the relationship between climate change and geomorphology to address the surprising observation that geomorphic work seems to have had little impact upon the work of the Intergovernmental Panel for Climate Change. However, recent papers show that methodological innovation has allowed geomorphological reconstruction over timescales highly relevant to late 20th century and 21st century climate change. In turn, these and other developments are allowing links to be made between climatic variability and geomorphology, to begin to predict geomorphic futures and also to appreciate the role that geomorphic processes play in the flux of carbon and the carbon cycle.

Movement, impacts and management of plant distributions in response to climate change: insights from invasions

A major challenge in this era of rapid climate change is to predict changes in species distributions and their impacts on ecosystems, and, if necessary, to recommend management strategies for maintenance of biodiversity or ecosystem services. Biological invasions, studied in most biomes of the world, can provide useful analogs for some of the ecological consequences of species distribution shifts in response to climate change. Invasions illustrate the adaptive and interactive responses that can occur when species are confronted with new environmental conditions. Invasion ecology complements climate change research and provides insights into the following questions: i) how will species distributions respond to climate change? ii) how will species movement affect recipient ecosystems? and iii) should we, and if so how can we, manage species and ecosystems in the face of climate change? Invasion ecology demonstrates that a trait-based approach can help to predict spread speeds and impacts on ecosystems, and has the potential to predict climate change impacts on species ranges and recipient ecosystems. However, there is a need to analyse traits in the context of life-history and demography, the stage in the colonisation process (e.g., spread, establishment or impact), the distribution of suitable habitats in the landscape, and the novel abiotic and biotic conditions under which those traits are expressed. As is the case with climate change, invasion ecology is embedded within complex societal goals. Both disciplines converge on similar questions of "when to intervene?" and "what to do?" which call for a better understanding of the ecological processes and social values associated with changing ecosystems.

Late Early Triassic climate change: Insights from carbonate carbon isotopes, sedimentary evolution and ammonoid paleobiogeography

The late Early Triassic sedimentary-facies evolution and carbonate carbon-isotope marine record (delta(13)C(carb)) of ammonoid-rich, outer platform settings show striking similarities between the South ChinaBlock (SCB) and the widely distant Northern Indian Margin (NIM). The studied sections are located within the Triassic Tethys Himalayan belt (Losar section, Himachal Pradesh, India) and the Nanpanjiang Basin in the South China Block (Jinya section, Guangxi Province), respectively. Carbon isotopes from the studied sections confirm the previously observed carbon cycle perturbations at a time of major paleoceanographic changes in the wake of the end-Permian biotic crisis. This study documents the coincidence between a sharp increase in the carbon isotope composition and the worldwide ammonoid evolutionary turnover (extinction followed by a radiation) occurring around the Smithian-Spathian boundary. Based on recent modeling studies on ammonoid paleobiogeography and taxonomic diversity, we demonstrate that the late Early Triassic (Smithian and Spathian) was a time of a major climate change. More precisely, the end Smithian climate can be characterized by a warm and equable climate underlined by a flat, pole-to-equator, sea surface temperature (SST) gradient, while the steep Spathian SST gradient suggests latitudinally differentiated climatic conditions. Moreover, sedimentary evidence suggests a transition from a humid and hot climate during the Smithian to a dryer climate from the Spathian onwards. By analogy with comparable carbon isotope perturbations in the Late Devonian, Jurassic and Cretaceous we propose that high atmospheric CO(2) levels could have been responsible for the observed carbon cycle disturbance at the Smithian-Spathian boundary. We suggest that the end Smithian ammonoid extinction has been essentially caused by a warm and equable climate related to an increased CO(2) flux possibly originating from a short eruptive event of the Siberian igneous province. This increase in atmospheric CO(2) concentrations could have additionally reduced the marine calcium carbonate oversaturation and weakened the calcification potential of marine organisms, including ammonoids, in late Smithian oceans. (c) 2006 Elsevier B.V. All rights reserved.

Predicted effect of climate change on the invasibility and distribution of the Western corn root-worm

1 Insect pests, biological invasions and climate change are considered to representmajor threats to biodiversity, ecosystem functioning, agriculture and forestry.Deriving hypothesis of contemporary and/or future potential distributions of insectpests and invasive species is becoming an important tool for predicting the spatialstructure of potential threats.2 The western corn rootworm (WCR) Diabrotica virgifera virgifera LeConte is apest of maize in North America that has invaded Europe in recent years, resultingin economic costs in terms of maize yields in both continents. The present studyaimed to estimate the dynamics of potential areas of invasion by the WCR under aclimate change scenario in the Northern Hemisphere. The areas at risk under thisscenario were assessed by comparing, using complementary approaches, the spatialprojections of current and future areas of climatic favourability of the WCR. Spatialhypothesis were generated with respect to the presence records in the native rangeof the WCR and physiological thresholds from previous empirical studies.3 We used a previously developed protocol specifically designed to estimatethe climatic favourability of the WCR. We selected the most biologicallyrelevant climatic predictors and then used multidimensional envelope (MDE) andMahalanobis distances (MD) approaches to derive potential distributions for currentand future climatic conditions.4 The results obtained showed a northward advancement of the upper physiologicallimit as a result of climate change, which might increase the strength of outbreaksat higher latitudes. In addition, both MDE and MD outputs predict the stability ofclimatic favourability for the WCR in the core of the already invaded area in Europe,which suggests that this zone would continue to experience damage from this pestin Europe.