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Aim: Species interactions are predicted to become stronger toward low latitudes and elevations, and these predictions have been supported in large experiments measuring daily predation rates on early life‐stages. However, the overall strength and importance of predation depend on both the daily risk of being attacked and how long prey are exposed, and gradients in exposure time are rarely quantified. Here, we test whether time‐to‐germination, which determines seeds' exposure to post‐dispersal attack, is faster in high‐predation environments: low latitudes, low elevations, and warmer wetter climates. Location: Global data synthesis. Taxon: Angiosperms. Methods: We synthesized data on time‐to‐germination from 1410 plant species spanning 118° latitude. We divided data by study environment (lab, greenhouse, garden, nature), as we predicted different patterns depending on whether seeds experienced only intrinsic versus intrinsic + extrinsic germination cues. We tested how mean days‐to‐germination varied with geography (latitude, elevation) and climate (annual mean and seasonality of temperature and precipitation). We also explored whether patterns could be explained by seed size or phylogeny, which vary latitudinally. Results: Seeds germinated faster toward higher latitudes across study environments but slower toward higher elevations when experiencing intrinsic + extrinsic germination cues (in nature). Germination was faster in drier, more seasonal and—when tested in nature—warmer environments. Seed size explained some latitudinal variation in time‐to‐germination, whereas accounting for phylogeny did not improve predictions. Germination was slower in natural versus lab environments. Main Conclusions: We found little evidence that seeds have commonly evolved faster germination in high‐predation environments. While time‐to‐germination varied with geography and climate, patterns were inconsistent among predictors, and were weaker than those reported for daily seed predation rates. Detected gradients in time‐to‐germination would partially counter elevational gradients in daily seed predation rates but exacerbate latitudinal gradients in predation rates, such that tropical seeds likely experience much stronger lifetime predation risk than high‐latitude seeds. [ABSTRACT FROM AUTHOR]

Aim: Altitudinal and latitudinal treeline ecotones have not consistently responded to climate warming in the direction and/or magnitude predicted by climate alone, suggesting that non‐climatic mechanisms (e.g. biotic interactions) also mediate treeline range dynamics. Through a collaborative research approach, we assessed environmental conditions associated with pre‐dispersal insect cone granivory and how this biotic interaction may govern the reproductive potential, and therefore range dynamics, of spruce‐dominated treelines across northern Canada. Location: In all, 10 boreal forest treelines, tundra and alpine, from Yukon to Newfoundland and Labrador, Canada. Taxa: White spruce (Picea glauca [Moench] Voss), Black spruce (Picea mariana [Mill.] B.S.P.), Strobilomyia spp., Megastigmus spp. Methods: Treeline sites were assessed for presence and magnitude of pre‐dispersal seed granivory by insects along with viable seed availability. We quantified stand density metrics, organic layer depth and understorey vegetation composition at each location and, subsequently, incorporated those variables into generalized linear mixed models to establish predictors of granivory magnitude and viability of available seed. Results: Insect granivory was widespread across sites; however, site‐specific patterns of granivory were associated with increased moss cover and decreased shrub cover and stand density. While all black spruce‐dominated sites exhibited seed viability rates > 50%, the number of seeds produced per cone varied, suggesting that within‐site abiotic conditions and biotic interaction pressures limit successful colonization of novel environments in advance of seed dispersal. Main Conclusions: The modelled relationships between granivory, seed viability and environmental conditions represent an essential step towards generalizing how and when biotic interactions across subarctic treelines influence boreal tree range dynamics before seed dispersal. Connections between granivory magnitude and site‐level treeline characteristics (e.g. stand density, understorey vegetation) will provide a more comprehensive understanding of treeline range dynamics under continued climate change. [ABSTRACT FROM AUTHOR]

Aim: Abundances of animals vary according to species‐specific habitat selection, but habitats are undergoing rapid change in response to anthropogenic alterations of land use and climate. The long‐term decline of snowfall is one of the most dramatic abiotic changes in boreal regions, with potential to alter species communities and shape future ecosystems. However, the effects of snow cover on habitat‐specific abundances remain unclear for many taxa. Here we explore whether long‐term declines in snow cover affect the abundances of overwintering birds. Taxon Fifty bird species. Location: Finland, Northern Europe. Methods: We used generalized linear mixed models to analyse citizen‐led monitoring data from 196 transects over a 32‐year period to assess whether abundances of birds have changed in built‐up areas, farmlands and forests, and whether these covary with warming temperatures and decreasing snow. We then explored if changes in abundance can be explained by body mass, migration strategy or feeding guilds of the species. Results: Over the study period, the abundance of overwintering birds increased. This increase was most pronounced in farmlands (69.6%), where abundances were positively associated with decreasing snow depth. On the other hand, while abundances in built‐up habitats (19.5%) decreased over the study period, they increased in periods of high snow depths. Finally, we found that the short‐distance migration strategy explains changes in bird abundances with snow. In farmlands, ground feeding birds and heavier birds also show a positive trends in abundance with decreasing snow depths. Main conclusions: Local snow conditions are driving habitat selection of birds in the winter; birds in farmlands were most responsive to a decrease in snow depth. Changing snow depths can affect bird movements across habitats in the winter, but also influence migratory patterns and range shifts of species. [ABSTRACT FROM AUTHOR]

Aim: The climate variability hypothesis (CVH) predicts that locations with reduced seasonal temperature variation select for species with narrower thermal ranges. Here we (a) test the CVH by assessing the effect of latitude and elevation on the thermal ranges of Andean vascular plant species and communities, and (b) assess tropical alpine plants vulnerability to warming based on their thermal traits. Location: High tropical Andes. Taxon: Vascular plants. Methods: Temperature data for 505 vascular plant species from alpine communities on 49 summits, were extracted from 29,627 georeferenced occurrences. Species thermal niche traits (TNTs) were estimated using bootstrapping for: minimum temperature, optimum (mean) temperature and breadth (maximum‐minimum). Plant community‐weighted scores were estimated using the TNTs of their constituent species. CVH was tested for species, biogeographical species groups and communities. Vulnerability to global warming was assessed for species, biogeographical species groups and communities. Results: Species restricted to the equator showed narrower thermal niche breadth than species whose ranges stretch far from the equator, however, no difference in niche breadth was found across summits' elevation. Biogeographical species groups distributed close to the equator and restricted to alpine regions showed narrower niche breadth than those with broader ranges. Community‐weighted scores of thermal niche breadth were positively related to distance from equator but not to elevation. Based on their TNTs, species restricted to equatorial latitudes and plant communities dominated by these species were identified as the most vulnerable to the projected 1.5°C warming, due to a potentially higher risk of losing thermal niche space. Main conclusions: Our study confirms that the CVH applies to high tropical Andean plant species and communities, where latitude has a strong effect on the thermal niche breadth. TNTs are identified as suitable indicators of species' vulnerability to warming and are suggested to be included in long‐term biodiversity monitoring in the Andes. [ABSTRACT FROM AUTHOR]

Abstract: Aim: Reconstruct the long‐term ecosystem dynamics of the region across an elevational gradient as they relate to climate and local controls. In particular, we (1) describe the dominant conifers' history; (2) assess changes in vegetation composition and distribution; and (3) note periods of abrupt change versus stability as means of better understanding vegetation responses to environmental variability. Location: Greater Yellowstone Ecosystem (GYE; USA). Time period: 16.5 ka bp‐present. Major taxa studied: Juniperus, Picea, Abies, Pinus, Pseudotsuga. Methods: The vegetation reconstruction was developed from 15 pollen records. Results were interpreted based on modern pollen–vegetation relationships estimated from a suite of regression‐based approaches. Results: Calibrated pollen data suggest that late‐glacial vegetation, dominated by shrubs and Juniperus, lacks a modern counterpart in the area. Picea, Abies and Pinus expanded at 16 ka bp in association with postglacial warming and co‐occurred in mixed‐conifer parkland/forest after 12 ka bp. This association along with Pinus contorta forest, which was present after 9 ka bp, has persisted with little change at middle and high elevations to the present day. This stability contrasts with the dynamic history of plant communities at low elevations, where shifts between parkland, steppe and forest over the last 8,000 years were likely driven by variations in effective moisture and fire. Main conclusions: The postglacial vegetation history of the GYE highlights the dynamic nature of mountain ecosystems and informs on their vulnerability to future climate change: (1) most of the conifers have been present in the area for >12,000 years and survived climate change by adjusting their elevational ranges; (2) some plant associations have exhibited stability over millennia as a result of nonclimatic controls; and (3) present‐day forest cover is elevationally more compressed than at any time in history, probably due to the legacy of the Medieval Climate Anomaly and the Little Ice Age. [ABSTRACT FROM AUTHOR]

Abstract: Aims: It has been assumed that montane species will undergo upslope shifts in response to climate warming and their range sizes are therefore predicted to decrease. However, this view has been challenged because a recent study (Elsen & Tingley, ) indicated that land surface area increases with increasing altitude in some mountains. To test this prediction, we used one of the world's biodiversity hotspots as a study system to examine overall patterns of plant distribution shift in response to climate warming. Location: The Hengduan Mountains and adjacent regions. Methods: Based on distribution data for 151 species at a resolution of 2.5 arc minutes, we employed ecological niche modelling to model their distributions under the climatic conditions of the Last Glacial Maximum, Current (2017), and 2050 separately. We examined the distributional shifts of these species, especially with respect to altitude and range size, in response to two periods of stepwise climate warming. Results: All the montane plants sampled shifted upward during the two warming stages, but not only northward, some shifted westward or in other directions. In contrast with the expected consistent loss of range when shifting upward, 63.6% of the plants expanded their range size continuously since the LGM. Only 11.9% of the plants contracted their range size continuously from the LGM to 2050. Estimates of species richness in the regions studied changed greatly, but in an unbalanced manner, from the LGM to the Current and from the Current to 2050. Main conclusions: Numerous montane plants in the Hengduan Mountains are predicted to expand their range sizes as they shift upslope in response to climate warming. Our results highlight the possibility that more available land surface area due to the heterogeneous topography along altitudinal gradients and the adjacent large Qinghai‐Tibet Plateau sensu stricto can mediate the range loss of the montane plants under climate warming. These findings are crucial for estimating the future range sizes of plants and planning biodiversity protection for mountain ecosystems under the anticipated warming of the world's climate. [ABSTRACT FROM AUTHOR]

Aim To describe the distribution of two congeneric species of cave-dwelling spiders under current climatic conditions and future warming scenarios, keeping into account their bioclimatic requirements, dispersal capacity and competition dynamics. Location Europe and North Africa. Methods We gathered detailed occurrence data for Meta menardi and M. bourneti (Araneae: Tetragnathidae) and modelled their distribution across their bioclimatic range. We evaluated the breadth of the bioclimatic niche of the two species and assessed the potential overlap between their multidimensional Hutchinsonian hypervolumes. We compared these results with their current distribution maps obtained by species distribution modelling (SDMs) keeping into account dispersal and competition dynamics, and we projected future trends of distribution according to different climatic scenarios. Results The overall size of the niche hypervolumes of the two species was very similar and highly overlapping. However, when accounting for competition in the model, the predicted ranges of the two species showed only minor areas of overlap. On the base of SDM analysis, we predicted a significant poleward shift in the distribution of both species, with the appearance of a new contact area especially in Central Europe, southern UK, France and northern Spain. Main conclusions Interspecific competition keeps the current ranges of the two European Meta species apart, although their fundamental bioclimatic niches are very similar. Rapid poleward shifts of the two species are likely due to the high dispersal capacity of the two spiders. The case of Meta spiders exemplifies rapid shift in range of distribution associated with global warming, which are unlikely to occur in the case of most cave-dwelling arthropods. [ABSTRACT FROM AUTHOR]

Aim Palaeoecological reconstructions document past vegetation change, with estimates of fast shifts in species distributions. The resulting rates of plant spread are often not matched by model simulations of climate-driven vegetation dynamics. Genetic surveys of extant plant populations document directions of the post-glacial spread of trees, challenging traditional interpretations. Our aim is to examine an updated continental pollen data set from Europe in the light of the new ideas about vegetation dynamics emerging from genetic research and vegetation modelling studies. Location Europe. Methods We use pollen data from the European Pollen Database ( EPD) to construct interpolated maps of pollen percentages documenting changes in the distribution and abundance of major plant genera and the grass family in Europe over the last 15,000 years. Results Our analyses confirm high rates of post-glacial spread with at least 1000 m year−1 for Corylus, Ulmus and Alnus and average rates of 400 m year−1 for Tilia, Quercus, Fagus and Carpinus. The late Holocene expansions of Picea and Fagus populations in many European regions cannot be explained by migrational lag. Both taxa shift their population centres towards the Atlantic coast suggesting that climate may have played a role in the timing of their expansions. The slowest rates of spread were reconstructed for Abies. Main conclusions The calculated rates of post-glacial plant spread are higher in Europe than those from North America, which may be due to more rapid shifts in climate mediated by the Gulf Stream and westerly winds. Late Holocene anthropogenic land use practices in Europe had major effects on individual taxa, which in combination with climate change contributed to shifts in areas of abundance and dominance. The high rates of spread calculated from the European pollen data are consistent with rapid tracking of early Holocene climate change by common tree species, documenting that plants can spread fast tracing their climate space, regardless of their dispersal strategy. [ABSTRACT FROM AUTHOR]

Aim To assess the extent of the possible future conflict between skiing and biodiversity driven by climate change, human adaptation and species' distribution shifts. Location Italian Alps. Methods We assessed the extent of the possible future conflict between skiing and biodiversity by predicting locations likely to be suitable for both skiing and for high-elevation birds in the Italian Alps by modelling ski-piste and species presence in relation to climate, topography and habitat. Potential conflict was assessed by comparing the overlap of areas projected as suitable for skiing and those suitable for four high-elevation bird species under different scenarios of climate change for the year 2050. Results Areas suitable for both ski-pistes and birds were projected to contract towards upper elevations, which for birds resulted in an average decrease of 58-67% of suitable area. The degree of overlap between species and skiing was projected to increase, especially for the most valuable sites, that is, those hosting the most species, or the most threatened species. Main conclusions Given the alarming range contractions forecast for high-elevation species, and the potential impact of ski-pistes on those species, it is essential to safeguard high-mountain grasslands against negative effects of ski development. An effective conservation strategy at a landscape scale needs to consider prevention of ski-piste construction in sites of high conservation value. The approach developed here provides a means by which such a strategy could be formulated, and which could be potentially applied elsewhere to investigate the effect of human adaptation on biodiversity. [ABSTRACT FROM AUTHOR]

Aim The American pika ( Ochotona princeps) appears to have experienced climate-mediated upslope range contraction in the Great Basin of North America, but this result has not yet been extended to other portions of the pika's range. Our goals were: first, to determine the environmental parameters that most influence current pika distribution within California; second, to infer whether these constraints explain extirpations that have occurred in California; third, to predict future extirpations; and fourth, to advance methods for assessing the degree to which pikas and other climate-sensitive mammals are threatened by climate change. Location Historical pika record locations in California, USA, spanning four degrees of latitude and longitude, from Mount Shasta to the southern Sierra Nevada. Methods We identified 67 precise historical pika record locations and surveyed them exhaustively, over multiple years, to determine whether pika populations persist at those sites. We used an information theoretic approach and logistic regression to model current pika occupancy as a function of 16 environmental variables, tested our best-performing model as a predictor of historical occupancy, and then used our model to predict future pika occupancy given anticipated climate change. Results Pikas no longer occurred at 10 of 67 (15%) historical sites in California. The best predictors of occupancy were average summer temperature and talus habitat area within a 1-km radius. A logistic model fitted to this relationship correctly predicted current occupancy at 94% of sites and correctly hindcasted past occupancy at 93% of sites, suggesting that the model has strong temporal transferability. Depending on the future climate scenario, our model projects that by 2070 pikas will be extirpated from 39% to 88% of these historical sites in California. Main conclusions Our simple species distribution model for pikas performs remarkably well for both current and historical periods. Pika distribution appears to be governed primarily by behavioural restrictions mediated by summer temperature and by the configuration of talus habitat available to pikas locally. Pikas, and other montane species in the western USA, may be subjected to above-average exposure to climate change because summer temperature is projected to rise more than annual temperature. [ABSTRACT FROM AUTHOR]

Aim We analyse the taxonomic status, phylogenetic relationships, distribution and age of a newly discovered ant taxon found in the mountaintops of the island of Mallorca (Spain). We also consider the potential impact of short-term climate change on the survival of this ant and make proposals on its conservation status, risks and management. Location Balearic Islands (Spain). Methods We used morphological, molecular and ecological evidence to assess the specific status of the potential new species. We gathered distribution data to conduct climate-based distribution modelling of present and future occupancy under several SRES emission scenarios. Results The existence of a new non-cryptic species of ant (Lasius balearicus Talavera, Espadaler & Vila, sp. nov.) is described from the island of Mallorca. Its distribution was found to be extremely restricted (Serra de Tramuntana) and elevationally constrained to island summits (between 800 and 1400 m a.s.l.). Molecular dating indicated that this species diverged about 1.51 million years ago from its nearest relatives, from which it can be distinguished based on several morphological traits. Ecological niche modelling shows a dramatic reduction of areas with suitable climatic conditions under the different scenarios studied. Main conclusions Lasius balearicus represents the first endemic ant to be described in the Balearic Islands, as well as the first endemic Lasius species in the Mediterranean islands. Distribution modelling predictions, the low intraspecific genetic diversity observed, and the geographical and elevational isolation of the populations indicated a low probability for the survival of the species in the short term, thus making it a potential model to study real-time climate-based biodiversity loss. As a consequence, we strongly recommend including L. balearicus in the IUCN Red List of Threatened Species under the category 'Endangered'. This case illustrates that a fraction of biodiversity remains unexplored even within Europe, arguably the best-studied region of the planet, and that the available time-window for us to study and protect it may be in some instances notably narrow. [ABSTRACT FROM AUTHOR]