Shifts In Species Distributions Research Articles

Will borealization of Arctic tundra herbivore communities be driven by climate warming or vegetation change?

Poleward shifts in species distributions are expected and frequently observed with a warming climate. In Arctic ecosystems, the strong warming trends are associated with increasing greenness and shrubification. Vertebrate herbivores have the potential to limit greening and shrub advance and expansion on the tundra, posing the question of whether changes in herbivore communities could partly mediate the impacts of climate warming on Arctic tundra. Therefore, future changes in the herbivore community in the Arctic tundra will depend on whether the community tracks the changing climates directly (i.e. occurs in response to temperature) or indirectly, in response to vegetation changes (which can be modified by trophic interactions). In this study, we used biogeographic and remotely sensed data to quantify spatial variation in vertebrate herbivore communities across the boreal forest and Arctic tundra biomes. We then tested whether present-day herbivore community structure is determined primarily by temperature or vegetation. We demonstrate that vertebrate herbivore communities are significantly more diverse in the boreal forest than in the Arctic tundra in terms of species richness, phylogenetic diversity and functional diversity. A clear shift in community structure was observed at the biome boundary, with stronger northward declines in diversity in the Arctic tundra. Interestingly, important functional traits characterizing the role of herbivores in limiting tundra vegetation change, such as body mass and woody plant feeding, did not show threshold changes across the biome boundary. Temperature was a more important determinant of herbivore community structure across these biomes than vegetation productivity or woody plant cover. Thus, our study does not support the premise that herbivore-driven limitation of Arctic tundra shrubification or greening would limit herbivore community change in the tundra. Instead, borealization of tundra herbivore communities is likely to result from the direct effect of climate warming.

Climate change projections suggest severe decreases in the geographic ranges of bird species restricted to Mexican humid mountain forests

Climate change-driven modifications in thermal and precipitation patterns can result in shifts in species distributions. Avian species in humid mountain forests (HMF) are among the most vulnerable to these atmospheric changes. In this study, we assessed the extent to which climate change could cause distribution shifts in 34 bird species spatially restricted to HMF ecosystems in Mexico. In addition, we analyzed the representation of the species in protected areas (PAs) and the extension these areas covered in the entire range of each species. Species distribution models (SDMs) were generated using Maxent algorithm. Future SDM scenarios were considered using two scenarios: The Interdisciplinary Climate Research Model (MIROC5) and The Community Climate System Model (CCSM4) with a single representative concentration pathway (RCP6.0). We found that by 2050, under MIROC5, modeled species distributions showed an average reduction of 34%, and under CCSM4, a decrease of 40%. By 2070, MIROC5 showed an average a reduction of 51% and under CCSM4 of 54%. SDMs for 20 species overlapped with protected areas (PA), although nine species would reduce their presence in the PAs by 2050 under MIROC5 and 11 under CCSM4. By 2070, 11 and 12 species respectively for both scenarios, would reduce their distribution range in the PAs. More than 94% of the bird species considered, have less than 10% of their distribution in PAs in the current and future scenarios. The species distribution models of 14 species, particularly those of small range, showed no overlap with any PA under the current or future scenarios. To ensure that HMF endemic bird species are represented in different protected areas in the future, conservation schemes such as protected social and community areas and biological corridors could be valuable in ensuring the conservation of endemic birds in the long-term, especially in those regions underrepresented by PAs.

Climate Change Impacts the Protective Effect of Forests: A Case Study in Switzerland

In steep terrain, forests play an important role as natural means of protection against natural hazards, such as rockfall. Due to climate warming, significant changes in the protection service of these forests have to be expected in future. Shifts of current to more drought adapted species may result in temporary or even irreversible losses in the reduction of rockfall risk provided by these forests. In this study, we assessed how the protective capacity against rockfall of a protection forest in the western part of the Valais in the Swiss Alps may change in future, by combining dynamic forest modelling with a quantitative risk analysis. Current and future forest development was modelled with the spatially explicit forest model TreeMig under a moderate (RCP4.5) and an extreme (RCP8.5) climate change scenario. The simulated forest scenarios were compared to ground-truth data from the current forest complex. We quantified the protective effect of the different forest scenarios based on the reduction of rockfall risk for people and infrastructure at the bottom of the slope. Rockfall risk was calculated on the basis of three-dimensional rockfall simulations. The forest simulations predicted a clear decrease in basal area of most of the currently occuring species (Fagus sylvatica, Picea abies, Larix decidua, and Abies alba) in future. The forest turned into a Quercus pubescens dominated forest, for both climate scenarios, mixed with Pinus sylvestris under RCP4.5. With climate warming, a clear increase in risk is expected for both climate change scenarios. In the long-term (>100 years), a stabilization of risk, or even a slight decline may be expected due to an increase in biomass of the trees. The results of this study further indicate that regular forest interventions may promote regeneration and thus accelerate the shift in species distribution. Future research should explore into more details the long-term effect of different adaptive forest management strategies on the protection service of forests under climate change.

First circumpolar assessment of Arctic freshwater phytoplankton and zooplankton diversity: Spatial patterns and environmental factors

Abstract Arctic freshwaters are facing multiple environmental pressures, including rapid climate change and increasing land___use activities. Freshwater plankton assemblages are expected to reflect the effects of these stressors through shifts in species distributions and changes to biodiversity. These changes may occur rapidly due to the short generation times and high dispersal capabilities of both phyto___ and zooplankton. Spatial patterns and contemporary trends in plankton diversity throughout the circumpolar region were assessed using data from more than 300 lakes in the U.S.A. (Alaska), Canada, Greenland, Iceland, the Faroe Islands, Norway, Sweden, Finland, and Russia. The main objectives of this study were: (1) to assess spatial patterns of plankton diversity focusing on pelagic communities; (2) to assess dominant component of __ diversity (turnover or nestedness); (3) to identify which environmental factors best explain diversity; and (4) to provide recommendations for future monitoring and assessment of freshwater plankton communities across the Arctic region. Phytoplankton and crustacean zooplankton diversity varied substantially across the Arctic and was positively related to summer air temperature. However, for zooplankton, the positive correlation between summer temperature and species numbers decreased with increasing latitude. Taxonomic richness was lower in the high Arctic compared to the sub___ and low Arctic for zooplankton but this pattern was less clear for phytoplankton. Fennoscandia and inland regions of Russia represented hotspots for, respectively, phytoplankton and zooplankton diversity, whereas isolated regions had lower taxonomic richness. Ecoregions with high __ diversity generally also had high __ diversity, and turnover was the most important component of __ diversity in all ecoregions. For both phytoplankton and zooplankton, climatic variables were the most important environmental factors influencing diversity patterns, consistent with previous studies that examined shorter temperature gradients. However, barriers to dispersal may have also played a role in limiting diversity on islands. A better understanding of how diversity patterns are determined by colonisation history, environmental variables, and biotic interactions requires more monitoring data with locations dispersed evenly across the circumpolar Arctic. Furthermore, the importance of turnover in regional diversity patterns indicates that more extensive sampling is required to fully characterise the species pool of Arctic lakes.

The effects of climate, oceanography, and habitat on the distribution and abundance of northern California Current continental shelf groundfishes

AbstractThe California Current Ecosystem has experienced variable climate regimes, hypoxia, and marine heatwave events that have the potential to impact groundfishes and their associated fisheries. Using bottom trawl survey data collected by NOAA Fisheries, we assessed changes over the last four decades in northern California Current continental shelf (≤200 m) groundfish assemblage composition, species' presence, and relationships to environmental and habitat variables. We focus on the currently understudied continental shelf area, due to its ecological and economic importance, especially after the recent opening of historically important areas to trawling. We found a temporally consistent separation in groundfish assemblages between depth zones based on NMS analysis using species found in over 1% of samples, with shallow, mid‐, and deep shelf groupings. Grain size, species richness, and diversity were associated with assemblage composition. Then, focusing on petrale sole, rex sole, lingcod, arrowtooth flounder, sablefish, English sole, Pacific sanddab, and Dover sole, we examined what factors impact groundfish presence and abundance on the shelf. Bottom temperature, sediment characteristics, and depth were correlated with abundance for all species. These results corroborate previous work indicating recent reductions in presence of hypoxia‐intolerant species. Shallow‐water groundfishes known to tolerate warmer water and low dissolved oxygen concentrations exhibit reductions offshore, possibly a result of low recruitment. There have been significant spatiotemporal changes in the shelf groundfish populations over the past several decades, and while assemblage composition over most of the shelf remains consistent, single species distributional shifts may impact access to target species in newly reopened areas.

How Does Climate Change Affect Emergent Properties of Aquatic Ecosystems?

Emergent properties of ecosystems are community attributes, such as structure and function, that arise from connections and interactions (e.g., predator–prey, competition) among populations, species, or assemblages that, when viewed together, provide a holistic representation that is more than the sum of its individual parts. Climate change is altering emergent properties of aquatic ecosystems through component responses, a combination of shifts in species range, phenology, distribution, and productivity, which lead to novel ecosystems that have no historical analog. The reshuffling, restructuring, and rewiring of aquatic ecosystems due to climate impacts are of high concern for natural resource management and conservation as these changes can lead to species extinctions and reductions in ecosystem services. Overall, we found that substantial progress has been made to advance our understanding of how climate change is affecting emergent properties of aquatic ecosystems. However, responses are incredibly complex, and high uncertainty remains for how systems will reorganize and function over the coming decades. This cross‐system perspective summarizes the state of knowledge of climate‐driven emergent properties in aquatic habitats with case studies that highlight mechanisms of change, observed or anticipated outcomes, as well as insights into confounding non‐climate effects, research tools, and management approaches to advance the field.

Marine Biodiversity Observation Network (MBON): An Observing System for Life in the Sea

Life in the sea provides immense benefits to humans, from the food we eat to the air we breathe to the climate we live in. And because of human activities, the once seemingly vast and inexhaustible seas are changing—increasingly threatened by global-scale impacts, such as warming and acidification, as well as those that are more localized, like overfishing and pollution. Meanwhile, many of the species that live in the sea remain unknown. Even for the known species, our understanding of their roles in the ecosystem is still limited. Now more than ever, increased observation of life in the sea is required to find and describe unknown species, observe shifts in species abundance and distribution, identify adaptability and resilience to climate change, and understand vital roles that species play in our marine systems. New and emerging technologies promise to enable observation over the required temporal and spatial scales. And emerging data systems will allow development of critical ecological understanding, while informing responsible use of marine natural resources. This will lead to continued, sustainable ecosystem services and the benefits we derive from them, benefits that are only possible through conserving biodiversity and managing human actions wisely.

Impact of climate change on alpine plant community in Qilian Mountains of China.

There is growing evidence that mountains are experiencing some of the highest rates of climate warming, but assessment of the ecological impacts of climate change is often limited due to a lack of long-term monitoring data for comparative study in many ecosystems. In this study, we present an empirical work for assessing ecological responses with botanical legacy data in the Qilian Mountains of China. Plot-scale and transect-wide survey was conducted for alpine shrub communities along an elevational gradient 20 years ago. Recently, we resampled the permanent plots to investigate how the community changes may be linked to climatic variability. We found no significant temporal shifts in species richness; but the community structure underwent substantial changes, as indicated by visible shifts in the relative density of dominant shrub species and the frequency of occurrence of understory herbaceous species. This reshuffling of plant community composition reflected a series of complex responses to climate change. Specifically, wet-demanding species have become more frequent due to the recently enhanced precipitation, while the replacement of some low-statured plants with different requirements for light was indirectly regulated by climate warming via reshaping the altitudinal patterns of dominant shrubs. Climate-mediated shifts in shrub species distribution altered the expected evolutional trajectory of alpine community, which increased the complexity and nonlinearity of the responses of the communities at different altitudes to climatic variability. Our results suggested that in-depth knowledge of indirect effects can facilitate to lessen the uncertainty in predicting future community dynamics in a changing climate.

State changes: insights from the U.S. Long Term Ecological Research Network

AbstractUnderstanding the complex and unpredictable ways ecosystems are changing and predicting the state of ecosystems and the services they will provide in the future requires coordinated, long‐term research. This paper is a product of a U.S. National Science Foundation funded Long Term Ecological Research (LTER) network synthesis effort that addressed anticipated changes in future populations and communities. Each LTER site described what their site would look like in 50 or 100 yr based on long‐term patterns and responses to global change drivers in each ecosystem. Common themes emerged and predictions were grouped into state change, connectivity, resilience, time lags, and cascading effects. Here, we report on the “state change” theme, which includes examples from the Georgia Coastal (coastal marsh), Konza Prairie (mesic grassland), Luquillo (tropical forest), Sevilleta (arid grassland), and Virginia Coastal (coastal grassland) sites. Ecological thresholds (the point at which small changes in an environmental driver can produce an abrupt and persistent state change in an ecosystem quality, property, or phenomenon) were most commonly predicted. For example, in coastal ecosystems, sea‐level rise and climate change could convert salt marsh to mangroves and coastal barrier dunes to shrub thicket. Reduced fire frequency has converted grassland to shrubland in mesic prairie, whereas overgrazing combined with drought drive shrub encroachment in arid grasslands. Lastly, tropical cloud forests are susceptible to climate‐induced changes in cloud base altitude leading to shifts in species distributions. Overall, these examples reveal that state change is a likely outcome of global environmental change across a diverse range of ecosystems and highlight the need for long‐term studies to sort out the causes and consequences of state change. The diversity of sites within the LTER network facilitates the emergence of overarching concepts about state changes as an important driver of ecosystem structure, function, services, and futures.

Fur loss syndrome and lice infestations observed on Arctic foxes in central Nunavut, Canada

As temperatures in the circumpolar north continue to warm, shifts in species distribution and the breakdown of environmental barriers for arthropods may impact the diversity and distribution of ectoparasites in Arctic ecosystems. In May 2019, fur loss over the neck and shoulders was observed on Arctic foxes in a terrestrial Arctic ecosystem (Karrak Lake) in central Nunavut, Canada. This was inconsistent with normal patterns of shedding winter fur and had not been observed on Arctic foxes in this population over the previous 19 years of live-trapping. Operculated eggs attached to hair shafts were collected from one affected fox. Conventional PCR using universal louse primers targeting conserved regions of mitochondrial 12S and 16S rDNA confirmed that the eggs belonged to the order Phthiraptera. Sequencing results were inconclusive at the species level. Further investigation revealed a single unpublished report of an Arctic fox with similar fur loss trapped on mainland Nunavut, in 1997. Adult lice collected from this fox were identified as sucking lice (potentially from the genus Linognathus). Our findings emphasize the need for further monitoring and have significant implications for trappers and wildlife management, as infestations negatively impact the pelt quality of these important furbearers.

Contrast of warm and cold phases in the Bering Sea to understand spatial distributions of Arctic and sub-Arctic gadids

The influence of climate on the dynamics of Arctic gadids is of increasing interest, particularly as research and survey effort expands in the Pacific Arctic. Understanding species-specific thermal tolerance may inform models of species distribution and projections of available habitat and also clarify implications of warming for ecological communities. Analyzing shifts in species distribution in warm and cold periods, this study considers the effects of a warming climate on the distribution of two keystone Arctic gadids (polar cod, saffron cod) and two commercially important sub-Arctic gadids (walleye pollock, Pacific cod). Shifts in distribution were used to derive temperature tolerance thresholds and to project how these species might react to a warming Arctic. Significant shifts were noted in comparisons of warm (2002–2005, 2014–2016, 2017–2018) and cold (2006–2013) periods. Sub-Arctic species expanded and contracted their range as environmental conditions shifted. In contrast, Arctic species appeared constrained, such that population densities increased or decreased within the same core geographic area. Additionally, species with a demersal life history were able to tolerate a wider range of thermal conditions. These results provide important insights on relative thermal tolerance of each species, differential influence of temperature on pelagic versus demersal life histories, and depth as thermal refuge. This study demonstrates both the need to understand the spatial response of fish to changing ocean conditions in polar regions and the utility of distributional analyses to inform that effort.

Increased functional diversity warns of ecological transition in the Arctic.

As temperatures rise, motile species start to redistribute to more suitable areas, potentially affecting the persistence of several resident species and altering biodiversity and ecosystem functions. In the Barents Sea, a hotspot for global warming, marine fish from boreal regions have been increasingly found in the more exclusive Arctic region. Here, we show that this shift in species distribution is increasing species richness and evenness, and even more so, the functional diversity of the Arctic. Higher diversity is often interpreted as being positive for ecosystem health and is a target for conservation. However, the increasing trend observed here may be transitory as the traits involved threaten Arctic species via predation and competition. If the pressure from global warming continues to rise, the ensuing loss of Arctic species will result in a reduction in functional diversity.

Physiological determinants of biogeography: The importance of metabolic depression to heat tolerance.

A quantitative understanding of physiological thermal responses is vital for forecasting species distributional shifts in response to climate change. Many studies have focused on metabolic rate as a global metric for analyzing the sublethal effects of changing environments on physiology. Thermal performance curves (TPCs) have been suggested as a viable analytical framework, but standard TPCs may not fully capture physiological responses, due in part to failure to consider the process of metabolic depression. We derived a model based on the nonlinear regression of biological temperature-dependent rate processes and built a heart rate data set for 26 species of intertidal molluscs distributed from 33°S to ~40°N. We then calculated physiological thermal performance limits with continuous heating using , the temperature at which heart rate is decreased to 50% of the maximal rate, as a more realistic measure of upper thermal limits. Results indicate that heat-induced metabolic depression of cardiac performance is a common adaptive response that allows tolerance of harsh environments. Furthermore, our model accounted for the high inter-individual variability in the shape of cardiac TPCs. We then used these TPCs to calculate physiological thermal safety margins (pTSM), the difference between the maximal operative temperature (95th percentile of field temperatures) and of each individual. Using pTSMs, we developed a physiological species distribution model (pSDM) to forecast future geographic distributions. pSDM results indicate that climate-induced species range shifts are potentially less severe than predicted by a simple correlative SDM. Species with metabolic depression below the optimum temperature will be more thermal resistant at their warm trailing edges. High intraspecific variability further suggests that models based on species-level vulnerability to environmental change may be problematic. This multi-scale, mechanistic understanding that incorporates metabolic depression and inter-individual variability in thermal response enables better predictions about the relationship between thermal stress and species distributions.

Rewiring of interactions in a changing environment: nettle‐feeding butterflies and their parasitoids

Climate and land use change can alter the incidence and strength of biotic interactions, with important effects on the distribution, abundance and function of species. To assess the importance of these effects and their dynamics, studies quantifying how biotic interactions change in space and time are needed.We studied interactions between nettle‐feeding butterflies and their shared natural enemies (parasitoids) locally and across 500 km latitudinal gradient in Sweden. We also examined the potential impact of the range‐expansion of the butterfly Araschnia levana on resident butterflies via shared parasitoids, by studying how parasitism in resident butterflies covaries with the presence or absence of the newly‐established species. We collected 6777 larvae of four nettle‐feeding butterfly species (Aglais urticae, Aglais io, Ar. levana and Vanessa atalanta), over two years, at 19 sites distributed along the gradient. We documented the parasitoid complex for each butterfly species and measured their overlap, and analysed how parasitism rates were affected by butterfly species assemblage, variations in abundance, time, and the arrival of Ar. levana. Parasitoids caused high mortality, with substantial overlap in the complex of parasitoids associated with the four host butterflies. Levels of parasitism differed significantly among butterflies and were influenced by the local butterfly species assemblage. Our results also suggest that parasitism in resident butterflies is elevated at sites where Ar. levana has been established for a longer period.In our study system, variations in butterfly species assemblages were associated in a predictable way with substantial variations in rates of parasitism. This relationship is likely to affect the dynamics of the butterfly host species, and potentially cascade to the larger number of species with which they interact. These results highlight the importance of indirect interactions and their potential to reorganise ecological communities, especially in the context of shifts in species distributions in a warmer world.

Climate-Driven Range Shifts Are Rapid Yet Variable Among Recreationally Important Coastal-Pelagic Fishes

Shifts in species distributions are occurring globally in response to climate change, but robust comparisons of redistribution rates among species are often prevented by methodological inconsistencies, challenging the identification of species that are most rapidly undergoing range shifts. In particular, comparable assessments of redistributions among harvested species are essential for identifying climate-driven changes in fishing opportunities and prioritising the development of management strategies. Here we utilise consistent datasets and methodologies to comparably analyse rates of climate-driven range shifts over 21 years for four recreationally important coastal-pelagic fishes (Australian bonito, Australian spotted mackerel, narrow-barred Spanish mackerel, and common dolphinfish) from the eastern Australian ocean warming hotspot. Latitudinal values corresponding to the poleward edge of species’ core oceanographic habitats were extracted from species distribution models (SDMs). Rates of poleward shifts in core oceanographic habitats ranged between 148.7 (i.e., common dolphinfish) and 278.6 (i.e., narrow-barred Spanish mackerel) km per decade over the study period. However, rates of redistribution varied by approximately 130 km per decade among species, demonstrating that subtle differences in species’ environmental responses can manifest in highly variable rates of climate-driven range shifts. These findings highlight the capacity for coastal-pelagic species to undergo rapid, yet variable, poleward range shifts, which have implications for ecosystem structure and the changing availability of key resources to fisheries.

Cod movement ecology in a warming world: Circumpolar arctic gadids

AbstractUnderstanding fish movement in the Arctic is paramount during the current era of rapidly warming seas, receding sea ice and associated shifting species distributions and fishing effort. We synthesized the literature and identified key knowledge gaps on the movement ecology of Arctic cod (Boreogadus saida) and Polar/Ice cod (Arctogadus glacialis, both Gadidae) in the context of climate change. Standardized web‐based English‐language literature searches yielded 51 articles directly relevant and 122 indirectly relevant for the movement ecology of these species combined. Most articles were primarily relevant toB. saida(85% of total filtered articles), occurred during open water season (49/38%) with focus on distribution (32/22%), predators (30/22%), seasonal spawning/feeding movements (22/19%), sea ice association (22/26%), climate change (20/15%) and vertical movements (17/19%) with few focused on horizontal dynamics (3/0%;B. saida/A. glacialis, respectively). Disproportionate data resolution has resulted in greater predictive power of movement models for the European (29% of articles) and North American (86%) Arctic regions relative to the logistically challenging Central Arctic Ocean and Russian‐Siberian Arctic shelves (both 7%). The movements of circumpolar Arctic gadids are dependent on complex dynamics that include regional currents, the longevity of ice‐flows and polynyas, water stratification and coastal hydrology. Dependence on these interactive and often co‐dependent processes highlights major pathways and barriers to movement and distribution at higher latitudes. Despite a recent increase in impactful research, there is a critical need for more direct research on circumpolar gadid movements to aid understanding of climate change impacts on Arctic ecosystems and fisheries.

Past and future potential range changes in one of the last large vertebrates of the Australian continent, the emu Dromaius novaehollandiae

In Australia, significant shifts in species distribution have occurred with the loss of megafauna, changes in indigenous Australian fire regime and land-use changes with European settlement. The emu, one of the last megafaunal species in Australia, has likely undergone substantial distribution changes, particularly near the east coast of Australia where urbanisation is extensive and some populations have declined. We modelled emu distribution across the continental mainland and across the Great Dividing Range region (GDR) of eastern Australia, under historical, present and future climates. We predicted shifts in emu distribution using ensemble modelling, hindcasting and forecasting distribution from current emu occurrence data. Emus have expanded their range northward into central Australia over the 6000 years modelled here. Areas west of the GDR have become more suitable since the mid-Holocene, which was unsuitable then due to high precipitation seasonality. However, the east coast of Australia has become climatically sub-optimal and will remain so for at least 50 years. The north east of NSW encompasses the range of the only listed endangered population, which now occurs at the margins of optimal climatic conditions for emus. Being at the fringe of suitable climatic conditions may put this population at higher risk of further decline from non-climatic anthropogenic disturbances e.g. depredation by introduced foxes and pigs. The limited scientific knowledge about wild emu ecology and biology currently available limits our ability to quantify these risks.

Preliminary Illinois Bee Species Checklist (Hymenoptera: Apoidea) and use of Museum Collections

Climate change and landscape alterations may influence biodiversity by shifting species distributions or causing local extirpations. Museum records are needed in order to track these changes over long periods of time. Bees are a group of organisms known to be in global decline, but tracking regional shifts is difficult. In Illinois, where there have been significant alterations to the landscape, no bee species checklist is available to compare recent collecting efforts. We used museum specimens from Illinois housed at the Illinois Natural History Survey (INHS) at the University of Illinois at Urbana-Champaign, augmented by specimen records from other museums, to investigate the use of museum collections to identify species occurrences and possible declines. The result is a preliminary state checklist of 491 species of bee, with an additional 51 records considered either doubtful or possible but needing confirmation. We report 74 confirmed new state records compared to records housed at INHS, with five additional species considered doubtful and four possible but needing confirmation. Three putatively undescribed species include two Andrena species and one Lasioglossum (Dialictus) species, although further verification is needed to resolve their status. Continued support for natural history collections and the institutions that maintain them is essential for further research on the impacts to ecosystems caused by human and natural influences and to identify areas and species in need of conservation.

Genetic and demographic trends from rear to leading edge are explained by climate and forest cover in a cold‐adapted ectotherm

AbstractAimDetermining whether altitudinal shifts in species distributions leave molecular footprints on wild populations along their range margins from rear to leading edge.LocationSouth‐west France.MethodsWe compared the demographic and genetic variation in 42 wild populations of the Western oviparous subclade B2 of a cold‐adapted lizard (Zootoca vivipara louislantzi). These populations can be divided into four ecological units across altitudinal clines in South‐west France (rear edge: <100 m, admixture zone: 100–500 m, continuous range: 500–1,300 m and leading edge: >1,300 m above sea level).ResultsWithin the rear edge were found the highest levels of inbreeding, genetic differentiation and evidence of interrupted gene flow compared to central or colonizing areas. Within the leading edge, altitudinal range expansion occurred over the last centuries and populations showed relatively low genetic diversity. These demographic and genetic trends were better explained by inhospitable (warm and dry) climate conditions and forest cover.Main conclusionsThis empirical evidence illustrates that molecular footprints of climate conditions and habitat quality on wild population trends can be perceived after recent events, which should be of particular importance to accurately understand and anticipate human‐induced global change on wild species and ecosystems.

Transporting Biodiversity Using Transmission Power Lines as Stepping-Stones?

The most common ecological response to climate change is the shifts in species distribution ranges. Nevertheless, landscape fragmentation compromises the ability of limited dispersal species to move following these climate changes. Building connected environments that enable species to track climate changes is an ultimate goal for biodiversity conservation. Here, we conducted an experiment to determine if electric power transmission lines could be transformed in a continental network of biodiversity reserves for small animals. We analysed if the management of the habitat located inside the base of the transmission electric towers (providing refuge and planting seedlings of native shrub) allowed to increase local richness of target species (i.e., small mammals and some invertebrates’ groups). Our results confirmed that by modifying the base of the electric transmission towers we were able to increase density and diversity of several species of invertebrates and small mammals as well as number of birds and bird species, increasing local biodiversity. We suggest that modifying the base of the electric towers would potentially facilitate the connection of fragmented populations. This idea would be easily applicable in any transmission line network anywhere around the world, making it possible for the first time to build up continental scale networks of connectivity.