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The article challenges traditional views on pronghorn habitat by highlighting the use of high-elevation summer ranges in the Carter Mountain area of the Greater Yellowstone Ecosystem in Wyoming. Through GPS tracking, researchers found that some pronghorn migrate to alpine meadows and plateaus above 3000m, a behavior previously considered anomalous. The study raises questions about the processes that generate and maintain diversity in animal movement tactics, emphasizing the need for further research to understand the implications of pronghorn using high-elevation habitats. The article acknowledges the Indigenous communities with cultural and spiritual ties to the region, respecting their connection to the land. [Extracted from the article]

Pollination success of alpine plants is often restricted by low and unpredictable pollinator activity because of harsh and unstable weather conditions, where nocturnal pollination is rare. The alpine orchid, Platanthera tipuloides (Orchidaceae), has inconspicuous greenish yellow flowers with a sweet scent and a long spur that contains nectar. These floral traits are expected to be related to nocturnal moth pollination. To elucidate the pollination mode and reproductive characteristics of this species, we measured floral traits (spur length, nectar content in the spur, floral scent), documented flower visitors using camera traps, and quantified self‐compatibility and the degree of pollen limitation through controlled pollinations at two study plots in the Taisetsu Mountains, northern Japan. It was revealed that P. tipuloides is self‐incompatible and pollen limitation was absent at one of the study plots. The flowers emitted more volatile substances during the night, including lilac aldehyde isomers, which are known to attract moths. A nocturnal moth, Entephria amplicosta, was observed foraging nectar from the flowers, while no diurnal visitors were observed. The proboscis of E. amplicosta was shorter than the spur length, but it was long enough to access the accumulated nectar in the spurs. These results suggest that nocturnal pollination by moths is possible and can be efficient even in an alpine ecosystem with harsh environmental conditions. [ABSTRACT FROM AUTHOR]

Many ecosystems are defined and shaped by one or a few common, foundation species. Even though such species hold a key role in the restoration of these ecosystems, the demographic processes involved in their re‐establishment have rarely been studied. Foundation species' population dynamics, re‐establishment history, and the abiotic and biotic factors that affect individual establishment at restored sites can be studied by addressing population spatial patterns and age structure. Such an approach to studying population dynamics is particularly relevant for long‐lived species with low mortality, such as shrubs in alpine areas. We studied a population of the foundation species Empetrum nigrum ssp. hermaphroditum at an alpine spoil heap site and found evidence of population re‐establishment starting within a decade after construction. High Empetrum densities close to the spoil heap edges indicated that short distances to seed sources in the surroundings had a strong positive effect on establishment of individuals. Empetrum individuals were significantly clustered, which indicated intraspecific facilitation. As revealed by spatial analyses of recruits and older, established individuals, clustering developed gradually over time, which indicated a shift from no interaction to increased facilitation. We conclude that intraspecific facilitation promotes Empetrum reestablishment at the studied alpine spoil heap. Synthesis: We show that population spatial patterns and age structure can be successfully used to unveil the re‐establishment history of a foundation species in a restoration context. Efficient seed dispersal and intraspecific facilitation seem to be important factors behind Empetrum's successful re‐establishment at alpine spoil heaps. Identification of abiotic and biotic factors determining foundation species' establishment success at restored sites can support planning and improve success of restoration. [ABSTRACT FROM AUTHOR]

Remote sensing is an invaluable tool for tracking decadal‐scale changes in vegetation greenness in response to climate and land use changes. While the Landsat archive has been widely used to explore these trends and their spatial and temporal complexity, its inconsistent sampling frequency over time and space raises concerns about its ability to provide reliable estimates of annual vegetation indices such as the annual maximum normalised difference vegetation index (NDVI), commonly used as a proxy of plant productivity. Here we demonstrate for seasonally snow‐covered ecosystems, that greening trends derived from annual maximum NDVI can be significantly overestimated because the number of available Landsat observations increases over time, and mostly that the magnitude of the overestimation varies along environmental gradients. Typically, areas with a short growing season and few available observations experience the largest bias in greening trend estimation. We show these conditions are met in late snowmelting habitats in the European Alps, which are known to be particularly sensitive to temperature increases and present conservation challenges. In this critical context, almost 50% of the magnitude of estimated greening can be explained by this bias. Our study calls for greater caution when comparing greening trends magnitudes between habitats with different snow conditions and observations. At a minimum we recommend reporting information on the temporal sampling of the observations, including the number of observations per year, when long‐term studies with Landsat observations are undertaken. [ABSTRACT FROM AUTHOR]

This study investigated regional and site level diversity for alpine and subalpine systems. The aim was to assess whether differing analytical methods could track diversity through time. The study was undertaken within Kosciusko National Park in south‐eastern Australia (6900 km2) which encompasses most of the alpine zone (~2500 km2 or 48% of its occurrence on mainland Australia). Multivariate ordination, species richness and the relationship of diversity to landscape patterns were assessed and considered in relation to changes predicted to impinge upon these systems over coming decades. Species richness had limited capacity to detect predicted changes; however, ordination based on floristic patterns may have more capacity to detect change if adequate replication is applied. Complex patterns across landscapes and at the site level contributed to these analytical challenges. Species richness is commonly used to assess ecosystem status and to provide benchmark values, but it had very limited capacity to do so in the assessed alpine and subalpine ecosystems, including the most threatened. Government agencies often rely heavily on species richness to assess ecosystem change and this urgently needs re‐evaluation. [ABSTRACT FROM AUTHOR]

Background and Aims: Human-driven nitrogen (N) deposition can alter soil biogeochemistry and plant communities, both critical to soil biota. However, understanding the relative impact of the relationship between nutrient resources and plants on soil communities has been hindered by a lack of experimental manipulations of both factors. We hypothesized that soil nematode communities would be structured predominantly by N addition via overall increased abundance, decreased diversity, and compositional shifts to dominance of r-selected bacterial-feeding nematodes. In contrast, we expected plant effects to be less evident and restricted to nematodes directly associated with plants. Methods: We used a long-term (18-yrs) experiment in moist meadow alpine tundra involving N addition and codominant plant (nitrophilic Deschampsia cespitosa and nitrogen-sensitive Geum rossii) removal. We characterized nematode communities via 18S rRNA metabarcoding and used soil biogeochemistry, plant, and microbial variables to determine factors shaping their communities. Results: The N addition treatment increased overall nematode abundance, decreased diversity, and affected the composition of all nematode trophic groups. Overall, nematode communities shifted to dominance of bacterial-feeding nematode taxa adapted to N-enriched environments. The likely drivers of this shift were increased soil nitrate and lower pH. The direct effects of codominant plants were more limited, with only changes in Geum rossii appearing to affect nematode responses. Conclusion: Overall, nematode communities in N-limited alpine ecosystems are highly sensitive to increases in N availability, irrespective of the nature of N preferences of codominant plants. The resulting nematode community restructuring could signify future shifts in soil functioning throughout alpine landscapes. [ABSTRACT FROM AUTHOR]

Alpine plant–pollinator communities play an important role in the functioning of alpine ecosystems, which are highly threatened by climate change. However, we still have a poor understanding of how environmental factors and spatiotemporal variability shape these communities. Here, we investigate what drives structure and beta diversity in a plant–pollinator metacommunity from the Australian alpine region using two approaches: pollen DNA metabarcoding (MB) and observations. Individual pollinators often carry pollen from multiple plant species, and therefore we expected MB to reveal a more diverse and complex network structure. We used two gene regions (ITS2 and trnL) to identify plant species present in the pollen loads of 154 insect pollinator specimens from three alpine habitats and construct MB networks, and compared them to networks based on observations alone. We compared species and interaction turnover across space for both types of networks, and evaluated their differences for plant phylogenetic diversity and beta diversity. We found significant structural differences between the two types of networks; notably, MB networks were much less specialized but more diverse than observation networks, with MB detecting many cryptic plant species. Both approaches revealed that alpine pollination networks are very generalized, but we estimated a high spatial turnover of plant species (0.79) and interaction rewiring (0.6) as well as high plant phylogenetic diversity (0.68) driven by habitat differences based on the larger diversity of plant species and species interactions detected with MB. Overall, our findings show that habitat and microclimatic heterogeneity drives diversity and fine‐scale spatial turnover of alpine plant–pollinator networks. [ABSTRACT FROM AUTHOR]

Understanding the influence of non‐native herbivores on ecosystems by means of dietary foraging and seed dispersal is important for understanding how non‐native species can alter an invaded landscape, yet requires multiple methodologies. In south‐eastern Australia, introduced sambar deer (Rusa unicolor) are rapidly expanding in range and placing native ecosystems at risk through browsing and as vectors for seed dispersal. We simultaneously investigated sambar deer dietary composition and seed dispersal using DNA sequencing and germination trials, from faecal pellets collected in alpine and wet forest ecosystems. This allowed us to contrast the dietary impacts of introduced sambar deer in different environments, and to explore the potential for habitat‐specific variation in diet. DNA sequencing of the trnL, ITS2 and rbcL gene regions revealed a diverse plant species dietary composition comprising 1003 operational taxonomic units (OTUs). Sambar deer exhibited intermediate feeder behaviours dominated by forbs in alpine and shrubs in wet forest ecosystems. A large proportion of plant OTUs were considered likely to be native, however, the proportion of exotic species in the diet in both ecosystems was greater than would be expected based on the proportion of exotic species in each of the two landscapes. Seed germination trials indicated that sambar deer can disperse a substantial number of native and exotic species in both alpine and wet forest ecosystems. In alpine ecosystems, an individual sambar deer was estimated to disperse on average 816 (±193) seeds per day during the study period, of which 652 (±176) were exotic. Synthesis and applications. Our results suggest that native plant species comprise the majority of sambar deer diets in Australian ecosystems and that the introduced species is dispersing both native and exotic plant species via endozoochory. However, exotic species seedling germination numbers were significantly higher in alpine ecosystems, and given the large daily movements of sambar deer, represents a significant vector for the spread of exotic plant species. Management of native plant species and vegetation communities of conservation significance, or at risk to sambar deer browsing is of high priority, through either the removal of sambar deer or implementation of exclusion‐based methods. [ABSTRACT FROM AUTHOR]

Global change is altering patterns of community assembly, with net outcomes dependent on species' responses to the abiotic environment, both directly and mediated through biotic interactions. Here, we assess alpine plant community responses in a 15‐year factorial nitrogen addition, warming and snow manipulation experiment. We used a dynamic competition model to estimate the density‐dependent and ‐independent processes underlying changes in species‐group abundances over time. Density‐dependent shifts in competitive interactions drove long‐term changes in abundance of species‐groups under global change while counteracting environmental drivers limited the growth response of the dominant species through density‐independent mechanisms. Furthermore, competitive interactions shifted with the environment, primarily with nitrogen and drove non‐linear abundance responses across environmental gradients. Our results highlight that global change can either reshuffle species hierarchies or further favour already‐dominant species; predicting which outcome will occur requires incorporating both density‐dependent and ‐independent mechanisms and how they interact across multiple global change factors. [ABSTRACT FROM AUTHOR]

Mountain ecosystems have special significance for biodiversity and are vulnerable to climate and other environmental changes. However, few assessments of drivers of change have been conducted in these areas in comparison to other more accessible biomes. In this study, we developed an objective and broad definition of a mountain bird, and systematically reviewed the existing literature for the 34 European mountain and upland species identified in order to quantify which drivers of environmental change have been most consistently associated with positive or negative demographic responses. Raptors and gamebirds were the most‐studied species, whereas mountain specialists and arctic–alpine species were little studied. Using a standardized threat classification, the analyses reported significant negative impacts of hunting, collision with energy‐generation infrastructures, predation by competitive species, human disturbance and poisoning. There were significant positive effects for management of non‐target species, but less support for effects of drivers operating over longer timescales, such as climate and land‐use changes. Analysis of trends in drivers found evidence of increasing temperatures and vegetation encroachment, whereas agricultural impacts decreased, which was largely related to abandonment of grazing. A lack of fine‐grained studies investigating ecological mechanisms and population responses to widespread impacts were highlighted. We have found that some drivers are well studied, but we need to collect more detailed and longer‐term data on species requirements and on the impacts that bird populations face to devise priorities for conservation action and research for mountain and upland birds. [ABSTRACT FROM AUTHOR]

Long-range transported atmospheric pollutants (or transboundary pollutants) include trace metals with isotope ratios and compositions that vary from those of domestic pollutants, which threaten mountain ecosystems. These differences can be applied as indices to evaluate the influence of transboundary pollutants on mountain ecosystems. Mosses play important ecological functions in mountains and are sensitive to atmospheric deposition. Therefore, using these indices for moss biomonitoring can provide a more accurate indication of ecosystem health. However, studies on indices that are appropriate for moss biomonitoring are limited. Here, the effectiveness of moss biomonitoring using trace metal indices was examined to evaluate transboundary pollutants in mountainous areas in Japan. Transboundary pollutants in these areas originate from mainland Asia and are characterized by high lead isotope ratios, lead-to-zinc (Pb/Zn) ratios, and arsenic-to-vanadium (As/V) ratios. Given that the abundance of transboundary pollutants decreases with distance from mainland Asia, these three indices are also expected to vary with distance. The Pb isotope ratios were found to decrease with distance from mainland Asia; in contrast, the Pb/Zn and As/V ratios did not display any notable relationship with distance. These results are likely attributed to biological and environmental factors that affect trace metal content in moss. Thus, moss Pb isotope ratios are useful indicators of transboundary pollutants in Japan's mountains, offering an important tool for comparable moss biomonitoring studies in East Asia. [ABSTRACT FROM AUTHOR]

From the aboveground vegetation to the belowground microbes, terrestrial communities differ between the highly divergent alpine (above treeline) and subalpine (below treeline) ecosystems. Yet, much less is known about the partitioning of microbial communities between alpine and subalpine lakes. Our goal was to determine whether the composition of bacterioplankton communities of high-elevation mountain lakes differed across treeline, identify key players in driving the community composition, and identify potential environmental factors that may be driving differences. To do so, we compared bacterial community composition (using 16S rDNA sequencing) of alpine and subalpine lakes in the Southern Rocky Mountain ecoregion at two time points: once in the early summer and once in the late summer. In the early summer (July), shortly after peak runoff, bacterial communities of alpine lakes were distinct from subalpine lakes. Interestingly, by the end of the summer (approximately 5 weeks after the first visit in August), bacterial communities of alpine and subalpine lakes were no longer distinct. Several bacterial amplicon sequence variants (ASVs) were also identified as key players by significantly contributing to the community dissimilarity. The community divergence across treeline found in the early summer was correlated with several environmental factors, including dissolved organic carbon (DOC), pH, chlorophyll-a (chl-a), and total dissolved nitrogen (TDN). In this paper, we offer several potential scenarios driven by both biotic and abiotic factors that could lead to the observed patterns. While the mechanisms for these patterns are yet to be determined, the community dissimilarity in the early summer correlates with the timing of increased hydrologic connections with the terrestrial environment. Springtime snowmelt brings the flushing of mountain watersheds that connects terrestrial and aquatic ecosystems. This connectivity declines precipitously throughout the summer after snowmelt is complete. Regional climate change is predicted to bring alterations to precipitation and snowpack, which can modify the flushing of solutes, nutrients, and terrestrial microbes into lakes. Future preservation of the unique alpine lake ecosystem is dependent on a better understanding of ecosystem partitioning across treeline and careful consideration of terrestrial-aquatic connections in mountain watersheds. [ABSTRACT FROM AUTHOR]

Conservation managers are under increasing pressure to make decisions about the allocation of finite resources to protect biodiversity under a changing climate. However, the impacts of climate and global change drivers on species are outpacing our capacity to collect the empirical data necessary to inform these decisions. This is particularly the case in the Australian Alps which have already undergone recent changes in climate and experienced more frequent large‐scale bushfires. In lieu of empirical data, we use a structured expert elicitation method (the IDEA protocol) to estimate the change in abundance and distribution of nine vegetation groups and 89 Australian alpine and subalpine species by the year 2050. Experts predicted that most alpine vegetation communities would decline in extent by 2050; only woodlands and heathlands are predicted to increase in extent. Predicted species‐level responses for alpine plants and animals were highly variable and uncertain. In general, alpine plants spanned the range of possible responses, with some expected to increase, decrease or not change in cover. By contrast, almost all animal species are predicted to decline or not change in abundance or elevation range; more species with water‐centric life‐cycles are expected to decline in abundance than other species. While long‐term ecological data will always be the gold standard for informing the future of biodiversity, the method and outcomes outlined here provide a pragmatic and coherent basis upon which to start informing conservation policy and management in the face of rapid change and a paucity of data. [ABSTRACT FROM AUTHOR]

Summary: Assumptions about the germination ecology of alpine plants are presently based on individual species and local studies. A current challenge is to synthesise, at the global level, the alpine seed ecological spectrum.We performed a meta‐analysis of primary data from laboratory experiments conducted across four continents (excluding the tropics) and 661 species, to estimate the influence of six environmental cues on germination proportion, mean germination time and germination synchrony; accounting for seed morphology (mass, embryo : seed ratio) and phylogeny.Most alpine plants show physiological seed dormancy, a strong need for cold stratification, warm‐cued germination and positive germination responses to light and alternating temperatures. Species restricted to the alpine belt have a higher preference for warm temperatures and a stronger response to cold stratification than species whose distribution extends also below the treeline. Seed mass, embryo size and phylogeny have strong constraining effects on germination responses to the environment.Globally, overwintering and warm temperatures are key drivers of germination in alpine habitats. The interplay between germination physiology and seed morphological traits further reflects pressures to avoid frost or drought stress. Our results indicate the convergence, at the global level, of the seed germination patterns of alpine species. [ABSTRACT FROM AUTHOR]

Global climate and land use change are causing woody plant encroachment in arctic, alpine, and arid/semi‐arid ecosystems around the world, yet our understanding of the belowground impacts of this phenomenon is limited. We conducted a globally distributed field study of 13 alpine sites across four continents undergoing woody plant encroachment and sampled soils from both woody encroached and nearby herbaceous plant community types. We found that woody plant encroachment influenced soil microbial richness and community composition across sites based on multiple factors including woody plant traits, site level climate, and abiotic soil conditions. In particular, root symbiont type was a key determinant of belowground effects, as Nitrogen‐fixing woody plants had higher soil fungal richness, while Ecto/Ericoid mycorrhizal species had higher soil bacterial richness and symbiont types had distinct soil microbial community composition. Woody plant leaf traits indirectly influenced soil microbes through their impact on soil abiotic conditions, primarily soil pH and C:N ratios. Finally, site‐level climate affected the overall magnitude and direction of woody plant influence, as soil fungal and bacterial richness were either higher or lower in woody encroached versus herbaceous soils depending on mean annual temperature and precipitation. All together, these results document global impacts of woody plant encroachment on soil microbial communities, but highlight that multiple biotic and abiotic pathways must be considered to scale up globally from site‐ and species‐level patterns. Considering both the aboveground and belowground effects of woody encroachment will be critical to predict future changes in alpine ecosystem structure and function and subsequent feedbacks to the global climate system. [ABSTRACT FROM AUTHOR]

The fruticose lichen genus Gowardia (Parmeliaceae) was recently segregated from Alectoria based on phylogeny, morphology, secondary chemistry, ecology and distribution. As currently circumscribed, Gowardia comprises two wide-ranging species of arctic-alpine regions. Here we describe a third species, G. zebrina sp. nov., apparently endemic to subalpine regions in mountainous northwestern North America. Gowardia zebrina differs from other species in the genus by its combined subpendent habit, uniformly capillary branches, predominantly isotomic branching, pale-and-dark banding of the terminal branches, and epiphytic ecology. Morphological examination of North American herbarium specimens filed under A. nigricans suggests the existence of several additional undescribed species of Gowardia. A brief overview of morphological diversity in these species is given, shedding new light on the question of whether Gowardia should be subsumed under Alectoria, as some have suggested, or is more appropriately recognized as a distinct genus. [ABSTRACT FROM AUTHOR]

Ongoing climate change involves increasing snow scarcity, which results in more frequent freeze-thaw cycles (FTCs) in polar and alpine soils. Although repeated FTCs have been shown to alter the structure and functions of soil microbial communities, a thorough understanding on the influence of FTCs frequency on polar and especially alpine soil microbiomes is still elusive. Here, we investigated the impact of repeated weekly vs. daily FTC frequencies on the structure and functions of prokaryotic and fungal communities from north- and south-exposed soils from two mountain ridges, one in the Arctic and one in the High-Alps. FTCs affected prokaryotic communities more strongly than fungal communities, where mainly cold-tolerant and opportunistic fungi (e.g., Mrakia , Mortierella) were responsive. Prokaryotic communities were more affected by weekly FTCs than by daily FTCs. Daily FTCs favored fast-growing bacteria (e.g., Arthrobacter), while oligotrophic and largely uncultured taxa (e.g., Verrucomicrobia) benefited from weekly FTCs. FTCs negatively affected microbial respiration but had minor impacts on C-, N- and P-acquiring enzymatic activities. Plausible pre-adaptation of the microbial communities to naturally occurring frequent FTCs at their site of origin did not show a clear influence on the microbial responses to the tested FTCs. Altogether, our study provides an integrative overview on potential structural and functional changes of soil microbial communities in polar and alpine regions in response to the projected increase in FTCs; therefore advancing our understanding on the impact of climate change in these rapidly changing ecosystems. [ABSTRACT FROM AUTHOR]

Climate change is expected to have significant and complex impacts on ecological communities. In addition to direct effects of climate on species, there can also be indirect effects through an intermediary species, such as in host–plant interactions. Indirect effects are expected to be more pronounced in alpine environments because these ecosystems are sensitive to temperature changes and there are limited areas for migration of both species (i.e. closed systems), and because of simpler trophic interactions. We tested the hypothesis that climate change will reduce the range of an alpine butterfly (Parnassius smintheus) because of indirect effects through its host plant (Sedum sp.). To test for direct and indirect effects, we used the simulations of climate change to assess the distribution of P. smintheus with and without Sedum sp. We also compared the projected ranges of P. smintheus to four other butterfly species that are found in the alpine, but that are generalists feeding on many plant genera. We found that P. smintheus gained distributional area in climate‐only models, but these gains were significantly reduced with the inclusion of Sedum sp. and in dry‐climate scenarios which resulted in a reduction in net area. When compared to the more generalist butterfly species, P. smintheus exhibited the largest loss in suitable habitat. Our findings support the importance of including indirect effects in modelling species distributions in response to climate change. We highlight the potentially large and still neglected impacts climate change can have on the trophic structure of communities, which can lead to significant losses of biodiversity. In the future, communities will continue to favour species that are generalists as climate change induces asynchronies in the migration of species. [ABSTRACT FROM AUTHOR]

Aim: To assess how species traits modulate the responses of carabids to elevational gradients, and how consistent these relationships are across different Alpine regions. Location: Italian Alps. Taxon: Coleoptera, Carabidae (ground beetles). Methods: Carabid communities were sampled using pitfall traps along elevational gradients (697–2,840 m) in 416 study sites comprising a range of habitat types. The probability of carabid occurrence was modelled in relation to elevation and its interaction with two key traits, body size and wing development, using a mixed‐modelling framework. The consistency of these associations was then assessed across three geographically separated regions. Results: Carabid occurrence declined with increasing elevation, although this relationship was modulated by both body size and wing development. Smaller species were less likely to occur than larger‐bodied species at lower elevations. There was a steep decline in occurrence of larger species from low to high elevation, but a slight increase in smaller species, when considering all regions combined. All wing development types declined with elevation, most notably for brachypterous (reduced wings) species. However, these patterns also varied regionally, especially for wing development, indicating that trait‐elevation interactions are not geographically consistent. Habitat could not explain the differences between regions for body size, but was likely an important driver of regional differences in the role of wing development on carabid occurrence. Main conclusions: Species traits are important in explaining the distribution of carabids along elevational gradients in mountains, and they may help to identify the species that are the most vulnerable, and the most resilient, to future environmental change. Increased probability of occurrence of smaller species at higher elevations suggests that they may be particularly vulnerable to environmental change in the future. However, the difference in responses to elevation between regions has important implications for modelling species distributions, as it suggests low model transferability, that is, a trait‐based model derived from one region cannot necessarily be used to project relative elevational shifts in a wider area. [ABSTRACT FROM AUTHOR]

Environmental gradients drive variation in community composition across a range of spatial scales. In alpine regions, areas of long‐lasting snow ('snow patches') create snowmelt gradients that drive considerable change in vegetation structure and composition over small spatial scales. This study examined whether there is parallel variation in arthropod communities using snowmelt gradients in the Australian Alps. Mites (Acarina) were the most common arthropods in snow patches, followed by springtails while, among the insects, the orders Hymenoptera (primarily Formicidae), Diptera, Coleoptera (primarily Carabidae) and Hemiptera (primarily Cicadellidae) dominated. Along the snowmelt gradient, arthropod assemblages changed from having equal proportions of predators and herbivores in early‐melting zones to being predator‐dominated in late‐melting zones, particularly early in the growing season. This followed a transition in vegetation cover and composition and was driven by higher numbers of predacious carabid beetles in later‐melting zones. Overall, however, our results suggest that snowbed arthropod communities in the Australian alpine zone are more sensitive to short‐term effects, such as time since snowmelt, than to differences in vegetation structure and composition or long‐term patterns of snowmelt. Continued advancement of snowmelt timing due to warmer spring temperatures is therefore likely to have more impact on the seasonality of snowbed arthropod communities than on the overall community composition. [ABSTRACT FROM AUTHOR]

The effects of climate change appear to be amplified in mountains compared with lowland areas, with rapid changes in plant community composition, soil properties, and increased substrate for biological development following retreat of glaciers. Associated soil gaseous fluxes in alpine ecosystems contribute to the global balance of greenhouse gases, but methane and carbon dioxide soil fluxes and their controls are not well known. We used a dynamic closed-chamber method to measure methane and carbon dioxide fluxes along a successional gradient during the peak growing season in the North Selkirk Mountains, British Columbia, Canada. Soil physico-chemical properties, vegetation cover, and topographic variables were quantified to determine mechanisms influencing these fluxes. Mean methane uptake ranged from − 155 µg CH4-C m− 2 h−1 in well vegetated sites to zero in recently deglaciated terrain. Soil total carbon (TC) and water content were the primary drivers of methane uptake. Sites with TC greater than 4% and moisture below 0.22 water fraction by volume (w.f.v) corresponded to the strongest methane sinks. Increased vegetation cover and relatively drier soil conditions, anticipated with future climate change, suggest that methane uptake may increase in these alpine ecosystems. [ABSTRACT FROM AUTHOR]

Species distributions are influenced by climate and topography in alpine ecosystems, yet resource selection studies of alpine species are uncommon. Basic characteristics of habitats used by alpine‐endemic white‐tailed ptarmigan (Lagopus leucura) have been described to explain foraging behavior, morphology, and survival in many alpine regions; however, there is a lack of information about fine‐scale habitat selection for nesting and brood‐rearing, particularly in the southern extent of the species' range. Few studies have tested whether nest and brood‐site selection by white‐tailed ptarmigan are influenced by fine‐scale components such as vegetation and arthropod communities. We assessed these fine‐scale habitat characteristics analyzing paired use‐available resource selection for nest (n = 61) and brood (n = 54) sites. We used conditional logistic regression for data collected in 2 alpine areas along the Front Range of Colorado, USA, during 2014 and 2015. We evaluated resource selection at larger (patch) and finer (nest site) scales. Nest‐site selection at the patch scale was best predicted by cover (%) of forage forbs, rock and gravel, and shrubs. Forage forb cover explained more variation in our top nest model at the patch scale when compared to models with specific vegetation species. Females placed their nests along elevational gradients but more so at lower elevations and selected for less graminoid cover at the nest‐site scale. Brood habitat selection at the patch level was influenced by cover (%) of rock and gravel and proximity to shrubs (m). Analysis of a subset of our brood data (n = 34) revealed females selected brood habitat that contained high arthropod abundance (e.g., Cicadellidae) over high vegetation cover, likely as a response to meet dietary requirements of chicks. Our results demonstrate how and where white‐tailed ptarmigan are currently selecting these different breeding sites in Colorado's alpine, giving us insight into consequences this alpine‐endemic bird may face if their breeding habitat is altered. © 2019 The Wildlife Society. Our results confirm the fine‐scale characteristics known to influence habitat selection of nesting and brood‐rearing sites by ptarmigan. Our study highlights how habitat selection by ptarmigan can vary depending upon spatial scale and breeding stage, and that selection can be influenced by vegetation and arthropod communities. [ABSTRACT FROM AUTHOR]

[Display omitted] • Different evolutionary histories were shown for intraspecific clades during Pleistocene climatic changes. • Differences in the genetic structure of intraspecific clades were influenced by habitat differentiation. • The clade distributed at lower altitudes and the clade distributed at higher altitudes showed different distributional shift patterns. • In the future, due to global warming, different distributional shift patterns are predicted for different intraspecific clades. The distribution of organisms is influenced by complex factors such as the phylogenetic evolutionary histories of species, the physiological and ecological characteristics of organisms, climate, and geographical and geohistorical features. In this study, we focused on a caddisfly, Asynarchus sachalinensis (Trichoptera: Limnephilidae), which has adapted to cold habitats. From phylogeographic analyses based on the mitochondrial DNA (mtDNA) cytochrome c oxidase subunit I (COI) and 16S rRNA regions and the nuclear DNA (nDNA) 18S rRNA, 28S rRNA, carbamoyl-phosphate synthetase (CAD), elongation factor-1 alpha (EF1-α), and RNA polymerase II (POLII) regions, two distinct genetic clades were detected. Clade I was shown to be widely distributed from Sakhalin to Honshu, whereas Clade II was only distributed within Honshu. The distributions of these clades overlapped in Honshu. The habitats were located at relatively lower altitudes for Clade I and higher altitudes for Clade II. The divergence time of these clades was estimated to be during the Pleistocene, indicating that repeated climatic changes facilitated distributional shifts. Haplotype network and demographic analyses based on the mtDNA COI region showed contrasting genetic structures in the two clades. It was indicated that the population sizes of Clade I had expanded rapidly in a recent period, whereas Clade II had maintained stable population sizes. The habitats of Clade II were typically isolated and scattered at high altitudes, resulting in restricted migration and dispersal because of their discontinuous "Sky Island" habitats. The habitats of Clade I were located at relatively low altitudes, and it was assumed that the populations were continuous, which resulted in a higher frequency of migration and dispersal between populations. Thus, differences in the spatial scale of the adapted habitats of each clade may have resulted in different patterns of population connectivity and fragmentation associated with repeated climatic changes during the Pleistocene. Our study provided new insight into the distributional patterns of cold-adapted aquatic insects in the Japanese Archipelago. Furthermore, the distributional shifts predicted by ecological niche modeling under future climatic change conditions were different for each clade. Therefore, different principles are required in the assessment of each clade to predict temporal changes in their distributions. [ABSTRACT FROM AUTHOR]

Unsanctioned travel routes through alpine ecosystems can influence water drainage patterns, cause sedimentation of streams, and erode soils. These disturbed areas can take decades to revegetate. In 2012, a volunteer‐driven project restored a 854‐m section of unsanctioned road along the Continental Divide in Colorado, United States. The restored area was seeded with three native grass species and then treated by installing erosion matting or adding supplemental rock cover. Four years later, results suggest that the seeding along with the use of erosion matting or supplemental rock can enhance revegetation. Matting appeared to accumulate litter, and this effect might have contributed to enhanced moisture retention. Treated areas contained 40% of the vegetation cover found on adjacent controls, which averaged 69% vascular plant absolute cover. Recovery on both treatments was markedly higher than published estimates of passive revegetation of disturbed areas measured elsewhere suggesting seeding with added cover or protection led to substantial vegetative cover after 4 years. Two of the 3 seeded grass species, Trisetum spicatum and Poa alpina, dominated the restored plots, composing 81.7% of relative vegetation cover on matting sites and 73.4% of relative cover on rock‐supplemented areas. Presumably due to its preference for moister sites, Deschampsia cespitosa had low establishment rates. Volunteer species, that is species that appeared on their own, contributed 6.3% to the absolute vegetation cover of matting and rock sites, and species such as Minuartia biflora, Minuartia obtusiloba, Poa glauca, and Festuca brachyphylla should be considered for use in future restorations. [ABSTRACT FROM AUTHOR]

Background: Alpine and arctic tundra are particularly sensitive ecosystems to the impacts of global climate change. Yet, warming studies versus observational studies in these ecosystems yield different and sometimes conflicting results. Many short-term changes may be phenotypic responses to warming rather than shifts at the community level. Aims: We posit that long-term monitoring of permanently marked plots provides data for making predictions of the impact of climate change on alpine tundra communities. Methods: We surveyed plant community composition and cover at four sampling time points over a forty-year span (1971–2011). Results: We observed an expansion of shrub cover, both within the shrub tundra and encroaching into moist and dry meadow communities. This shrub cover expansion coincides with increased litter and decreased species richness at the plot level. Overall, despite some shifts in functional group cover and species richness, plant community composition remained mostly intact across forty years. Conclusions: Our results corroborate with other published studies demonstrating the rapid expansion and impacts of woody shrubs in tundra ecosystems. This study demonstrates a surprising resistance of alpine tundra plant communities under current global climate change over a 40-year period. Additional studies are needed to disentangle the many potential drivers that explain plant community shifts and community stability. [ABSTRACT FROM AUTHOR]

Alpine plants occurring at high elevation are vulnerable to ongoing climate change, yet relatively little is known about the potential for high‐elevation species to adapt to changing environmental conditions. In particular, the extent to which high‐elevation plants will be able to resist predicted increases in the intensity of biotic interactions, such as herbivory, remains unclear.Species distributed across broad elevational ranges provide an opportunity to investigate evolutionary mechanisms and traits involved in adaptation to varying abiotic and biotic environments. This study focused on the perennial alpine plant Arabis alpina and combined field surveys and climate chamber experiments to test for intraspecific genetic divergence in traits related to growth and defence against herbivores. We screened multiple populations from low, intermediate and high elevations across a broad geographic area, characterising differences in growth form, leaf structural traits, palatability for herbivores and defensive chemistry. We then quantified the proportion of variation explained by elevation and population‐level effects.Our results document within‐species genetic divergence in multiple traits relevant for adaptation to the different abiotic and biotic pressures experienced at low and high elevations. Rates of herbivore damage declined with increasing elevation in the field, but plants from high‐ and intermediate‐elevation populations were generally more palatable for specialist herbivores than those from low‐elevation populations in feeding assays. Elevational clines were also observed in several glucosinolate defence compounds, and leaf herbivory more strongly induced glucosinolates in plants from high‐elevation populations than in those from low‐elevation populations. Leaf trichome density and growth form also diverged among populations contributing to growth–defence phenotypes associated with different elevations.However, populations from similar elevations often differed significantly in both growth‐ and defence‐related traits, with trait variation often better explained by population‐level effects than by elevation alone.Synthesis. Arabis alpina exhibits patterns of genetic variation in growth and defence traits consistent with adaptation to different elevations. However, populations from similar elevations also diverge in many of these ecologically relevant traits. Together, the extent of the observed trait variation suggests that this alpine species has considerable potential to adapt to a changing biotic environment. [ABSTRACT FROM AUTHOR]

Increased atmospheric nitrogen (N) pollution affects N deposition in alpine ecosystems. Moss often dominates these ecosystems and their N content (%N) and stable isotope ratio (δ15N) are used as indicators of atmospheric N deposition. Here, we used a single moss species (Hylocomium splendens) as a bioindicator of atmospheric N deposition in the mountainous areas of Japan. The moss was collected from 38 sites on all slope aspects (east, west, south, and north) ranging from 1800 to 2800 m in altitude. The correlation between moss N variables (%N and δ15N) and environmental conditions (altitude and slope aspects) was analyzed using linear models based on a hierarchical Bayesian framework. In the constructed models, %N showed a significant or weak negative correlation with altitude on all slope aspects. In contrast, δ15N was significantly and positively correlated with altitude, with high values on the western alpine slopes. When using δ15N as a marker of N sources, N in alpine moss on the west slope seemed to be influenced by transboundary N pollutants through particulate matter (PM), which is brought to Japan from mainland Asia by prevailing westerly winds and northwest monsoons. However, as moss N is also affected by other factors, such as different N chemical forms, fixed N from cyanobacteria, and seasonal differences in atmospheric N, further research should directly compare moss N with atmospheric N deposition to elucidate the influence of transboundary N pollutants on moss N. Image 1 • Increased nitrogen (N) deposition is a serious concern for alpine ecosystems. • Moss N was used as a bioindicator to examine how N pollutants affect alpine moss. • Alpine moss was influenced by transboundary N pollutants in particulate matter. • Slope aspect affected the susceptibility of alpine moss to these pollutants. • Transboundary N was incorporated by alpine moss through wet deposition via snowmelt. [ABSTRACT FROM AUTHOR]

Premise: At the intersection of ecology and evolutionary biology, community phylogenetics can provide insights into overarching biodiversity patterns, particularly in remote and understudied ecosystems. To understand community assembly of the high alpine flora in the Sawtooth National Forest, USA, we analyzed phylogenetic structure within and between nine summit communities. Methods: We used high‐throughput sequencing to supplement existing data and infer a nearly completely sampled community phylogeny of the alpine vascular flora. We calculated mean nearest taxon distance (MNTD) and mean pairwise distance (MPD) to quantify phylogenetic divergence within summits, and assessed whether maximum elevation explains phylogenetic structure. To evaluate similarities between summits, we quantified phylogenetic turnover, taking into consideration microhabitats (talus vs. meadows). Results: We found different patterns of community phylogenetic structure within the six most species‐rich orders, but across all vascular plants phylogenetic structure was largely not different from random. There was a significant negative correlation between elevation and tree‐wide phylogenetic diversity (MPD) within summits: overdispersion degraded as elevation increased. Between summits, we found high phylogenetic turnover driven by greater niche heterogeneity on summits with alpine meadows. Conclusions: Our results provide further evidence that stochastic processes may also play an important role in the assembly of vascular plant communities in high alpine habitats at regional scales. However, order‐specific patterns suggest that adaptations are still important for assembly of specific sectors of the plant tree of life. Further studies quantifying functional diversity will be important in disentangling the interplay of eco‐evolutionary processes that likely shape broad community phylogenetic patterns in extreme environments. [ABSTRACT FROM AUTHOR]

Alpine areas make excellent research sites for investigating questions of plant ecology due to harsh climatic filtering, compressed ecological/environmental gradients, limited species pools, and the presence of potentially isolated sub-populations on habitat islands. In northeastern North America, alpine areas are rare and potentially highly vulnerable to climate change. Despite a renewed focus by researchers on these ecosystems, much remains unknown about the environmental adaptations, species interactions, and dynamics of alpine species and communities in the region and how they may respond to future climate change. Here, we review the use of common garden experiments in alpine areas of northeastern North America and outline the many ways they can effectively address some of our region's most pressing questions in alpine plant ecology and conservation. We also present common garden research priorities, including investigating the influence of environmental conditions on plant trait variation, the response of populations and communities to environmental change, and identifying high-elevation ecotypes. Last, we present practical guidelines for future common garden research in the region, including discussions of experimental design, data collection and analysis, and interpretation and sharing of results. [ABSTRACT FROM AUTHOR]

A warming climate has been shown to drive thermophilization—shifts in species abundance toward those adapted to warm and dry conditions. The community dynamics shaping this process have been proposed to vary between temperature-limited alpine plant communities and those that are both temperature and moisture limited. In nine sites across the xeric alpine zone in the White Mountains, California, USA, we experimentally increased summertime temperature and precipitation for three seasons and quantified community responses with a climatic niche analysis. We asked if thermophilization occurred in response to experimental heating, and if this effect was ameliorated by experimental watering. Under experimentally warmer conditions, we found no change in the mean community-weighted climatic niche (CCN); however, thermophilization of this community was observed based on a shift in the seventy-fifth percentile of the CCN and an increase in the proportional abundance of the hottest, driest adapted species. In addition, total vegetation abundance increased and species richness decreased with heating. Experimental watering did not ameliorate these effects of heating. Together, these results suggest that warming in arid alpine areas may result in less diverse plant communities dominated by hot, dry associated species, although short-term responses may be limited because of community lags. [ABSTRACT FROM AUTHOR]

High-elevation ecosystems will experience increasing periods of above-average warmth and altered precipitation changes because of climate change. This causes uncertainties for community properties such as productivity and biodiversity. Increasing temperature may increase productivity by increasing growing season length and metabolic rate or decrease productivity by causing drought stress. Competitive outcomes between species may change with altered climatic conditions, causing shifts in community composition. This study investigates the resistance of aboveground biomass and plant community composition of montane and alpine grassland ecosystems to abruptly altered temperature and precipitation conditions. Intact plant-soil communities were translocated downslope spanning an elevational gradient of 2,090 m in the European Alps. We hypothesize that increasing temperature leads to (1) increased aboveground biomass in the absence of precipitation deficits, (2) decreased species richness, and (3) shifts in plant community composition. After one year of exposure to their new environment, aboveground biomass changes appeared to be dependent on precipitation regimes, whereas species richness declined consistently with changed climatic conditions. No deterministic shift in community composition was found. Abrupt changes in climatic conditions can lead to rapid responses of community properties, indicating that these high-elevation communities may have low initial resistance to future heat waves and droughts. [ABSTRACT FROM AUTHOR]

The alpine ecosystem of the Rocky Mountains is experiencing significant increases in growing season length, summer maximum temperatures, and shifting patterns in precipitation. Alpine herbs are specifically sensitive to these changes. Biomass accumulation and reproductive effort are often negatively affected by elevated temperatures and earlier snowmelt. Here, we assess the use of herb-chronology, the study of annual growth rings in the woody underground organs, to retroactively monitor effects of monthly to seasonal climate on growth of the alpine forb species Penstemon whippleanus. We explored methods for building the strongest growth chronology possible by comparing the mean interseries correlations (MICs) of the whole population to that of groupings by cohorts, spatial locations, and random groupings using a permutation procedure. MIC for the whole population was low (0.034). Our permutation grouping performed best, producing a maximum MIC of 0.263. Using the permutation-derived chronology (2008–2015), we found significant decrease in growth with increased maximum temperatures in July, decreased May rainfall, increased drought between April and August, and lower minimum temperatures in September. Herb-chronology proved useful for understanding growth dynamics with climate in this alpine system; expanding this practice to similar systems could elucidate unknown effects of shifting climate on annual growth of alpine herbaceous species. [ABSTRACT FROM AUTHOR]

Managing protected areas effectively requires information about patterns of visitor use, but these data are often limited. We explore how geotagged photos on Flickr, a popular photo-sharing social-media site, can generate hotspot maps and distribution models of temporal and spatial patterns of use in two mountain-protected areas of high conservation value. In Aconcagua Provincial Park (Argentina), two routes to the summit of Aconcagua were used in summer, but most visitors stayed close to the main road, using formal and informal walking trails and the Visitor Centre, while in winter, there was very limited visitation. In Kosciuszko National Park (Australia), alpine walking trails were popular in summer, but in winter, most visitors stayed in the lower altitude ski resorts and ski trails. Results demonstrate the usefulness of social-media data alone as well as a complement for visitor monitoring, providing spatial and temporal information for site-specific and park-level management of visitors and potential impacts in conservation areas. [ABSTRACT FROM AUTHOR]

Abstract: Global change is modifying species communities from local to landscape scales, with alterations in the abiotic and biotic determinants of geographic range limits causing species range shifts along both latitudinal and elevational gradients. An important but often overlooked component of global change is the effect of anthropogenic disturbance, and how it interacts with the effects of climate to affect both species and communities, as well as interspecies interactions, such as facilitation and competition. We examined the effects of frequent human trampling disturbances on alpine plant communities in Switzerland, focusing on the elevational range of the widely distributed cushion plant Silene acaulis and the interactions of this facilitator species with other plants. Examining size distributions and densities, we found that disturbance appears to favor individual Silene growth at middle elevations. However, it has negative effects at the population level, as evidenced by a reduction in population density and reproductive indices. Disturbance synergistically interacts with the effects of elevation to reduce species richness at low and high elevations, an effect not mitigated by Silene. In fact, we find predominantly competitive interactions, both by Silene on its hosted and neighboring species and by neighboring (but not hosted) species on Silene. Our results indicate that disturbance can be beneficial for Silene individual performance, potentially through changes in its neighboring species community. However, possible reduced recruitment in disturbed areas could eventually lead to population declines. While other studies have shown that light to moderate disturbances can maintain high species diversity, our results emphasize that heavier disturbance reduces species richness, diversity, as well as percent cover, and adversely affects cushion plants and that these effects are not substantially reduced by plant–plant interactions. Heavily disturbed alpine systems could therefore be at greater risk for upward encroachment of lower elevation species in a warming world. [ABSTRACT FROM AUTHOR]

Abstract: Rising global temperature is expected to increase alpine glacier mass loss with cascading effects on alpine habitats and biota. Currently, there is limited information on the effects of climate change on alpine riparian vegetation including quantitative assessments of geophysical habitat context. We measured geomorphic conditions and riparian vegetation composition of alpine streams across a chronosequence of sites supported hydrologically by glaciers, permanent snowfields (PS) and seasonal snowfields (SS) in Glacier National Park (GNP), Montana, USA. Responses in the system to possible climate‐driven shifts in hydrologic regime were identified using multivariate analyses. Glacier‐fed streams had higher discharge and stream power and lower substrate stability than streams fed by PS and SS. Streams fed by PS supported a higher number of species than other stream types. Glacier‐fed streams were characterised by higher abundance of disturbance‐adapted shrub species than PS and SS. By applying projections from climate models that forecast total glacial loss in GNP by 2030 to our data, we predict that stream geophysical conditions will shift, resulting in a loss of physical habitat for shrub species, an increase in habitat for herbaceous species, and ultimately a homogenisation of riparian communities in the alpine zone. Our study identifies glaciers as drivers of alpine riverine ecosystems and highlights the importance of examining geophysical habitat linked to hydrologic regimes and glaciers to better understand the impacts to biota under future climate scenarios. We provide a framework for relating fluvial biological and hydrogeomorphic processes in the context of alpine glacial recession. [ABSTRACT FROM AUTHOR]

In recent years, genomic analyses have arisen as an exciting way of investigating the functional capacity and environmental adaptations of numerous micro-organisms of global relevance, including cyanobacteria. In the extreme cold of Arctic, Antarctic and alpine environments, cyanobacteria are of fundamental ecological importance as primary producers and ecosystem engineers. While their role in biogeochemical cycles is well appreciated, little is known about the genomic makeup of polar and alpine cyanobacteria. In this article, we present ways that genomic techniques might be used to further our understanding of cyanobacteria in cold environments in terms of their evolution and ecology. Existing examples from other environments (e.g. marine/hot springs) are used to discuss how methods developed there might be used to investigate specific questions in the cryosphere. Phylogenomics, comparative genomics and population genomics are identified as methods for understanding the evolution and biogeography of polar and alpine cyanobacteria. Transcriptomics will allow us to investigate gene expression under extreme environmental conditions, and metagenomics can be used to complement tradition amplicon-based methods of community profiling. Finally, new techniques such as single cell genomics and metagenome assembled genomes will also help to expand our understanding of polar and alpine cyanobacteria that cannot readily be cultured. [ABSTRACT FROM AUTHOR]

Snow is one of the most important factors in the ecology of alpine ecosystems. In Australia, both the depth and duration of snow cover have declined significantly in recent decades and this trend is projected to continue with global warming. Many small arthropods remain active throughout the winter, within a space beneath the snowpack (subnivean) where the snow's insulation creates a thermally stable environment. Using field surveys and experimental manipulation of snow depth at two locations in the Australian alpine region, we explored the diversity of winter-active arthropods and their response to reduced snow. Individuals from 18 arthropod Orders were detected beneath the snow during winter, with Collembola, Araneae, Acari and Coleoptera accounting for 95-98% of the individuals collected. The subnivean taxa represented a distinct subset of those active outside the winter months. Removal of the snow layer increased daily temperature fluctuations, increased the number of days below freezing and raised the mean surface temperatures. Community composition was altered by snow removal, driven by changes in the numbers of two abundant springtail taxa at each location. We found a strong reduction in the abundances of both taxa at one study site, and contrasting responses (one strong positive and one strong negative) to snow removal at the second study site. Subnivean arthropod communities in Australia thus appear sensitive to snow conditions at small spatial scales. [ABSTRACT FROM AUTHOR]

Austromonticola gen. n. is proposed for a group of eight New Zealand alpine broad-nosed weevil species, all of which are here described: A. atriarius sp. n. (type locality: Umbrella Mountains, Central Otago), A. caelibatus sp. n. (type locality: Ohau Range, Mackenzie), A. furcatus sp. n. (type locality: Old Man Range, Central Otago), A. inflatus sp. n. (type locality: Hawkdun Range, Central Otago), A. planulatus sp. n. (type locality: St Marys Range, Central Otago), A. postinventus sp. n. (type locality: Kirkliston Range, South Canterbury), A. mataura sp. n. (type locality: Mt Dick, Otago Lakes) and A. rotundus sp. n. (type locality: Old Man Range, Central Otago). All species occur exclusively above 1000 m elevation in the mountains of Central Otago and South Canterbury in the South Island. A phylogeny of the genus, including six outgroups, was inferred from 33 morphological characters. It resolved the genus as monophyletic, and revealed two strongly supported clades within Austromonticola. DNA sequences of four gene regions were obtained from five species. Of these, the 3' end of COI proved to be the most suitable for the identification of specimens. Females of all species have diagnostic secondary sexual structures on the elytra and ventrites. These structures are hypothesised to have evolved to assist with oviposition in and beside cushion plants or by selection for structures to mitigate the costs to females of prolonged mating. [ABSTRACT FROM AUTHOR]

Climate change is driving the thinning and retreat of many glaciers globally. Reductions of ice-melt inputs to mountain rivers are changing their physicochemical characteristics and, in turn, aquatic communities. Glacier-fed rivers can serve as model systems for investigations of climate-change effects on ecosystems because of their strong atmospheric-cryospheric links, high biodiversity of multiple taxonomic groups, and significant conservation interest concerning endemic species. From a synthesis of existing knowledge, we develop a new conceptual understanding of how reducing glacier cover affects organisms spanning multiple trophic groups. Although the response of macroinvertebrates to glacier retreat has been well described, we show that there remains a relative paucity of information for biofilm, microinvertebrate, and vertebrate taxa. Enhanced understanding of whole river food webs will improve the prediction of river-ecosystem responses to deglaciation while offering the potential to identify and protect a wider range of sensitive and threatened species. [ABSTRACT FROM AUTHOR]

Mountain ecosystems will be strongly impacted by climate change, yet little is known of extant biodiversity in high-elevation lakes, particularly in North America. In this study, we sampled the littoral zone of six alpine and subalpine lakes in Grand Teton National Park (GRTE), Wyoming, to characterise invertebrate diversity and environmental variation in these climate change-threatened ecosystems. Overall, we collected 19 aquatic invertebrate taxa, and found that each lake harboured a unique assemblage of invertebrates despite close geographic proximity in some instances (e.g. less than 5 km). The results of this study complement previous efforts focused on macroinvertebrate diversity of streams in the Teton Range, highlighting much lower diversity in montane lakes vs nearby streams. Taken together, the two studies establish an important baseline understanding of mountain freshwater biodiversity in GRTE. With rapidly changing hydrologic inputs to mountain lakes driven primarily by the recession of alpine glaciers, these results may help target aquatic invertebrates to monitor as climate change affects the region. Moreover, these data clarify habitat factors, both biotic and abiotic, that influence high-elevation lake assemblages of the Teton Range. [ABSTRACT FROM AUTHOR]

Tall-shrub expansion into low-statured communities, a hallmark of recent vegetative change across tundra ecosystems, involves three major genera: Alnus, Betula and Salix. Which genus expands most into tundra landscapes will determine ecosystem properties., We show that Alnus and Salix shrubs segregate thermal space (elevation × insolation) and colonize tundra landscapes differently in response to climate warming, thereby replacing different tundra types., Vegetative change estimated from repeat photography should account for hill-slope. Methodologically, slope determines surface area estimated from orthophotos as projected pixel area times secant of pixel slope. Ecologically, the change in thermally responsive vegetative area is sensitive to terrain steepness, scaling as the cosecant of hill-slope, so that studies should expect more shrub expansion in areas of shallow slopes than steep slopes., Repeat aerial photography in Alaska's Chugach Mountains from 1972 to 2012 orthorectified on a high-resolution lidar digital elevation model indicated tall Salix was rare in 1972 and colonized warmer slopes by 2012. Tall Alnus colonized steeper, cooler slopes both by 2012 and by 1972. Salix and forest colonized similar thermal space. Colonization probability for both shrub genera was maximized at intermediate elevations., Alnus colonization adjacent to dwarf-shrub tundra was twenty times as likely as Salix colonization. Salix colonization adjacent to low-shrub/herbaceous tundra was three times as likely as Alnus colonization. Replacement of dwarf-shrub tundra by Alnus and of low-shrub/herbaceous communities by Salix will affect herbivores and soil properties., Good agreement between observations of plant functional type and multinomial predictions in a thermal space defined by elevation and insolation suggested that these two variables were sufficient for forecast modelling. Spatially explicit, climate-driven generalized linear multinomial and random forest classification models in available thermal space forecast surface areas of forest, Alnus, Salix and tundra over a range of warming, modelled as upward shifted isotherms, including expected IPCC scenarios. Both modelling approaches indicated that shrubs may respond nonlinearly to warming., Synthesis. The provision of taxon-specific coefficients for climate-driven, spatially explicit models using high-resolution digital elevation models is necessary for accurately forecasting vegetative change due to climate warming in montane and arctic regions. [ABSTRACT FROM AUTHOR]

Soil carbon sequestration is strongly affected by soil properties, climate, and anthropogenic activities. Assessing these drivers is key to understanding the effect of land use on soil organic matter stabilization. We evaluated land use and soil depth influencing patterns of soil organic matter stabilization in three types of soil profiles located under the same pedogenetic matrix and alpine conditions but with different vegetation cover. The stock in soil organic carbon in the mean 0-20 cm layer increased from prairie (31.9 t ha-1) to prairie in natural reforestation (42 t ha-1) to forest (120 t ha-1), corresponding to increments of 1.3-fold prairie, for prairie in natural reforestation, and of 3.8-fold prairie for forest. The forest showed the highest humic carbon (21.7 g kg-1), which was 2.8 times greater than the prairie in natural reforestation and 4 times higher than the prairie. 13C-NMR spectroscopic measurements suggested a different C pattern. The prairie in natural reforestation and the prairie were characterized by a higher content in O,N-alkyl C with respect to the forest. Alkyl C and aromatic C in the prairie in natural reforestation and prairie did not show relevant differences while they decreased with respect to the forest. Carboxyl and phenolic C groups were markedly higher in forest and prairie than prairie in natural reforestation. Alkyl C, carboxyl C, and phenolic C prevailed in the Ah horizons whereas aromatic C and O,N-alkyl C were dominant in the B horizons. Overall, the marked distribution of O,N-alkyl C and alkyl C in humic substances (HS) indicates a low degree of humification. Nevertheless, in forest, the relatively high presence of aromatic C designated HS endowed with a relatively high humification degree. Thus, our results might suggest that in the alpine environment of NE Italy differences in soil organic matter (SOM) stocks and characteristics are affected by land use and anthropic activities. [ABSTRACT FROM AUTHOR]

Bogong moths are an iconic Australian insect. They migrate annually in spring from low elevation locations in southern Australia to the Australian Alps where they aestivate during summer. As summer ends they make their return journey to the breeding grounds where they mate, lay eggs, and die. Given the moth's extreme behaviour in seeking out cool alpine habitat and with the knowledge that average temperatures at their aestivation sites are rising because of climate change, we first asked whether increased temperatures affect bogong moth activity during aestivation. We found that moth behaviour patterns changed from showing peaks at dawn and dusk with supressed activity during the day at cooler temperatures to near-constant activity at all times of day at 15 °C. Second, we asked whether moth mass changes after aestivating at different temperatures for a week due to dehydration or consumption of body energy reserves. We found that moth wet mass loss increased with increasing temperature, but found no difference in dry mass among temperature treatments. Overall, our results suggest that bogong moth aestivation behaviour changes with temperature and that it may be lost at around 15 °C. The impact of warming on the likelihood of individuals to complete their aestivation in the field should be investigated as a matter of priority to better understand the impact of climate change on the Australian alpine ecosystem. • Average temperatures at bogong moth aestivation sites are increasing. • Bogong moth aestivation behaviour was disrupted in 15 °C temperatures. • Bogong moth wet mass loss increased in elevated temperature conditions. • Disrupted aestivation behaviour may affect the success of moth aestivation and return migration. [ABSTRACT FROM AUTHOR]

ABSTRACT In this short communication, we report on dissolved organic and inorganic carbon concentrations from a summer stream monitoring campaign at the main hydrological catchment of the Tarfala Research Station in northern Sweden. Further, we place these unique high-alpine observations in the context of a relevant subset of Sweden's national monitoring programme. Our analysis shows that while the monitoring programme (at least for total organic carbon) may have relatively good representativeness across a range of forest coverages, alpine/tundra environments are potentially underrepresented. As for dissolved inorganic carbon, there is currently no national monitoring in Sweden. Since the selection of stream water monitoring locations and monitored constituents at the national scale can be motivated by any number of goals (or limitations), monitoring at the Tarfala Research Station along with other research catchment sites across Fennoscandia becomes increasingly important and can offer potential complementary data necessary for improving process understanding. Research catchment sites (typically not included in national monitoring programmes) can help cover small-scale landscape features and thus complement national monitoring thereby improving the ability to capture hot spots and hot moments of biogeochemical export. This provides a valuable baseline of current conditions in high-alpine environments against which to gauge future changes in response to potential climatic and land cover shifts. [ABSTRACT FROM AUTHOR]

Three permanent alpine springs and their associated pools in the Australian Alps were studied over a summer season to understand their hydrochemical function and characterise the (previously unreported) aquatic macroinvertebrate communities. These 'source' pools represent an extremely limited habitat within Australian alpine peatlands and are likely vulnerable to groundwater flow changes associated with climate change. The pools provide an extremely stable habitat for 30 macroinvertebrate taxa in the harsh alpine environment with near chemostatic conditions and pool temperatures constrained to 5.6-6.3°C despite air temperatures varying between −4.5°C and 30.6°C. Although small in area source pools have a significant effect on nitrate concentrations (decreases) and pH (increases) of waters flowing to downstream Sphagnum-dominated peatlands. The macroinvertebrate communities were distinctly different to that found in peatlands and headwater streams and were dominated by the amphipod Austrocrangonyx sp. (76.6% of total abundance), despite the low pH conditions (pH 5.27-5.56). Some of the macroinvertebrate taxa ( Nannochorista, Anzacladius, and Parochlus) have a Gondwanan and circum-Antarctic distribution, similar to the bryophytes that also occur in these pools ( Bartramia and Blindia). These source pools contribute to the diversity of alpine fauna and should be separately recognised and protected. [ABSTRACT FROM AUTHOR]

Insect flight loss is a repeated phenomenon in alpine habitats, where wing reduction is thought to enhance local recruitment and increase fecundity. One predicted consequence of flight loss is reduced dispersal ability, which should lead to population genetic differentiation and perhaps ultimately to speciation. Using a dataset of 15,123 SNP loci, we present comparative analyses of fine-scale population structure in codistributed Zelandoperla stonefly species, across three parallel altitudinal transects in New Zealand's Rock and Pillar mountain range. We find that winged populations (altitude 200-500 m; Zelandoperla decorata) show no genetic structuring within or among streams, suggesting substantial dispersal mediated by flight. By contrast, wingless populations ( Zelandoperla fenestrata; altitude 200-1100 m) exhibit distinct genetic clusters associated with each stream, and additional evidence of isolation by distance within streams. Our data support the hypothesis that wing-loss can initiate diversification in alpine insect populations over small spatial scales. The often deep phylogenetic placement of lowland Z. fenestrata within their stream-specific clades suggests the possibility of independent alpine colonization events for each stream. Additionally, the detection of winged, interspecific hybrid individuals raises the intriguing possibility that a previously flightless lineage could reacquire flight via introgression. [ABSTRACT FROM AUTHOR]

Background:Nitrogen (N) deposition in the Front Range of the southern Rocky Mountains has been increasing for several decades, and has exceeded the critical load for several ecological metrics. Aims:Our objective was to predict potential future ecological changes in alpine zones in response to anthropogenic N deposition based on a review of research from Niwot Ridge, Colorado. Results:Empirical observations and experimental studies indicate that plant, algal and soil microbe species compositions are changing in response to N deposition, with nitrophilic species increasing in abundance. Biotic sequestration of N deposition is insufficient to compensate for greater nitrate production, leading to the potential for acidification and base cation loss. Conclusions:Changes in biotic composition in both terrestrial and aquatic ecosystems have important impacts on ecosystem functioning, including a lower capacity to take up and neutralise the acidifying effect of anthropogenic N, increasing phosphorus limitation of production in terrestrial and aquatic systems, and shifts in rates of N and carbon cycling. Continued elevated N deposition rates coupled with ongoing climate change, including warmer summer temperatures and lower snow cover of shorter duration, will influence the ecological thresholds for biotic and functional changes. We suggest that these thresholds will occur at lower inputs of N deposition under future climate change, meriting reconsideration of current N critical loads to protect sensitive alpine ecosystems. [ABSTRACT FROM PUBLISHER]

The White Mountain arctic butterfly [WMA; Oeneis melissa semidea (Say)] is endemic to the alpine zone of Mts. Washington and Jefferson, New Hampshire, USA, and because of its small and declining population size, it is considered threatened. White Mountain arctic adults occur only within four alpine meadows, and it has been suggested that dispersal, and hence gene flow, may be restricted among these meadow subpopulations. Furthermore, although the WMA likely is biennial (i.e., requires 2 years for development) like all other species of Oeneis, adults emerge annually. Thus the WMA population may be further structured into two allochronic cohorts, reproductively isolated by their asynchronous adult emergence in either even- or odd-numbered years. We assessed the spatial (among meadows) and temporal (between even- and odd-year cohorts) genetic structure and diversity of the WMA using mtDNA and AFLP markers generated from non-lethally sampled wing and leg tissue. We found no evidence for restricted gene flow among meadows. AFLPs indicated weak differentiation between alternate year cohorts; however, it remains unclear whether this resulted from allochronic reproductive isolation or genetic drift. Despite the WMA's small population size and isolation, levels of AFLP genetic diversity were generally high. Rather than focusing on factors related to population connectivity and adult dispersal, our results suggest that management efforts for the WMA should instead focus explicitly on factors affecting recruitment and mortality. [ABSTRACT FROM AUTHOR]

Pseudogymnoascus destructans is the causative fungal agent of white-nose syndrome (WNS), an emerging fungal-borne epizootic. WNS is responsible for a catastrophic decline of hibernating bats in North America, yet we have limited understanding of the physiological interactions between pathogen and host. Pseudogymnoascus destructans severely damages wings and tail membranes, by causing dryness that leads to whole sections crumbling off. Four possible mechanisms have been proposed by which infection could lead to dehydration; in this study, we tested one: P. destructans infection could cause disruption to passive gasexchange pathways across the wing membranes, thereby causing a compensatory increase in water-intensive pulmonary respiration. We hypothesized that total evaporativewater loss would be greater when passive gas exchange was inhibited. We found that bats did not lose more water when passive pathways were blocked. This study provides evidence against the proposed proximal mechanism that disruption to passive gas exchange causes dehydration and death to WNS-infected bats. [ABSTRACT FROM AUTHOR]

Alpine ecosystems are globally at risk from climate change. We use the International Union for the Conservation of Nature ( IUCN) Red List Criteria for ecosystems to assess the risk of ecosystem collapse in Australian alpine snow patch herbfields. These ecosystems occur on both mainland Australia and Tasmania. They are restricted to steep, south-easterly slopes where snow pack persists well into the summer growing season. Consequently, they are rare, and have high conservation significance. We evaluated the risk of snow patch herbfield 'ecosystem collapse' against criteria that accounted for the ecosystem's restricted distribution, projected decline in the snowpack and increased rates of invasion by taller growing native species of shrub and grass. Our analyses revealed considerable uncertainty in estimates of risk based on some criteria, particularly those related to thresholds of ecosystem collapse caused by biotic change. On the basis of the IUCN Red List criteria, we conclude that the ecosystem is 'endangered'. This is because of the restricted geographical distribution of the ecosystem, a substantial and highly likely decline in the abundance of snow (the principal abiotic driver of the ecosystem), and the prospect of invasion of much of the ecosystem by taller growing native shrubs and grasses. Our case study demonstrates the utility of the Red List methodology for assessing risks to biodiversity in rare ecosystems where changes to both abiotic factors and the relative dominance of native species constitute major threats. Our findings indicate the importance of snow patch herbfields as refugia for dwarf alpine plant species in the face of climate change, the need for continued monitoring, the removal of feral animals from the Australian Alps and scenario planning. [ABSTRACT FROM AUTHOR]