Alpine Habitats Research Articles

The phylogeny of Syntrichia: An ecologically diverse clade of mosses with an origin in South America.

To address the biodiversity crisis, we need to understand the evolution of all organisms and how they fill geographic and ecological space. Syntrichia is one of the most diverse and dominant genera of mosses, ranging from alpine habitats to desert biocrusts, yet its evolutionary history remains unclear. We present a comprehensive phylogenetic analysis of Syntrichia, based on both molecular and morphological data, with most of the named species and closest outgroups represented. In addition, we provide ancestral-state reconstructions of water-related traits and a global biogeographic analysis. We found 10 major well-resolved subclades of Syntrichia that possess geographical or morphological coherence, in some cases representing previously accepted genera. We infer that the extant species diversity of Syntrichia likely originated in South America in the early Eocene (56.5-43.8 million years ago [Mya]), subsequently expanded its distribution to the neotropics, and finally dispersed to the northern hemisphere. There, the clade experienced a recent diversification (15-12 Mya) into a broad set of ecological niches (e.g., the S. caninervis and S. ruralis complexes). The transition from terricolous to either saxicolous or epiphytic habitats occurred more than once and was associated with changes in water-related traits. Our study provides a framework for understanding the evolutionary history of Syntrichia through the combination of morphological and molecular characters, revealing that migration events that shaped the current distribution of the clade have implications for morphological character evolution in relation to niche diversity.

Mortierellaceae from subalpine and alpine habitats: new species of Entomortierella, Linnemannia, Mortierella, Podila and Tyroliella gen. nov.

Fungi are incredibly diverse, but they are unexplored, especially in the subalpine and alpine zone. Mortierellaceae are certainly one of the most abundant, species-rich, and widely distributed cultivable soil fungal families in terrestrial habitats, including subalpine and alpine zones. The phylogeny of Mortierellaceae was recently resolved based on current state of the art molecular techniques, and the paraphyletic genus Mortierella sensu lato (s.l.) was divided into 13 monophyletic genera. Our extensive sampling campaigns in the Austrian Alps resulted in 139 different Mortierellaceae pure culture isolates representing 13 new species. For the definition of taxa, we applied both classical morphological criteria, as well as modern DNA-based methods. Phylogenetic relationships were resolved based on the ribosomal DNA internal transcribed spacer (rDNA ITS), the large subunit (LSU), and the DNA-directed RNA polymerase II largest subunit 1 (RPB1). In this study, we proposed a new genus and described 13 new species belonging to the genera Entomortierella, Linnemannia, Mortierella and Podila. In addition, we proposed eight new combinations, re-defined E. jenkinii at species level, defined a neotype for M. alpina and lecto- as well as epitypes for M. fatshederae, M. jenkinii, and M. longigemmata. The rDNA ITS region is generally applied as classical barcoding gene for fungi. However, the obtained phylogenetic resolution is often too low for an accurate identification of closely related species of Mortierellaceae, especially for small sampling sizes. In such cases, unambiguous identification can be obtained based on morphological characters of pure culture isolates. Therefore, we also provide dichotomous keys for species identification within phylogenetic lineages. Taxonomic novelties: new genus: Tyroliella Telagathoti, Probst & Peintner; New species: Entomortierella galaxiae Telagathoti, M. Probst & Peintner, Linnemannia bainierella Telagathoti, M. Probst & Peintner, Linnemannia stellaris Telagathoti, M. Probst & Peintner, Linnemannia nimbosa Telagathoti, M. Probst & Peintner, Linnemannia mannui Telagathoti, M. Probst & Peintner, Linnemannia friederikiana Telagathoti, M. Probst & Peintner, Linnemannia scordiella Telagathoti, M. Probst & Peintner, Linnemannia solitaria Telagathoti, M. Probst & Peintner, Mortierella triangularis Telagathoti, M. Probst & Peintner, Mortierella lapis Telagathoti, M. Probst & Peintner, Podila himami Telagathoti, M. Probst & Peintner, Podila occulta Telagathoti, M. Probst & Peintner, Tyroliella animus-liberi Telagathoti, Probst & Peintner; New combinations: Entomortierella basiparvispora (W. Gams & Grinb.) Telagathoti, M. Probst & Peintner, Entomortierella jenkinii (A.L. Sm.) Telagathoti, M. Probst & Peintner; Entomortierella sugadairana (Y. Takash. et al.) Telagathoti, M. Probst & Peintner, Linnemannia zonata (Linnem. ex W. Gams) Telagathoti, M. Probst & Peintner, Linnemannia fluviae (Hyang B. Lee et al.) Telagathoti, M. Probst & Peintner, Linnemannia biramosa (Tiegh.) Telagathoti, M. Probst & Peintner, Linnemannia cogitans (Degawa) Telagathoti, M. Probst & Peintner, Tyroliella pseudozygospora (W. Gams & Carreiro) Telagathoti, M. Probst & Peintner; Epitypifications (basionyms): Mortierella bainieri var. jenkinii A.L. Sm., Mortierella fatshederae Linnem., Mortierella longigemmata Linnem. Neotypification (basionym): Mortierella alpina Peyronel. Citation: Telagathoti A, Probst M, Mandolini E, Peintner U (2022). Mortierellaceae from subalpine and alpine habitats: new species of Entomortierella, Linnemannia, Mortierella, Podila and Tyroliella gen. nov. Studies in Mycology 103: 25-58. doi: 10.3114/sim.2022.103.02.

The selective advantage of mast flowering in Veratrum album subsp. oxysepalum: Implications of the predator satiation hypothesis.

Synchronous, highly variable flower or seed production among years within a population (i.e., masting) has been reported in numerous perennial plants. Although masting provides ecological advantages such as enhancing pollination efficiency and/or escape from predator attack, little is known about the degree of these advantages and variations in masting behavior among populations of conspecific plants. We determined flowering ramet density and reproductive success (fruit-set success and herbivorous damage) of a perennial herb, Veratrum album subsp. oxysepalum, across six lowland and six alpine populations in northern Japan during 2-3 years. We then analyzed the relationship between floral density and reproductive success to assess the ecological significance of mast flowering. Flowering intervals of individual plants were estimated by counting annual scars on rhizomes. Most populations had mast flowering, but the intervals between flowering for individual plants were shorter in the alpine populations than in the lowland populations. Floral damage by stem borers (dipteran larvae) and seed predation by lepidopteran larvae were intense in the lowland populations. Seed production of individual ramets increased with higher floral density owing to the effective avoidance of floral-stem damage and seed predation. Although stem borers were absent in the alpine habitat, seed predation decreased with higher floral density also in the alpine populations. Pollination success was independent of floral density in both of the alpine and lowland populations. These results strongly support the predator satiation hypothesis for mast flowering by this species.

Hotspots of (sub)alpine plants in the Irano‐Anatolian global biodiversity hotspot are insufficiently protected

AbstractAimThe mountainous regions in SW Asia harbour a high number of endemic species, many of which are restricted to the high‐elevation zone. The (sub)alpine habitats of the region are under particular threat due to global change, but their biodiversity hotspots and conservation status have not been investigated so far.LocationSubalpine‐alpine habitats of SW Asia.MethodsDistribution data of all (sub)alpine vascular plant species of the region were compiled, resulting in 19,680 localities from 1672 (sub)alpine species, the majority of them being restricted to the region (76%). Six quantitative indices of species diversity were used on the basis of 0.5° × 0.5° grid cells to identify (sub)alpine hotspots. Hotspots whose surface area in the (sub)alpine zone was covered by nature reserves maximally by 10% were defined as conservation gaps.ResultsA high proportion (80%) of the endemic species of the study area is range‐restricted and narrowly distributed. The results of all six indices were highly correlated. Using the top 5%, 10% and 20% richest cells supported by any index, 32, 53 and 98 cells, respectively, were identified as Hotspots. Almost 60% of these Hotspots at all three levels were identified as unprotected (i.e. constituted Conservation Gaps). Generally, only 22%, 18% and 16%, respectively, of the alpine surface area of the identified Hotspots were covered by nature reserves for the top 5%, 10% and 20% richest cells, respectively.Main conclusionsAlthough the rate of protection in (sub)alpine Hotspots exceeds that of the entire region it is still insufficient, because these Hotspots are much richer in endemic and in range‐restricted species, but at the same time are under high pressure of global change. Therefore, the establishment of new nature reserves with high conservation efficiency in (sub)alpine habitats with a particular focus on the identified Hotspots is strongly recommended.

Effects of Altitude and Leaf Age on Leaf Shape in an Alpine Shrub: The Relevance for the Leaf Area Estimation Model

Nondestructive methods to estimate leaf area (LA) by leaf length (L) and/or width (W) are useful in plant physiology and ecology studies. However, both environmental and ontogenic factors may influence leaf size and/or shape, which may alter the coefficient of LA models. We carried an investigation along an altitudinal gradient in the Sergyemla Mountains, southeast Tibet. In August 2009, we selected nine sites at about every 50 m in altitude from 4,250 m to 4,640 m a.s.l. A total of 4,245 different leaf-aged Rhododendron aganniphum var. schizopeplum (a dominant overstory species) leaves were measured. Compared with the single dimensional models, the two-dimensional model encompassing both L and W (model 5) reflected higher R2 (0.98–0.99) and lower MSE (1.19–3.21) across different leaf age groups for each site, implying that such model could provide the best fit for LA estimation. Analysis of covariance further illustrated that two leaf dimensions model was irrespective of leaf age effects in eight out of the nine sites. Leaf shape (L:W ratio) varied between sites and tended to decrease at higher altitudes (4500–4640 m a.s.l.), leading to significant differences in coefficients of the two-dimension model between every two adjacent sites. For overstory species in alpine habitats, altitude rather than leaf age may affect leaf shape which alters the coefficients of LA estimation models. Since leaf shape of different species (overstory species versus understory ones) may show different responses to a certain environmental gradient, researchers must pay attention to the variation of leaf shape when estimating species-specific LA by measuring L and W, especially when leaves of the top overstory species were collected at different sites.

GABB: A global dataset of alpine breeding birds and their ecological traits

Alpine ecosystems represent varied climates and vegetation structures globally, with the potential to support rich and functionally diverse avian communities. High mountain habitats and species are under significant threat from climate change and other anthropogenic factors. Yet, no global database of alpine birds exists, with most mountain systems lacking basic information on species breeding in alpine habitats, their status and trends, or potential cryptic diversity (i.e., sub-species distributions). To address these critical knowledge gaps, we combined published literature, regional monitoring schemes, and expert knowledge from often inaccessible, data-deficient mountain ranges to develop a global list of alpine breeding bird species with their associated distributions and select ecological traits. This dataset compiles alpine breeding records for 1,310 birds, representing 12.0% of extant species and covering all major mountain regions across each continent, excluding Antarctica. The Global Alpine Breeding Bird dataset (GABB) is an essential resource for research on the ecological and evolutionary factors shaping alpine communities, as well as documenting the value of these high elevation, climate-sensitive habitats for conserving biodiversity.

Global warming pushes the distribution range of the two alpine 'glasshouse' Rheum species north- and upwards in the Eastern Himalayas and the Hengduan Mountains.

Alpine plants’ distribution is being pushed higher towards mountaintops due to global warming, finally diminishing their range and thereby increasing the risk of extinction. Plants with specialized ‘glasshouse’ structures have adapted well to harsh alpine environments, notably to the extremely low temperatures, which makes them vulnerable to global warming. However, their response to global warming is quite unexplored. Therefore, by compiling occurrences and several environmental strata, we utilized multiple ensemble species distribution modeling (eSDM) to estimate the historical, present-day, and future distribution of two alpine ‘glasshouse’ species Rheum nobile Hook. f. & Thomson and R. alexandrae Batalin. Rheum nobile was predicted to extend its distribution from the Eastern Himalaya (EH) to the Hengduan Mountains (HM), whereas R. alexandrae was restricted exclusively in the HM. Both species witnessed a northward expansion of suitable habitats followed by a southerly retreat in the HM region. Our findings reveal that both species have a considerable range shift under different climate change scenarios, mainly triggered by precipitation rather than temperature. The model predicted northward and upward migration for both species since the last glacial period which is mainly due to expected future climate change scenarios. Further, the observed niche overlap between the two species presented that they are more divergent depending on their habitat, except for certain regions in the HM. However, relocating appropriate habitats to the north and high elevation may not ensure the species’ survival, as it needs to adapt to the extreme climatic circumstances in alpine habitats. Therefore, we advocate for more conservation efforts in these biodiversity hotspots.

Parallel Differentiation and Plastic Adjustment of Leaf Anatomy in Alpine Arabidopsis arenosa Ecotypes.

Functional and structural adjustments of plants in response to environmental factors, including those occurring in alpine habitats, can result in transient acclimation, plastic phenotypic adjustments and/or heritable adaptation. To unravel repeatedly selected traits with potential adaptive advantage, we studied parallel (ecotypic) and non-parallel (regional) differentiation in leaf traits in alpine and foothill ecotypes of Arabidopsis arenosa. Leaves of plants from eight alpine and eight foothill populations, representing three independent alpine colonization events in different mountain ranges, were investigated by microscopy techniques after reciprocal transplantation. Most traits clearly differed between the foothill and the alpine ecotype, with plastic adjustments to the local environment. In alpine populations, leaves were thicker, with altered proportions of palisade and spongy parenchyma, and had fewer trichomes, and chloroplasts contained large starch grains with less stacked grana thylakoids compared to foothill populations. Geographical origin had no impact on most traits except for trichome and stomatal density on abaxial leaf surfaces. The strong parallel, heritable ecotypic differentiation in various leaf traits and the absence of regional effects suggests that most of the observed leaf traits are adaptive. These trait shifts may reflect general trends in the adaptation of leaf anatomy associated with the colonization of alpine habitats.

Host generalists dominate fungal communities associated with alpine knotweed roots: a study of Sebacinales.

Bistorta vivipara is a widespread herbaceous perennial plant with a discontinuous pattern of distribution in arctic, alpine, subalpine and boreal habitats across the northern Hemisphere. Studies of the fungi associated with the roots of B. vivipara have mainly been conducted in arctic and alpine ecosystems. This study examined the fungal diversity and specificity from root tips of B. vivipara in two local mountain ecosystems as well as on a global scale. Sequences were generated by Sanger sequencing of the internal transcribed spacer (ITS) region followed by an analysis of accurately annotated nuclear segments including ITS1-5.8S-ITS2 sequences available from public databases. In total, 181 different UNITE species hypotheses (SHs) were detected to be fungi associated with B. vivipara, 73 of which occurred in the Bavarian Alps and nine in the Swabian Alps–with one SH shared among both mountains. In both sites as well as in additional public data, individuals of B. vivipara were found to contain phylogenetically diverse fungi, with the Basidiomycota, represented by the Thelephorales and Sebacinales, being the most dominant. A comparative analysis of the diversity of the Sebacinales associated with B. vivipara and other co-occurring plant genera showed that the highest number of sebacinoid SHs were associated with Quercus and Pinus, followed by Bistorta. A comparison of B. vivipara with plant families such as Ericaceae, Fagaceae, Orchidaceae, and Pinaceae showed a clear trend: Only a few species were specific to B. vivipara and a large number of SHs were shared with other co-occurring non-B. vivipara plant species. In Sebacinales, the majority of SHs associated with B. vivipara belonged to the ectomycorrhiza (ECM)-forming Sebacinaceae, with fewer SHs belonging to the Serendipitaceae encompassing diverse ericoid–orchid–ECM–endophytic associations. The large proportion of non-host-specific fungi able to form a symbiosis with other non-B. vivipara plants could suggest that the high fungal diversity in B. vivipara comes from an active recruitment of their associates from the co-occurring vegetation. The non-host-specificity suggests that this strategy may offer ecological advantages; specifically, linkages with generalist rather than specialist fungi. Proximity to co-occurring non-B. vivipara plants can maximise the fitness of B. vivipara, allowing more rapid and easy colonisation of the available habitats.

Homogenization of bryophyte species after alpine grassland restoration.

The causes of decreasing plant species richness include abandonment of traditional management and the spread of invasive species, even in alpine habitats. Studies on the restoration and management of alpine habitats are predominantly focused on vascular plants, although an important part of alpine vegetation and its diversity is formed by bryophytes. We used bryophytes to indicate changes that occur after the clearcutting of nonindigenous dwarf pine (Pinus mugo Turra) and attempted to reveal the community to which the development of bryophyte species structure was directed. We compared species richness and composition between surveys to test for changes in spatial heterogeneity bryophyte communities. We also tried to reveal the main ecological drivers of the restoration process. The study was performed in the (sub)alpine area of the Eastern High Sudetes Mts. (the Czech Republic). We estimated bryophyte species cover and compared the composition of the bryophyte community in autochthonous grassland areas, areas under the dwarf pine canopy, and clearcut areas to reveal the pattern of shifts 9 years after the treatment. We also measured soil characteristics to reveal the environmental habitat conditions. Evidence of taxonomic homogenization of habitat after dwarf pine removal was found. Light conditions and attributes of litter were the driving factors of successional changes in the bryophyte communities, which led to taxonomic homogenization. This finding explains the slow restoration process due to dwarf pine legacy on the clearcut area. The succession trends were also shaped by unobserved factors, such as climate change and environmental eutrophication. We highly recommended active management and long-term monitoring.

Pollen DNA metabarcoding reveals cryptic diversity and high spatial turnover in alpine plant-pollinator networks.

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.

Description of the female of Platycheirus altomontis Merlin & Nielsen in Nielsen, 2004 (Diptera, Syrphidae) with notes on the occurrence and hilltopping behaviour of rare French montane and Alpine Syrphidae

A focused search in very high (2500–3200 m asl) Alpine mountain tops in France resulted in the discovery of the very rare Alpine-endemic syrphid Platycheirus altomontis Merlin & Nielsen in Nielsen, 2004, including its hitherto unknown female. A description of the female is given and further complemented with behavioural observations of this species with special reference to hilltopping. Additional records and behavioural observations are provided for rare and new species for the French fauna from the montane and Alpine habitat with focus on species of high altitude (>2750 m) and hilltopping behaviour. The species Rohdendorfia alpina Sack 1938 is new to France and was observed in large numbers at scree slopes above 2750 m and males were found sitting at hilltops up to 3200 m. Hilltopping behaviour of Syrphidae was observed over the whole altitudinal range visited, and multiple species engaged in this behaviour even at above 3000 m. Hilltopping appears to be more common in some genera (e.g. Parasyrphus and Pipizella) than in others and may be linked to specific phenotypes in some species. The latter was observed for the species Cheilosia melanura (Becker, 1894) of which at high hilltops much smaller males were found than at lower altitudes.

High nest failure but better nestling quality for early breeders in an alpine population of Northern Wheatear (Oenanthe oenanthe)

Climate change is leading to the advancement of spring conditions, resulting in an earlier snowmelt and green‐up, with highest rates of change in highly seasonal environments, including alpine habitats. Migratory birds breeding at high elevations need to time their arrival and lay dates accurately with this advancement, but also with the annually variable spring conditions at their breeding sites, to maximize nest survival probabilities and reproductive output. Nest survival probability and mean nestling mass were analysed in relation to lay date and habitat conditions in an alpine population of the migratory Northern Wheatear Oenanthe oenanthe collected over six consecutive breeding seasons in the Western Italian Alps. This open grassland species showed the lowest nest survival probability in years with an early onset of spring conditions. Within‐season, nest survival was highest when breeding late, at lower elevations, and when grass cover and grass height were higher. Both across‐ and within‐season, severe weather conditions may indirectly lead to higher early season nest failure rates by increasing predation risk. By contrast, mean nestling mass, and thus the quality of the fledglings, was lower when breeding late. This might be driven by a mismatch with the peak in food abundance. Breeding early is thus generally advantageous in terms of chick quality in our high‐elevation population, but reproductive success is limited by the risk of nest failure that is higher in early springs and early in the season. This trade‐off between breeding early and late may thus allow Northern Wheatears to maximize fitness under highly variable spring conditions. However, climate change may cause disruption to this trade‐off, and shifts in phenology could become a threat for migratory alpine birds that might not be able to keep track of advancing spring conditions.

Energetics of Paper Wasps (Polistes sp.) from Differing Climates during the Breeding Season.

Simple SummaryPaper wasps are widely distributed in nearly all regions of Europe. They are found in the warm Mediterranean, and in the harsh Alpine climate. Some species are very careful in the choice of nesting sites to ensure a proper development of the brood. We investigated microclimate conditions at the nests of three species (P. dominula, P. gallicus, P. biglumis) from differing climates, in order to characterize fine-scale environment conditions and conduct energetic calculations for an entire breeding season. The microclimate conditions (temperature) at the nests differed significantly in the Mediterranean, temperate, and Alpine habitats, but in all habitats the mean ambient nest temperatures were about 2 to 3 °C above the standard meteorological climate data. The wasps’ energetic expenditure depended strongly on temperature. P. gallicus from the warm Mediterranean climate exhibited the highest energetic costs, whereas P. biglumis from the harsh Alpine climate had the lowest costs during a breeding season. The energetic expenditure of P. dominula from the temperate climate was somewhat lower than in the Mediterranean species, but clearly higher than in the Alpine species. Temperature increase due to climate change may have a severe impact on the wasps’ survival as energetic costs increase.Paper wasps are widely distributed in Europe. They live in the warm Mediterranean, and in the harsh Alpine climate. Some species are very careful in their choice of nesting sites to ensure a proper development of the brood. We investigated microclimate conditions at the nests of three species (P. dominula, P. gallicus, P. biglumis) from differing climates, in order to characterize environmental conditions and conduct energetic calculations for an entire breeding season. The mean ambient nest temperature differed significantly in the Mediterranean, temperate, and Alpine habitats, but in all habitats it was about 2 to 3 °C above the standard meteorological data. The energetic calculations of adult wasps’ standard and active metabolic rate, based on respiratory measurements, differed significantly, depending on the measured ambient temperatures or the wasps’ body temperatures. P. gallicus from the warm Mediterranean climate exhibited the highest energetic costs, whereas P. biglumis from the harsh Alpine climate had the lowest costs. Energetic costs of P. dominula from the temperate climate were somewhat lower than those in the Mediterranean species, but clearly higher than those in the Alpine species. Temperature increase due to climate change may have a severe impact on the wasps’ survival as energetic costs increase.

Repeated colonization of alpine habitats by Arabidopsis arenosa viewed through freezing resistance and ice management strategies.

Success or failure of plants to cope with freezing temperatures can critically influence plant distribution and adaptation to new habitats. Especially in alpine environments, frost is a likely major selective force driving adaptation. In Arabidopsis arenosa (L.) Lawalrée, alpine populations have evolved independently in different mountain ranges, enabling studying mechanisms of acclimation and adaptation to alpine environments. We tested for heritable, parallel differentiation in freezing resistance, cold acclimation potential and ice management strategies using eight alpine and eight foothill populations. Plants from three European mountain ranges (Niedere Tauern, Făgăraș and Tatra Mountains) were grown from seeds of tetraploid populations in four common gardens, together with diploid populations from the Tatra Mountains. Freezing resistance was assessed using controlled freezing treatments and measuring effective quantum yield of photosystem II, and ice management strategies by infrared video thermography and cryomicroscopy. The alpine ecotype had a higher cold acclimation potential than the foothill ecotype, whereby this differentiation was more pronounced in tetraploid than diploid populations. However, no ecotypic differentiation was found in one region (Făgăraș), where the ancient lineage had a different evolutionary history. Upon freezing, an ice lens within a lacuna between the palisade and spongy parenchyma tissues was formed by separation of leaf tissues, a mechanism not previously reported for herbaceous species. The dynamic adjustment of freezing resistance to temperature conditions may be particularly important in alpine environments characterized by large temperature fluctuations. Furthermore, the formation of an extracellular ice lens may be a useful strategy to avoid tissue damage during freezing.

Effects of thermal acclimation on the proteome of the planarian Crenobia alpina from an alpine freshwater spring

ABSTRACTSpecies' acclimation capacity and their ability to maintain molecular homeostasis outside ideal temperature ranges will partly predict their success following climate change-induced thermal regime shifts. Theory predicts that ectothermic organisms from thermally stable environments have muted plasticity, and that these species may be particularly vulnerable to temperature increases. Whether such species retained or lost acclimation capacity remains largely unknown. We studied proteome changes in the planarian Crenobia alpina, a prominent member of cold-stable alpine habitats that is considered to be a cold-adapted stenotherm. We found that the species' critical thermal maximum (CTmax) is above its experienced habitat temperatures and that different populations exhibit differential CTmax acclimation capacity, whereby an alpine population showed reduced plasticity. In a separate experiment, we acclimated C. alpina individuals from the alpine population to 8, 11, 14 or 17°C over the course of 168 h and compared their comprehensively annotated proteomes. Network analyses of 3399 proteins and protein set enrichment showed that while the species' proteome is overall stable across these temperatures, protein sets functioning in oxidative stress response, mitochondria, protein synthesis and turnover are lower in abundance following warm acclimation. Proteins associated with an unfolded protein response, ciliogenesis, tissue damage repair, development and the innate immune system were higher in abundance following warm acclimation. Our findings suggest that this species has not suffered DNA decay (e.g. loss of heat-shock proteins) during evolution in a cold-stable environment and has retained plasticity in response to elevated temperatures, challenging the notion that stable environments necessarily result in muted plasticity.

Green-up selection by red deer in heterogeneous, human-dominated landscapes of Central Europe.

The forage maturation hypothesis (FMH) assumes that herbivores cope with the trade‐off between digestibility and biomass in forage by selecting vegetation at intermediate growth. The green wave hypothesis (GWH) extends the FMH to suggest how spatiotemporal heterogeneity in plant quality shapes migratory movements of herbivores. Growing empirical support for these hypotheses mainly comes from studies in vast landscapes with large‐scale habitat heterogeneity. It is unclear, however, to what extent ungulates surf green waves in human‐altered landscapes with small‐scale heterogeneity in terms of land use and topography. We used plant phenological proxies derived from Sentinel 2 satellite data to analyze the habitat selection of 93 collared red deer (Cervus elaphus) in montane and alpine habitats. Using a step selection analysis, we investigated how plant phenology, that is, the instantaneous rate of green‐up (IRG) and normalized difference vegetation index (NDVI), and a set of variables describing topography and human presence influenced red deer resource selection in open habitats. We learned that red deer selected areas with high biomass at green‐up and avoided habitats with possible exposure to human activity. Additionally, landscape structure and topography strongly influenced spatial behavior of red deer. We further compared cumulative access to high‐quality forage across migrant strategies and found migrants gained better access than residents. Many migratory individuals surfed the green wave, and their surfing behavior, however, became less pronounced with decreasing distance to settlements. Within the constraints of topography and human land use, red deer track spring green‐up on a fine spatiotemporal scale and follow the green wave across landscapes in migration movements. Thus, they benefit from high‐quality forage even in human‐dominated landscapes with small‐scale heterogeneity and vegetation emerging in a heterogenic, dynamic mosaic.

Genome size of alpine plants does not predict temperature resistance.

Genome size of alpine plants is not related to their resistance against frost and heat. Genome size is a variable trait in angiosperms, and it was suggested that large genome size represents a constraint in stressful environments. We measured genome size and resistance to frost and heat in 89 species of plants from tropical and temperate alpine habitats. Genome size of the species, ranging from 0.49pg to 25.8pg across the entire dataset, was not related to either frost or heat resistance in either group of plants. Genome size does not predict resistance to extreme temperatures in alpine plants and is thus not likely to predict plant responses to climate changes.

Genotoxic effects of transboundary pollutants in Pinus mugo in the high mountain habitats

This study evaluated the environmental genotoxic load of mountain and alpine habitats of Slovak mountains caused by the total mixture of air pollutants at 69 sites using the phytoindicator Pinus mugo. The level of overall genotoxicity was determined by pollen grain abortion assay. This shows that the test is sensitive enough to detect contamination from more distant sources, including long-range transboundary pollutants. It extends the applicability of this test to mountain environments. Soil and plant samples (pollen, one-two year old needles) were collected during a three-year growing period (2011–2013). The study identified source regions of pollutants by assessments at different altitudes and slope exposures. The highest genotoxicity was found in the Little Fatra Mts. on Suchy Mt., with pollen abortivity 3.52 % which represented a 23.5 times higher genotoxic load than at the control site. Samples from mountain peaks showed a higher genotoxicity in 2012 than in 2011 on most mountains. A gradual increase of pollen abortivity and needle Pb content (one year old) with increasing altitude was found in the vertical transect in Belian Tatras. The influence of subsoil type was analysed; higher genotoxicity and Pb content in soil and needles were found on limestone subsoil (Sivy vrch Mt.) and higher values of needle Cd were on granite (Brestova Mt.). The highest Pb and Cd concentrations in needles were measured in the Great Fatra Mts. on Krizna Mt. situated between highly-industrialized areas. The other mountain ranges with the high loading by Pb, Cd were Chocske vrchy Mts. and Low Tatra Mts. The lead content increased with needle age, but the correlation between soil Pb and needle Pb was not confirmed. The positive correlation between soil Pb and abortivity was found only at mountain peaks. The results showed a significant impact of both local industrial and transboundary sources of pollutants. Based on the results, the studied Slovak mountains were not strongly burdened by Pb, Cd and an overall mixture of air pollutants. This methodological approach may contribute to the assessment of urban exposome by comparing the external exposure in urban environment of big cities with background - mountain areas, where the only possible source is long-range transport.

Ectomycorrhizal fungal communities of Swiss stone pine (Pinus cembra) depend on climate and tree age in natural forests of the Alps

Background and AimsPinus cembra represent a typical and important tree species growing in European subalpine and alpine habitats. The ectomycorrhizal (ECM) fungal communities associated to this tree under natural conditions are largely unknown.MethodsIn this study, we investigated the ECM fungal abundance and composition at four high-altitude sites (two northern-exposed and two southern-exposed habitats) in South Tyrol (Italy), and included also two different age classes of P. cembra. The ECM partners were characterized morphologically, and identified by rDNA ITS sequence analysis.ResultsThe degree of mycorrhization in adult P. cembra was typically 100% in these natural habitats, with a total species diversity of 20 ECM species. The four high-altitude sites were similar concerning their species richness and mycobiont diversity, but they differed significantly in ECM species composition. Young P. cembra had a mycorrhization degree of 100% and a total of 10 species were observed. All mycorrhizal partners of naturally regenerated young P. cembra were only detected in one specific location, with the exception of Cenococcum sp. and Amphinema sp. which were detected at two sites. Young trees harbour a distinct ectomycorrhizal fungal diversity, which is clearly lower than the diversity detected in adult P. cembra trees. The P. cembra bolete (Suillus plorans) is the most important symbiotic partner of P. cembra at Southern Tyrolean high-altitude sites and is known for its strict, species-specific host association.ConclusionsThe ectomycorrhizal fungal community composition strongly depends on geographic region and on the slope exposure (north or south) of the site.