Alpine Habitats Research Articles

Warming had contrasting effects on the importance of facilitative interactions with a cushion nurse species on native and non‐native species in the high‐Andes of central Chile

Alpine habitats are regarded as particularly vulnerable to the effects of climate change. On one hand, global warming is supposed to contributes to alpine environments becoming less stressful. On the other hand, altered snowpack due to warmer temperatures can intensify the stress in these habitats. The presence of non‐native plants on some of these habitats is due to the facilitative effects exerted by native nurse plants, becoming an additional threat. According to the stress gradient hypothesis the importance of facilitative interactions with nurse species is expected to diminish as environmental harshness decreases due to climate change yet remains important if climate change heightens the stress in alpine habitats. However, the responses also depend on climate change's impact on the nurse species. We conducted an experimental warming experiment in the Andes of the central Chile to assess the effects of warmer temperatures on the growth, reproduction and photochemical efficiency of the cushion nurse plant Azorella madreporica. Further we performed a cushion removal experiment involving three native species (Gamocarpha ventosa, Nocaccea magellanica and Rytidosperma pictum) and two non‐native species (Cerastium arvense and Taraxacum officinale) to assess whether facilitative interactions changed with warming. We expected that under warmer conditions facilitation continued be important for the native species but decreased for the non‐natives as the latter are abundant at warmer low elevations. We found that warmer conditions increased the photochemical efficiency and growth of the nurse cushions. Removal of cushions resulted in high mortality rates for all species. However, under warmer conditions, native species exhibited lower survival rates, whereas non‐natives showed no significant changes compared to control groups. In summary, warmer temperatures were beneficial for the nurses maintaining the importance of facilitative interactions for native species, but not for the non‐natives.

A new approach for assessing winning and losing plant species facing climate change on the GLORIA alpine summits

Climate change in alpine habitats has a direct impact on vascular plant species, and is leading to changes in species abundance and distribution. Alpine plant communities are expected to experience a turnover of species over time, due to the loss of cold-adapted specialists and the upslope migration of more thermophilic taxa. Therefore, assessments of single species changes are important for research and conservation. Here, we propose a new analysis protocol for the GLORIA (GLobal Observation Research Initiative in Alpine environments) network, and potentially, for other monitoring programmes capable of defining winning and losing plant species. The proposed approach involves the non-parametric Cliff's ‘Delta’ measure of ‘effect size’, which provides a measure of the intensity of species abundance changes over time and is applicable for vegetation data collected using both re-visitation and long-term monitoring approaches. Compared to other methods, Cliff's ‘Delta’ was more conservative and efficient in detecting winning/losing taxa, as well as being suitable to analyse data of rare species with few records. To test the effectivity of the Cliff ‘Delta’ method, we analysed the vegetation data from three Italian GLORIA sites. We investigated 413 vascular plant species and found a total of 41 winning and 24 losing species. Moreover, we used Cliff ‘Delta’ to assess whether plant assemblages are responding differently among sites and plant growth forms. Our findings showed that alpine plant communities are changing faster on Apennines sites and that growth form types respond differently across the study sites.

Habitat turnover in Iberian and Italian lizards: Is it climatically, spatially, or phylogenetically determined?

AbstractThe Mediterranean peninsulas host rich assemblages of lizards, but little is known about the factors that limit their habitat use on large spatial scales. In this study, we investigated the variation in habitat use of 29 species of lacertid lizards on the Iberian and Italian peninsulas and the transitional region of southeastern France. We investigated whether the types of habitat used were phylogenetically determined or, in contrast, were more influenced by spatial or climatic effects. We characterized the vegetal composition of 483 habitats used by lacertids and estimated the contribution of each component to habitat variability using distance‐based redundancy analysis. We showed that overall turnover patterns were determined similarly in both peninsulas, despite differences in the composition of the lacertid assemblages. The aridity‐related component dominated over the phylogenetic one, which has a weak influence in both regions. The species showed different turnover patterns, being low in those present in cold alpine habitats and shrub‐steppe specialists. In some Iberian endemics, habitat turnover occurs within relatively homogeneous climatic bands. However, in the Italian species, habitat turnover has a comparatively stronger climatic component, suggesting lower climatic specialization. This study shows that species distributions across habitats provide information to assess community properties and can be applied to explore differences among faunal assemblages over large geographic areas. Our results provide evidence that beta diversity can play a key role in structuring patterns of habitat turnover.

Assessing global warming vulnerability of restricted and common plant species in alpine habitats on two Oceanic Islands

Climate change is modifying plant communities and ecosystems around the world. Alpine ecosystems are of special concern on oceanic islands, due to their characteristic higher endemicity percentage, small area and undergoing severe climate change impact in the last few decades. During recent decades there has been increasing interest in the effects of climate change on biodiversity and a range of methods have been developed to assess species vulnerability. However, some new insights are necessary to obtain useful information for species management on oceanic islands. Here in the alpine area of two oceanic islands (Tenerife and La Palma) we evaluate the drivers that best explain the vulnerability of 63 endemic species along three scenarios, covering recent past to present and two future projections (2041–2060 and 2061–2080). The selected drivers were: loss of potential area, mismatch index between potential and occupied areas in different scenarios, and adaptive capacity constraints. We assess the influence of potential area size and whether the drivers of risk and the vulnerability for common, restricted and rare species are significantly different. Our results indicate that management must be widely distributed over the species, and not only focus on restricted species. Evidence for this was that drivers directly deriving from climate change showed no significant differences in their impact on the rarity groups identified. Vulnerability depends partially on the potential area size, showing a more complex picture where constraints on the adaptive capacity of the species have a strong enough influence to modify the effects of the characteristic drivers of climate change.

Oligochaete distribution in alpine freshwaters: not a mere question of altitude

Alpine freshwater biodiversity is at risk of extinction due to climate change and some species could remain undescribed before they go extinct. These species are not yet included in red lists of protection by law, such as annelids in alpine habitats. Within this context, we studied the annelid fauna in 20 sites located between 1223 and 2703 m asl, belonging to different habitat types (kryal, glacio-rhithral, non-glacial streams, springs, littoral lake zone), in three glaciated catchments of the Italian Alps (Noce Bianco, Careser and Conca-Carè Alto; Trentino Province). The aim of this study was to describe the annelid communities of the different habitat types collected with different sampling methods (kick sampling and drift) and investigate the relationships between species richness and abundance with altitude. Between the years 2000 and 2005, we collected 4,765 individuals in 418 samples. One genus of Polychaeta (Aeolosoma) and 36 species of Oligochaeta were identified, distributed in four families: Enchytraeidae (28), Lumbriculidae (4), Naididae (3 and Tubificinae juveniles) and Haplotaxidae (1). Five species were new to Italy: Cernosvitoviella carpatica, Cernosvitoviella cf. crassoductus, Henlea brucei, Henlea glandulifera and Mesenchytraeus sanguineus. As expected, Enchytraeidae prevailed in all sites with the genera Cernosvitoviella and Cognettia the most abundant and frequent. The regression and cluster analyses and the generalized linear mixed models we performed, highlighted that the differences in species richness and abundance among sites are explainable partly by altitude but mainly by habitat type. A clear longitudinal species turnover was evident only in the Noce Bianco and Careser glacier-fed streams, where taxonomic diversity (tested by Seriation analysis) and abundance increased with increasing distance from the glacier front and decreasing altitude. Also expected, the harsh kryal habitat was the poorest in species and individuals, with a dominance of semi-aquatic and terrestrial enchytraeid taxa. Drift was found to be more effective than kick sampling in collecting oligochaetes, especially in glacier-fed streams where the use of the pond net is generally hindered by their high and highly variable discharge. In conclusion, this study provides new data on oligochaete fauna in alpine freshwaters, useful to implement the prevision models for Alpine biodiversity up to date not including annelid fauna.

Snow flies self-amputate freezing limbs to sustain behavior at sub-zero temperatures

Temperature profoundly impacts all living creatures. In spite of the thermodynamic constraints on biology, some animals have evolved to live and move in extremely cold environments. Here, we investigate behavioral mechanisms of cold tolerance in the snow fly (Chionea spp.), a flightless crane fly that is active throughout the winter in boreal and alpine environments of the northern hemisphere. Using thermal imaging, we show that adult snow flies maintain the ability to walk down to an average body temperature of -7°C. At this supercooling limit, ice crystallization occurs within the snow fly's hemolymph and rapidly spreads throughout the body, resulting in death. However, we discovered that snow flies frequently survive freezing by rapidly amputating legs before ice crystallization can spread to their vital organs. Self-amputation of freezing limbs is a last-ditch tactic to prolong survival in frigid conditions that few animals can endure. Understanding the extreme physiology and behavior of snow insects holds particular significance at this moment when their alpine habitats are rapidly changing due to anthropogenic climate change. VIDEO ABSTRACT.

Habitat Loss and Biotic Velocity Response to Climate Change for Alpine Plant Species in Atlantic Oceanic Islands

Climate change may shift species outside of their current climatic tolerances, which can be problematic for oceanic islands with limited options for species migration. Their alpine habitats, which represent islands within islands, are a special concern due to high endemism rates. The Canary Islands have two examples for such fragile ecosystems above 2000 m, on La Palma and Tenerife. This study contributes an assessment of the Canary Islands’ climatic habitat for 47 alpine plant species under observed climate change (1959–1989 versus 1990–2019 periods) as well as for future projections (2041–2060 and 2061–2080 periods). We analyzed the contraction of climatic habitats and migration requirements (biotic velocity) for each species to compensate for observed and predicted climate change. Our results suggest that temporary climate refugia exist on Tenerife but are insufficient on La Palma, where habitat loss due to historical climate change has already created an area of significant concern: the Cumbre Vieja Natural Park. On Tenerife, current alpine species can find suitable climate habitats in the caldera area and on the Teide-Pico Viejo volcano. That said, migration paths toward these refugia are long and complex, and human-assisted migration may be required. Species-specific statistics to support such management interventions are provided in this study.

Bacterial community diversity and underlying assembly patterns along vertical soil profiles in wetland and meadow habitats on the Zoige Plateau, China

Microorganisms are found throughout the soil, however, our understanding of microbial diversity and the underlying assembling patterns is mostly limited to the surface horizons (0–20 cm). In this study, soil samples were collected from a total of 12 integral vertical soil profiles (from the surface layer to the parent material, up to 5 m depth) from two typical alpine habitats (wetland and meadow) in the Zoige Plateau, China. As determined from 16S rRNA sequencing, soil bacterial diversity and community composition were unique to each habitat. Similar decays in bacterial similarity over distance along soil vertical profiles were observed in both habitats, and taxonomic turnover rates were higher than phylogenetic ones. Bacterial distribution greatly depended on soil depth, with most oligotrophic taxa residing in deeper soil layers. Soil macro-nutrients were major factors regulating bacterial assembly, however, in deeper soil layers with lower nutrient effectiveness, minerals such as manganese, potassium, and sulfur were more influential. Along the whole profile, community assembly was driven mainly by deterministic processes (mostly heterogeneous selection) and to a lesser extent by stochastic processes, as shown by both a null model-based β-nearest taxon index and a normalized stochastic ratio. The habitats differed in the importance of these processes, however, with deterministic processes playing a larger role in bacterial assembly in meadows than in wetlands, and with community members in alpine meadows having narrower environmental thresholds and stronger phylogenetic signals. Additionally, bacterial communities in the subsoil exhibited a narrower niche breadth and were susceptible to deterministic processes. This trend was accompanied by the weaker phylogenetic conservation, suggesting their lower adaptation to environmental changes compared to the topsoil. Overall, our study investigated bacterial biodiversity patterns and the potential processes underlying bacterial assemblage along the vertical soil profile, and provided the first data regarding the vertical geography of soil bacterial communities in typical alpine habitats.

Forced sympatry? Spatiotemporal interactions of ursids, the Himalayan brown bear and the Asiatic black bear, along a gradient of anthropic disturbances in Western Himalaya

AbstractThe coexistence of species with similar ecological niches implies that species must segregate along one or more niche axes in order to avoid competition. Partitioning of time, space, or resources is an essential niche dimension along which competitor species tend to coexist. The intensity of interspecific competition may vary under varying anthropogenic pressures, but such knowledge is scarce. We investigated the co‐occurrence patterns of two bear species, Asiatic Black Bear Ursus thibetanus and Himalayan Brown Bear Ursus arctos isabellinus, at two sites in the Western Himalayan region of India with similar ecological conditions and varying anthropogenic pressures. Camera trap datasets from the Great Himalayan National Park (GHNP) in Himachal Pradesh and the Bhagirathi basin in Uttarakhand were used to assess the species interactions. We used two species interaction models and kernel density estimates to understand the co‐occurrence pattern of the bear species and their interactions with humans. Our results provide insights into the spatiotemporal behavior of the two bear species and reveal their sympatric and allopatric relationships in two different anthropogenic environments. We found (1) a prominent association between the two bear species (98%) indicating spatial overlap in GHNP, but found spatial separation among the two species (93%) in Bhagirathi basin (2). In GHNP, the spatially co‐occurring bear species were found to be temporarily segregated, whereas in Bhagirathi, they showed spatial avoidance and similar activity patterns (3). In GHNP, human activities in the alpine habitat had a significant negative impact on brown bear presence. The comparative study revealed that the brown bear uses the forested habitats of GHNP due to high anthropogenic disturbances in the alpine areas, whereas no spatial association was observed in the Bhagirathi basin with comparatively low anthropogenic disturbances. The results highlight that, in addition to biological factors, anthropogenic pressures can also influence interspecific competition.

Underestimated diversity in high elevations of a global biodiversity hotspot: two new endemic species of Aethionema (Brassicaceae) from the alpine zone of Iran.

Although the mountains in South-West Asia are a global biodiversity hotspot, our understanding of their biodiversity, especially in the commonly remote alpine and subnival zones, is still limited. This is well exemplified here by Aethionema umbellatum (Brassicaceae), a species considered to have a wide yet disjoint distribution in the Zagros and Yazd-Kerman mountains of western and central Iran. Morphological and molecular phylogenetic data (based on plastid trnL-trnF and nuclear ITS sequences) show that A. umbellatum is restricted to a single mountain range in southwestern Iran (Dena Mts., southern Zagros), whereas populations from central Iran (Yazd-Kerman and central Zagros) and from western Iran (central Zagros) belong to species new to science, A. alpinum and A. zagricum, respectively. Both new species are phylogenetically and morphologically close to A. umbellatum, with which they share unilocular fruits and one-seeded locules. However, they are easily distinguishable by leaf shape, petal size, and fruit characters. This study confirms that the alpine flora of the Irano-Anatolian region is still poorly known. As the proportion of rare and local endemic species in alpine habitats is high, these habitats are of prime interest for conservation efforts.

Stoichiometric Characteristics of Abies georgei var. smithii Plants in Southeast Tibet

In order to elucidate the adaptation mechanisms of the stoichiometric characteristics of Abies georgei var. smithii in southeastern Tibet to different habitats, the spatial and temporal dynamics of the nutrient contents and stoichiometric ratios among the leaf, branch, stem, and root organs were analyzed on Sejila Mountain in southeastern Tibet at different elevations (3500 m, 3900 m, and 4300 m). The results show that (1) the C and K contents of the fir organs did not change significantly with increasing elevation in the same season, while the N and P contents showed an overall increasing trend with increasing elevation, with the C and N contents being the highest in the leaves. The distribution order was leaves > branches > roots > stem; the P and K content order in each organ was branches > leaves > roots > stem. (2) At the same elevation and in different seasons, the Abies georgei var. smithii organs showed a similar convergence in terms of nutrient storage and utilization strategies, and more nutrients were optimally allocated between the assimilated and stored organs in the alpine habitats, which represents a “trade-off” strategy. (3) Compared to the findings of the global-scale studies, this study area has low N, P, and K contents, and its growth is limited by both N and P. Due to physiological and nutrient balance constraints, the content of the N-limited elements in the plants is relatively stable, which is in line with the “limiting element stability hypothesis”. (4) Principal component analysis showed that the influence of environmental factors on the stoichiometric characteristics of the different organs of Abies georgei var. smithii had a spatial scale effect, and that Abies georgei var. smithii demonstrated increased accumulation of N and P contents when subjected to environmental stress, which promoted the domestication and adaptation of the plant, enabling it to show good nutrient accumulation capacity and good adaptation strategies even at high elevation; thus, it has become a pioneer tree species at high elevations. This research work shows that the resilient adaptation of Abies georgei var. smithiir to environmental change has led to differences in the nutrient uptake and use efficiency and the adaptation patterns of the organs at different altitudinal gradients, with each organ adapting to habitat changes by adjusting its nutrient storage strategy between habitats.

Sampling a pika's pantry: Temporal shifts in nutritional quality and winter preservation of American pika food caches

AbstractClimate change is increasing temperature, decreasing precipitation, and increasing atmospheric CO2 concentrations in many ecosystems. As atmospheric carbon rises, plants may increase carbon‐based defenses, such as phenolics, thereby potentially affecting food quality, foraging habits, and habitat suitability for mammalian herbivores. In alpine habitats, the American pika (Ochotona princeps) is a model species for studying effects of changing plant chemistry on mammals. To survive between growing seasons, pikas cache “haypiles” of plants rich in phenolics. Although they are toxic to pikas, phenolic compounds facilitate retention of plant biomass and nutrition during storage, and they degrade over time. Alpine avens (Geum rossii, Rosales: Rosaceae) is a high‐phenolic plant species that comprises up to 75% of pika haypiles in Colorado. Here, we tested the hypothesis that contemporary climate change has affected the nutritional value of alpine avens to pikas in the last 30 years. Specifically, we compared phenolic activity, nutritional quality, and overwinter preservation of plants collected at Niwot Ridge, Colorado (USA), in 1992 to those collected between 2010 and 2018, spanning nearly three decades of climate change. Phenolic activity increased in alpine avens since 1992, while fiber and nitrogen content decreased. Importantly, overwinter preservation of plant biomass also increased, particularly on windblown slopes without long‐lasting snow cover. Previous studies indicate that pikas at this site still depend on alpine avens for their winter food caches. Higher phenolic content in alpine avens could therefore enhance the preservation of haypiles over winter; however, if pikas must further delay consuming these plants to avoid toxicity or invest extra energy in detoxification, then the nutritional gains from enhanced preservation may not be beneficial. This study provides important insights into how climate‐driven changes in plant chemistry will affect mammalian herbivores in the future.

A Comparison of Small Rodent Assemblages after a 20 Year Interval in the Alps.

Human-induced environmental alterations in the Alps may importantly affect small mammal species, but evidence in this sense is limited. We live-trapped small rodents in the Central-Eastern Italian Alps in three close-by habitat types (rocky scree, alpine grassland, and heath) at 2100 m a.s.l. during summer-fall, in 1997 and 2016. We compared small rodent assemblages through a Redundancy Detrended Analysis (RDA). In both surveys, we detected two specialist species, i.e., the common vole (Microtus arvalis) and the snow vole (Chionomys nivalis), and, unexpectedly, the forest generalist bank vole (Myodes glareolus). In 1997, grassland was mainly occupied by the common vole, while the bank vole and the snow vole were sympatric in the other habitats. In 2016, the snow vole was detected only in the scree, while other species did not show distribution changes. We discuss a series of hypotheses that might have driven the differences observed across decades, among which is a species-specific response to abiotic and biotic environmental alterations, with the alpine habitat specialist moving out of sub-optimal habitats. We encourage further research on this topic, e.g., via long-term longitudinal studies.

Habitat selection and population status of breeding Wood Snipe Gallinago nemoricola in an alpine meadow in Sichuan, China

Summary The Wood Snipe Gallinago nemoricola is one of the least known shorebird species, and its habitat associations are very poorly understood. Here we provide the first assessment of the habitat use of the Wood Snipe during the breeding season. Between May and July 2021 at a 4-km2 alpine meadow in Sichuan province, China, we conducted population surveys and behavioural observations to identify sites where breeding Wood Snipe occurred and foraged. We quantified the habitat characteristics and food resource availability of these sites and compared them with randomly selected “background” sites. Comparison between 34 occurrence sites and 25 background sites indicated that during the breeding season, Wood Snipes are not distributed evenly across alpine meadow habitats, but preferred habitats in the lower part (3,378–3,624 m) of the alpine meadow with intermediate levels of soil moisture. In addition, comparison between 17 foraging sites and 24 background sites showed that the Wood Snipe tended to forage at sites with higher soil fauna abundance. We found weak evidence for denser vegetation cover at its height and no evidence for other biotic habitat variables such as vegetation composition or other abiotic habitat variables such as slope, soil penetrability, or disturbance level to influence Wood Snipe habitat associations. Our results suggest that the actual distribution range of the Wood Snipe during the breeding season may be smaller than expected from the extent of apparently suitable habitat. We advise caution in evaluating the potential habitat availability and distribution of the Wood Snipe, and call for further research to better understand the ecology of this rare species to inform its conservation.

Is Fluctuating Asymmetry a Sufficient Indicator of Stress Level in Two Lizard Species (Zootoca vivipara and Lacerta agilis) from Alpine Habitats?

Alpine habitats are exposed to increasing anthropogenic pressure and climate change. The negative impacts can lead to chronic stress that can affect the survival and reproductive success of individuals and even lead to population extinction. In this study, we analyse different morphological and ecological traits and indices of abiotic and biotic stressors (such as head size and shape, fluctuating asymmetry, body condition index, tail autotomy, and population abundance) in alpine and subalpine populations of two lacertid species (Zootoca vivipara and Lacerta agilis) from Serbia and North Macedonia. These lizards live under different conditions: allotopy/syntopy, different anthropogenic pressure, and different levels of habitat protection. We found differences between syntopic and allotopic populations in pileus size, body condition index (in both species), pileus shape, fluctuating asymmetry (in L. agilis), and abundance (in Z. vivipara). Differences between populations under anthropogenic pressure and populations without it were observed in pileus shape, body condition index (in both species), pileus size, fluctuating asymmetry, tail autotomy and abundance (in L. agilis). On the basis of our results, it is necessary to include other stress indicators in addition to fluctuating asymmetry to quickly observe and quantify the negative effects of threat factors and apply protective measures.

The impact of elevated aestivation temperatures on the behaviour of bogong moths (Agrotis infusa)

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.

Ecosystem engineers in the extreme: The modest impact of marmots on vegetation cover and plant nitrogen and phosphorus content in a cold, extremely arid mountain environment.

Burrowing mammals strongly impact plant communities. One of the main effects is accelerating nutrient cycling and thus promoting plant growth. This mechanism is well-studied in grasslands and alpine habitats, but less is known about this phenomenon in arid, cold mountain environments. We studied ecosystem engineering by long-tailed marmots (Marmota caudata) by measuring the content of plant nitrogen and phosphorus, as well as nitrogen stable isotopes in plant biomass and marmot feces in a distance gradient up to 20 m from marmot burrows in an extremely arid glacier valley in Eastern Pamir, Tajikistan. We also captured aerial images of the area inhabited by marmots to study the spatial distribution of vegetation. There was a weak relationship between the presence of burrows and vegetation cover on soil not covered by burrow material. Burrow mounds were not colonized by plants, as opposed to other studies, where mounds are often microhabitats that enhance plant diversity. A significant increase in N and P in aboveground green plant biomass in the proximity of burrows was found in one out of six studied plant species. Contrary to our expectations, stable N isotopes did not give further insight into N routing. We assume that plant growth is strongly limited by water availability, which prevents them from utilizing the local increase in nutrients, certainly provided by marmot activity. The results are contrary to numerous studies, which showed that the role of burrowing animals as ecosystem engineers increases with increasing abiotic stress, including aridity. This shows a lack of this type of study at the end of the gradient of abiotic factors.

Effect of geographic isolation on genetic variation and population structure of Euphrasia nankotaizanensis, a threatened endemic alpine herb in Taiwan

Euphrasia nankotaizanensis (Orobanchaceae) is a rare alpine herb that is endemic to Taiwan. Only four small populations remain in Xue, Nanhu, and Cilai Mountains of Taiwan. The distribution of alpine herbs is severely threatened by climate change, which influences genetic variation and population structure. In this study, we investigated the effects of the natural isolation of alpine habitats on the genetic diversity and geographic structure of populations of E. nankotaizanensis using chloroplast (cp) and nuclear DNA (nrDNA) markers. We found lower levels of genetic diversity in E. nankotaizanensis than in other alpine plants and little to no genetic variation within populations, which could be mainly attributed to the small population size and genetic drift. Only one nrDNA haplotype was present in each population. The lack of monophyly of the four populations in cpDNA probably resulted from lineage sorting or occasional long-distance seed dispersal. Phylogeographic analysis suggested that Nanhu Mountain was probably a refugium over the glacial maxima, agreeing with the potential refugia in central Taiwan. The STRUCTURE and AMOVA analyses revealed significant genetic differentiation in nrDNA among the mountains, which resulted from geographical isolation among these mountains. Estimates of the effective population size (Ne) and demography reflected lower Ne values and a recent population decline, probably implying a greater extinction risk for E. nankotaizanensis. We observed genetic depletion and considerable genetic differentiation among mountain populations, which should be considered in future conservation efforts for this species. In addition, this study provides important insights into the long-term potential of alpine herbs in Taiwan, which are useful for a better prediction of their responses to future climate change.

The snow alga Chloromonas kaweckae sp. nov. (Volvocales, Chlorophyta) causes green surface blooms in the high tatras (Slovakia) and tolerates high irradiance.

Seasonally slowly melting mountain snowfields are populated by extremophilic microalgae. In alpine habitats, high-light sensitive, green phytoflagellates are usually observed in subsurface layers deeper in the snowpack under dim conditions, while robust orange to reddish cyst stages can be seen exposed on the surface. In this study, uncommon surface green snow was investigated in the High Tatra Mountains (Slovakia). The monospecific community found in the green surface bloom consisted of vegetative Chloromonas cells (Volvocales, Chlorophyta). Molecular data demonstrated that the field sample and the strain isolated and established from the bloom were conspecific, and they represent a new species, Chloromonas kaweckae sp. nov., which is described based on the morphology of the vegetative cells and asexual reproduction and on molecular analyses of the strain. Cells of C. kaweckae accumulated approximately 50% polyunsaturated fatty acids, which is advantageous at low temperatures. In addition, this new species performed active photosynthesis at temperatures close to the freezing point showed a light compensation point of 126 ± 22 μmol photons·m-2 ·s-1 and some signs of photoinhibition at irradiances greater than 600 μmol photons·m-2 ·s-1 . These data indicate that the photosynthetic apparatus of C. kaweckae could be regarded as adapted to relatively high light intensities, otherwise unusual for most flagellate stages of snow algae.

Phylogeny of Saxifraga section Saxifraga subsection Arachnoideae (Saxifragaceae) and the origin of low elevation shade-dwelling species.

Saxifraga section Saxifraga subsection Arachnoideae is a lineage of 12 species distributed mainly in the European Alps. It is unusual in terms of ecological diversification by containing both high elevation species from exposed alpine habitats and low elevation species from shady habitats such as overhanging rocks and cave entrances. Our aims are to explore which of these habitat types is ancestral, and to identify the possible drivers of this remarkable ecological diversification. Using a Hybseq DNA-sequencing approach and a complete species sample we reconstructed and dated the phylogeny of subsection Arachnoideae. Using Landolt indicator values, this phylogenetic tree was used for the reconstruction of the evolution of temperature, light and soil pH requirements in this lineage. Diversification of subsection Arachnoideae started in the late Pliocene and continued through the Pleistocene. Both diversification among and within clades was largely allopatric, and species from shady habitats with low light requirements are distributed in well-known refugia. We hypothesize that low light requirements evolved when species persisting in cold-stage refugia were forced into marginal habitats by more competitive warm-stage vegetation. While we do not claim that such competition resulted in speciation, it very likely resulted in adaptive evolution.