Elevational Shifts Research Articles

A coupled modelling framework for predicting tree species’ altitudinal migration velocity in montane forest

Climate change is projected to cause rapid elevational migration of mountain plants. However, it is poorly understood the direction and magnitude of elevational range shifts across species because species’ life history traits are highly individualistic. Species with limited dispersal ability, reproductive rate, and ecological generalization may hardly expand into new regions under climate change. Therefore, such species’ shifts may not keep pace with climate change. We used a new framework for coupling a forest ecosystem model (LINKAGES) and a landscape model (LANDIS PRO), that accounted for climate change, population dynamics, and species’ life history traits to predict tree species’ migrations. We quantified the velocity of tree migration under different climate scenarios. We further investigated the effects of climate change and life history traits on tree species’ elevational migration. We found climate change accelerated the upward shifts at the optimum elevation and the leading edge, and limited the downward migration capacity of tree species at optimum elevation and the rear edge. The velocities of tree species’ elevational shifts (usually < 1.5 m/year) lagged behind those of climate change (about 25 m/year) under the climate change scenario. Range shifts at the leading edge, optimum elevation, and rear edge tended to be associated with temperature, precipitation, and thermal tolerance. However, species’ drought tolerance, shade tolerance, and seed dispersal ability had little effect on the velocity of simulated range shifts. Our results suggest that wide variation in tree range shift is likely driven by individual species’ life history traits in response to interacting environmental factors. This study underscores the importance of understanding the role of species’ life history traits when predicting future tree species’ distribution.

An elevational shift facilitated the Mesoamerican diversification of Azure-hooded Jays (Cyanolyca cucullata) during the Great American Biotic Interchange.

The Great American Biotic Interchange (GABI) was a key biogeographic event in the history of the Americas. The rising of the Panamanian land bridge ended the isolation of South America and ushered in a period of dispersal, mass extinction, and new community assemblages, which sparked competition, adaptation, and speciation. Diversification across many bird groups, and the elevational zonation of others, ties back to events triggered by the GABI. But the exact timing of these events is still being revealed, with recent studies suggesting a much earlier time window for faunal exchange, perhaps as early as 20 million years ago (Mya). Using a time-calibrated phylogenetic tree, we show that the jay genus Cyanolyca is emblematic of bird dispersal trends, with an early, pre-land bridge dispersal from Mesoamerica to South America 6.3-7.3 Mya, followed by a back-colonization of C. cucullata to Mesoamerica 2.3-4.8 Mya, likely after the land bridge was complete. As Cyanolyca species came into contact in Mesoamerica, they avoided competition due to a prior shift to lower elevation in the ancestor of C. cucullata. This shift allowed C. cucullata to integrate itself into the Mesoamerican highland avifauna, which our time-calibrated phylogeny suggests was already populated by higher-elevation, congeneric dwarf-jays (C. argentigula, C. pumilo, C. mirabilis, and C. nanus). The outcome of these events and fortuitous elevational zonation was that C. cucullata could continue colonizing new highland areas farther north during the Pleistocene. Resultingly, four C. cucullata lineages became isolated in allopatric, highland regions from Panama to Mexico, diverging in genetics, morphology, plumage, and vocalizations. At least two of these lineages are best described as species (C. mitrata and C. cucullata). Continued study will further document the influence of the GABI and help clarify how dispersal and vicariance shaped modern-day species assemblages in the Americas.

Local colonisations and extinctions of European birds are poorly explained by changes in climate suitability

Climate change has been associated with both latitudinal and elevational shifts in species’ ranges. The extent, however, to which climate change has driven recent range shifts alongside other putative drivers remains uncertain. Here, we use the changing distributions of 378 European breeding bird species over 30 years to explore the putative drivers of recent range dynamics, considering the effects of climate, land cover, other environmental variables, and species’ traits on the probability of local colonisation and extinction. On average, species shifted their ranges by 2.4 km/year. These shifts, however, were significantly different from expectations due to changing climate and land cover. We found that local colonisation and extinction events were influenced primarily by initial climate conditions and by species’ range traits. By contrast, changes in climate suitability over the period were less important. This highlights the limitations of using only climate and land cover when projecting future changes in species’ ranges and emphasises the need for integrative, multi-predictor approaches for more robust forecasting.

A Holocene pollen-inferred climate reconstruction for Vermont, USA

AbstractA 13.0 cal ka BP pollen record from Twin Ponds, Vermont, provides new insights into the climate history of the northeastern United States. Modern analogs were used to produce qualitative and quantitative climate reconstructions for Twin Ponds. The Twin Ponds record was compared with nearby Knob Hill Pond to develop a Vermont reconstruction that was compared with reconstructions from two sites at a similar latitude. Postglacial warming at 11.5 cal ka BP followed a cool, wet Younger Dryas and was the largest temperature change of the record. The warmest, driest conditions occurred at ca. 9.0 cal ka BP, followed by an increase in moisture. Latitudinal and elevational shifts in the location of modern analogs from 5.7 to 4.0 cal ka BP were used to infer cooling and increased moisture during the Tsuga canadensis decline. Analysis of the timing of pollen events between the two Vermont sites suggests a more rapid decline in T. canadensis at the more northern Knob Hill Pond and further supports the possibility that colder temperatures contributed to this event. The other northern sites show similar trends until 2.5 cal ka BP, when precipitation in the easternmost site diverges, indicating the establishment of modern climatic gradients.

Photocatalytic water splitting from MXene and substoichiometric molybdenum oxide ultrathin nanowire Schottky heterojunction

Due to the positive conduction band of MoO3, it is typically unable to generate hydrogen under photocatalysis. In this work, we reported direct photocatalytic hydrogen evolution from substoichiometric MoO3-x ultrathin nanowire using sacrificial triethanolamine. By incorporating trace amounts of oleylamine and the ligand polyvinyl pyrrolidone, blue ultrathin MoO3-x nanowires with the diameter of approximately 2 nm were effectively created through a simple hydrothermal method. These one-dimensional MoO3-x ultrathin nanowires boast a modified energy band structure, which promotes an elevated shift in the conduction band and favors the availability of more active sites. These factors jointly contribute to direct photocatalytic hydrogen evolution by MoO3-x ultrathin nanowires. Moreover, we introduced MXene Ti3C2Tx as a cocatalyst, enabling the fabrication of MXene Ti3C2Tx-MoO3-x composites via a simple two-phase composite method. The implementation of MXene Ti3C2Tx as a substrate effectively isolates photogenerated electron-hole duos, resulting in boosted performance in generating hydrogen and oxygen through photocatalysis. The optimized MXene Ti3C2Tx-MoO3-x composites demonstrate exceptional photocatalytic performance, with hydrogen and oxygen evolution rates reaching 36.1 and 1044.2 μmol·h-1g-1, respectively. These values signify a remarkable 6 and 3.2-fold increase over raw material. This method of synthesizing size-tunable MoO3-x nanowires and MXene Ti3C2Tx-MoO3-x composites presents a promising avenue for research in energy and allied fields.

Analysis of the Vigor of Pinus hartwegii Lindl. along an Altitudinal Gradient Using UAV Multispectral Images: Evidence of Forest Decline Possibly Associated with Climatic Change

Future climate forecasts predict major changes that will have negative impacts on the distribution, abundance, and dynamics of forest ecosystems. In Mexico, there is evidence of symptoms of massive forest decline; however, there is no consensus in terms of attributing these symptoms to climate change. This study aimed to provide evidence of forest decline possibly associated with climatic change in the highland pine (Pinus hartwegii Lindl.) populations of the Nevado de Toluca Flora and Fauna Protection Area. Using unmanned aerial vehicles (UAV) equipped with multispectral sensors, the study applied digital photogrammetry techniques, automated tree crown detection algorithms, and calculation of the normalized difference vegetation index (NDVI) and leaf chlorophyll index (LCI) to assess forest health across an altitudinal transect (from 3300 m to the timberline at 4040 m elevation). Climate analysis was conducted with TerraClimate data using mean annual temperature (MAT), April temperature, and Palmer Drought Severity Index (PDSI) from the studied altitudinal transect and its xeric limit. We found that lower altitude populations had significantly higher stress levels, indicating forest decline phenomena, while intermediate altitude populations showed greater vigor of the detected trees. Statistically significant differences in the NDVI and LCI values along the altitudinal gradient provided evidence of forest decline in terms of forest vigor and productivity, with the greatest disturbance found at the lower altitude of the examined forest species. The analysis of the climatic data revealed an increase in April temperature +1.4 °C of the xeric limit of the transect (low altitude) when comparing the reference period, 1961–1990 (mean: 12.17 °C), with the decade prior to our study (2011–2020; mean: 13.57 °C). This would be equivalent to an upward shift in elevation of 280 m of the xeric limit. In addition, the PDSI analysis revealed that droughts are becoming increasingly intense at a rate of 0.06 PDSI units per decade, with greater intensity in the last five years. These findings highlight the negative impacts of climate change on forest ecosystems and the urgent need for alternative forest management and conservation practices to increase resilience and adaptation in the temperate forests of Mexico. This study sets a precedent for further research to improve our understanding of the impacts of climate change on forest ecosystems and the development of sustainable management practices.

Elevational shift in seed plant distributions in China's mountains over the last 70 years

AbstractAimSignificant changes in species elevational ranges in mountains have been repeatedly documented, yet the direction, magnitude and drivers of these shifts remain controversial. Presently, there is still lacking evidence about the general nature of species elevational range shifts in eastern Eurasia in response to anthropogenic climate change. By using historical specimen records and recent field observations for 735 seed plant species across 29 China's mountains, we assessed changes in species' elevational centroids and their drivers.LocationChina.Time Period1950–2018.Major Taxa StudiedSeed plant species.MethodsThe elevation records of all sampled occurrences in each mountain during the two time periods were estimated, and the null models were developed to test the sampling bias. Ecological niche models (ENMs) were used to evaluate the relative importance of climate factors in constraining each species distribution. Generalized linear models (GLMs) to test the relationships between the centroid elevational range shifts of species and different divers.ResultsWe found that 54% of the species shifting upward and 46% downhill. However, species' elevational shifts significantly differed among species and mountains. Herbaceous and lowland species moved upward faster than woody and high‐elevation species. Species in temperate mountains and in mountains with taller elevational gradients moved upward, while species in subtropical mountains and in mountains with shorter elevational gradients moved downward. Precipitation changes experienced by species, species' climatic adaptations, several species' functional traits and mountain size all contributed to explain the magnitude of species' centroid elevational range shifts.Main ConclusionsOur results highlight complex biodiversity redistribution of seed plants across Chinese mountains, not necessarily conforming to the trend of species upward shifts in elevation. Changes in precipitation regimes may blur the simplistic assumption of isotherm tracking. This study fills an important geographic shortfall for our understanding of biodiversity redistribution under anthropogenic climate change.

Drivers of strong isolation and small effective population size at a leading range edge of a widespread plant

Climate change has influenced species distributions worldwide with upward elevational shifts observed in many systems. Leading range edge populations, like those at upper elevation limits, are crucial for climate change responses but can exhibit low genetic diversity due to founder effects, isolation, or limited outbreeding. These factors can hamper local adaptation at range limits. Using the widespread herb, Argentina anserina, we measured ecological attributes (population density on the landscape, area of population occupancy, and plant and flower density) spanning a 1000 m elevation gradient, with high elevation populations at the range limit. We measured vegetative clonal potential in the greenhouse for populations spanning the gradient. We combined these data with a ddRAD-seq dataset to test the hypotheses that high elevation populations would exhibit ecological and genomic signatures of leading range edge populations. We found that population density on the landscape declined towards the high elevation limit, as is expected towards range edges. However, plant density was elevated within edge populations. In the greenhouse, high elevation plants exhibited stronger clonal potential than low elevation plants, likely explaining increased plant density in the field. Phylogeographic analysis supported more recent colonization of high elevation populations which were also more genetically isolated, had more extreme heterozygote excess and had smaller effective population size than low. Results support that colonization of high elevations was likely accompanied by increased asexuality, contributing to a decline in effective population size. Despite high plant density in leading edge populations, their small effective size, isolation and clonality could constrain adaptive potential.

Physiologically vulnerable or resilient? Tropical birds, global warming, and redistributions.

Tropical species are considered to be more threatened by climate change than those of other world regions. This increased sensitivity to warming is thought to stem from the assumptions of low physiological capacity to withstand temperature fluctuations and already living near their limits of heat tolerance under current climatic conditions. For birds, despite thorough documentation of community-level rearrangements, such as biotic attrition and elevational shifts, there is no consistent evidence of direct physiological sensitivity to warming. In this review, we provide an integrative outlook into the physiological response of tropical birds to thermal variation and their capacity to cope with warming. In short, evidence from the literature suggests that the assumed physiological sensitivity to warming attributed to tropical biotas does not seem to be a fundamental characteristic of tropical birds. Tropical birds do possess the physiological capacities to deal with fluctuating temperatures, including high-elevation species, and are prepared to withstand elevated levels of heat, even those living in hot and arid environments. However, there are still many unaddressed points that hinder a more complete understanding of the response of tropical birds to warming, such as cooling capacities when exposed to combined gradients of heat and humidity, the response of montane species to heat, and thermoregulation under increased levels of microclimatic stress in disturbed ecosystems. Further research into how populations and species from different ecological contexts handle warming will increase our understanding of current and future community rearrangements in tropical birds.

Building a mechanistic understanding of climate-driven elevational shifts in birds

Mountains hold much of the world’s taxonomic diversity, but global climate change threatens this diversity by altering the distributions of montane species. While numerous studies have documented upslope shifts in elevational ranges, these patterns are highly variable across geographic regions and taxa. This variation in how species’ range shifts are manifesting along elevational gradients likely reflects the diversity of mechanisms that determines elevational ranges and modulates movements, and stands in contrast to latitudinal gradients, where range shifts show less variability and appear more predictable. Here, we review observed elevational range shifts in a single taxonomic group–birds–a group that has received substantial research attention and thus provides a useful context for exploring variability in range shifts while controlling for the mechanisms that drive range shifts across broader taxonomic groups. We then explore the abiotic and biotic factors that are known to define elevational ranges, as well as the constraints that may prevent birds from shifting. Across the literature, temperature is generally invoked as the prime driver of range shifts while the role of precipitation is more neglected. However, temperature is less likely to act directly on elevational ranges, instead mediating biotic factors such as habitat and food availability, predator activity, and parasite prevalence, which could in turn modulate range shifts. Dispersal ability places an intrinsic constraint on elevational range shifts, exacerbated by habitat fragmentation. While current research provides strong evidence for the importance of various drivers of elevational ranges and shifts, testing the relative importance of these factors and achieving a more holistic view of elevational gradients will require integration of expanding datasets, novel technologies, and innovative techniques.

Parallel evolution and cryptic diversification in a common and widespread Amazonian tree, Protium subserratum.

The lowland Amazon rainforest houses some of the greatest tree diversity on Earth. While the vast majority of these species are rare, a small number are common and widespread and thus considered to play a disproportionate role in many of the global ecosystem services provided by the Amazon. However, the extent to which dominant Amazonian tree species actually include multiple clades, each on their own unique evolutionary trajectory, is unknown. Here we investigate the extent to which lineage divergence may be occurring within Protium subserratum (Burseraceae), a common and widespread tree species that is monophyletic with populations exhibiting genotypic and phenotypic differences associated with soil and geography. Utilizing a combination of phylogenomic and population genomic methods with sampling from across the range, we found that P.subserratum contains at least eight distinct clades. Specialization onto white-sand soils has evolved independently at least twice within the species; however, phenotype is not correlated with soil type. Finally, cryptic diversity at the base of the Andes is associated with elevational shifts. Together these results lend support to the hypothesis that common and widespread Amazon tree species may not represent evolutionary cohesive units. Instead, these dominant species may more commonly represent species complexes, undergoing evolutionary transitions on a trajectory to become multiple range-restricted, specialist species.

Tree rings as an ecological indicator of the reaction of Swiss stone pine (Pinus cembra L.) to climate change and disturbance regime in the extreme environment of cliff forests

Tree rings are an ecological indicator, useful for studying the adaptation of trees in a changing environment, especially in the unique habitat of high-elevation cliff forests. The main aim of this study was to characterize tree-ring changes in Stone pine (Pinus cembra L.) growing in the extreme conditions of cliff forests of the Western Carpathians (at elevation 1300–1600 m a.s.l.), in order to reconstruct the growth release pattern and to better understand the influence of climate. The study was based on 104 tree ring series covering a 449-year-long chronology (1561–2009). In the last century, mean annual temperature has increased by +2.0 °C and precipitation has decreased slightly in the Tatras. The growth of stone pine was strongly related to summer temperature of June and July. In the last decades, the negative influence of summer precipitation on tree growth has abated; this may be related to warmer summers and decreasing precipitation. Temperature of the previous autumn, winter, and early spring, which had a significant influence on stone pine growth in the past, is not an important factor now. In the extreme environment of mountain cliffs, the influence of temperature and precipitation on tree growth is not stable over time under changing climate. The current changes in climate seem to promote stone pine and its potential upward elevational shift. The numerous past disturbance events have affected a limited number of trees, suggesting that single individuals have been randomly eliminated from the cliff stands during the last three centuries. Our results highlight the complex pattern of the reaction of stone pine on cliffs to changes in the environment. Swiss stone pine, a long-lived tree species, shows high adaptability for colonization of mountain cliffs and is an excellent object for studying the response of plants to changing climate. Understanding the effect of interactions between climate, disturbances, and the radial growth of trees in extreme environments of cliff forests on different temporal scales (monthly, seasonal, yearly) should increase our knowledge of such ecologically valuable areas.

Areography, environmental heterogeneity and spatial models explain patterns of past and present diversity inEdraianthus(Campanulaceae)

AbstractThis paper aims to shed light on distribution patterns and the relationship between species diversity and environmental heterogeneity of 17 Edraianthus taxa. We examined present and past distributions (Last Glacial Maximum) by applying ecological niche modelling. The environmental space occupied by the taxa was analysed using niche comparison methods. The results support the idea that the central and southern Dinaric Alps represent a centre of diversity and endemism in the western Balkan Peninsula. Diversity in Edraianthus is best explained by topographic (slope) and bioclimatic predictors (maximum temperature of warmest month, precipitation seasonality, precipitation of warmest quarter, precipitation of coldest quarter), suggesting that mountain areas with the most diversified relief have higher diversity. Niche modelling results suggest considerable range dynamics during the climatically unstable Quaternary. Thermophilic and lowland taxa responded with longitudinal shifts to ecologically suitable areas farther south, whereas high-mountain taxa responded mainly with elevational shifts. The greatest niche similarity is found among phylogenetically closely related taxa and among ecologically similar and often sympatric taxa. The least similarity was observed in species with marked differences in habitat elevation and in more geographically isolated species. Our results suggest that the extent of range and niche overlap varied among some taxa throughout their evolutionary history, which may have led to diversification at both allopatric and sympatric levels. The correlation between the genetic diversity of the most widespread taxon and the richness of taxa could be a consequence of past and present contacts. On the other hand, alternate periods of isolation may have favoured the emergence of taxa that are reproductively isolated and ecologically specialized.

Elevational variation in soil phosphorus pools and controlling factors in alpine areas of Southwest China

As an important life element in the Earth’s ecosystem, soil phosphorus (P) is of great significance to stability and sustainable development of terrestrial ecosystems. However, seasonal variations in different soil P pools and their regulatory mechanisms along elevations are not fully understood. Here, we investigated seasonal variations in soil P pools including total P (TP), available P (AP), inorganic P (IP), organic P (OP), labile P, moderately labile P, and stable P in topsoil (0–15 cm) along different elevations (2600–3900 m) in the Yulong Snow Mountain. The associated drivers including leaf nutrient contents, soil properties, micro-climate, and microbial parameters were also examined. We found that all soil P fractions reached a maximum at mid-elevations (2,900 m and 3,200 m), possibly due to the more active microorganisms and suitable soil climatic conditions for advancing P weathering. Meanwhile, soil AP pool was also observed to be tightly related to the leaf P content along elevations. Unexpectedly, most soil P pools did not show seasonal changes, except for AP showing significantly higher level in the wet season than in the dry season, owing to the high temperature and microbial activity for promoting P release in the wet season. Consequently, we found that microbial P, acid phosphatase and dissolved organic carbon had a stronger influence on different P pools than other soil factors. Moreover, there was a strong interaction of labile P and moderately labile P with soil environments (i.e. soil moisture, temperature, dissolved organic carbon). Collectively, our results revealed the elevational shifts in soil P pools and potential mechanisms in Yulong Mountain, and provided an important theoretical basis for soil P dynamics in response to environments in mountain ecosystems.

A new method for quantifying treeline-ecotone change based on multiple spatial pattern dimensions

ContextTreeline-ecotone spatial patterns and their dynamics reflect underlying processes. Changes in ecotone pattern may reflect changes in natural drivers or land-use practices. However, characterizing these dynamics presents a major challenge, limiting our ability to map, understand and predict changes in the upper limits of mountain forests.ObjectiveThis paper proposes a new method using multiple pattern dimensions to describe treeline-ecotone spatial pattern shifts. This standardized protocol should be able to (i) distinguish different types of treeline-ecotone patterns within a large study area, (ii) characterize temporal pattern shifts in spatial pattern between two or more dates.MethodWe mapped alpine treeline ecotones (ATE) at 648 sites in the eastern French Pyrenees using aerial images from ~ 1955 and ~ 2015, identifying forest and non-forest areas at the hillslope scale. Extracted patch metrics were summarized using a Principle Component Analysis (PCA) and spatial pattern change was quantified from the shift in the PCA space and compared to elevational shifts.ResultsThree clusters of patterns were distinguished: diffuse, discrete and island-forming ATEs. Between 1955 and 2015, about half of the sites changed from one pattern cluster to another. Shifts into discrete ATEs were associated with smaller and negative elevational shifts, while shifts into diffuse ATEs coincided with the highest positive elevational shifts.ConclusionThe proposed method allows a standardized and repeatable quantification of vegetation pattern change in alpine treeline ecotones based on historical aerial imagery. Seeing the importance of treeline-ecotone shifts for alpine biodiversity, we encourage the use of this protocol to better understand treeline dynamics at treelines globally.

The benefits of being smaller: Consistent pattern for climate-induced range shift and morphological difference of three falconiforme species

Climate exerts a dominant control over the distribution of species. Generally, species migrate to higher elevations to track thermal niches, but variations in morphological traits can result in trait-specific responses to climate change. Here we attempted to explore how three sympatrically distributed raptor species (the Upland Buzzard Buteo hemilasius, UB; the Common Kestrel, also called Eurasian ​Kestrel Falco tinnunculus, EK; and the Saker Falcon Falco cherrug, SF) would respond to climate change over time, and whether their responses would bias by different morphology. We tested the alternative hypotheses for Allen's rule for UB, EK, and SF in Qinghai Province, China, by modeling their current and future habitat suitability and confirming whether a consistent pattern exists between climate-induced range shifts and morphological differences among species. The extent of the projected distribution range within protected areas was also calculated for each species. We identified the future downward elevation shift for all the species, but with the notable northeastward shifting of the suitable climate space for UB and SF. Climate change would induce range contraction in the future, and the most acute influence is always the result of the pessimistic SSP585 scenario. No obvious pattern in climate-induced range shift was found for EK, for whom the morphological traits were significantly smaller all the time. More seriously, the ratios of highly suitable habitats being protected for our three raptor species were almost at a deficient level (below 1%). This study firstly tested the alternative hypothesis of Allen's rule among raptors in Qinghai Province unprecedently, confirmed the morphological basis for different responses to changing climate across species, and demonstrated the protection deficiency under the current protected area design. We advocate more related studies in the future to verify our findings across more taxa.

916 THE SMARTWATCH DETECTS ECG ABNORMALITIES TYPICAL OF BRUGADA SYNDROME

Abstract Introduction Brugada syndrome (BrS) is a genetic disorder with a characteristic pattern on the electrocardiogram (ECG) that predisposes to lethal arrhythmias and sudden cardiac death (SCD). Precise diagnosis is therefore mandatory. Aims We evaluated the feasibility and accuracy of a smartwatch in recording multiple ECG leads and detecting ST-segment changes diagnostic for BrS both in basal condition and after ajmaline infusion. Materials and Methods Twelve-leads and smartwatch ECGs were obtained in 32 unselected patients admitted at our institution with type II/III ST-segment elevation suspected for BrS from September 2021 to March 2022. After written informed consent for continuous ECG monitoring during ajmaline test (1 mg/kg, i.v. for 10 min), consecutive ECG strips acquired with both techniques were analyzed before and after drug administration. For each patient smartwatch was tested at three different sites: wrist, abdomen and chest, and intercostal spaces from second to fourth were further studied. The concordance among the results of the smartwatch and standard ECG recordings was assessed using the Cohen κ coefficient and Bland-Altman analysis. Results Subjects were 42±15 y.o. on average; 67% were men (n=25), and diagnosis of BrS was reached in 12 cases (37.5%). Concordance was found between the smartwatch and standard ECG for the identification of the following findings: i) a normal/negative ECG (Cohen κ coefficient, 0.89); ii) ST-segment elevation shift (Cohen κ coefficient, 0.934). In addition, the Bland-Altman analysis demonstrated concordance between the smartwatch and the standard ECG in the assessment of the amplitude of ST-segment elevation shift (bias, −0.003; SD, 0.68; lower limit, −0.52; and upper limit, -0.031). The smartwatch power in diagnosing normal ECG showed a sensitivity of 92% (95% CI, 66%-99%) and a specificity of 100% (95% CI, 64%-100%); for detection of ST-segment elevation and BrS diagnosis, sensitivity was 92% (95% CI, 64%-99%) and specificity was 95% (95% CI, 76%-99%). Conclusions The findings of this study suggest agreement between the multichannel smartwatch acquisition and standard ECG for the identification of Brugada syndrome-associated ST-segment changes.

Shifting plant leaf anatomical strategic spectra of 286 plants in the eastern Qinghai-Tibet Plateau: Changing gears along 1050–3070 m

Leaf anatomical traits can reflect plant adaptation to environmental changes. However, whether the trade-offs among leaf anatomical traits can reflect the strategies spectrum of plant response to environmental changes and the strategic spectrum will shift with altitudes are not clear. In this study, 286 plant species from 19 altitudinal gradients from 1050 m to 3070 m on the eastern Tibetan Plateau were selected and 16 anatomical characters of blade, mesophyll and midrib were measured. The strategic spectra of leaf anatomical trait formation were studied by the principal components analysis, followed by generalized additive models of the strategic spectra with shift in elevation to test the shift of strategy spectra along altitudes. There are differences in response mode and intensity between woody plants and herbaceous plants along altitudes. Blade strategic spectrum (BSS), blade and mesophyll strategic spectrum (BMSS) and midrib strategic spectrum (MSS) were formed in the tissue of leaves, and the score of principal component one (PC1) was not significant between herbs and woody plants (P > 0.05). There was mainly the spectrum of conservation and supported strategies and the spectrum of resource acquisition and consumption. With increasing altitudes, the habita tended to become unsuitable for plant growth and the resources available to plants reduced. Consequently, the plants shifted from a “invest-fast-reap” acquisition strategy to a “invest-slow-reap” conservative strategy.

Elevational shift of endangered European yew under climate change in Hyrcanian mountain forests: Rethinking conservation-restoration strategies and management

Prioritizing new areas for conservation in the Hyrcanian mountain forests is important because future climate change is an immediate threat to endangered species in these areas. Taxus baccata L. (European yew) is one of the most important coniferous species of the Hyrcanian forests that is endangered today for various reasons; therefore, the conservation and restoration of this valuable species is essential. The present study was conducted in order to identify areas with high potential for restoration and conservation of yew with consideration of future climate change. Maximum Entropy (MaxEnt) was used to model the current and future distribution of yew in Hyrcanian forests of northern Iran. VIKOR fuzzy model applied to prioritize conservation and restoration areas. The results showed that MaxEnt model has high efficiency in modeling the distribution of yew with area under curve (AUC) = 0.98 in the study area. Importance analysis of explanatory variables showed that distance from rivers, geology, slope, precipitation of warmest quarter (bio18), and annual precipitation (bio12) were more important than other variables in the potential distribution of yew. The results showed that at current condition, suitable areas for yew in the Hyrcanian forests of Iran are distributed along an elevation gradient from sea level to 2600 m, and under the future climate change (2050 and 2070) this species will shift to higher elevations and lose the lower elevation habitats. The findings of this study predict that the desired habitats of yew in Hyrcanian forests will be severely affected by climate change. Given these cases, it is necessary to make management and conservation decisions in relation to this species, taking into account the effects of climate change and adaptation in the Hyrcanian forests.

Different range shifts and determinations of elevational redistributions of native and non-native plant species in Jinfo Mountain of subtropical China

Species are changing their elevational distributions in response to climate change, leading to biodiversity loss and changes in community structure. Yet whether native and non-native species have consistent elevational shifts remains to be evaluated. Subtropical mountains are rich in biodiversity, sensitive to climate change, and are experiencing high risks of biological invasion. Hence exploring the changes in species elevational distributions induced by climate change in subtropical mountains is an urgent need. Here, we explored the impact of climate change on the elevational distribution of seed plant species in Jinfo Mountain (Mt. Jinfo), a subtropical mountain in China with rich plant diversity. Notably, we compared the elevational redistributions of native and non-native plants in response to climate change. The results showed that the elevational centroids of native plant species moved downhill, while those of non-native plants shifted upward on average. The upper limit of native plants shifted downward, while the upper limit of non-native plants shifted upward on average. The elevational shifts of non-native plants were dominated by changes in the upper range limits, while those of native plants were affected by the lower limits. These opposite elevational shifts of native vs non-native species led to the increase in the elevational range size of the non-native plants, but decrease in the elevational range size of native plants, especially in high altitudes. The differences in the directions and magnitudes of elevational shifts between the native and non-native plants are mainly due to differences in their climate adaptation. Changes in temperature and precipitation influenced the elevational range shifts of native plants but not of non-native ones. This study provides a new perspective for understanding the elevational redistribution of native and non-native plant species in subtropical mountains, and suggests that climate change has stronger influence on native than non-native species.