At high elevations, tree saplings and shrubs are usually protected by mid-winter snow cover, although climate change is expected to extend the snow-free (SF) period. Exposure to winter drought, freeze-thaw events and freezing temperatures will therefore increase, inducing damages to the hydraulic system and to living cells, resulting in reduced growth and increased mortality. A snow removal experiment was carried out at 1700 m. above sea level on saplings of five different species (Acer pseudoplatanus, Juniperus communis, Larix decidua, Picea abies and Sorbus aucuparia). Stem diameter was continuously monitored and compared with spring hydraulic conductivity (PLCspring), living cell mortality (PLDspring), nonstructural carbohydrates (NSCs), growth and survival rates. Under SF conditions, saplings had higher PLCspring and higher PLDspring, and thus experienced greater winter dehydration, resulting in lower growth compared with snow-covered saplings. Summer mortality was strongly correlated with PLCspring and PLDspring. These two key ecophysiological parameters predicted the risk of mortality in all species, whereas only PLDspring reduced growth. By monitoring stem diameter during winter, we have defined indices to quantify resistance and recovery of woody plants under increased frost pressure. Recovery strategies such as resprouting or embolism repair were critical for survival, highlighting the potential vulnerability of saplings to climate change at high elevations.

Objectives. To develop age-specific percentile curves for mean arterial pressure (MAP), diastolic blood pressure (DBP), and systolic blood pressure (SBP) in Peruvian adults aged 20-59 years, stratified by altitude of residence. Materials and methods. An analytical cross-sectional study was conducted using data from the 2014-2024 Demographic and Family Health Survey (ENDES). Adults aged 20-59 years with two valid blood pressure measurements and no prior diagnosis of hypertension were included. Altitude of residence was classified as <2500, 2500–3499, and ≥3500 meters above sea level (masl). Percentile curves (P5-P95) for MAP, DBP, and SBP were estimated using Generalized Additive Models for Location, Scale, and Shape (GAMLSS) with the Box–Cox Cole and Green (BCCG) distribution. Results. A total of 227,093 adults were analyzed (mean age: 35.7 years; 56.2% women). Across all altitude strata, MAP, DBP, and SBP increased progressively from ages 20 to 50, although the magnitude of increase was attenuated at higher altitudes. MAP and DBP showed relative stability after age 50, whereas SBP continued to rise more steadily. At ages 50 and 59, SBP values were consistently lower at ≥3500 compared with <2500 masl. Conclusions. Blood pressure distribution varies according to altitude of residence, with less pronounced age-related increases at higher elevations. The percentile reference curves generated here may support context-specific interpretation of blood pressure in high-altitude populations and strengthen epidemiological surveillance.

Insight into the significant impact of ozone-depleting substances emissions from animal dung burning on stratospheric ozone depletion potential in Qinghai-Tibet Plateau over the past 20 years.

Abstract Understanding past landscapes through sedimentary pollen records relies on precise knowledge of modern pollen–vegetation relationships. In mountain environments, however, altitudinal gradients, geomorphological complexity and prevailing air currents affect pollen deposition and make reconstructions of vegetation dynamics harder. This study investigates whether pollen assemblages can effectively differentiate between open habitats above and below the timberline (forest limit) in the Krkonoše mountains, or whether the effects of strong atmospheric circulation outweigh the diverging characteristics of these sites. We used 23 years of annual pollen trap data and vegetation surveys from 19 open sites distributed across an altitudinal gradient. Pollen deposition patterns were analysed using hierarchical clustering, ordination and dissimilarity analyses. Pollen assemblages from above and below the forest limit were statistically distinct, with differences driven mainly by quantitative variation rather than qualitative changes in composition of pollen types. The primary gradient was expressed by the proportion of long-distance transported pollen types, which dominated alpine and subalpine areas. Arboreal taxa formed a major component of background pollen, accompanied by low but consistent levels of wind pollinated herbs commonly interpreted as indicators of human impact. Other herbaceous taxa generally reflected their local presence, except for Vaccinium -t., which was under-represented. For sites above and below the upper forest limit, we characterised pollen composition in terms of percentages and accumulation rates, and established presence/absence thresholds for Pinus , Picea , Fagus , Abies , Betula , Corylus , Alnus , Quercus , Cerealia and Urtica . These findings improve our understanding of the role of long-distance pollen transport in high mountain treeless areas and provide baseline data for interpreting fossil pollen records from high elevation sites in Central Europe.

Cryosphere and lithology influence the hydrological gradients of high elevation Alpine catchments

ABSTRACT This study presents a 1:150,000 scale geomorphological map of the Gulf of Corinth (central Greece), integrating terrestrial and submarine landforms. The Gulf, an asymmetric WNW-ESE half-graben, is one of the tectonically most active areas in the eastern Mediterranean, with an uplifting southern flank and a downward flexed northern one. A multidisciplinary approach, combining field surveys and high-resolution seafloor bathymetry, was used to map the emerged and submerged geological and geomorphological features. The southern terrestrial sector shows clear evidence of tectonic uplift, such as marine terraces, elevated Gilbert deltas, tidal notches at higher elevations, and reversed drainage features. In contrast, the northern part is notable for the absence of Quaternary marine or lacustrine sediments and displays a gently sloping shelf with submerged tidal notches, indicating ongoing tectonic subsidence. The map offers a comprehensive view of the complex geomorphology of the region, shaped by Quaternary tectonic activity.

Abstract. Arid endorheic basins exhibit limited water availability shaped by strong precipitation and evaporation variability. Understanding these processes is crucial for sustainable water resources management in such fragile environments. This study examines how rainfall and evaporation drive the spatial and temporal dynamics of groundwater recharge and water balance in an arid endorheic basin, using the Salar del Huasco in the Chilean Altiplano as a case study. For this, we implemented a modified semi-distributed rainfall-runoff model integrated with a 40 year record (1980–2019) of satellite-derived precipitation and evaporation estimates. Results show that, on average over the catchment, about 12 % of total rainfall (17 mm yr−1) recharges the aquifers, with a ∼35 d lag between rainfall and peak groundwater recharge. Spatial analysis reveals that most water infiltrates and recharges the groundwater system at high elevations (∼65 % of total recharge), while low-lying wetlands, shallow lagoons, and riparian zones lose most of the water via evaporation (up to 950 mm yr−1). Our findings highlight that when summer rainfall ceases, groundwater becomes the main water source supporting high evaporation rates, while recharge reaches a minimum by the end of autumn that persists until the end of the year. These results suggest a trade-off between groundwater recharge and evaporation for available water during the dry season. Moreover, while the basin receives around 145 mm yr−1 of annual precipitation, evaporation reaches 230 mm yr−1. These values imply a substantial water loss or an unaccounted groundwater inflow, challenging the endorheic assumption of the basin's hydrogeological boundaries. Future research should revisit this assumption and incorporate fully coupled groundwater-surface water simulations to explicitly include interactions with lateral groundwater flows and groundwater levels, as well as with snow dynamics and vegetation processes currently omitted. Also, validating satellite-derived inputs against additional local observations is essential to strengthen the reliability of the water balance assessment. Nonetheless, these results provide a valuable framework and a first-approximation for quantifying water balance components in an arid basin, offering insights for water resources management in a context of water scarcity and climate change.

Background and aims – Madagascar’s rich flora originated mostly from in situ diversification, and the large-scale plant species richness pattern is mainly explained by spatial heterogeneity. However, mechanisms underlying plant community assembly remain largely unexplored. We aimed to understand the coexistence of a species swarm in the Malagasy olive ( Noronhia , Oleaceae) on the northern massif of Montagne d’Ambre and to gain insights into the factors influencing community assembly. Material and methods – We used 13 environmental and 17 trait variables sampled across 24 plots and 13 species on the mountain, respectively. We determined likely trait-environment relationships across space using the multivariate RLQ analysis, the bivariate fourth-corner method, and their combination. We also checked for phylogenetic signal (Blomberg’s K and Moran’s I ) among traits and assessed the phylogenetic community structure (SES.MPD and SES.MNTD) using nested spatial and phylogenetic scales. Key results – Significant trait-environment relationships were recovered with the multivariate and the combined multi–bivariate analyses at a large spatial scale, whereas patterns at small spatial scales were unclear. Distinct assemblages at lower and higher elevations were identified and appeared to be influenced by bioclimate and soil gradients. Strong phylogenetic signals were detected in seven traits across spatial scales, regardless of phylogenetic scales. The communities exhibited an overall pattern of phylogenetic clustering with a large phylogenetic scale, while a hint of overdispersion emerged in the low-elevation assemblage with a small phylogenetic scale. Conclusion – Multiple mechanisms may influence the coexistence of the Noronhia swarm on Montagne d’Ambre, with environmental filtering and niche partitioning seemingly acting on vegetative and reproductive functions, respectively. More focus on reproductive biology will provide further insights into the assembly of Malagasy plant communities. This study also highlights the conservation values of Montagne d’Ambre as a unique ecosystem supporting the flora, fauna, and human populations of the northernmost region of Madagascar.

Background Rhizosphere microorganisms play a critical role in plant growth and medicinal quality, yet their altitudinal patterns and interactions with soil nutrients and bioactive compounds in Angelica sinensis ( A. sinensis ) remain poorly understood. Methods Using Illumina MiSeq sequencing, we analyzed bacterial, fungal, arbuscular mycorrhizal (AM) fungal, and archaeal diversity across an altitudinal gradient, alongside soil physicochemical characteristics and bioactive components. Results As cultivation elevation increased, bacterial and fungal diversity initially increased significantly and then stabilized ( p < 0.05). In contrast, AM fungal and archaeal communities remained relatively stable. Bacterial communities varied significantly across altitudes (stress < 0.1, p = 0.001), as did soil nutrients and enzyme activities ( p < 0.05). Bioactive components, except for ferulic acid, varied significantly with altitude. Redundancy analysis (RDA) confirmed that altitude and soil factors are key drivers of microbial community assembly. Mantel tests and structural equation modeling (SEM) demonstrated significant correlations between soil properties, microbial diversity, and medicinal properties of A. sinensis ( p < 0.05). Conclusion The mid-to high elevation zone (2520–2717 m) was identified as optimal for both yield and bioactive compound accumulation. These findings deepen the understanding of how microbes adapt to different altitudes in medicinal plants and offer a framework for precise cultivation of A. sinensis , thereby supporting the high-altitude symbiosis theory.

Accurately quantifying the sensitivity of alpine vegetation to climate change is a key prerequisite for formulating regional climate change adaptation policies. The sensitivity of the fragile alpine grasslands on the Tibetan Plateau to climate change has received widespread attention. However, the spatiotemporal dynamics and driving mechanisms of this sensitivity are still unclear under continuous warming and wetting. This study, based on MODIS_NDVI and meteorological data from 2000 to 2023, constructed a dynamic Vegetation Sensitivity Index (VSI) framework and integrated Random Forest (RF) and eXtreme Gradient Boosting (XGBoost) models with Shapley Additive exPlanations (SHAP) attribution analysis to reveal the spatiotemporal evolution characteristics and driving mechanisms of vegetation sensitivity on the Tibetan Plateau. The results show that (1) the VSI of alpine grasslands exhibited a spatial pattern of higher values in the southwest and lower values in the northeast, with an overall upward trend. Specifically, 56.31% of the region showed an increase in the VSI, with the upward trend being more pronounced in the northern plateau. (2) The dominant role of different climate factors varied regionally; vegetation sensitivity to precipitation increased in the northern plateau, and temperature sensitivity decreased in the central plateau, while sensitivity to solar radiation significantly increased in the central plateau. (3) SHAP attribution analysis indicated that elevation was the core factor driving VSI differentiation, showing a higher sensitivity at higher elevations, with lower growth rates. These findings reveal the dynamic evolution of vegetation sensitivity under the warming and wetting climate trend and its elevation-regulated mechanism, providing important scientific insights for regional ecological adaptation management.

ABSTRACT White pine blister rust (WPBR) is a disease on North American five‐needle white pine trees caused by the non‐native fungal pathogen Cronartium ribicola that is causing widespread decline and mortality of Pinus flexilis (limber pine) in high elevation western forests. Elucidating the infection process is important for developing solutions for managing the disease. As an obligate biotroph, C. ribicola infects pine needles through stomatal pores and parasitizes needle tissue before growing into the stem, causing stem cankers. Pinus flexilis retains 8–9 years of needles on shoots, and it remains unclear whether infection and fungal colonisation, as well as the quantities of epicuticular wax, differ between needles of various age classes or between trees with and without major gene resistance to WPBR. To assess the relationship between quantity of C. ribicola DNA in P. flexilis needles, needle age, and resistance status, P. flexilis shoots from mature resistant and susceptible field trees were artificially inoculated with C. ribicola , where dispersal of fungal inoculum was applied evenly across all needle age classes. The quantity of epicuticular wax by needle age class and tree resistance status was explored. The results demonstrate that all needle age classes of P. flexilis are susceptible to C. ribicola infection. A significant positive correlation between needle age class and C. ribicola DNA quantity, regardless of tree resistance status, was noted. Additionally, epicuticular wax weight increased significantly with needle age, and wax did not appear to hinder needle colonisation by C. ribicola .

Climate change is causing the loss or movement of suitable habitats, forcing species to undergo range shifts. However, many may be unable to move to suitable locations, resulting in increased extinctions. Climate refugia, areas maintaining suitable conditions for species now and in the future, offer protection from climate change. These refugia are categorised as in situ, where species are currently present, and ex situ, where they are not. We aimed to identify climate refugia for rare vascular plant species in Britain and examined whether refugia with the highest number of suitable species share any common features. Using predicted 2080 distributions, we identified protected areas in Britain that act as in situ or ex situ refugia for 12 of Plantlife's focal plant species. This study revealed that many current habitats will become unsuitable by 2080, highlighting the urgent need to protect refugia. The limited availability of in situ refugia underscores the importance of ex situ refugia as potential habitats. Our findings indicated that protected areas with higher elevations, larger elevational ranges, higher latitude and longitude and larger area will provide climate refugia for a greater number of species. This information can be used to guide the selection and management of protected areas and identify receptor sites for species introductions.

ABSTRACT Wild lowbush blueberry (Vaccinium angustifolium Ait.) production is conducted in fields with heterogeneous growing conditions due to topography, soil properties, and crop density. This crop generally grows on sandy, acidic, and nutrient-poor soils. Precision agriculture technologies provide means to manage different cropping areas according to their site-specific needs. The objective was to determine wild blueberry crop response to nitrogen (N) fertilization according to four management zones in one undulated field (FieldUnd) and one flat field (FieldFlat). Four management zones were established on each field: Low Elevation: High ECa; Low Elevation: Low ECa; High Elevation: High ECa; and High Elevation: Low ECa. The N treatments consisted of four rates of ammonium sulfate (0 to 90 kg N ha−1) applied in the sprout year. Fruit yield was measured in the production year. Soil pH and ammonium (NH4-N) were determined. Fruit yields increased by 72% in the FieldUnd and 54% in the FieldFlat with N rates. For the FieldUnd, the response to N fertilization was greater when the soil ECa was Low with High Elevation (increase of 2242 kg ha−1), and for the FieldFlat, the response was greater when the soil elevation was High but with High ECa (increase of 2335 kg ha−1). Nitrogen fertilization had a rapid effect on soil pH but management zones had limited effect. Soil NH4-N increased rapidly after N application. The residual N remained under 3 kg NH4-N ha−1. The greatest response to N fertilizer was obtained in management zones with High Elevation, regardless of the field, but under Low ECa in the FieldUnd and High ECa in the FieldFlat.

Climate fluctuations are expected to drive a decline in the growth of many conifer and broadleaf species, especially in the Mediterranean region, where these species grow at or very near the southern limits of their distribution. Such trends have important implications not only for forest productivity but also for plant diversity, as shifts in species performance may alter competitive interactions and long-term community composition. Using tree-ring data sourced from two Abies cephalonica stands with different elevation in Mount Parnassus in Central Greece, we evaluate the growth responses of the species to climatic variability employing a dendroecological approach. We hypothesize that radial growth at higher elevations is more strongly influenced by climate variability than at lower elevations. Despite the moderate to relatively good common signal indicated by the expressed population signal (EPS: 0.645 for the high-altitude stand and 0.782 for the low-altitude stand), the chronologies for both sites preserve crucial stand-level growth patterns, providing an important basis for ecological insights. The calculation of the Average Tree-Ring Width Index (ARWI) for both sites revealed that fir in both altitudes exhibited a decline in growth rates from the late 1980s to the early 1990s, followed by a general recovery and increase throughout the late 1990s. They also both experienced a significant decline in growth between approximately 2018 and 2022. The best-fit model for annual ring-width variation at lower elevations was a simple autoregressive model of order one (AR1), where growth was driven exclusively by the previous year’s growth (p < 0.001). At the higher elevation, a more complex model emerged: while previous year’s growth remained significant (p < 0.001), other variables such as maximum growing season temperature (p = 0.041), annual temperature (inverse effect, p = 0.039), annual precipitation (p = 0.017), and evapotranspiration (p = 0.039) also had a statistically significant impact on tree growth. Our results emphasize the prominent role of carry-over effects in shaping their annual growth patterns.

ABSTRACT Urbanisation increases land surface temperature (LST) in subtropical coastal cities, yet long-term, interpretable analyses of LST drivers are limited for the Fuzhou metropolitan area and its suburbs. We address this gap by combining a 25-year Landsat time series with n Explainable Gradient-Boosting (XGBoost) model to evaluate the land cover impacts. Multi-epoch Landsat data, XGBoost and SHAP were integrarted to assess the relative, nonlinear, and moderating effects of impervious surfaces, vegetation, and elevation on LST. Dense vegetation remained dominant (45–51%), while built-up area increased from 5% to 12%; by 1999–2023, built-up surfaces became the most prevalent class, replacing bare land. Enhanced scatter-regression attribution reveals imperviousness (NDBI, BSI) raises LST, while vegetation and moisture (NDVI, NDWI, NDMI) and higher elevation, reduce it, elevation strongly moderates LST in this humid coastal region. Multivariate regression and variance partitioning indicate that elevation is the primary and most often uniquely attributable LST driver. The XGBoost model accurately predicts LST with an RMSE of approximately 1.3. Policymakers should promote green infill, protect moisture-rich corridors, and limit impervious surfaces in heat-prone areas. This approach provides a transferable framework for climate-smart urban planning in Fuzhou and similar coastal cities.

New constructions in landfill zones have caused movement and cracks in large-scale retaining walls that are characterized by their high elevations and long lengths, necessitating unusual measurements for geotechnical experts to find a solution. A terrestrial laser scanner is one of the best ways to create a detailed 3D model. Laser scanning reduces the time required for on-site data collection by 50-70%, compared to traditional surveying. Laser scanning improves processes, accuracy, and cost, making it a viable tool for structural monitoring and deformation research. Coordinate transformation equations were used to align the X-axis with the wall's length, the Z-axis with the wall height, and the Y-axis perpendicular to the wall, creating a cross-section and contour map that shows how the wall has moved and cracked relative to the initial case. Geotechnical specialists can readily assess deformation and determine permanent solutions with these sections and contour maps. Vertical sections were generated every 5.0 m along the length of the retaining wall, accompanied by contour maps with a contour interval of 1 cm. The maximum movement is about 45 cm. One articulates the distinction as a swift and precise observation of deformation compared to conventional surveying methods.

The mechanisms governing soil bacterial community assembly along elevational gradients in cold-arid mountains remain poorly understood, despite their critical role in these fragile ecosystems. This study investigates these mechanisms along a pronounced climatic and vegetational gradient (1,707–3,548 m) on the northern slope of the Central Kunlun Mountains. The results show that bacterial α-diversity increased with elevation, while β-diversity exhibited a hump-shaped pattern. Mean annual precipitation (MAP) and vegetation cover were the primary drivers of these patterns, exerting stronger influences than soil pH. This suggests that arid-adapted bacteria possess unique environmental tolerances. Notably, after accounting for multicollinearity among environmental factors, the soil organic carbon-to-nitrogen (C/N) ratio emerged as the dominant factor shaping community assembly. At higher elevations (≥2,746 m), we observed increased phylogenetic clustering, linked to vegetation-driven deterministic selection via stable organic matter inputs and root exudates. However, stochastic processes still dominated the overall assembly. These findings highlight a pivotal mechanism wherein vegetation mediates bacterial community assembly primarily through modulating the soil C/N ratio in arid mountains. This study refines microbial biogeographic models by emphasizing the interplay between vegetation and soil stoichiometry under environmental stress, providing crucial insights for predicting ecosystem responses to climate change.

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Although almost 40% of the world's plant species are likely rare, little is known about the determinants of range size, a major axis of rarity, particularly in the tropics. Narrow geographic ranges make species more susceptible to extinction, so understanding factors that correlate with small range sizes is key to prioritising conservation efforts. The niche breadth - range size hypothesis predicts range restricted species to have narrow environmental tolerances. Here, we tested the niche breadth - range size hypothesis in two big tropical plant genera, Solanum and Begonia. We used taxonomically verified occurrence data to quantify the range size of 1,065 species native to Southern America, calculated their climatic niche breadth based on six bioclimatic variables, and used spatial null models to determine whether the observed niche breadth - range size relationship differed significantly from spatial autocorrelation. The correlation between climatic niche breadth and range size did not differ significantly from null expectations in either genus. Range-restricted species across both genera occur at higher elevations and have narrower elevational ranges than widespread species, however. More than two-thirds of the species had their minimum niche breadth in temperature seasonality, with strong increases between range-restricted and widespread species, suggesting that niche breadth in terms of temperature seasonality plays a key role in shaping species distributions. Our findings support the view that niche breadth and range size correlations can artificially arise just from spatial autocorrelation. Macroclimatic conditions capture only a part of the ecological niche, and additional niche properties such as adaptations to soil and fire and biotic interactions are likely to influence species' ranges in particularly in species diverse tropical groups. Our findings emphasise that tropical mountains such as the Andes and the Atlantic forests of Brazil are globally important centres of range-restricted plant species.

Annual density chronologies of Pinus sylvestris var. mongolica L. at high and low elevations in the northern Greater Khingan Range were analyzed, and the responses of earlywood and latewood densities to climatic factors were examined. Significant elevational differentiation was observed in the growth response. At low elevation (630 m), earlywood density was positively correlated with temperatures in c4, c6, and c7 (c, current year) and negatively correlated with precipitation in p11 and c6 (p, previous year). Latewood density was negatively correlated with temperatures in c1–c5 and positively correlated with temperatures in c7–c8. At high elevation (1000 m), earlywood density was significantly negatively correlated with temperatures in p10, p11, c3, and c6, and with precipitation in p11, c2, c3, c5–c7, and c9; latewood density was significantly negatively correlated only with temperature in p11. Following an abrupt temperature shift in 1987, the low-elevation earlywood density chronology shifted from a decreasing to a strongly increasing trend, the low-elevation latewood chronology shifted from a strongly decreasing to a strongly increasing trend, and the high-elevation latewood chronology shifted from a strongly decreasing to an increasing trend. July temperature in the year of the shift drove the trend changes in the low-elevation earlywood and high-elevation latewood chronologies, and May temperature drove the trend change in the latewood density chronology at low-elevation, thereby explaining the shift in the latewood trend. Sliding-window correlation analyses further showed that low-elevation trees are more sensitive to climate fluctuations and exhibit lower growth stability, whereas high-elevation trees are less sensitive to climate fluctuations and show higher growth stability. Thus, the growth of low-elevation P. sylvestris var. mongolica is affected by combined water and heat stress, while the growth of high-elevation trees is primarily limited by temperature. Under ongoing warming, growth potential is likely to increase near the treeline but decline at low-elevation sites. These results provide a robust scientific basis for elucidating the response mechanisms of mountain forests in the Greater Khingan Range to climate change.