Plant species differ in their nutrient uptake, yet the relative importance of species identity versus environmental variables in shaping foliar elemental composition remains poorly understood. We collected foliar samples from ten alpine plant species across 21 plots spanning an elevational gradient of 1000 m on the silicate-based soils of Schrankogel, Austria. Our aim was to disentangle the effects of species identity, site properties, and leaf traits on the concentrations of 16 elements. Foliar elemental concentrations showed a clear correlation structure, reflecting similarities in uptake mechanisms, physiological function, and stoichiometric requirements. Species identity was the dominant driver, explaining 41
Despite their critical role in shaping Alpine and non-Alpine ecosystems, the specific impacts of extreme flood events on riparian vegetation remain poorly understood. In Alpine habitats, such events induce rapid channel reworking, entailing abrupt sediment redistribution and changes in channel width, which trigger immediate vegetation responses. This review employed distinct search syntaxes across Scopus, Web of Science (WoS), and Google Scholar databases to identify relevant papers on this topic. Through a systematic screening of 1,948 records, complemented by citation searching, we identified 22 studies in which the response of riparian vegetation to high-magnitude or flash-flood events was the primary focus. Only a few of these concerned the European Alps, so the synthesis also draws on transferable evidence from comparable mountain and temperate rivers. Analysis of these datasets reveals that geomorphology and hydrology predominate, while studies focusing on riparian vegetation remain scarce. Studies report that flash events often remove pioneer and herbaceous cover while areas with dense woody vegetation (e.g., willows and poplars) exhibit some resistance against erosion. Alpine systems are marked by steep gradients and snowmelt-driven floods. They show both high biodiversity and shifts in species composition, as post-flood recovery progresses from early-successional, flood-tolerant species toward native shrubs and trees. In fact, the typical habitats of such environments are listed in the Annex I of the EU Habitat Directive. Many studies cite the value of integrating remote sensing with field validation, yet they also note gaps in long-term, multi-site assessments of sediment, large wood transport, and species-specific recovery trajectories in Alpine riparian zones. This review highlights a lack of studies employing a phytosociological approach to track post-flood successional trajectories in Alpine plant communities, thereby providing a foundational step towards comprehensively addressing the ecological effects of flash floods in riparian zones.
Species distribution models (SDMs) are widely used to anticipate biodiversity responses to climate change, yet most rely on coarse climatic datasets that fail to capture the fine-scale thermal heterogeneity characteristic of mountain environments. This mismatch is particularly problematic for alpine plants, which abiotic environment is characterized by strong topographic gradients that generate substantial climatic heterogeneity over short distances. Here we argue that improving the spatial and temporal representation of climate datasets based on standard 2 m air temperature measurements is essential for ecologically realistic SDMs in mountains. Using CHclim25, a newly developed 25 m resolution daily topoclimate dataset for Switzerland, we show that fine-scale climatic predictors better represent the spatial and temporal variability in air temperature across elevation gradients. Comparisons with WorldClim and CHELSA demonstrate that CHclim25 more accurately reproduces air temperature patterns, especially in topographically complex terrain. While CHclim25 does not explicitly simulate organism-level microclimates, it provides a substantially improved representation of near-surface temperature conditions at spatial grains closer to ecological observations. When integrated with high-resolution environmental datasets such as SWECO25 and national-scale SDM initiatives like SDMapCH, CHclim25 enables the identification of fine-scale gradient, the mapping of fine-scale habitat structure, and more reliable projections of species’ climatic niches. The growing availability of very high-resolution elevation models further strengthens the potential for similar downscaling approaches in other mountain regions. Together, these developments highlight the need for SDMs that incorporate fine-scale climatic variation and call for broader adoption of high-resolution climatic datasets to improve biodiversity forecasting in alpine landscapes.
Alpine herbaceous communitiesare sensitive to climate-driven increases in shrub cover, yet the pathways linking terrain, snow dynamics, and shrub functional groups to herbaceous composition remain poorly understood. We used piecewise structural equation models (SEMs) to quantify direct, indirect, and total effects of terrain features, late-spring-to-summer snow persistence, and shrub functional groups — classified by structural growth form (erect vs. prostrate) and leaf lifespan (deciduous vs. evergreen) — on herbaceous cover and richness across 338 quadrats (0.25 m²) at Cardinal Divide in the Canadian Rocky Mountains. Concave terrain features and cooler-facing slopes drove patterns in summertime snow persistence, which was the dominant abiotic force structuring herbaceous cover and richness. All shrub functional groups negatively affected herbaceous cover and richness. However, indirect pathways through shrubs substantially modified — and in some cases mediated — these direct effects, revealing that functional group identity determines the net impact of increased shrub cover on herbaceous communities. Notably, shrub cover did not have uniform effects on herbaceous cover and richness. Some functional groups suppressed others, generating positive indirect pathways on herbaceous composition that offset some of their initial negative effects. These results underscore the importance of accounting for indirect pathways when predicting how alpine plant communities will respond to ongoing shifts in snow dynamics and shrub cover under climate change.
On recently deglaciated terrain, soil instability can be a physical barrier limiting seedling establishment. Here we used a space-for-time approach to study the role of biological soil crust (biocrust) as soil surface stabilizer and facilitator of ecological succession along a glacier forefield chronosequence at the retreating Conejeras glacier in the Tropical Andes. We used the point-intercept method to estimate surface cover of plants, biocrust, bare ground and rocks, as well as soil surface roughness; and a field soil aggregate kit to estimate soil stability. As hypothesized, following a bare-ground stage near the edge of the glacier, the successional trajectory involved the development of a biocrust belt, including bryophytes and lichens, followed by an increasing vascular plant cover. The development of biocrust was accompanied by higher soil surface roughness and soil stability, which likely increased seed entrapment and seedling establishment. Our results suggest that the development of cyanobacterial-dominated biocrust at the forefield of the Conejeras glacier may favor the establishment of plants with large seeds, such as graminoids from the Festuca genus. Overall, our findings highlight the key role of biocrusts in the ecological dynamics that follow glacier melt in the Tropical Andes.
Expansion of treeline ecotones and krummholz in alpine ecosystems negatively affects alpine plant diversity at small (quadrat) scales. However, tree encroachment also increases microhabitat variability, which supports diversity at regional scales. Here, we compared variability in surface microclimates across open and krummholz alpine habitats at Cardinal Divide, Alberta, Canada. We used generalized linear mixed effects models to assess the effects of krummholz tree cover, non-vegetated ground cover, and surface temperatures on alpine plant alpha (Shannon’s) diversity and partial Mantel tests to examine the influence of spatial variability in diel surface temperatures and cover on within- and between-plot species turnover (beta diversity). Sites were spaced across the divide to represent terrain features and were at a similar elevation (2000–2150 m) with eight pairs of 8 × 8 m plots established in adjacent open alpine and krummholz habitats, with each plot having 24 within-plot sample locations. We found a 2.1 °C increase (p = 0.003) in within-plot maximum diel surface temperature variation (standard deviation) in krummholz plots (8.7 °C) compared with open alpine plots (6.6 °C). Interactions between diel surface temperature range and tree cover (non-linear) were associated with decreased alpha diversity in krummholz plots. On average, surface temperature variability was positively correlated to within- and between-plot beta diversity in open and krummholz habitats, with krummholz showing stronger correlations. Similarly, tree cover differences corresponded with increased beta diversity within- and between-plots, indicating that at larger (plot-level) scales, treeline expansion may increase diversity. As krummholz will likely expand, it is important to understand how they alter their environment and microclimates across different scales to better predict changes in biodiversity.
Aspect and steepness with ridges and depressions of different spatial extent, hence, the topography of high-elevation terrain affects the incidence angle of sun rays, the influence of wind, the redistribution of snow and the sorting action of gravity for water, nutrients, diaspores and sediments. These factors jointly shape life in the treeless alpine world, beyond the influences related to the strong vertical profile of the air temperature with a mean lapse rate of 0.55 K 100 m−1. On top of diverse soil types, the resulting thermal habitat conditions within a given elevation belt substantially exceed the current (+2.9 K) and future (+4 K) climatic warming in the European Alps. To account for the full spectrum of life conditions, the spatial scale of analysis is essential. We show that pronounced topography effects on microclimate on nunatak-type cliffs above the trimline of glacial ice shields could most likely not fully counteract the then lower and hostile temperatures. Life conditions across snowbeds exemplify the effect of season length on alpine plant’s phenology and growth over short distances, with halved aboveground biomass production for a shortening of the season by two to three weeks. Furthermore, we highlight potential pitfalls in microclimate assessments of topography effects in open terrain, but also explain how to improve such measurements. Throughout this review, we emphasize the interactive effect of plant canopy structure (height, density) with topography, mutually creating life conditions not predictable from standard meteorological sources, but responsible for the over-proportional plant species richness of the alpine flora globally.
Alpine ecosystems are among the most environmentally sensitive systems and are increasingly threatened by climate change. Responding to these changes, adaptive management strategies supported by robust scientific data are needed. Species distribution models (SDMs) offer a powerful framework for forecasting range shifts, but their reliability depends on the quality and ecological relevance of input variables. Remote sensing offers a cost-effective means of capturing the complex heterogeneity of alpine ecosystems, either by describing proxies for other environmental variables or by providing direct estimates of specific drivers. This review synthesizes findings from studies that integrated variables obtained through passive remote sensing (RS) into SDMs targeting alpine vegetation. We assess the types of RS data used, their ecological role in modeling, geographic and methodological trends, and whether RS integration improves model performance. Most studies report enhanced predictive accuracy – particularly when using RS data to capture snow persistence, vegetation structure, or land surface temperature – though the degree of improvement varies by species and modeling approach. We identify limitations, including the risk of overfitting and challenges in scaling RS data appropriately. The review highlights both the benefits and caveats of using RS in SDMs and outlines future directions for improving model robustness, transferability, and relevance to conservation. Our findings suggest that integrating RS into SDMs can significantly enhance their ecological realism and support more effective conservation planning in mountain environments.
Understanding the germination ecology of alpine species is critical for predicting their regeneration responses under climate change and for informing conservation strategies. Azorella compacta Phil. (Apiaceae) is a long-lived cushion plant of the Central Andean highlands (> 3,500 m a.s.l.) characterized by extremely low natural recruitment and currently classified as Vulnerable in Chile. Here, we evaluated the effects of cold stratification duration (4 and 6 months), thermoperiod (10/5°C, 20/10°C, and 25/15°C), and their interaction on final germination, mean germination time (MGT), time to 50
Mountain plants often show preferences for certain topographic characteristics, both for warming and cooling effects, which can modify the response of plants to warming temperatures. We located 12,717 endangered Puya raimondii giant rosettes from satellite imagery and determined their topographic preferences (elevation, slope, aspect) in a study area in the south of Peru. We identified present-day habitat patches matching the species’ preferences in the study area, and projected ahead, in the same region, to 2100 using temperature change scenarios of + 1–5 °C. We adjusted habitat availability in line with the species’ poor dispersal ability. Puya raimondii rosettes in the study area preferred elevations of 3900–4200 m, slopes of 20–50°, and aspects of WNW through to ENE. Approximately 4
Shrub encroachment has become a common consequence of climate change in many alpine regions. However, the influence of existing shrubs on the growth of new shrub seedlings is not well understood. Facilitative interactions, such as microclimatic buffering, could play an increasingly important role in alpine seedling establishment as the climate changes. Here, we conducted a five-year field experiment in the Australian Alps to investigate whether seedling survival, leaf production and height growth of a common shrub (Grevillea australis) vary between leeward (SE-facing, sheltered) and windward (NW-facing, exposed) microsites associated with adult shrubs, and whether these responses are related to adult shrub structural traits. To do so, locally growing seedlings were transplanted to both sides of established shrubs of three dominant species and monitored annually. Overall, we found that seedling survival was higher on the leeward side of the adult shrubs, particularly near larger ones, but only at the site characterised by a dense and earlier melting snow and a drier growing season. In contrast, neither microsite position nor adult shrub traits affected seedling height or leaf production. Over the five-year period, survival and height growth trajectories differed between microsites;: leeward seedlings followed more stable, near-linear trajectories, whereas windward seedlings exhibited greater variability and more pronounced non-linear dynamics, particularly during periods of stress such as drought. These findings highlight the role of shrub-associated microsites and shrub structural traits in shaping seedling establishment, suggesting that local-scale environmental amelioration may become increasingly important for recruitment as snow cover decreases and climate extremes intensify.
Ecuador, recognized as a megadiverse country, faces growing threats from biological invasions, particularly in the mountainous ecosystems of the Andes. We described patterns of native and non-native plant richness and diversity along an elevational gradient (2,000–4,400 m a.s.l.) on the Tungurahua volcano, testing whether patterns of non-native plant diversity are consistent with directional environmental filtering along the gradient or explained by the effects of residence time, climate-matching, and disturbance intensity. Twenty-five 10 × 2 m transects were established at 100-m elevational intervals following a MIREN-T-adapted protocol. Vegetation cover, abundance, and disturbance were recorded in each plot. A total of 247 taxa were identified, distributed across 75 families and 171 genera. Of these, 180 were native (including 11 endemic), 38 non-native, and the remainder of undetermined origin. Non-native taxa were predominantly herbaceous and originated from Africa, Europe, and Asia. Along the gradient, non-native taxa were concentrated at lower elevations, with narrower elevational ranges and lower maximum elevations than native taxa. Native richness exhibited a mid-elevation peak ( 3,400 m), whereas non-native richness declined steadily with elevation. Alpha diversity decreased with elevation in both groups, but sharply in non-natives. Beta diversity analyses showed higher turnover among native assemblages, while non-native communities were more homogeneous along the gradient. Overall, these patterns support the directional environmental filtering hypothesis, with climatic constraints limiting the upslope expansion of non-native taxa and weaker evidence for effects of residence time, climate-matching, or disturbance intensity. These findings provide key insights for the management and conservation of tropical mountain ecosystems.
Most studies of natural selection acting on floral traits only quantify selection pressures within a single species. The lack of complete estimation of the three patterns of selection (directional, quadratic and correlational) in a large array of related species limits our understanding of which pattern of selection operates most commonly or exerts the strongest influence in this process. We quantified these three patterns of selection on three single traits (corolla size, corolla tube length and number of flowers) and all possible trait combinations across seven Primula species. The results indicated that directional selection for a greater number of flowers was detected for all seven Primula species, whereas selection for a shorter corolla tube length was detected only in Primula alpicola. By contrast, quadratic selection on number of flowers and correlational selection on the combination of corolla size and number of flowers and on the combination of corolla tube length and number of flowers was detected only in P. florindae and P. cawdoriana, respectively. These findings illustrate the contributions of different patterns of selection on floral traits and highlight that directional selection is more common and robust than quadratic or correlational selection on floral traits in these primrose species.
This study examines functional trait variation in two sympatric Mexican alpine pines (Pinus culminicola and Pinus hartwegii) along an elevational gradient (2900–3700 m a.s.l.) on Cerro El Potosí, Nuevo León, Mexico. Five foliar traits (thickness, area, dry matter content, succulence, and specific leaf area) were measured in 25 Pinus hartwegii individuals (five elevations) and 15 Pinus culminicola individuals (three elevations) following standardized protocols. P. culminicola exhibited coordinated trait variation with elevation: needle thickness increased 23
Temperature is a major environmental cue for seed germination in alpine plant species, where high temperatures tend to promote seed germination. However, the extent to which germination responses to temperature differs between vegetation belts remains poorly studied, especially along elevational gradients in the temperate Andes. We quantified germination across three fluctuating temperature regimes (10/5° C, 20/10° C, 25/15° C) on 21 species representative of the Low- and High-Andean vegetation belts of central Chile. Using mixed-effects models with species as a random factor, we evaluated how temperature, vegetation belt, and their interaction influence final germination percentage and germination speed. Temperature significantly affected germination dynamics, with faster germination generally occurring under intermediate thermal conditions. In contrast, neither vegetation belt nor the belt × temperature interaction exerted significant effects on final germination or germination speed, indicating that elevational zone alone does not structure thermal germination niches. Species identity accounted for the largest portion of variance in both metrics, indicating intrinsic differences in germination responses. Classification of species into thermal response categories (cold-optimized, intermediate-temperature specialists, warm-enhanced germinators, and broad-temperature generalists) showed that all categories were represented in both vegetation belts. This lack of elevational segregation suggests that germination responses to temperature are not determinant on the elevational distribution in the central Chilean Andes. The facts that temperature influences germination speed more consistently than total germination, and that species-specific effects dominate germination responses suggest that climatic warming may differentially alter germination phenology among coexisting Andean species without uniformly increasing germination success.
Throughout two investigation periods, we estimated the canopy transpiration, understory evapotranspiration and total stand water use of Alnus alnobetula at three stands within the treeline ecotone of the Central Austrian Alps. Our study included one site at the lower edge of the treeline ecotone and two plots at the tree limit: one north-facing leeward and one south-east facing windward. Canopy transpiration (Tc) was estimated at each site by taking sap flow measurements on six stems and scaling them up to stand canopy level. Understory and soil evapotranspiration (ETu) were derived using the soil water budget method. Throughout the treeline ecotone, normalized sap flow density was significantly correlated with solar radiation and vapour pressure deficit. By contrast, soil water content had no effect on normalised sap flow density, suggesting that A. alnobetula is highly tolerant of the limited soil water availability in the topsoil. Our estimated total stand evapotranspiration (ETtot = Tc + ETu) for the treeline ecotone on Mt. Patscherkofel averaged 4.3 ± 0.6 mm per day, while Tc averaged 3.6 ± 0.5 mm per day. These values considerably exceed the means reported for the growing season of adjacent isolated Pinus cembra trees, dwarf shrub communities, and grasslands, and should be taken into account when forecasting the potential effects of shrub encroachment on the water balance of the treeline ecotone.
High-altitude environments constitute a multifaceted stress matrix characterized by the convergence of intense ultraviolet radiation, severe diurnal temperature fluctuations, and hypobaric hypoxia. However, the genus Artemisia has not only colonised but also thrived in these habitats worldwide. Traditional research, which has focused on cataloguing isolated traits, has failed to explain the synergistic resilience observed in these plants. This review provides a multi-level integrated synthesis of global research on alpine Artemisia, framing adaptation as an emergent property of a dynamic, multi-level system. We demonstrate that the survival of these species is orchestrated by a dynamic system spanning four organizational levels: a foundational genomic and phylogeographic scaffold; a core physiological and metabolic network managing strategic resource trade-offs; a protective suite of engineered morphological traits; and a regulatory interface in which transcription factor networks integrate environmental signals. We present compelling evidence of this integration, from the precise metabolic reallocation in Artemisia brevifolia to the molecular cascades, such as the AabHLH112-AaERF1 module in cold adaptation, which orchestrate a system-wide response. This synthesis resolves disparate findings into a unified paradigm, revealing adaptation as an emergent property of an interconnected system. By shifting the focus from isolated traits to their functional integration, this synthesis provides a framework for identifying vulnerabilities and informing strategies to enhance the resilience of alpine biodiversity, such as assisted migration or targeted conservation of critical refugia in the face of rapid climate change.
Caragana roborovskyi is prevalent in the arid and semi-arid regions of Northwest China, demonstrating a strong adaptation to extreme habitats. However, the population genetic differentiation and molecular mechanisms underlying its adaptation to diverse environments remain unclear. This study integrated multi-scale environmental sampling, population genetics analysis, and ecological niche modeling to investigate the genetic structure and adaptive mechanisms of Caragana roborovskyi. The results revealed high genetic diversity within populations and frequent gene flow among them. Gradient forest and redundancy analyses indicated that genetic variation was closely associated with environmental factors such as BIO3, BIO1, BIO10,and UV-B radiation, underscoring the role of environmental filtering in driving genetic differentiation. MaxEnt modeling suggested that the Hexi Corridor-Qilian Mountains region may have served as a glacial refuge for this species. Overall, the study elucidated the genetic responses of Caragana roborovskyi to Quaternary climate changes and recent environmental gradients. It confirmed that populations can evolve environmental adaptability by maintaining high genetic diversity, despite gene flow. These findings provide new insights into the adaptation mechanisms of desert plants and support the conservation and utilization of germplasm resources from Caragana species.
Andean páramo peatlands are fragile high-altitude ecosystems characterized by frequent fog, intense seasonal solar radiation, strong daily temperature fluctuations, water saturation, and nutrient scarcity. These extreme conditions make them ideal systems for examining facilitative plant interactions and their influence on microclimate, soil nutrient dynamics, and biodiversity. We recorded 65 plant species and 5,368 individuals; 54
Deciphering how plants interact with each other across environmental gradients is important to understand plant community assembly, as well as potential future plant responses to environmental change. Plant − plant interactions are expected to shift from predominantly negative (i.e. competition) to predominantly positive (i.e. facilitation) along gradients of environmental severity. However, most experiments examine the net effects of interactions by growing plants in either the presence or absence of neighbours, thereby neglecting the interplay of both negative and positive effects acting simultaneously within communities. To partially unravel these effects, we tested how the seedling establishment of 10 mountain grassland plants varied in the presence versus absence of plant communities at two sites along an elevation gradient. We created a third experimental treatment (using plastic plant mats to mimic surrounding vegetation) that retained the main hypothesised benefits of plant neighbours (microsite amelioration), while reducing a key negative effect (competition for soil resources). In contrast to our expectations, we found evidence for net positive effects of vegetation at the low elevation site, and net negative effects at the high elevation site. Interestingly, the negative effects of plant neighbours at high elevation were driven by high establishment rates of low elevation grasses in bare soil plots. At both sites, establishment rates were highest in artificial vegetation (after excluding two low elevation grasses at the high elevation site), indicating that positive effects of above-ground vegetation are partially offset by their negative effects. Our results demonstrate that both competition and facilitation act jointly to affect community structure across environmental gradients, while emphasising that competition can be strong also at higher elevations in temperate mountain regions. Consequently, plant − plant interactions are likely to influence the establishment of new, and persistence of resident, species in mountain plant communities as environments change.
