Alpine Region Research Articles

Phytogeographic Considerations on the Flora of Mt. Abu

The Aravallis intersect the State of Rajasthan in a southwest-northeast direction. Mt. Abu on the Aravallis is the highest point in the wide gap between the Himalayas and the Nilgiris, and thus has phytogeographlc significance. The flora of Mt. Abu has been compared with that of other hilly regions of India, and also with the flora of adjacent regions of the dry zones. It is observed that : i. the flora of Mt. Abu has some representation of mountain element belonging to subtropical and temperate regions of India. This element comprises three groups of plants, namely, (a) those occurring in all or most hilly regions of India, such as in Himalayas, Parasnath, Pachmarhi, Western Ghats, Nilgiris, etc. (26 species); (b) plants found in the Himalayas or moist places of northern India, whose southern limit is the Mt. Abu (19 species); and (c) plants found in the Ghats and hills of Deccan Peninsula and whose northern limit of distribution is Mt. Abu 38 species).ii. there are only a few plants of alpine regions in this flora;iii. large number of plants are of wide general distribution;iv. biotic factors are resulting in increase of xerophytic species on this hill.A study ofthe world distribution of the plants of Mt. Abu shows that:i. out of 469 species, 267 are tropical;ii. 80 species are eastern, southeastern, Asian and Australian;iii, 46 species are African-Arabian; andiv. 22 species are American. The American plants are mostly weeds of cultivation.

Modeling Climate Characteristics of Qinghai Lake Ice in 1979–2017 by a Quasi-Steady Model

Lakes on the Qinghai Tibet Plateau (QTP) are widely distributed spatially, and they are mostly seasonally frozen. Due to global warming, the thickness and phenology of the lake ice has been changing, which profoundly affects the regional climate evolution. There are a few studies about lake ice in alpine regions, but the understanding of climatological characteristics of lake ice on the QTP is still limited. Based on a field experiment in the winter of 2022, the thermal conductivity of Qinghai Lake ice was determined as 1.64 W·m−1·°C−1. Airborne radar ice thickness data, meteorological observations, and remote sensing images were used to evaluate a quasi-steady ice model (Leppäranta model) performance of the lake. This is an analytic model of lake ice thickness and phenology. The long-term (1979–2017) ice history of the lake was simulated. The results showed that the modeled mean ice thickness was 0.35 m with a trend of −0.002 m·a−1, and the average freeze-up start (FUS) and break-up end (BUE) were 30 December and 5 April, respectively, which are close to the field and satellite observations. The simulated trend of the maximum ice thickness from 1979 to 2017 (0.004 m·a−1) was slightly higher than the observed result (0.003 m·a−1). The simulated trend was 0.20 d·a−1 for the FUS, −0.34 d·a−1 for the BUE, and −0.54 d·a−1 for the ice duration (ID). Correlation and detrending analysis were adopted for the contribution of meteorological factors. In the winters of 1979–2017, downward longwave radiation and air temperature were the two main factors that had the best correlation with lake ice thickness. In a detrending analysis, air temperature, downward longwave radiation, and solar radiation contributed the most to the average thickness variability, with contributions of 42%, 49%, and −48%, respectively, and to the maximum thickness variability, with contributions of 41%, 45%, and −48%, respectively. If the six meteorological factors (air temperature, downward longwave radiation, solar radiation, wind speed, pressure, and specific humidity) are detrending, ice thickness variability will increase 83% on average and 87% at maximum. Specific humidity, wind, and air pressure had a poor correlation with ice thickness. The findings in this study give insights into the long-term evolutionary trajectory of Qinghai Lake ice cover and serve as a point of reference for investigating other lakes in the QTP during cold seasons.

Study on the Performance Evolution of Hydraulic Concrete under the Alternating Action of Freeze–Thaw and Abrasion

The hydraulic concrete in the alpine region is subjected to alternating actions of freeze–thaw (F) and abrasion (W) during operation, resulting in significant deterioration of concrete durability. In this paper, the water/binder ratio (W/B) was employed as the test variable, the working condition F group and W group were set as the control group, and the working condition F-W group was used as the test group. Fast-freezing and underwater methods are used for the alternating test. By measuring the mass loss, relative dynamic elastic modulus (RDEM), surface morphological characteristics, fractal dimension of concrete in each alternating cycle, and the evolution law of concrete performance under the alternating action of F and W was explored. The results show that compared with the control group, the alternating action will accelerate the mass loss of concrete, reduce the RDEM, and cause the deterioration of surface wear. The maximum increase in mass loss and RDEM of concrete is 1.92% and 20.11%, respectively. During this process, the fractal dimension of the concrete increases as the number of alternating cycles increases, but it still does not exceed the limit of 2.4. In addition, a relationship function between the fractal dimension and the mass loss rate, volume loss, was established. It was found that the experimental group had a good linear correlation, and the correlation was close to 95%, which was about 20% higher than that of the control group.

Effects of the freeze–thaw process on sources and pathways of subsurface flow in an alpine hillslope on the northeastern Qinghai-Tibet Plateau

The impact of the freeze–thaw process on the active layer is reflected in the changed subsurface flow (SSF) process in cold alpine regions. Identifying sources and pathways of SSF in the freeze–thaw process is critical but difficult, and the related dominant factors and mechanisms are still unknown. In this paper, the effective identification and analysis of SSF are promoted based on field sampling data from the thawing (June) to freezing (September) period of 2022 in the Qinghai Lake basin on the northeastern Qinghai-Tibetan Plateau. By the proposed method with a high sampling frequency and refined sampling spatial scale, the sources and pathways of SSF are clearly identified. The results are as follows: (1) The soil temperature is considered the most fundamental factor affecting the SSF pathways, it influences water infiltration to the deep layer and the effect is extended to the saprolite and weathered bedrock layers. (2) Thawing promotes water to infiltrating into deep layer. 30 cm soil water contributes the most to SSF (2 %–86 %) in the thawing period, while the contribution difference of the water from the 30 cm, 60 cm, and 90 cm layers is small (ranging from 32 %–33 %, 24 %–26 %, and 32 %–35 %, respectively) in the thawed period. (3) Meanwhile, the soil water from different slope positions contribute differently to SSF, and the SSF from deep soil layer is transit in prolong paths and depths. It is caused by the out-of-sync water transit process in the hillslope. With continuing climate warming, we propose that the differences in the water sources of SSF across soil layers may decrease, while the differences in the transit processes of SSF across soil layers may increase.

Alpine plant communities and current topographic microrefugia vary with regional climates

Topographic microrefugia on slopes are assumed to be critical for the persistence of alpine plant species and the maintenance of alpine plant community diversity in a warming climate. They create microclimates, some of which are cooler and/or wetter than others, which may buffer continuing climate change. However, the current relationship of plant communities to microtopography at individual slope scale could differ among regional climates, and if so resilience in new climates would also differ.Vegetation cover and topographic site characteristics at a fine scale were recorded in the field in three alpine regions of the Rocky Mountains, USA: Glacier National Park, MT, the Indian Peaks Area, CO, and Taos Ski Valley, NM. Elements of alpine slopes were identified and transformed into ordinal variables. Two indicators of insolation were calculated from slope angle, slope aspect, and latitude, and soil depth indicators and elevation were recorded. In each region, the contribution of these variables to the variation in the plant community composition were compared using nonmetric multidimensional scaling and random forest models.The partitioned variance explained by the topographic and topography-derived climatic variables differed among the three regions. Variables related to moisture conditions were more important in the snowiest, northern region and the central region, while those related to energy were more important in the southern region with higher radiation and temperature. Lower correlations of mesoscale variables set microrefugia in a hierarchical context.The more extreme regional topographically derived climatic variables better explain the differentiation of alpine plant communities. These variables may not play the same role in potentially novel future climates. Because topographic features mediate regional climates to niche dimensions, setting microrefugia in a multiscale framework can focus research on climate change impacts.

137Cesium (137Cs) assessment in wild boars from northwestern Italy.

Radionuclide contamination is a serious health issue caused by nuclear experiments and plant accidents, as seen for the Chernobyl and Fukushima nuclear plants. Italy has been especially interested in northwestern alpine regions, as have several other nations. The aim of this work was to indagate 134Cs and 137Cs contamination in wild boars, which were considered bioindicators sampled in the Chisone/Germanasca Valley and the Pellice Valley districts (Piedmont, Italy) in two hunting seasons (2014 and 2016). In the 2014 season, only the livers of the animals (n = 48) were sampled, whereas in 2016, five different anatomical sampling sites were sampled for each animal (n = 16). The analyses were conducted in an accredited laboratory (Agenzia Regionale per la Protezione dell'Ambiente-ARPA) by the aid of an HPGe detector (Ortec) with a relative efficiency of 50%. In general, the contamination levels registered in 2014 were under the detection limit for 134Cs and low for 137Cs (Chisone/Germanasca valley: min: 0.0, max: 23.9 median 11.0 Bq/kg vs Pellice valley: min 0, max: 31.7, median: 9.6 Bq/kg) and no health concern can be supposed. In the first-year samples, the liver showed a negative correlation between age and contamination level. In the second year of sampling, low levels were confirmed (min: 3.1 Bq/kg, max: 113.3; median 17.7 Bq/kg). Multiple sampling from the same animal showed that the diaphragm (median = 27.7 Bq/kg) kidney (27.4) and tongue (27.6) were more contaminated than the liver (17.7) and spleen (15.3). Moreover, a linear mixed model revealed a negative organ-by-age interaction, meaning that interorgan differences in contamination level were greater in younger (5-11 months) than in older (18-36 months) animals. Different feeding habits can be the explanation. Our paper shows that muscle sites (diaphragm and tongue) can be useful for radionuclide pollution surveillance in wild boar populations and that younger animals show more interorgan variability in contamination levels than older animals. More investigations are needed to confirm this correlation and to fulfill the request for more data to achieve better risk assessment.

The impact of desertification on soil health stability in Semi-Arid alpine Regions: A case study of the Qilian Mountains in the northeastern Tibetan Plateau, China

Desertification poses a serious threat to ecosystem health, and with global changes, the variability and uncertainty of ecological functions in semi-arid alpine regions are increasing. A pressing issue is quantifying how desertification affects the soil system functions in these areas. However, empirical evidence is still lacking in exploring the interaction between desertification degradation gradients and soil functions under natural conditions by coupling soil physicochemical properties, soil microbiota, and vegetation. For this purpose, we conducted a survey sampling of soil and vegetation at five sites with no, light, moderate, severe and extremely severe desertification in Qinghai Area of Qilian Mountains National Park, China. We introduced a new concept soil health stability (SHS) to represent the actual health status of soil systems in semi-arid alpine regions and assessed the impact of desertification on this stability. We observed that the intensification of desertification has led to a significant decrease in soil organic matter, relative abundance of soil microorganisms, and plant factors. The contributions of plant factors and soil microbiota to SHS showed a negative correlation with the degradation gradient. SHS varied across different degradation gradients, rather than following a single linear relationship, with a relatively rapid decline in the transition from non-desertification to moderate desertification. Our work emphasizes that the coupled contributions of soil physicochemical properties, soil microbiota, and vegetation to SHS. It calls for intensified prevention and treatment of mild and moderate desertification, while providing new methods and deeper scientific understanding for accurately evaluating soil system functions in semi-arid alpine regions.

Numerical Simulation Study on Blasting-induced Damage Characteristics of Frozen Rock

Rock masses in cold regions are exposed to a negative temperature environment for extended periods, causing significant changes in their mechanical properties. This inevitably results in substantial differences in the blasting characteristics compared to rocks at normal temperatures. To reveal the influence of different temperatures on the blasting characteristics of frozen rocks, this paper utilized a finite element method-based LS-DYNA software for numerical simulation of single borehole blasting at freezing temperatures of -5°C, -10°C, -20°C, and -30°C. The results showed that under negative temperature conditions, the degree of rock blasting-induced damage gradually decreased as the rock temperature decreased. As the temperature decreased from -5°C to -30°C, the volume of rock blasting-induced damage decreased by approximately 14%. Additionally, this paper has further investigated the effects of ignition locations, free surface, and borehole burdens on the blasting-induced damage characteristics of frozen rock. It was found that the volume of the blast cavity is the largest in reverse detonation. While forward detonation is more favorable for damaging the top rock and helps to improve the rock fragmentation at the orifice. Increasing the free surface can significantly improve the effect of blasting-induced damage. There is an optimal borehole burden distance, which can fully utilize the explosive energy and break the rock efficiently. Finally, based on multivariate nonlinear regression analysis, an empirical formula of the reduction coefficient of the specific charge for frozen rock mass is developed, which can provide a theoretical basis for designing and optimizing rock engineering blasting in alpine and cold regions.

Shrubs exhibit competitive interactions with herbaceous plants and shape community assemblage and functional composition in the alpine western Himalaya

AbstractQuestionsIn the alpine region of the Himalaya, shrubs play a vital role in maintaining the diversity and functional composition of associated herbaceous communities through competition–facilitation interactions under varying environmental stress conditions. In this study, we specified the following questions: (1) what is the mode of interaction between dominant shrubs and the associated herbaceous communities; (2) how do differences in resource availability between contrasting microhabitats mediate interactions between shrub and herbaceous communities; and (3) how do dominant shrubs influence the functional composition of herbaceous communities under the canopy as compared to ones in the open?Study areaAn alpine region of the western Himalaya, in India (32.24–33.15° N, 76.51–78.13° E).MethodsField studies were conducted to evaluate the canopy effects of alpine shrubs such as Caragana versicolor, Juniperus polycarpos and Rhododendron anthopogon on species richness, abundance and functional composition of coexisting herbaceous communities.ResultsThe dominant alpine shrubs of the western Himalaya exert competitive interactions with associated herbaceous communities and have low species richness and abundance under their canopies compared to open habitats. Further, contrary to expectations, competitive interactions were more prominent at higher elevations than at lower ones, especially for J. polycarpos and C. versicolor. Although the shrub undercanopies possessed richer soil nutrient pools, this did not contribute toward the facilitation of herbaceous species under the canopies. Moreover, herbaceous species under the canopies were found to exhibit resource‐acquisitive functional strategies, whereas those in the open were resource‐conservative.ConclusionsThe interaction between dominant alpine shrubs and the herbaceous community of the western Himalaya is competitive in nature, which influences species and functional composition and reorganizes herbaceous community assembly. Moreover, under future climate change scenarios the dominance of these shrubs will favour those herbaceous species that possess more competitive and resource‐acquisitive functional strategies.

A Novel Method for Characterizing the Inter‐ and Intra‐Lake Variability of CH4 Emissions: Validation and Application Across a Latitudinal Transect in the Alpine Region

AbstractLakes in the Alpine region are recognized as critical methane (CH4) emitters, but a robust characterization of the magnitude and variability of CH4 fluxes is missing. We developed a mobile platform for CH4 eddy covariance (EC) flux measurements to tackle this gap. The mobile system was deployed at nine lakes across a latitudinal transect in the Alps and validated by comparing the measured fluxes with fixed on‐shore EC station and to chamber and boundary layer flux estimates. Our approach was shown to be well suited to capture different CH4 emission pathways and to integrate the within lake variability, therefore, overcoming the limitations of other methods (e.g., boundary layer method). Additionally, this mobile system offers a tool to characterize inter‐lake variability of fluxes with consistent measurements. Methane fluxes were explained by dissolved nitrogen, total phosphorus, dissolved oxygen, seston and lake size. The highest fluxes and most substantial seasonal variability were found in a shallow low‐altitude lake in the Southern Alps. We suggest that characterizing the intra‐lake emission heterogeneity and consistent measurements for a better understanding of inter‐lake emission differences is fundamental for a solid estimate of freshwater CH4 budgets.

Climate change impairs the effects of vegetation improvement on soil erosion control in the Qinghai-Tibetan Plateau

Water erosion is a wide ecosystem degradation threat for the Qinghai-Tibetan Plateau (QTP) region and surrounding areas. Climate wetting and vegetation greening in the QTP could have complex impacts on water erosion. However, there is limited information about the erosion dynamics under climate change and the effects of vegetation improvement on erosion control in this alpine region. By calibrating the Revised Universal Soil Loss Equation (RUSLE) model, we estimated water erosion in the QTP and simulated future changes using different Shared Socioeconomic Pathway-Representative Concentration Pathway (SSP) scenarios. We showed intensified erosion and that the benefits of vegetation improvement to erosion control was impaired under climate change. Under the SSP585 scenario, annual water erosion in the QTP was predicted to increase by 0.35 t∙ha−1∙yr−1 and be dominated by an accelerative rise of rainfall erosivity (R factor of RUSLE). Compared with historical observations, the C factor of RUSLE under the SSP585 scenario was believed to reduce by 4.35 % on average during the 2081–2100 period, but predicted soil loss will increase by more than 90 %. Although more considerable vegetation improvement could occur under high climate forcing, there may also be more intensified rainfall erosivity and water erosion across the QTP than those under SSP126 and SSP245 scenarios. Our results suggest that mitigating climate change rather than vegetation improvement is essential to address climate-dominated ecosystem degradation threats such as water erosion in the QTP.

Subsidy-Dominated Non-Farm Income Improves Herder Household Livelihoods and Promotes Income Equality in North Tibet, China

The non-farm sector is critical in supporting sustainable economies, alleviating poverty, and improving human well-being. However, the drivers of non-farm income and how it impacts income inequality remain underexplored, especially in alpine regions worldwide. Herein, we conducted face-to-face interviews using semi-structured questionnaires with 665 herder households across 54 villages in North Tibet from 2018 to 2020. We assessed the role of non-farm income in household economies and explored the determinants of household income using basic statistical methods, Gini coefficient analysis, and mixed-effects modeling. Our results showed that non-farm income accounted for approximately 80% of the total household income. It contributed to lower income inequality in rural North Tibet, with government subsidies playing a more vital role than wages and business income in this reduction. Results indicated that the number of migrant workers was the most significant positive predictor of both non-farm income and total household income, whereas livestock units dominated farm income. Given the modest contributions of livestock-derived income (~5%) and wage and business revenues (~18%) to overall earnings, this study suggests that policies should primarily focus on strengthening rural livestock husbandry. Simultaneously, it is imperative to foster environments that encourage entrepreneurship and non-farm activities and to expand access to skill-based training. Such initiatives and measures are essential for diversifying livelihood strategies and improving resident welfare in North Tibet.

Transfer learning in environmental data-driven models: A study of ozone forecast in the Alpine region

Many environmental variables, in particular, related to air or water quality, are measured in a limited number of points and often for a limited time span. This forbids the development of accurate models for interesting locations with missing or insufficient data and poses the question of whether a model developed for another measurement site can be reliably applied. Such a question is particularly critical when the model is entirely data-driven, such as a neural network. In this context, the paper proposes a procedure to evaluate the expected performance of an existing neural network model applied to a new unmonitored station. This transferability assessment is exemplified by the problem of forecasting ozone concentrations in different environmental settings around the Alpine Arc. Long Short-Term Memory (LSTM) neural network models are applied for predicting hourly concentrations in 20 stations of different types (urban, rural, and mountain). The analysis of the results allows us to determine the expected performance of such models in new cases and reduce the transferability uncertainty when the existing models can be partitioned into clusters. The LSTM models demonstrate the possibility of high accuracy in ozone forecasting at all sites. Given the significant impacts of this gas on human health and the environment, this can contribute to better decision-making and mitigation strategies for air pollution control.

Causes for Decadal Trends in Surface Solar Radiation in the Alpine Region in the 1981–2020 Period

AbstractExtending across seven countries, the Alps represent an important element for climate and atmospheric circulation in Central Europe. Its complex topography affects processes on different scales within the atmospheric system. This is of major relevance for the decadal trends in surface solar radiation (SSR), also known as periods of global dimming and brightening (GDB). In this study we analyzed data from 38 stations in and around the Swiss and Austrian Alps, over a period ranging from the 1980s up to the 2020s, with the aim of characterizing the spatio‐temporal variations of the GDB and understanding the causes for such trends in this region. Our results show a different behavior in the SSR decadal trends in the western part of the Alps in comparison to the eastern part. Our results also suggest a remarkable difference between the causes of such trends at the stations at low altitudes in comparison to the stations at higher altitudes. Significant contributions from changes in cloud optical depth and surface albedo to the SSR decadal trends at high elevation sites were also found, in contrast to a substantial clear‐sky forcing that strongly dominates at low elevations. Results from previous literature and available data suggest that cloud optical depth changes at high altitudes and clear‐sky forcing at low altitudes could be associated with the indirect and direct aerosol effects, respectively, due to differing pollution levels at low and high elevation sites.

The Hasli Formation of the Irchel Plateau – A key record for older Early Pleistocene interglacial sediments in northern Switzerland

In the Alpine region of Central Europe, terrestrial Early Pleistocene deposits with preserved faunal and botanical remains are rare. The predominantly gravelly Höhere Deckenschotter (HDS) deposits of northern Switzerland and adjoining south-western Germany are considered the oldest Quaternary sediments in the northern Alpine Foreland, linked with the first extensive Quaternary Alpine glaciations.This multidisciplinary study investigates the Hasli Formation (HF), a unique silty unit with well-preserved biological remains within an HDS sequence at the Irchel Plateau north of Zürich, providing new climatic and environmental data for these exceptional deposits, as well as crucial information about their age. Systematic mapping of the HF, in addition to the underlying and covering gravel units, has been coupled with sedimentary logging and biostratigraphic analysis at several sites. The HF is present over an area c.4 by up to 1.4 km, and where studied is 1.6–6.2 m thick. The sediments and biological material are indicative of overbank deposits accumulating within the damp floodplain of a large meandering river.The recovered small mammal remains are from eight arvicolid species or genera, including Mimomys pliocaenicus, M. reidi/tigliensis and Clethrionomys cf. kretzoii, which became extinct c.1.8 Ma, and Pliomys episcopalis/simplicior, which first appeared c.2 Ma ago. The over 75k identified molluscs, include c.72k coming from 89 terrestrial species and over 3k from 28 aquatic taxa. The molluscan faunas from all locations where the HF has been studied share important biostratigraphic marker species, and indicate analogous climatic and environmental conditions. The marker species include several that became extinct during the Early Pleistocene, of which Clausilia stranzendorfensis and Cochlostoma salomoni, present throughout the HF, are the most important as they disappeared c.1.8 Ma. Many marker species have modern or palaeo-distributions that lie far to the west, south and east of the Swiss Plateau, showing that the climate was much warmer than today, typical for the Tiglian warm stage. The alluvial floodplain was covered by rather dense, mature woodland.Amino acid (AA) analysis shows that molluscan remains from the HF are among the oldest of the Quaternary shell material studied from across the Swiss Plateau. Palaeomagnetic data shows a change from reversed to normal polarity within the upper part of the HF. When combined, the small mammal and molluscan remains, palaeomagnetic measurements, AA geochronology and sedimentary data, suggest an age of 2.1–1.8 Ma for the HF. Recently produced cosmogenic dates bracket the age of the HDS gravels beneath the HF to depositional periods between 2.6 and 0.9 Ma, with the youngest ages being in disagreement with our findings. The abundance and diversity of the molluscs from the Irchel Plateau, with several rare extinct species, together with a notable small mammal assemblage, make this a key palaeontological site and an important reference point for European Quaternary biostratigraphy.

Fine evaluation of ecological service functions in alpine and deep valley regions: A case study of the southeast Tibetan Plateau

Refined evaluation of ecosystem service functions in deep valleys in high mountain areas is an important means of precise protection of ecosystems. As the population continues to increase, human needs and demands on ecosystems continue to increase, and deep valleys in high mountain areas with good ecological integrity face the risk of development, it is urgent to balance protection and development and carry out precise protection of ecosystems. Based on the principles of typicality, specificity, feasibility and sustainability, this paper constructs an evaluation system for the ecosystem service function of the alpine deep valley area, consisting of 12 indicators from four aspects: Regulating functions, Provisioning functions, Supporting functions and Cultural functions. The Entropy Weight method was used to assign the weights of the relevant indicators in a hierarchical manner, and to complete the evaluation of the importance of ecosystem service functions and the importance zoning of the southeastern Tibetan Plateau. The results showed that: the importance of the ecosystem service functions of the Southeast Tibetan Plateau gradually decreases from southwest to northeast; the extremely important area is mainly distributed in the forest ecosystems with good originality and integrity in the south, accounting for 2.61% of the total area of the region, which needs to focus on ecological protection; the slightly important area is mainly distributed in the northern high altitude area with low vegetation cover and weak soil and water conservation capacity and grassland ecosystem, accounting for 58.89% of the total area of the region, which can be prioritized for development. The results of the study provide new ideas for precise protection of ecosystems and resolution of conflicts between ecological protection and development, as well as for the planning of functional areas for ecosystem services in deep valleys of high mountains, and also provide scientific references for regional sustainable development.

Plant diversity increases spatial stability of aboveground productivity in alpine grasslands.

Plant diversity can significantly affect the grassland productivity and its stability. However, it remains unclear how plant diversity affects the spatial stability of natural grassland productivity, especially in alpine regions that are sensitive to climate change. We analyzed the interaction between plant (species richness and productivity, etc.) and climatic factors (precipitation, temperature, and moisture index, etc.) of alpine natural grassland on the Qinghai-Tibetan Plateau. In addition,we tested the relationship between plant diversity and spatial stability of grassland productivity. Results showed thatan increase in plant diversity significantly enhanced community productivity and its standard deviation, while reducing the coefficient of variation in productivity. The influence of plant diversity on productivity and the reciprocal of productivity variability coefficient was not affected by vegetation types. The absolute values of the regression slopes between climate factors and productivity in alpine meadow communities with higher plant diversity were smaller than those in alpine meadow communities with lower plant diversity. In other words, alpine meadow communities with higher plant diversity exhibited a weaker response to climatic factorsin terms of productivity, whereas those with lower plant diversity showed a stronger response. Our results indicate that high plant diversity buffers the impact of ambient pressure (e.g., precipitation, temperature) on alpine meadow productivity, andsignificantly enhanced the spatial stability of grassland productivity. This finding provides a theoretical basis for maintaining the stability of grassland ecosystems and scientifically managing alpine grasslands under the continuous climate change.

Dispersal potential does not predict recent range expansions of sub-Antarctic plant species

AbstractDispersal influences many key aspects of plant ecology at both fine- and broad scales. However, dispersal events are challenging to quantify as they are difficult to observe and measure accurately, despite the importance of understanding species’ dispersal capacity. In this study, we quantified dispersal estimates for the dominant vascular flora of sub-Antarctic Marion Island, using a mechanistic model to estimate dispersal potential via anemochory and standardized experiments that simulate dispersal events via zoochory, human activity, and thalassochory, to test if dispersal capacity correlates to contemporary range expansion of the island’s native and alien species. Our results demonstrate the broad range of dispersal potential in the island’s flora and represent the first quantification of the dispersal potential (via multiple vectors) of the dominant vascular flora in the sub-Antarctic. Dispersal potential was not related to range expansion rates of native or alien species, suggesting that other mechanisms are responsible for the variation observed in species range expansion rates. Although this finding contradicts expectations and evidence from some other studies, it is consistent with research conducted in alpine regions (which may be climatically and physiognomically similar to this sub-Antarctic study site) where factors such as demography and competition are more important predictors of species range expansion than their dispersal ability, dispersal syndromes, or dispersal-related traits.

EU2030 biodiversity strategy: Unveiling gaps in the coverage of ecoregions and threatened species within the strictly protected areas of Italy

About 19 % of the Italian territory is covered by protected areas (PAs), 5.1 % of which fall in IUCN categories Ia and II, which can be considered strictly protected areas (StPAs). The 2030 EU Biodiversity Strategy sets a target of 30 % coverage for PAs (of which 10 % should be StPAs). We assessed the area coverage of StPAs, for the territory of Italy, with respect to biogeographical regions, ecoregions, elevation range, habitats, and the distribution of species threatened with extinction according to the IUCN Red List (Vulnerable, VU; Endangered, EN; or Critically Endangered, CR). We found that most of the StPAs are located in the Mediterranean biogeographical region, followed by the Alpine and Continental regions, and that the spatial distribution of such protected areas is biased towards higher elevation. Moreover, we found that three of the fourteen terrestrial ecoregions of Italy are not protected at all by StPAs (i.e., Illyrian, Ligurian-Provencal, and Central-Adriatic), while the Po Plain and the Sicilia Sections are only marginally protected. Moreover, nine habitats are not covered by any StPAs including one priority habitat (Inland salt meadows). Finally, we found unprotected species among freshwater fish (21), amphibians (3 VU, 3 CR), reptiles (1 CR), birds (2 NE), mammals (1 VU), and plants (20 VU, 14 EN, 21 CR). Our findings suggest that the current amount and spatial distribution of StPAs of Italy are far from the targets of the EU Biodiversity Strategy and needs improvements.

Formation mechanism of high-altitude glacial mineral water in the Kunlun Mountains of Tibetan Plateau: Insights from isotopes and hydrochemistry

Study regionThe Kunlun Mountains on Tibetan Plateau Study focusThe Tibetan Plateau, well known as Asian Water Tower, holds immense potential for the formation of glacial mineral water. The present research focuses on the hydrochemical and isotopic signatures and formation pattern of natural glacial mineral water in the alpine region on Tibetan Plateau. New hydrological insights for the regionThe investigated mineral groundwater has outstanding water quality and slightly alkaline nature. It is with fresh hydrochemical facies of HCO3-Na·Ca type with total dissolved solids (TDS) in the range of 384–964 mg/L, and featured by notably rich strontium with the concentrations of 0.67–0.81 mg/L, far exceeding the recommended mineral water minimum threshold of 0.20 mg/L. The mineral groundwater is originated from the glacier meltwater of mountainous area with elevation over 4500 m. It subsequently infiltrates into the bedrock and move within the groundwater system with a residence time of approximately 52 years. Its hydrochemical constituents are naturally governed by water-rock interactions of silicates dissolution, cation exchange, and celestite and strontianite dissolution. A conceptual model is proposed to outline the formation pattern of glacial mineral water in alpine region on Tibetan Plateau. Findings of this study can fill the study gap regarding glacial mineral water on Tibetan Plateau, and further contribute to the future study and development of natural glacial mineral water in alpine regions worldwide.