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Sample records for alpine temperature validation

  1. Analysis of a high-resolution regional climate simulation for Alpine temperature. Validation and influence of the NAO

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    Proemmel, K. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Kuestenforschung

    2008-11-06

    To determine whether the increase in resolution of climate models improves the representation of climate is a crucial topic in regional climate modelling. An improvement over coarser-scale models is expected especially in areas with complex orography or along coastlines. However, some studies have shown no clear added value for regional climate models. In this study a high-resolution regional climate model simulation performed with REMO over the period 1958-1998 is analysed for 2m temperature over the orographically complex European Alps and their surroundings called the Greater Alpine Region (GAR). The model setup is in hindcast mode meaning that the simulation is driven with perfect boundary conditions by the ERA40 reanalysis through prescribing the values at the lateral boundaries and spectral nudging of the large-scale wind field inside the model domain. The added value is analysed between the regional climate simulation with a resolution of 1/6 and the driving reanalysis with a resolution of 1.125 . Before analysing the added value both the REMO simulation and the ERA40 reanalysis are validated against different station datasets of monthly and daily mean 2m temperature. The largest dataset is the dense, homogenised and quality controlled HISTALP dataset covering the whole GAR, which gave the opportunity for the validation undertaken in this study. The temporal variability of temperature, as quantified by correlation, is well represented by both REMO and ERA40. However, both show considerable biases. The REMO bias reaches 3 K in summer in regions known to experience a problem with summer drying in a number of regional models. In winter the bias is strongly influenced by the choice of the temperature lapse rate, which is applied to compare grid box and station data at different altitudes, and has the strongest influence on inner Alpine subregions where the altitude differences are largest. By applying a constant lapse rate the REMO bias in winter in the high

  2. Alpine forest-tundra ecotone response to temperature change,Sayan Mountains, Siberia

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    Ranson, K Jon; Kharuk, Vyetcheslav I.

    2007-01-01

    Models of climate change predict shifts of vegetation zones. Tree response to climate trends is most likely observable in the forest-tundra ecotone, where temperature mainly limits tree growth. There is evidence of vegetation change on the northern treeline However, observations on alpine tree line response are controversial. In this NEESPI related study we show that during the past three decades in the forest-tundra ecotone of the Sayan Mountains, Siberia, there was an increase in forest stand crown closure, regeneration propagation into the alpine tundra, and transformation of prostrate Siberian pine and fir into arboreal forms. We found that these changes occurred since the mid 1980s, and strongly correlates with positive temperature (and to a lesser extent, precipitation) trends. Improving climate for forest growth( i.e., warmer temperatures and increased precipitation) provides competitive advantages to Siberian pine in the alpine forest-tundra ecotone, as well as in areas typically dominated by larch, where it has been found to be forming a secondary canopy layer. Substitution of deciduous conifer, larch, for evergreen conifers, decreases albedo and provides positive feedback for temperature increase.

  3. Relationship between alpine tourism demand and hot summer air temperatures associated with climate change

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    Rebetez, M.; Serquet, G.

    2010-09-01

    We quantified the impacts of hot summer air temperatures on tourism in the Swiss Alps by analyzing the relationship between temperature and overnight stays in 40 Alpine resorts. Several temperature and insolation thresholds were tested to detect their relationship to summer tourism. Our results reveal significant correlations between the number of nights spent in mountain resorts and hot temperatures at lower elevations. Alpine resorts nearest to cities are most sensitive to hot temperatures. This is probably because reactions to hot episodes take place on a short-term basis as heat waves remain relatively rare. The correlation in June is stronger compared to the other months, probably because school holidays and the peak domestic tourist demand in summer usually takes place in July and August. Our results suggest that alpine tourist resorts could benefit from hotter temperatures at lower elevations under future climates. Tourists already react on a short-term basis to hot days and spend more nights in hotels in mountain resorts. If heat waves become more regular, it seems likely that tourists choose to stay at alpine resorts more frequently and for longer periods.

  4. Plants in alpine environments

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    Germino, Matthew J.

    2014-01-01

    Alpine and subalpine plant species are of special interest in ecology and ecophysiology because they represent life at the climate limit and changes in their relative abundances can be a bellwether for climate-change impacts. Perennial life forms dominate alpine plant communities, and their form and function reflect various avoidance, tolerance, or resistance strategies to interactions of cold temperature, radiation, wind, and desiccation stresses that prevail in the short growing seasons common (but not ubiquitous) in alpine areas. Plant microclimate is typically uncoupled from the harsh climate of the alpine, often leading to substantially warmer plant temperatures than air temperatures recorded by weather stations. Low atmospheric pressure is the most pervasive, fundamental, and unifying factor for alpine environments, but the resulting decrease in partial pressure of CO2 does not significantly limit carbon gain by alpine plants. Factors such as tree islands and topographic features create strong heterogeneous mosaics of microclimate and snow cover that are reflected in plant community composition. Factors affecting tree establishment and growth and formation of treeline are key to understanding alpine ecology. Carbohydrate and other carbon storage, rapid development in a short growing season, and physiological function at low temperature are prevailing attributes of alpine plants. A major contemporary research theme asks whether chilling at alpine-treeline affects the ability of trees to assimilate the growth resources and particularly carbon needed for growth or whether the growth itself is limited by the alpine environment. Alpine areas tend to be among the best conserved, globally, yet they are increasingly showing response to a range of anthropogenic impacts, such as atmospheric deposition.

  5. Temperature-driven flower longevity in a high-alpine species of Oxalis influences reproductive assurance.

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    Arroyo, Mary T K; Dudley, Leah S; Jespersen, Gus; Pacheco, Diego A; Cavieres, Lohengrin A

    2013-12-01

    How high-alpine plants confront stochastic conditions for animal pollination is a critical question. We investigated the effect of temperature on potential flower longevity (FL) measured in pollinator-excluded flowers and actual FL measured in pollinated flowers in self-incompatible Oxalis compacta and evaluated if plastically prolonged potential FL can ameliorate slow pollination under cool conditions. Pollinator-excluded and hand-pollinated flowers were experimentally warmed with open-top chambers (OTCs) on a site at 3470 m above sea level (asl). Flower-specific temperatures, and pollinator-excluded and open-pollination flower life-spans were measured at six alpine sites between 3100 and 3470 m asl. Fruit set was analyzed in relation to inferred pollination time. Warming reduced potential FL. Variable thermal conditions across the alpine landscape predicted potential and actual FL; flower senescence was pollination-regulated. Actual FL and potential FL were coupled. Prolonged potential FL generally increased fruit set under cooler conditions. Plastic responses permit virgin flowers of O. compacta to remain open longer under cooler temperatures, thereby ameliorating slow pollination, and to close earlier when pollination tends to be faster under warmer conditions. Plastic potential FL provides adaptive advantages in the cold, thermally variable alpine habitat, and has important implications for reproductive success in alpine plants in a warming world. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  6. Comparative seed germination traits in alpine and subalpine grasslands: higher elevations are associated with warmer germination temperatures.

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    Fernández-Pascual, E; Jiménez-Alfaro, B; Bueno, Á

    2017-01-01

    Seed germination traits in alpine grasslands are poorly understood, despite the sensitivity of these communities to climate change. We hypothesise that germination traits predict species occurrence along the alpine-subalpine elevation gradient. Phylogenetic comparative analyses were performed using fresh seeds of 22 species from alpine and subalpine grasslands (1600-2400 m) of the Cantabrian Mountains, Spain (43° N, 5° W). Laboratory experiments were conducted to characterise germinability, optimum germination temperature and effect of cold and warm stratification on dormancy breaking. Variability in these traits was reduced by phylogenetic principal component analysis (phyl.PCA). Phylogenetic generalised least squares regression (PGLS) was used to fit a model in which species average elevation was predicted from their position on the PCA axes. Most subalpine species germinated in snow-like conditions, whereas most alpine species needed accumulation of warm temperatures. Phylogenetic signal was low. PCA1 ordered species according to overall germinability, whilst PCA2 ordered them according to preference for warm or cold germination. PCA2 significantly predicted species occurrence in the alpine-subalpine gradient, as higher elevation species tended to have warmer germination preferences. Our results show that germination traits in high-mountain grasslands are closely linked to the alpine-subalpine gradient. Alpine species, especially those from stripped and wind-edge communities, prefer warmer germination niches, suggesting that summer emergence prevents frost damage during seedling establishment. In contrast, alpine snowfield and subalpine grassland plants have cold germination niches, indicating that winter emergence may occur under snow to avoid drought stress. © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.

  7. Global warming in the context of 2000 years of Australian alpine temperature and snow cover.

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    McGowan, Hamish; Callow, John Nikolaus; Soderholm, Joshua; McGrath, Gavan; Campbell, Micheline; Zhao, Jian-Xin

    2018-03-13

    Annual resolution reconstructions of alpine temperatures are rare, particularly for the Southern Hemisphere, while no snow cover reconstructions exist. These records are essential to place in context the impact of anthropogenic global warming against historical major natural climate events such as the Roman Warm Period (RWP), Medieval Climate Anomaly (MCA) and Little Ice Age (LIA). Here we show for a marginal alpine region of Australia using a carbon isotope speleothem reconstruction, warming over the past five decades has experienced equivalent magnitude of temperature change and snow cover decline to the RWP and MCA. The current rate of warming is unmatched for the past 2000 years and seasonal snow cover is at a minimum. On scales of several decades, mean maximum temperatures have undergone considerable change ≈ ± 0.8 °C highlighting local scale susceptibility to rapid temperature change, evidence of which is often masked in regional to hemisphere scale temperature reconstructions.

  8. Temperature signal in suspended sediment export from an Alpine catchment

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    Costa, Anna; Molnar, Peter; Stutenbecker, Laura; Bakker, Maarten; Silva, Tiago A.; Schlunegger, Fritz; Lane, Stuart N.; Loizeau, Jean-Luc; Girardclos, Stéphanie

    2018-01-01

    Suspended sediment export from large Alpine catchments ( > 1000 km2) over decadal timescales is sensitive to a number of factors, including long-term variations in climate, the activation-deactivation of different sediment sources (proglacial areas, hillslopes, etc.), transport through the fluvial system, and potential anthropogenic impacts on the sediment flux (e.g. through impoundments and flow regulation). Here, we report on a marked increase in suspended sediment concentrations observed near the outlet of the upper Rhône River Basin in the mid-1980s. This increase coincides with a statistically significant step-like increase in basin-wide mean air temperature. We explore the possible explanations of the suspended sediment rise in terms of changes in water discharge (transport capacity), and the activation of different potential sources of fine sediment (sediment supply) in the catchment by hydroclimatic forcing. Time series of precipitation and temperature-driven snowmelt, snow cover, and ice melt simulated with a spatially distributed degree-day model, together with erosive rainfall on snow-free surfaces, are tested to explore possible reasons for the rise in suspended sediment concentration. We show that the abrupt change in air temperature reduced snow cover and the contribution of snowmelt, and enhanced ice melt. The results of statistical tests show that the onset of increased ice melt was likely to play a dominant role in the suspended sediment concentration rise in the mid-1980s. Temperature-driven enhanced melting of glaciers, which cover about 10 % of the catchment surface, can increase suspended sediment yields through an increased contribution of sediment-rich glacial meltwater, increased sediment availability due to glacier recession, and increased runoff from sediment-rich proglacial areas. The reduced extent and duration of snow cover in the catchment are also potential contributors to the rise in suspended sediment concentration through

  9. Temperature signal in suspended sediment export from an Alpine catchment

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    A. Costa

    2018-01-01

    Full Text Available Suspended sediment export from large Alpine catchments ( >  1000 km2 over decadal timescales is sensitive to a number of factors, including long-term variations in climate, the activation–deactivation of different sediment sources (proglacial areas, hillslopes, etc., transport through the fluvial system, and potential anthropogenic impacts on the sediment flux (e.g. through impoundments and flow regulation. Here, we report on a marked increase in suspended sediment concentrations observed near the outlet of the upper Rhône River Basin in the mid-1980s. This increase coincides with a statistically significant step-like increase in basin-wide mean air temperature. We explore the possible explanations of the suspended sediment rise in terms of changes in water discharge (transport capacity, and the activation of different potential sources of fine sediment (sediment supply in the catchment by hydroclimatic forcing. Time series of precipitation and temperature-driven snowmelt, snow cover, and ice melt simulated with a spatially distributed degree-day model, together with erosive rainfall on snow-free surfaces, are tested to explore possible reasons for the rise in suspended sediment concentration. We show that the abrupt change in air temperature reduced snow cover and the contribution of snowmelt, and enhanced ice melt. The results of statistical tests show that the onset of increased ice melt was likely to play a dominant role in the suspended sediment concentration rise in the mid-1980s. Temperature-driven enhanced melting of glaciers, which cover about 10 % of the catchment surface, can increase suspended sediment yields through an increased contribution of sediment-rich glacial meltwater, increased sediment availability due to glacier recession, and increased runoff from sediment-rich proglacial areas. The reduced extent and duration of snow cover in the catchment are also potential contributors to the rise in suspended sediment

  10. Early establishment of trees at the alpine treeline: idiosyncratic species responses to temperature-moisture interactions.

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    Loranger, Hannah; Zotz, Gerhard; Bader, Maaike Y

    2016-01-01

    On a global scale, temperature is the main determinant of arctic and alpine treeline position. However on a local scale, treeline form and position vary considerably due to other climatic factors, tree species ecology and life-stage-dependent responses. For treelines to advance poleward or uphill, the first steps are germination and seedling establishment. These earliest life stages may be major bottlenecks for treeline tree populations and will depend differently on climatic conditions than adult trees. We investigated the effect of soil temperature and moisture on germination and early seedling survival in a field experiment in the French Alps near the local treeline (2100 m a.s.l.) using passive temperature manipulations and two watering regimes. Five European treeline tree species were studied: Larix decidua, Picea abies, Pinus cembra, Pinus uncinata and Sorbus aucuparia In addition, we monitored the germination response of three of these species to low temperatures under controlled conditions in growth chambers. The early establishment of these trees at the alpine treeline was limited either by temperature or by moisture, the sensitivity to one factor often depending on the intensity of the other. The results showed that the relative importance of the two factors and the direction of the effects are highly species-specific, while both factors tend to have consistent effects on both germination and early seedling survival within each species. We show that temperature and water availability are both important contributors to establishment patterns of treeline trees and hence to species-specific forms and positions of alpine treelines. The observed idiosyncratic species responses highlight the need for studies including several species and life-stages to create predictive power concerning future treeline dynamics. © The Authors 2016. Published by Oxford University Press on behalf of the Annals of Botany Company.

  11. Increasing temperature causes flowering onset time changes of alpine ginger Roscoea in the Central Himalayas

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    Dharmalingam Mohandass

    2015-09-01

    Full Text Available Recent herbarium-based phenology assessments of many plant species have found significant responses to global climate change over the previous century. In this study, we investigate how the flowering phenology of three alpine ginger Roscoea species responses to climate change over the century from 1913 to 2011, by comparing between herbarium-based phenology records and direct flowering observations. According to the observations, flowering onset of the three alpine ginger species occurred either 22 days earlier or was delayed by 8–30 days when comparing the mean peak flowering date between herbarium-based phenology records and direct flowering observations. It is likely that this significant change in flowering onset is due to increased annual minimum and maximum temperatures and mean annual temperature by about 0.053°C per year. Our results also show that flowering time changes occurred due to an increasing winter–spring minimum temperature and monsoon minimum temperature, suggesting that these Roscoea species respond greatly to climate warming resulting in changes on flowering times.

  12. Constraints on Alpine Fault (New Zealand) Mylonitization Temperatures and Geothermal Gradient from Ti-in-quartz Thermobarometry

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    Kidder, Steven; Toy, Virginia; Prior, Dave; Little, Tim; MacRae, Colin

    2018-01-01

    We constrain the thermal state of the central Alpine Fault using approximately 750 Ti-in-quartz SIMS analyses from a suite of variably deformed mylonites. Ti-in-quartz concentrations span more than an order of magnitude from 0.24 to ~5 ppm, suggesting recrystallization of quartz over a 300° range in temperature. Most Ti-in-quartz concentrations in mylonites, protomylonites, and the Alpine Schist protolith are between 2 and 4 ppm and do not vary as a function of grain size or bul...

  13. [Progresses of alpine treeline formation mechanism.

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    Cong, Yu; He, Hong Shi; Gu, Xiao Nan; Xu, Wen Ru; Liu, Kai; Zong, Sheng Wei; Du, Hai Bo

    2016-09-01

    Alpine treelines represent one of the most distinct vegetation boundaries between canopy closed montane forest and treeless alpine vegetation. This transitional ecotone is highly sensitive to global and regional climate change and is considered as an ideal indicator of such changes. Treeline studies have evolved from morphological description to various hypotheses of treeline formation. Although individual hypothesis may provide reasonable explanation locally, a generalized hypothesis that is applicable on the global scale is still lacking. Temperature is considered the limited factor controlling the distribution of alpine treeline as low temperature restricts biochemical processes of tree growth. However, which particular biochemical processes are affected by low temperature remains unknown. This paper summarized the mechanisms of treeline formation with a focus on how low temperature affects photosynthesis characteristics, nutrient characteristics, non-structural carbohydrate (NSC) and antioxidant system. We also reviewed the key issues and future perspectives in treeline research.

  14. Validation of functional calibration and strap-down joint drift correction for computing 3D joint angles of knee, hip, and trunk in alpine skiing.

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    Fasel, Benedikt; Spörri, Jörg; Schütz, Pascal; Lorenzetti, Silvio; Aminian, Kamiar

    2017-01-01

    To obtain valid 3D joint angles with inertial sensors careful sensor-to-segment calibration (i.e. functional or anatomical calibration) is required and measured angular velocity at each sensor needs to be integrated to obtain segment and joint orientation (i.e. joint angles). Existing functional and anatomical calibration procedures were optimized for gait analysis and calibration movements were impractical to perform in outdoor settings. Thus, the aims of this study were 1) to propose and validate a set of calibration movements that were optimized for alpine skiing and could be performed outdoors and 2) to validate the 3D joint angles of the knee, hip, and trunk during alpine skiing. The proposed functional calibration movements consisted of squats, trunk rotations, hip ad/abductions, and upright standing. The joint drift correction previously proposed for alpine ski racing was improved by adding a second step to reduce separately azimuth drift. The system was validated indoors on a skiing carpet at the maximum belt speed of 21 km/h and for measurement durations of 120 seconds. Calibration repeatability was on average boots. Joint angle precision was <4.9° for all angles and accuracy ranged from -10.7° to 4.2° where the presence of an athlete-specific bias was observed especially for the flexion angle. The improved joint drift correction reduced azimuth drift from over 25° to less than 5°. In conclusion, the system was valid for measuring 3D joint angles during alpine skiing and could be used outdoors. Errors were similar to the values reported in other studies for gait. The system may be well suited for within-athlete analysis but care should be taken for between-athlete analysis because of a possible athlete-specific joint angle bias.

  15. Influence of snow cover distribution on soil temperature and nutrient dynamics in alpine pedoenvironments

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    Ermanno Zanini

    Full Text Available In Alpine sites snow is present on the ground from six to eight months per year in relation to elevation and exposure. Water is therefore immobilized into the solid state for the greater part of the winter season and released to the ground in a short period during spring snowmelt. In these areas, snow distribution exercises a fundamental role in influencing soil temperature and nutrient dynamics, in particular of nitrogen, with great consequences on plant nutrition. The dormant vegetation period, the low temperatures and the persistent snow cover suggest that soil biological activity is only concentrated during summer. As a matter of fact, soils covered with a consistent snow cover are isolated from the air temperature and can not freeze during winter. A snowpack of sufficient thickness, accumulated early in winter, insulates the ground from the surrounding atmosphere maintaining soil temperature closed to 0 °C during the whole winter season. The elevation of the snow line and the shorter permanence of snow on the ground, as a result of global warming (IPCC, 1996, 2001, might reduce the insulation effect of the snowpack, exposing soils of the mountain belt to lower temperatures and to a greater frequency of freeze/thaw cycles, which might alter organic matter dynamics and soil nutrient availability. Such thermal stresses may determine the lysis of microbial cells and the consequent increase of nitrogen and carbon mineralization by the survived microorganisms. Moreover, the freeze/thaw cycles can determine the exposure of exchange surfaces not available before, with release of organic matter of non-microbial origin, which may become available to surviving microorganisms for respiration. The reduced or absent microbial immobilization may cause the accumulation of remarkable amounts of inorganic nitrogen in soil, potentially leachable during spring snowmelt, when plants have not still started the growing season. Changes of snow distribution in

  16. Climate Change in Alpine Regions - Regional Characteristics of a Global Phenomenon by the Example of Air Temperature

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    Lang, Erich; Stary, Ulrike

    2017-04-01

    For nearly 50 years the Austrian Research Centre for Forests (BFW) has been engaged in research in the Alpine region recording measuring data at extreme sites. Data series of this duration provide already a good insight into the evolution of climate parameters. Extrapolations derived from it are suitable for comparison with results from climate change models or supplement them with regard to their informative value. This is useful because climate change models describe a simplified picture of reality based on the size of the data grid they use. Analysis of time series of two air temperature measuring stations in different torrent catchment areas indicate that 1) predictions of temperature rise for the Alpine region in Austria will have to be revised upwards, and 2) only looking at the data of seasons (or shorter time periods), reveals the real dramatic effect of climate change. Considering e.g. the annual average data of air temperature of the years 1969-2016 at the climate station "Fleissner" (altitude 1210m a.s.l; Upper Mölltal, Carinthia) a significant upward trend is visible. Using a linear smoothing function an increase of the average annual air temperature of about 2.2°C within 50 years emerges. The calculated temperature rise thus confirms the general fear of an increase of more than 2.0°C till the middle of the 21st century. Looking at the seasonal change of air temperature, significant positive trends are shown in all four seasons. But the level of the respective temperature increase varies considerably and indicates the highest increase in spring (+3.3°C), and the lowest one in autumn (+1.3°C, extrapolated for a time period of 50 years). The maximum increase of air temperature at the measuring station "Pumpenhaus" (altitude 980m a.s.l), which is situated in the "Karnische Alpen" in the south of Austria, is even stronger. From a time series of 28 years (with data recording starting in 1989) the maximum rise of temperature was 5.4°C detected for the

  17. Inflorescences of alpine cushion plants freeze autonomously and may survive subzero temperatures by supercooling

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    Hacker, Jürgen; Ladinig, Ursula; Wagner, Johanna; Neuner, Gilbert

    2011-01-01

    Freezing patterns in the high alpine cushion plants Saxifraga bryoides, Saxifraga caesia, Saxifraga moschata and Silene acaulis were studied by infrared thermography at three reproductive stages (bud, anthesis, fruit development). The single reproductive shoots of a cushion froze independently in all four species at every reproductive stage. Ice formation caused lethal damage to the respective inflorescence. After ice nucleation, which occurred mainly in the stalk or the base of the reproductive shoot, ice propagated throughout that entire shoot, but not into neighboring shoots. However, anatomical ice barriers within cushions were not detected. The naturally occurring temperature gradient within the cushion appeared to interrupt ice propagation thermally. Consequently, every reproductive shoot needed an autonomous ice nucleation event to initiate freezing. Ice nucleation was not only influenced by minimum temperatures but also by the duration of exposure. At moderate subzero exposure temperatures (−4.3 to −7.7 °C) the number of frozen inflorescences increased exponentially. Due to efficient supercooling, single reproductive shoots remained unfrozen down to −17.4 °C (cooling rate 6 K h−1). Hence, the observed freezing pattern may be advantageous for frost survival of individual inflorescences and reproductive success of high alpine cushion plants, when during episodic summer frosts damage can be avoided by supercooling. PMID:21151351

  18. Alpine research today

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    Jean-Jacques Brun

    2009-06-01

    Full Text Available Alpine research benefits from several international coordination networks, only one of which – ISCAR (the International Scientific Committee on Research in the Alps – works solely in the Alpine arc. The creation of ISCAR is a consequence of the input and involvement of various Alpine partners around the Alpine Convention. Alpine research now aims to promote an integrated vision of Alpine territories focusing on creating and maintaining spatial and temporal networks of sustainable relationships between humans and the other components of the ecosphere. It combines resource usage with conservation of the biological and cultural diversity that makes up the Alpine identity. This article aims to show: (1 how international Alpine research coordination is organised; (2 the role played by the Alpine Convention as a framework of reference for specifically Alpine research; and (3 the role that the ISCAR international commit-tee and the Interreg “Alpine Space” programmes play in uniting research around territorial challenges relating to biodiversity conservation and territorial development.La recherche sur les Alpes bénéficie de plusieurs réseaux de coordination internationaux dont un seul, le comité international recherche alpine (ISCAR, se consacre exclusivement à l’arc alpin. La création de l’ISCAR est une retombée de la mobilisation des divers partenaires alpins autour de la mise en place de la Convention alpine. Aujourd’hui, la recherche alpine vise à promouvoir une vision intégrée des territoires centrée sur la création et le maintien d’un réseau spatial et temporel de relations durables entre les hommes et les autres composantes de l’écosphère. Elle associe étroitement la mise en valeur des ressources et la conservation des diversités biologiques et culturelles qui constituent l’identité alpine. Cet article a pour ambition de montrer : (1 comment s’organise la coordination internationale des recherches sur les

  19. Global Warming and the Summertime Evapotranspiration Regime of the Alpine Region

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    Calanca, P.; Jasper, K. [Agroscope FAL Reckenholz, Swiss Federal Research Station for Agroecology and Agriculture, CH-8046 Zuerich (Switzerland); Roesch, A.; Wild, M. [Institute for Atmospheric and Climate Science, Swiss Federal Institute of Technology, CH-8092 Zuerich (Switzerland)

    2006-11-15

    Changes of the summer evapotranspiration regime under increased levels of atmospheric greenhouse gases are discussed for three Alpine river basins on the basis of a new set of simulations carried out with a high-resolution hydrological model. The climate change signal was inferred from the output of two simulations with a state-of-the-art global climate model (GCM), a reference run valid for 1961-1990 and a time-slice simulation valid for 2071-2100 under forcing from the A2 IPCC emission scenario. In this particular GCM experiment and with respect to the Alpine region summer temperature was found to increase by 3 to 4C, whereas precipitation was found to decrease by 10 to 20%. Global radiation and water vapor pressure deficit were found to increase by about 5% and 2 hPa, respectively. On this background, an overall increase of potential evapotranspiration of about 20% relative to the baseline was predicted by the hydrological model, with important variations between but also within individual basins. The results of the hydrological simulations also revealed a reduction in the evapotranspiration efficiency that depends on altitude. Accordingly, actual evapotranspiration was found to increase at high altitudes and to the south of the Alps, but to decrease in low elevation areas of the northern forelands and in the inner-Alpine domain. Such a differentiation does not appear in the GCM scenario, which predicts an overall increase in evapotranspiration over the Alps. This underlines the importance of detailed simulations for the quantitative assessment of the regional impact of climate change on the hydrological cycle.

  20. Sensitivity of Alpine Snow and Streamflow Regimes to Climate Changes

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    Rasouli, K.; Pomeroy, J. W.; Marks, D. G.; Bernhardt, M.

    2014-12-01

    Understanding the sensitivity of hydrological processes to climate change in alpine areas with snow dominated regimes is of paramount importance as alpine basins show both high runoff efficiency associated with the melt of the seasonal snowpack and great sensitivity of snow processes to temperature change. In this study, meteorological data measured in a selection of alpine headwaters basins including Reynolds Mountain East, Idaho, USA, Wolf Creek, Yukon in Canada, and Zugspitze Mountain, Germany with climates ranging from arctic to continental temperate were used to study the snow and streamflow sensitivity to climate change. All research sites have detailed multi-decadal meteorological and snow measurements. The Cold Regions Hydrological Modelling platform (CRHM) was used to create a model representing a typical alpine headwater basin discretized into hydrological response units with physically based representations of snow redistribution by wind, complex terrain snowmelt energetics and runoff processes in alpine tundra. The sensitivity of snow hydrology to climate change was investigated by changing air temperature and precipitation using weather generating methods based on the change factors obtained from different climate model projections for future and current periods. The basin mean and spatial variability of peak snow water equivalent, sublimation loss, duration of snow season, snowmelt rates, streamflow peak, and basin discharge were assessed under varying climate scenarios and the most sensitive hydrological mechanisms to the changes in the different alpine climates were detected. The results show that snow hydrology in colder alpine climates is more resilient to warming than that in warmer climates, but that compensatory factors to warming such as reduced blowing snow sublimation loss and reduced melt rate should also be assessed when considering climate change impacts on alpine hydrology.

  1. Photochemistry and aerosol in alpine region: mixing and transport; Photochimie et aerosol en region alpine: melange et transport

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    Chaxel, E

    2006-11-15

    The Alpine arc deeply interacts with general circulation of atmosphere. By studying configurations in summer and winter over various Alpine areas, this work explains how mixing and transport of airborne pollutants happen, both gaseous and particulate matter, from their emission sources to free troposphere. Using observational results and a comprehensive Eulerian modelling system, one focuses on mechanisms of pollution by ozone in summer and by particulate matter and benzene in winter. After having validated the modelling system using datasets from field experiments POVA, GRENOPHOT and ESCOMPTE, it is applied on two periods with principal interest in the Grenoble area: one is the heat-wave August 2003 and the other is a long episode of thermal inversion in February 2005. Uncertainties are also calculated. One finishes by applying the modelling chain to understand how a stratospheric intrusion following a tropopause fold affected the Alpine region in July 2004. (author)

  2. Alpine ecosystems

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    P.W. Rundel; C.I. Millar

    2016-01-01

    Alpine ecosystems are typically defined as those areas occurring above treeline, while recognizing that alpine ecosystems at a local scale may be found below this boundary for reasons including geology, geomorphology, and microclimate. The lower limit of the alpine ecosystems, the climatic treeline, varies with latitude across California, ranging from about 3500 m in...

  3. Vegetation Structure and Temperature Regimes of Tropical Alpine Treelines

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    Bader, M.Y.; Rietkerk, M.G.; Bregt, A.K.

    2007-01-01

    Alpine treeline ecotones can be gradual transitions, abrupt boundaries, or patchy mosaics, and these different patterns may indicate important processes and dynamic properties. We present observed spatial patterns of a wide range of tropical treelines and try to explain these patterns. Treelines

  4. Vegetation structure and temperature regimes of tropical alpine treelines

    NARCIS (Netherlands)

    Bader, M.; Rietkerk, M.; Bregt, A.K.

    2007-01-01

    Alpine treeline ecotones can be gradual transitions, abrupt boundaries, or patchy mosaics, and these different patterns may indicate important processes and dynamic properties. We present observed spatial patterns of a wide range of tropical treelines and try to explain these patterns. Treelines

  5. Frost resistance in alpine woody plants.

    Science.gov (United States)

    Neuner, Gilbert

    2014-01-01

    This report provides a brief review of key findings related to frost resistance in alpine woody plant species, summarizes data on their frost resistance, highlights the importance of freeze avoidance mechanisms, and indicates areas of future research. Freezing temperatures are possible throughout the whole growing period in the alpine life zone. Frost severity, comprised of both intensity and duration, becomes greater with increasing elevation and, there is also a greater probability, that small statured woody plants, may be insulated by snow cover. Several frost survival mechanisms have evolved in woody alpine plants in response to these environmental conditions. Examples of tolerance to extracellular freezing and freeze dehydration, life cycles that allow species to escape frost, and freeze avoidance mechanisms can all be found. Despite their specific adaption to the alpine environment, frost damage can occur in spring, while all alpine woody plants have a low risk of frost damage in winter. Experimental evidence indicates that premature deacclimation in Pinus cembra in the spring, and a limited ability of many species of alpine woody shrubs to rapidly reacclimate when they lose snow cover, resulting in reduced levels of frost resistance in the spring, may be particularly critical under the projected changes in climate. In this review, frost resistance and specific frost survival mechanisms of different organs (leaves, stems, vegetative and reproductive over-wintering buds, flowers, and fruits) and tissues are compared. The seasonal dynamics of frost resistance of leaves of trees, as opposed to woody shrubs, is also discussed. The ability of some tissues and organs to avoid freezing by supercooling, as visualized by high resolution infrared thermography, are also provided. Collectively, the report provides a review of the complex and diverse ways that woody plants survive in the frost dominated environment of the alpine life zone.

  6. Frost resistance of alpine woody plants

    Directory of Open Access Journals (Sweden)

    Gilbert eNeuner

    2014-12-01

    Full Text Available This report provides a brief review of key findings related to frost resistance in alpine woody plant species, summarizes data on their frost resistance, highlights the importance of freeze avoidance mechanisms, and indicates areas of future research.Freezing temperatures are possible throughout the whole growing period in the alpine life zone. Frost severity, comprised of both intensity and duration, becomes greater with increasing elevation and, there is also a greater probability, that small statured woody plants, may be insulated by snow cover.Several frost survival mechanisms have evolved in woody alpine plants in response to these environmental conditions. Examples of tolerance to extracellular freezing and freeze dehydration, life cycles that allow species to escape frost, and freeze avoidance mechanisms can all be found. Despite their specific adaption to the alpine environment, frost damage can occur in spring, while all alpine woody plants have a low risk of frost damage in winter. Experimental evidence indicates that premature deacclimation in Pinus cembra in the spring, and a limited ability of many species of alpine woody shrubs to rapidly reacclimate when they lose snow cover, resulting in reduced levels of frost resistance in the spring, may be particularly critical under the projected changes in climate.In this review, frost resistance and specific frost survival mechanisms of different organs (leaves, stems, vegetative and reproductive over-wintering buds, flowers and fruits and tissues are compared. The seasonal dynamics of frost resistance of leaves of trees, as opposed to woody shrubs, is also discussed. The ability of some tissues and organs to avoid freezing by supercooling, as visualized by high resolution infrared thermography, are also provided. Collectively, the report provides a review of the complex and diverse ways that woody plants survive in the frost dominated environment of the alpine life zone.

  7. Experimental Warming Aggravates Degradation-Induced Topsoil Drought in Alpine Meadows of The Qinghai-Tibetan Plateau

    Science.gov (United States)

    Xue, X.

    2017-12-01

    Climatic warming is presumed to cause topsoil drought by increasing evapotranspiration and water infiltration, and by progressively inducing land degradation in alpine meadows of the Qinghai-Tibetan Plateau. However, how soil moisture and temperature patterns of degraded alpine meadows respond to climate warming remains unclear. A six-year continuous warming experiment was carried out in both degraded and undegraded alpine meadows in the source region of the Yangtze River. The goal was to identify the effects of climatic warming and land degradation on soil moisture (θ), soil surface temperature (Tsfc), and soil temperature (Ts). In the present study, land degradation significantly reduced θ by 4.5-6.1% at a depth of 0-100 cm (P soil surface. Experimental warming aggravated topsoil drought caused by land degradation, intensified the magnitude of degradation, and caused a positive feedback in the degraded alpine meadow ecosystem. Therefore, an immediate need exists to restore degraded alpine meadow grasslands in the Qinghai-Tibetan Plateau in anticipation of a warmer future.

  8. Interaction between stream temperature, streamflow, and groundwater exchanges in alpine streams

    Science.gov (United States)

    Constantz, James E.

    1998-01-01

    Four alpine streams were monitored to continuously collect stream temperature and streamflow for periods ranging from a week to a year. In a small stream in the Colorado Rockies, diurnal variations in both stream temperature and streamflow were significantly greater in losing reaches than in gaining reaches, with minimum streamflow losses occurring early in the day and maximum losses occurring early in the evening. Using measured stream temperature changes, diurnal streambed infiltration rates were predicted to increase as much as 35% during the day (based on a heat and water transport groundwater model), while the measured increase in streamflow loss was 40%. For two large streams in the Sierra Nevada Mountains, annual stream temperature variations ranged from 0° to 25°C. In summer months, diurnal stream temperature variations were 30–40% of annual stream temperature variations, owing to reduced streamflows and increased atmospheric heating. Previous reports document that one Sierra stream site generally gains groundwater during low flows, while the second Sierra stream site may lose water during low flows. For August the diurnal streamflow variation was 11% at the gaining stream site and 30% at the losing stream site. On the basis of measured diurnal stream temperature variations, streambed infiltration rates were predicted to vary diurnally as much as 20% at the losing stream site. Analysis of results suggests that evapotranspiration losses determined diurnal streamflow variations in the gaining reaches, while in the losing reaches, evapotranspiration losses were compounded by diurnal variations in streambed infiltration. Diurnal variations in stream temperature were reduced in the gaining reaches as a result of discharging groundwater of relatively constant temperature. For the Sierra sites, comparison of results with those from a small tributary demonstrated that stream temperature patterns were useful in delineating discharges of bank storage following

  9. Alpine Windharvest: development of information base regarding potentials and the necessary technical, legal and socio-economic conditions for expanding wind energy in the Alpine Space - CFD modelling evaluation - Summary of WindSim CFD modelling procedure and validation

    Energy Technology Data Exchange (ETDEWEB)

    Schaffner, B.; Cattin, R. [Meteotest, Berne (Switzerland)

    2005-07-01

    This report presents the development work carried out by the Swiss meteorology specialists of the company METEOTEST as part of a project carried out together with the Swiss wind-energy organisation 'Suisse Eole'. The framework for the project is the EU Interreg IIIB Alpine Space Programme, a European Community Initiative Programme funded by the European Regional Development Fund. The project investigated the use of digital relief-analysis. The report describes the development of a basic information system to aid the investigation of the technical, legal and socio-economical conditions for the use of wind energy in the alpine area. The report deals with the use of computational fluid dynamics and wind simulation modelling techniques and their validation. Recommendations on the use of the results are made.

  10. La recherche alpine aujourd’hui

    Directory of Open Access Journals (Sweden)

    Jean-Jacques Brun

    2009-06-01

    Full Text Available Alpine research benefits from several international coordination networks, only one of which – ISCAR (the International Scientific Committee on Research in the Alps – works solely in the Alpine arc. The creation of ISCAR is a consequence of the input and involvement of various Alpine partners around the Alpine Convention. Alpine research now aims to promote an integrated vision of Alpine territories focusing on creating and maintaining spatial and temporal networks of sustainable relationships between humans and the other components of the ecosphere. It combines resource usage with conservation of the biological and cultural diversity that makes up the Alpine identity. This article aims to show: (1 how international Alpine research coordination is organised; (2 the role played by the Alpine Convention as a framework of reference for specifically Alpine research; and (3 the role that the ISCAR international commit-tee and the Interreg “Alpine Space” programmes play in uniting research around territorial challenges relating to biodiversity conservation and territorial development.La recherche sur les Alpes bénéficie de plusieurs réseaux de coordination internationaux dont un seul, le comité international recherche alpine (ISCAR, se consacre exclusivement à l’arc alpin. La création de l’ISCAR est une retombée de la mobilisation des divers partenaires alpins autour de la mise en place de la Convention alpine. Aujourd’hui, la recherche alpine vise à promouvoir une vision intégrée des territoires centrée sur la création et le maintien d’un réseau spatial et temporel de relations durables entre les hommes et les autres composantes de l’écosphère. Elle associe étroitement la mise en valeur des ressources et la conservation des diversités biologiques et culturelles qui constituent l’identité alpine. Cet article a pour ambition de montrer : (1 comment s’organise la coordination internationale des recherches sur les

  11. Temperature sensitivity of extreme precipitation events in the south-eastern Alpine forelands

    Science.gov (United States)

    Schroeer, Katharina; Kirchengast, Gottfried

    2016-04-01

    How will convective precipitation intensities and patterns evolve in a warming climate on a regional to local scale? Studies on the scaling of precipitation intensities with temperature are used to test observational and climate model data against the hypothesis that the change of precipitation with temperature will essentially follow the Clausius-Clapeyron (CC) equation, which corresponds to a rate of increase of the water holding capacity of the atmosphere by 6-7 % per Kelvin (CC rate). A growing number of studies in various regions and with varying approaches suggests that the overall picture of the temperature-precipitation relationship is heterogeneous, with scaling rates shearing off the CC rate in both upward and downward directions. In this study we investigate the temperature scaling of extreme precipitation events in the south-eastern Alpine forelands of Austria (SEA) based on a dense rain gauge net of 188 stations, with sub-daily precipitation measurements since about 1990 used at 10-min resolution. Parts of the study region are European hot-spots for severe hailstorms and the region, which is in part densely populated and intensively cultivated, is generally vulnerable to climate extremes. Evidence on historical extremely heavy short-time and localized precipitation events of several hundred mm of rain in just a few hours, resulting in destructive flash flooding, underline these vulnerabilities. Heavy precipitation is driven by Mediterranean moisture advection, enhanced by the orographic lifting at the Alpine foothills, and hence trends in positive sea surface temperature anomalies might carry significant risk of amplifying future extreme precipitation events. In addition, observations from the highly instrumented subregion of south-eastern Styria indicate a strong and robust long-term warming trend in summer of about 0.7°C per decade over 1971-2015, concomitant with a significant increase in the annual number of heat days. The combination of these

  12. Cuticular waxes in alpine meadow plants: climate effect inferred from latitude gradient in Qinghai-Tibetan Plateau.

    Science.gov (United States)

    Guo, Yanjun; Guo, Na; He, Yuji; Gao, Jianhua

    2015-09-01

    Alpine meadow ecosystems are susceptible to climate changes. Still, climate impact on cuticular wax in alpine meadow plants is poorly understood. Assessing the variations of cuticular wax in alpine meadow plants across different latitudes might be useful for predicting how they may respond to climate change. We studied nine alpine meadows in a climate gradient in the east side of Qinghai-Tibetan Plateau, with mean annual temperature ranging from -7.7 to 3.2°C. In total, 42 plant species were analyzed for cuticular wax, averaged 16 plant species in each meadow. Only four plant species could be observed in all sampling meadows, including Kobresia humilis,Potentilla nivea,Anaphalis lacteal, and Leontopodium nanum. The amounts of wax compositions and total cuticular wax in the four plant species varied among sampling meadows, but no significant correlation could be observed between them and temperature, precipitation, and aridity index based on plant species level. To analyze the variations of cuticular wax on community level, we averaged the amounts of n-alkanes, aliphatic acids, primary alcohols, and total cuticular wax across all investigated plant species in each sampling site. The mean annual temperature, mean temperature in July, and aridity index were significantly correlated with the averaged amounts of wax compositions and total cuticular wax. The average chain length of n-alkanes in both plant and soil linearly increased with increased temperature, whereas reduced with increased aridity index. No significant correlation could be observed between mean annual precipitation and mean precipitation from June to August and the cuticular wax amounts and average chain length. Our results suggest that the survival of some alpine plants in specific environments might be depended on their abilities in adjusting wax deposition on plant leaves, and the alpine meadow plants as a whole respond to climate change, benefiting the stability of alpine meadow ecosystem.

  13. High solar radiation hinders tree regeneration above the alpine treeline in northern Ecuador

    NARCIS (Netherlands)

    Bader, M.; Geloof, van I.; Rietkerk, M.

    2007-01-01

    Many tropical alpine treelines lie below their climatic potential, because of natural or anthropogenic causes. Forest extension above the treeline depends on the ability of trees to establish in the alpine environment. This ability may be limited by different factors, such as low temperatures,

  14. SEA in local land use planning - first experience in the Alpine States

    International Nuclear Information System (INIS)

    Jiricka, Alexandra; Proebstl, Ulrike

    2008-01-01

    In the Alpine area, planning decisions can result in far-reaching consequences because of the high sensitivity of the Alpine ecosystems. This article is based on two hypotheses: (1) The Alpine states/regions were aware of their sensitive environment and therefore recognized the necessity of introducing a comparable instrument to assess local land use planning. (2) By introducing this differentiated assessment tool, namely SEA, an increase in costs may be the consequence. However, better and more transparent planning can contribute to the enhancement of planning standards. To reveal the validity of these assumptions the legal implementation in the Alpine countries Austria, Germany, Italy and France was examined as well as first practical experience resulting from the determined procedures. The results of the implementation process in the four states were compared and discussed on the basis of selected process steps of SEA

  15. Are low altitude alpine tundra ecosystems under threat? A case study from the Parc National de la Gaspésie, Québec

    International Nuclear Information System (INIS)

    Dumais, Catherine; Ropars, Pascale; Denis, Marie-Pier; Dufour-Tremblay, Geneviève; Boudreau, Stéphane

    2014-01-01

    According to the 2007 IPCC report, the alpine tundra ecosystems found on low mountains of the northern hemisphere are amongst the most threatened by climate change. A treeline advance or a significant erect shrub expansion could result in increased competition for the arctic-alpine species usually found on mountaintops and eventually lead to their local extinction. The objectives of our study were to identify recent changes in the cover and growth of erect woody vegetation in the alpine tundra of Mont de la Passe, in the Parc National de la Gaspésie (Québec, Canada). The comparison of two orthorectified aerial photos revealed no significant shift of the treeline between 1975 and 2004. During the same period however, shrub species cover increased from 20.2% to 30.4% in the lower alpine zone. Dendrochronological analyses conducted on Betula glandulosa Michx. sampled at three different positions along an altitudinal gradient (low, intermediate and high alpine zone) revealed that the climatic determinants of B. glandulosa radial growth become more complex with increasing altitude. In the lower alpine zone, B. glandulosa radial growth is only significantly associated positively to July temperature. In the intermediate alpine zone, radial growth is associated positively to July temperature but negatively to March temperature. In the high alpine zone, radial growth is positively associated to January, July and August temperature but negatively to March temperature. The positive association between summer temperatures and radial growth suggests that B. glandulosa could potentially benefit from warmer temperatures, a phenomenon that could lead to an increase in its cover over the next few decades. Although alpine tundra vegetation is not threatened in the short-term in the Parc National de la Gaspésie, erect shrub cover, especially B. glandulosa, could likely increase in the near future, threatening the local arctic-alpine flora. (letter)

  16. Photochemistry and aerosol in alpine region: mixing and transport

    International Nuclear Information System (INIS)

    Chaxel, E.

    2006-11-01

    The Alpine arc deeply interacts with general circulation of atmosphere. By studying configurations in summer and winter over various Alpine areas, this work explains how mixing and transport of airborne pollutants happen, both gaseous and particulate matter, from their emission sources to free troposphere. Using observational results and a comprehensive Eulerian modelling system, one focuses on mechanisms of pollution by ozone in summer and by particulate matter and benzene in winter. After having validated the modelling system using datasets from field experiments POVA, GRENOPHOT and ESCOMPTE, it is applied on two periods with principal interest in the Grenoble area: one is the heat-wave August 2003 and the other is a long episode of thermal inversion in February 2005. Uncertainties are also calculated. One finishes by applying the modelling chain to understand how a stratospheric intrusion following a tropopause fold affected the Alpine region in July 2004. (author)

  17. The effects of wind and temperature on cuticular transpiration of Picea abies and Pinus cembra and their significance in dessication damage at the alpine treeline.

    Science.gov (United States)

    Baig, M N; Tranquillini, W

    1980-01-01

    The importance of high winter winds and plant temperatures as causes of winter desiccation damage at the alpine treeline were studied in the Austrian Alps. Samples of 1- and 2-year twigs of Picea abies and Pinus cembra were collected from the valley bottom (1,000 m a.s.l.), forestline (1,940 m a.s.l.), kampfzone (2.090 m a.s.l.), wind-protected treeline (2,140 m a.s.l.), and wind-exposed treeline (2,140 m a.s.l.). Cuticular transpiration was measured at three different levels of wind speed (4, 10, and 15 ms -1 ) and temperature (15°, 20°, and 25° C). At elevated wind speeds slight increases in water loss were observed, whereas at higher temperatures much greater increases occurred. Studies on winter water relations show a significant decline in the actual moisture content and osmotic potentials of twigs, especially in the kampfzone and at treeline. The roles of high winds and temperatures in depleting the winter water economy and causing desiccation damage in the alpine treeline environment are discussed.

  18. Modeling net ecosystem carbon exchange of alpine grasslands with a satellite-driven model.

    Directory of Open Access Journals (Sweden)

    Wei Yan

    Full Text Available Estimate of net ecosystem carbon exchange (NEE between the atmosphere and terrestrial ecosystems, the balance of gross primary productivity (GPP and ecosystem respiration (Reco has significant importance for studying the regional and global carbon cycles. Using models driven by satellite data and climatic data is a promising approach to estimate NEE at regional scales. For this purpose, we proposed a semi-empirical model to estimate NEE in this study. In our model, the component GPP was estimated with a light response curve of a rectangular hyperbola. The component Reco was estimated with an exponential function of soil temperature. To test the feasibility of applying our model at regional scales, the temporal variations in the model parameters derived from NEE observations in an alpine grassland ecosystem on Tibetan Plateau were investigated. The results indicated that all the inverted parameters exhibit apparent seasonality, which is in accordance with air temperature and canopy phenology. In addition, all the parameters have significant correlations with the remote sensed vegetation indexes or environment temperature. With parameters estimated with these correlations, the model illustrated fair accuracy both in the validation years and at another alpine grassland ecosystem on Tibetan Plateau. Our results also indicated that the model prediction was less accurate in drought years, implying that soil moisture is an important factor affecting the model performance. Incorporating soil water content into the model would be a critical step for the improvement of the model.

  19. Volatile organic compounds in alpine valleys: sources, evolutions and transformations; Les composes organiques volatils dans les vallees alpines: sources, evolutions et transformations

    Energy Technology Data Exchange (ETDEWEB)

    Colomb, A.

    2002-12-01

    Dynamic and chemical specificity in alpine valleys was the principal goal during the POVA project (Pollution des Vallees Alpines). Volatile Organic Compounds emissions in troposphere have important impacts on animal lives and environment. Then, the aim of this work was the improvement of the biogenic or anthropogenic VOC sources determination, of VOC transformation and evolution in mountain areas. During this project, the realisation of a daily continuous measurements campaign of a few chemical compounds allowed the understanding of the seasonal variations of these compounds. The goals of intensive field campaigns, realised in August 2000 and January 2001, were to understand photochemical process in a temporal and geographic small scale and to follow diurnal variation of different pollutants in summer and winter. Moreover, the VOC data would be used to develop and validate coupled atmospheric dynamic/chemical model. Therefore, these VOC measures give answer to two lacks of knowledge in alpine valleys about: - Biogenic and anthropogenic VOC respective part, and their main sources, - VOC photochemical reactions in alpine valleys, according to seasonal and diurnal cycles. Finally, we presented two atypical days results, in Maurienne valley during a Saharan episode in August 2000. This episode permitted to understand mass air transport mechanism in mountain region. (author)

  20. Grazing exclusion increases soil CO2 emission during the growing season in alpine meadows on the Tibetan Plateau

    Science.gov (United States)

    Guo, Na; Wang, Aidong; Allan Degen, A.; Deng, Bin; Shang, Zhanhuan; Ding, Luming; Long, Ruijun

    2018-02-01

    Soil CO2 emission is a key part of the terrestrial carbon cycle. Grazing exclusion by fencing is often considered a beneficial grassland management option to restore degraded grassland, but its effect on soil CO2 emission on the northeastern Tibetan Plateau is equivocal and is the subject of this study. Using a closed static chamber, we measured diurnal soil CO2 flux weekly from July, 2008, to April, 2009, in response to grazing and grazing exclusion in the alpine meadow and alpine shrub meadow. Concomitantly, soil temperature was measured at depths of 5 cm, 10 cm, 15 cm and 20 cm with digital temperature sensors. It emerged that: 1) non-grazed grasslands emitted more soil CO2 than grazed grasslands over the growing season; 2) the alpine shrub meadow emitted more soil CO2 than the alpine meadow; the annual cumulative soil CO2 emissions of alpine meadow and alpine shrub meadow were 241.5-326.5 g C/m2 and 429.0-512.5 g C/m2, respectively; 3) seasonal patterns were evident with more soil CO2 flux in the growing than in the non-growing season; and 4) the diurnal soil CO2 flux exhibited a single peak across all sampling sites. In addition, soil CO2 flux was correlated positively with soil temperature at 5 cm, but not at the other depths. We concluded that grazing exclusion enhanced soil CO2 emission over the growing season, and decreased carbon sequestration of alpine meadow and alpine shrub meadow on the northeastern Tibetan Plateau. Since an increase in soil temperature increased soil CO2 flux, global warming could have an effect on soil CO2 emission in the future.

  1. Alpine tourism

    Directory of Open Access Journals (Sweden)

    Andrea Macchiavelli

    2009-06-01

    Full Text Available The spectacular increase in tourism in the Alps in recent decades has been founded mainly on the boom in skiing, resulting in both strong real estate development and an increasing array of infrastructures and ski runs. Today the ski market seems to have virtually reached saturation point and the winter sports sector needs to diversify its offer through innovation. After a review of the main factors of change in mountain tourism, the paper presents a grid for interpreting the life cycle of alpine destinations, identifying the phases that characterize their evolution. The conditions that may favour innovation in alpine tourism are then identified, as well as the contradictions that frequently accompany them. In most cases, innovation is the result of a process that begins within the alpine community, frequently encouraged and supported by national and international institutions and with whose help structural difficulties are successfully overcome.La forte croissance qu’ont connue les pays alpins dans les dernières décennies a surtout été fondée sur l’offre des activités du ski, avec comme conséquence, un massif développement immobilier et la multiplication d’infrastructures et de pistes. Aujourd’hui, le marché du ski semble arriver à saturation, la Convention alpine a mis un frein à la poursuite du développement des domaines skiables et on observe donc avec intérêt la diversification de l’offre soutenue par l’innovation. Après avoir rappelé les facteurs de changement en cours les plus significatifs dans le tourisme montagnard, l’article présente une grille interprétative de l’évolution des destinations touristiques alpines, identifiant les phases qui ont caractérisé son développement. Ensuite, l’article propose une réflexion sur certaines conditions qui peuvent favoriser l’innovation dans le tourisme alpin, ainsi que sur les contradictions qui accompagnent souvent ces conditions. Dans la plupart des cas

  2. What triggers colour change? Effects of background colour and temperature on the development of an alpine grasshopper.

    Science.gov (United States)

    Valverde, J Pablo; Schielzeth, Holger

    2015-08-21

    Colour polymorphisms are a fascinating facet of many natural populations of plants and animals, and the selective processes that maintain such variation are as relevant as the processes which promote their development. Orthoptera, the insect group that encompasses grasshoppers and bush crickets, includes a particularly large number of species that are colour polymorphic with a marked green-brown polymorphism being particularly widespread. Colour polymorphism has been associated with the need for crypsis and background matching and background-dependent homochromy has been described in a few species. However, when and how different environmental conditions influence variation in colour remains poorly understood. Here we test for effects of background colour and ambient temperature on the occurrence of colour morph switches (green to brown or brown to green) and developmental darkening in the alpine dwelling club-legged grasshopper Gomphocerus sibiricus. We monitored individually housed nymphae across three of their four developmental stages and into the first week after final ecdysis. Our data show an absence of colour morph switches in G. sibiricus, without a single switch observed in our sample. Furthermore, we test for an effect of temperature on colouration by manipulating radiant heat, a limiting factor in alpine habitats. Radiant heat had a significant effect on developmental darkening: individuals under low radiant heat tended to darken, while individuals under high radiant heat tended to lighten within nymphal stages. Young imagoes darkened under either condition. Our results indicate a plastic response to a variable temperature and indicate that melanin, a multipurpose pigment responsible for dark colouration and presumed to be costly, seems to be strategically allocated according to the current environmental conditions. Unlike other orthopterans, the species is apparently unable to switch colour morphs (green/brown) during development, suggesting that

  3. Alpins and thibos vectorial astigmatism analyses: proposal of a linear regression model between methods

    Directory of Open Access Journals (Sweden)

    Giuliano de Oliveira Freitas

    2013-10-01

    Full Text Available PURPOSE: To determine linear regression models between Alpins descriptive indices and Thibos astigmatic power vectors (APV, assessing the validity and strength of such correlations. METHODS: This case series prospectively assessed 62 eyes of 31 consecutive cataract patients with preoperative corneal astigmatism between 0.75 and 2.50 diopters in both eyes. Patients were randomly assorted among two phacoemulsification groups: one assigned to receive AcrySof®Toric intraocular lens (IOL in both eyes and another assigned to have AcrySof Natural IOL associated with limbal relaxing incisions, also in both eyes. All patients were reevaluated postoperatively at 6 months, when refractive astigmatism analysis was performed using both Alpins and Thibos methods. The ratio between Thibos postoperative APV and preoperative APV (APVratio and its linear regression to Alpins percentage of success of astigmatic surgery, percentage of astigmatism corrected and percentage of astigmatism reduction at the intended axis were assessed. RESULTS: Significant negative correlation between the ratio of post- and preoperative Thibos APVratio and Alpins percentage of success (%Success was found (Spearman's ρ=-0.93; linear regression is given by the following equation: %Success = (-APVratio + 1.00x100. CONCLUSION: The linear regression we found between APVratio and %Success permits a validated mathematical inference concerning the overall success of astigmatic surgery.

  4. Hydrologic and Isotopic Sensitivity of Alpine Lakes to Climate Change in the Medicine Bow Mountains, Wyoming

    Science.gov (United States)

    Liefert, D. T.; Shuman, B. N.; Mercer, J.; Parsekian, A.; Williams, D. G.

    2017-12-01

    Climate reconstructions show that global average temperatures were 0.5°C higher than today during the mid-Holocene, falling well within projections for increases in global average temperature presented in the latest Intergovernmental Panel on Climate Change report. Despite the consensus for the prediction of a warmer climate, however, it is unclear how snowmelt from high-elevation watersheds will be affected by such a change. Snowmelt contributes substantially to major rivers in the western United States, and much of the water flows through lakes in the highest-elevation watersheds. Our water balance models show that modern alpine lakes with seasonably unstable water levels can desiccate primarily through groundwater outflow, resulting in increased groundwater storage that likely sustains baseflow in mountain streams once snowmelt has subsided in late summer. However, contribution of freshwater from alpine lakes to streams may vary over time as changes in climate alters snowpack, rates of evaporation, and the abundance of snowmelt-fed lakes. As such, alpine lakes with seasonally unstable water levels today may have dried out entirely during the mid-Holocene warm period and may dry out in the future as temperatures increase. To investigate the response of alpine lakes to temperatures of the mid-Holocene, we collected 9 sediment cores from closed-basin alpine lakes in the Medicine Bow Mountains of southern Wyoming that lose most their volumes each summer. We use radiocarbon-dating of charcoal in basal sediments to determine lake formation age, abundance of conifer needles to infer relative forest cover, and a δ18O carbonate record to determine changes in the ratio of evaporation to precipitation in an alpine lake that existed throughout the Holocene. Warming likely changed watershed hydrology through a) decreased snowpack and earlier snowmelt, b) increased evaporation, and c) increased transpiration associated with expanded forest cover and longer growing seasons

  5. Soil respiration in Tibetan alpine grasslands: belowground biomass and soil moisture, but not soil temperature, best explain the large-scale patterns.

    Directory of Open Access Journals (Sweden)

    Yan Geng

    Full Text Available The Tibetan Plateau is an essential area to study the potential feedback effects of soils to climate change due to the rapid rise in its air temperature in the past several decades and the large amounts of soil organic carbon (SOC stocks, particularly in the permafrost. Yet it is one of the most under-investigated regions in soil respiration (Rs studies. Here, Rs rates were measured at 42 sites in alpine grasslands (including alpine steppes and meadows along a transect across the Tibetan Plateau during the peak growing season of 2006 and 2007 in order to test whether: (1 belowground biomass (BGB is most closely related to spatial variation in Rs due to high root biomass density, and (2 soil temperature significantly influences spatial pattern of Rs owing to metabolic limitation from the low temperature in cold, high-altitude ecosystems. The average daily mean Rs of the alpine grasslands at peak growing season was 3.92 µmol CO(2 m(-2 s(-1, ranging from 0.39 to 12.88 µmol CO(2 m(-2 s(-1, with average daily mean Rs of 2.01 and 5.49 µmol CO(2 m(-2 s(-1 for steppes and meadows, respectively. By regression tree analysis, BGB, aboveground biomass (AGB, SOC, soil moisture (SM, and vegetation type were selected out of 15 variables examined, as the factors influencing large-scale variation in Rs. With a structural equation modelling approach, we found only BGB and SM had direct effects on Rs, while other factors indirectly affecting Rs through BGB or SM. Most (80% of the variation in Rs could be attributed to the difference in BGB among sites. BGB and SM together accounted for the majority (82% of spatial patterns of Rs. Our results only support the first hypothesis, suggesting that models incorporating BGB and SM can improve Rs estimation at regional scale.

  6. Temperature and snowfall trigger alpine vegetation green-up on the world's roof.

    Science.gov (United States)

    Chen, Xiaoqiu; An, Shuai; Inouye, David W; Schwartz, Mark D

    2015-10-01

    Rapid temperature increase and its impacts on alpine ecosystems in the Qinghai-Tibetan Plateau, the world's highest and largest plateau, are a matter of global concern. Satellite observations have revealed distinctly different trend changes and contradicting temperature responses of vegetation green-up dates, leading to broad debate about the Plateau's spring phenology and its climatic attribution. Large uncertainties in remote-sensing estimates of phenology significantly limit efforts to predict the impacts of climate change on vegetation growth and carbon balance in the Qinghai-Tibetan Plateau, which are further exacerbated by a lack of detailed ground observation calibration. Here, we revealed the spatiotemporal variations and climate drivers of ground-based herbaceous plant green-up dates using 72 green-up datasets for 22 herbaceous plant species at 23 phenological stations, and corresponding daily mean air temperature and daily precipitation data from 19 climate stations across eastern and southern parts of the Qinghai-Tibetan Plateau from 1981 to 2011. Results show that neither the continuously advancing trend from 1982 to 2011, nor a turning point in the mid to late 1990s as reported by remote-sensing studies can be verified by most of the green-up time series, and no robust evidence for a warmer winter-induced later green-up dates can be detected. Thus, chilling requirements may not be an important driver influencing green-up responses to spring warming. Moreover, temperature-only control of green-up dates appears mainly at stations with relatively scarce preseason snowfall and lower elevation, while coupled temperature and precipitation controls of green-up dates occur mostly at stations with relatively abundant preseason snowfall and higher elevation. The diversified interactions between snowfall and temperature during late winter to early spring likely determine the spatiotemporal variations of green-up dates. Therefore, prediction of vegetation growth

  7. Alpine hydropower schemes and their 'remote influence' on lakes and rivers downstream

    International Nuclear Information System (INIS)

    Wuest, A.

    2003-01-01

    This article discusses the effect that alpine dams and reservoirs have on lakes and rivers in the lowlands. Not only the contribution of Swiss alpine hydropower installations to Switzerland's electricity generation capacity is mentioned, but also the way they 'export' ecological deficits to lower-lying regions. Examples of this are quoted, including, for example, the filtering-out of around 50% of water-borne particles in the river Rhone by the dams in its catchment area. The consequences of such effects for the ecology of lakes and rivers are discussed. Further examples of how the alpine dams hold back nutrients and regulate the flow and temperature of rivers are given and the resulting ecological effects are commented on

  8. The long-term trends (1982-2006) in vegetation greenness of the alpine ecosystem in the Qinghai-Tibetan Plateau

    Science.gov (United States)

    Zhang, Li; Guo, Huadong; Wang, Cuizhen; Ji, Lei; Li, Jing; Wang, Kun; Dai, Lin

    2014-01-01

    The increased rate of annual temperature in the Qinghai-Tibetan Plateau exceeded all other areas of the same latitude in recent decades. The influence of the warming climate on the alpine ecosystem of the plateau was distinct. An analysis of alpine vegetation under changes in climatic conditions was conducted in this study. This was done through an examination of vegetation greenness and its relationship with climate variability using the Advanced Very High Resolution Radiometer satellite imagery and climate datasets. Vegetation in the plateau experienced a positive trend in greenness, with 18.0 % of the vegetated areas exhibiting significantly positive trends, which were primarily located in the eastern and southwestern parts of the plateau. In grasslands, 25.8 % of meadows and 14.1 % of steppes exhibited significant upward trends. In contrast, the broadleaf forests experienced a trend of degradation. Temperature, particularly summer temperature, was the primary factor promoting the vegetation growth in the plateau. The wetter and warmer climate in the east contributed to the favorable conditions for vegetation. The alpine meadow was mostly sensitive to temperature, while the steppes were sensitive to both temperature and precipitation. Although a warming climate was expected to be beneficial to vegetation growth in the alpine region, the rising temperature coupled with reduced precipitation in the south did not favor vegetation growth due to low humidity and poor soil moisture conditions.

  9. Rapid response of alpine timberline vegetation to the Younger Dryas climate oscillation in the Colorado Rocky Mountains, USA

    International Nuclear Information System (INIS)

    Reasoner, M.A.; Jodry, M.A.

    2000-01-01

    Paleobotanical records from two high-altitude (>3,300 m) sites in Colorado show a clear and immediate response to the Younger Dryas climate oscillation. The Black Mountain Lake and Sky Pond records indicate that alpine timberline migrated upslope to near-modern elevations during the late Bolling-Allerod (13.6--12.9 ka). Subsequent declines in arboreal pollen percentages and accumulation rates during the Younger Dryas interval (12.9--11.7 ka) reflect a downslope displacement of the alpine timberline ecotone of 60--120 m in elevation. This change translates to a cooling of summer temperature by ∼0.4--0.9 C and is consistent with proposed Younger Dryas advances of alpine glaciers in the Rocky Mountains to positions close to Little Ice Age maxima. Alpine timberline readvanced upslope to elevations above both sites between 11.7 and 11.4 ka. The concomitant response of temperature-sensitive alpine timberline vegetation in Colorado and late-glacial changes in North Atlantic thermohaline circulating implicates a rapid, widespread atmospheric transmission of the Younger Dryas climate oscillation

  10. Rapid response of alpine timberline vegetation to the Younger Dryas climate oscillation in the Colorado Rocky Mountains, USA

    Energy Technology Data Exchange (ETDEWEB)

    Reasoner, M.A.; Jodry, M.A.

    2000-01-01

    Paleobotanical records from two high-altitude (>3,300 m) sites in Colorado show a clear and immediate response to the Younger Dryas climate oscillation. The Black Mountain Lake and Sky Pond records indicate that alpine timberline migrated upslope to near-modern elevations during the late Bolling-Allerod (13.6--12.9 ka). Subsequent declines in arboreal pollen percentages and accumulation rates during the Younger Dryas interval (12.9--11.7 ka) reflect a downslope displacement of the alpine timberline ecotone of 60--120 m in elevation. This change translates to a cooling of summer temperature by {approximately}0.4--0.9 C and is consistent with proposed Younger Dryas advances of alpine glaciers in the Rocky Mountains to positions close to Little Ice Age maxima. Alpine timberline readvanced upslope to elevations above both sites between 11.7 and 11.4 ka. The concomitant response of temperature-sensitive alpine timberline vegetation in Colorado and late-glacial changes in North Atlantic thermohaline circulating implicates a rapid, widespread atmospheric transmission of the Younger Dryas climate oscillation.

  11. Le tourisme alpin

    Directory of Open Access Journals (Sweden)

    Andrea Macchiavelli

    2009-06-01

    Full Text Available La forte croissance qu’ont connue les pays alpins dans les dernières décennies a surtout été fondée sur l’offre des activités du ski, avec comme conséquence, un massif développement immobilier, la multiplication d’infrastructures et l’extension des domaines. Aujourd’hui, le marché du ski semble arriver à saturation, la Convention alpine a mis un frein à la poursuite du développement des domaines skiables et on observe donc avec intérêt la diversification de l’offre soutenue par l’innovation. Après avoir rappelé les facteurs de changement en cours les plus significatifs dans le tourisme montagnard, l’article présente une grille interprétative de l’évolution des destinations touristiques alpines, identifiant les phases qui ont caractérisé son développement. Puis il propose une réflexion sur certaines conditions qui peuvent favoriser l’innovation dans le tourisme alpin, ainsi que sur les contradictions qui les accompagnent souvent. Dans la plupart des cas l’innovation est le résultat d’un processus qui a été lancé et qui s’est développé au sein de la communauté alpine, souvent favorisé et soutenu par des institutions nationales et internationales, et grâce auquel les difficultés structurelles qui ont déjà été abordées précédemment ont pu être surmontées avec succès.The spectacular increase in tourism in the Alps in recent decades has been founded mainly on the boom in skiing, resulting in both strong real estate development and an increasing array of infrastructures and ski runs. Today the ski market seems to have virtually reached saturation point and the winter sports sector needs to diversify its offer through innovation. After a review of the main factors of change in mountain tourism, the paper presents a grid for interpreting the life cycle of alpine destinations, identifying the phases that characterize their evolution. The conditions that may favour innovation in alpine

  12. Photosynthesis and photosynthetic electron flow in the alpine evergreen species Quercus guyavifolia in winter

    Directory of Open Access Journals (Sweden)

    Wei Huang

    2016-10-01

    Full Text Available Alpine evergreen broadleaf tree species must regularly cope with low night temperatures in winter. However, the effects of low night temperatures on photosynthesis in alpine evergreen broadleaf tree species are unclear. We measured the diurnal photosynthetic parameters before and after cold snap for leaves of Quercus guyavifolia growing in its native habitat at 3290 m. On 11 and 12 December 2013 (before cold snap, stomatal and mesophyll conductances (gs and gm, CO2 assimilation rate (An, and total electron flow through PSII (JPSII at daytime were maintained at high levels. The major action of alternative electron flow was to provide extra ATP for primary metabolisms. On 20 December 2013 (after cold snap, the diurnal values of gs, gm, An and JPSII at daytime largely decreased, mainly due to the large decrease in night air temperature. Meanwhile, the ratio of photorespiration and alternative electron flow to JPSII largely increased on 20 December. Furthermore, the high levels of alternative electron flow were accompanied with low rates of extra ATP production. A quantitative limitation analysis reveals that the gm limitation increased on 20 December with decreased night air temperature. Therefore, the night air temperature was an important determinant of stomatal/mesophyll conductance and photosynthesis. When photosynthesis is inhibited following freezing night temperatures, photorespiration and alternative electron flow are important electron sinks, which support the role of photorespiration and alternative electron flow in photoportection for alpine plants under low temperatures.

  13. Coincidence of the alpine-nival ecotone with the summer snowline

    International Nuclear Information System (INIS)

    Gottfried, M; Toechterle, R; Grabherr, G; Hantel, M; Maurer, C; Pauli, H

    2011-01-01

    The alpine-nival ecotone is the transition between the lower located alpine grassland/tundra zone and the upper located sparsely vegetated nival zone in the mountains. Its characteristics are qualitatively known. Here we study the dynamics of the ecotone through a quantitative approach based on plant data (from Mt Schrankogel, 3497 m, observations 1994 and 2004) and snow data (from 268 routine climate stations in the Alps, observations 1975-2004). We introduce the nivality index as the area ratio of nival and alpine plants, and the snow duration as the length of the summer snow cover. We fit a nonlinear probabilistic model to our field data; it yields state functions of both quantities. The nivality index curve comprises the entire information of the plant data in one analytical function; the snow duration curve represents the equivalent for the full snow data set. Thus all relevant parameters of both quantities follow from the respective state function. We find that the analytical profile of the alpine-nival ecotone at Mt Schrankogel (based on nivality index observations from the altitude interval 2910-3090 m) happens to sit right in the center of the independently determined summer snow profile across the entire Alps; specifically, the central altitude of the Schrankogel ecotone coincides almost perfectly with the central altitude of Alpine snow duration. Both state functions show extreme temperature sensitivity at 2967 m (vegetation) and 2897 m (snow), and both altitudes exhibit a positive trend during the measurement period.

  14. Coincidence of the alpine-nival ecotone with the summer snowline

    Energy Technology Data Exchange (ETDEWEB)

    Gottfried, M; Toechterle, R; Grabherr, G [Research Platform Mountain Limits, University of Vienna, Faculty Center of Biodiversity, Rennweg 14, Wien 1030 (Austria); Hantel, M; Maurer, C [Research Platform Mountain Limits, University of Vienna, Theoretical Meteorology Research Forum, Berggasse 11, Wien 1090 (Austria); Pauli, H, E-mail: michael.hantel@univie.ac.at [Institute of Mountain Research (IGF), Austrian Academy of Sciences, c/o Faculty Center of Biodiversity, University of Vienna, Rennweg 14, 1030 Wien (Austria)

    2011-01-15

    The alpine-nival ecotone is the transition between the lower located alpine grassland/tundra zone and the upper located sparsely vegetated nival zone in the mountains. Its characteristics are qualitatively known. Here we study the dynamics of the ecotone through a quantitative approach based on plant data (from Mt Schrankogel, 3497 m, observations 1994 and 2004) and snow data (from 268 routine climate stations in the Alps, observations 1975-2004). We introduce the nivality index as the area ratio of nival and alpine plants, and the snow duration as the length of the summer snow cover. We fit a nonlinear probabilistic model to our field data; it yields state functions of both quantities. The nivality index curve comprises the entire information of the plant data in one analytical function; the snow duration curve represents the equivalent for the full snow data set. Thus all relevant parameters of both quantities follow from the respective state function. We find that the analytical profile of the alpine-nival ecotone at Mt Schrankogel (based on nivality index observations from the altitude interval 2910-3090 m) happens to sit right in the center of the independently determined summer snow profile across the entire Alps; specifically, the central altitude of the Schrankogel ecotone coincides almost perfectly with the central altitude of Alpine snow duration. Both state functions show extreme temperature sensitivity at 2967 m (vegetation) and 2897 m (snow), and both altitudes exhibit a positive trend during the measurement period.

  15. Within-season variability of fighting behaviour in an Australian alpine grasshopper.

    Science.gov (United States)

    Muschett, Giselle; Umbers, Kate D L; Herberstein, Marie E

    2017-01-01

    Throughout the breeding season, changing environmental and biological conditions can lead to variation in the reproductive landscape of many species. In alpine environments temperature is a key driver of behaviour for small ectotherms such as insects, but variable biotic factors such as mate quality and availability can also influence behaviour. Kosicuscola tristis is a small semelparous grasshopper of the Australian alpine region. In a rare behaviour among grasshoppers, K. tristis males engage in vigorous fights over access to females, involving mandible displays, kicking, biting and grappling. In this study we describe the variation in fighting behaviour of K. tristis throughout the breeding season and test several hypotheses related to temperature, body size, mating behaviour, and female quality. We show that K. tristis males are more aggressive toward each other at the end of the breeding season than at the beginning. This increased aggression is associated with decreased daily average temperatures (from ~20°C to ~9°C), decreased mating activity, increased female fecundity, and an unexpected trend toward an increase in female-to-male aggression. These results suggest that K. tristis is likely under increased selective pressure to time key life cycle events with favourable biological and climatic conditions. The stochastic nature of alpine environments combined with a relatively short life span and breeding season, as well as limited mating opportunities toward the end of the season may have contributed to the evolution of this extraordinary mating system.

  16. The potential for retreating alpine glaciers to alter alpine ecosystems in the Colorado Front Range

    Science.gov (United States)

    Hall, E.; Baron, J.

    2013-12-01

    Glaciers are retreating at an unprecedented rate. In mid-latitude alpine ecosystems the presence of glaciers and rock glaciers govern rates and ecology of alpine and sub-alpine ecosystems. Changes in the thermal environment due to the loss of isothermal habitat and inputs from glacier melt chemistry are altering alpine ecosystems in unpredictable ways. In particular, glacier may be a source of nitrogen that is altering alpine ecosystem dynamics. Loch Vale Watershed (LVWS) located within Rocky Mountain National Park. LVWS contains a surface glacier (Andrew's glacier) and a rock glacier (Taylor's glacier) at the headwater of each of the two drainages within the watershed. We collected precipitation from a National Atmospheric Deposition Site and surface water from multiple alpine lakes and streams during a particularly high and low snow year in the Colorado Front Range. We also sampled stream and lake sediments at each site to analyze the associated microbial community. Concentrations of nitrate and ammonium, relative abundance of amoA (the gene responsible for a key step in the microbial nitrification pathway), and the dual isotope signal to nitrate all point to snow melt as a key deliverer of nitrogen to ecosystems along the Colorado Front Range. However, late summer surface water chemistry is isotopically similar to the chemistry of glacial ice. This suggests that retreating glacier may be an additional source of N to alpine ecosystems and have the potential to alter microbial community composition, biogeochemical rate processes, and ecosystem function. These dynamics are most likely not unique to the Colorado Front Range and should be globally distributed as glaciers continue to retreat in high altitude ecosystems around the world.

  17. Les Nouvelles Traversées Alpines : la “cité-Europe” à l’épreuve de l’acceptabilité alpine ? The New alpine crossings : The “city-Europe” faces up to the alpine acceptability

    Directory of Open Access Journals (Sweden)

    Kevin Sutton

    2012-12-01

    Full Text Available La pensée des traversées alpines est indissociable de celle des réseaux urbains alpins et, au-delà, européens. La nouvelle phase de percée des tunnels de base le réaffirme : les “Nouvelles Traversées Alpines” se retrouvent au coeur de l’enjeu de connexion des réseaux ferroviaires européens à grande vitesse. L’invention de la “cité-Europe” passe ainsi par la réinvention d’un pacte alpin autour du dessein de franchissement entre les villes de piedmonts et les communautés montagnardes traversées. Ces dernières ont, en effet, la capacité de bloquer un projet par leur refus. L’exemple du projet Lyon-Turin l’illustre, en contre-point de la réussite du tunnel de base du Lötschberg. La réussite suisse semble tenir à la capacité de conjuguer les inventions technique et sociale du tunnel, ne niant pas la dimension territoriale de cet objet réticulaire.It is impossible to think about the alpine crossings without thinking about the alpine and European urban nets. The construction of the basis tunnels recalls it: the “New Alpine Crossings” are the kernel of the connection issue between the European high-speed railways nets. The invention of a “city-Europe” needs a reinvented pact, between the cities of the plains and the alpine communities, based on the reaffirmation of a common crossing destiny. The alpine communities can thwart the project by refusing it, as the example of the Lyon-Turin project shows, in contrast to the successful Lötschberg basis tunnel. The Swiss success seems to come from the capacity to mix technical and social inventions, replacing the territorial dimension in the reticular fundament.

  18. Warming-induced upward migration of the alpine treeline in the Changbai Mountains, northeast China.

    Science.gov (United States)

    Du, Haibo; Liu, Jie; Li, Mai-He; Büntgen, Ulf; Yang, Yue; Wang, Lei; Wu, Zhengfang; He, Hong S

    2018-03-01

    Treeline responses to environmental changes describe an important phenomenon in global change research. Often conflicting results and generally too short observations are, however, still challenging our understanding of climate-induced treeline dynamics. Here, we use a state-of-the-art dendroecological approach to reconstruct long-term changes in the position of the alpine treeline in relation to air temperature at two sides in the Changbai Mountains in northeast China. Over the past 160 years, the treeline increased by around 80 m, a process that can be divided into three phases of different rates and drives. The first phase was mainly influenced by vegetation recovery after an eruption of the Tianchi volcano in 1702. The slowly upward shift in the second phase was consistent with the slowly increasing temperature. The last phase coincided with rapid warming since 1985, and shows with 33 m per 1°C, the most intense upward shift. The spatial distribution and age structure of trees beyond the current treeline confirm the latest, warming-induced upward shift. Our results suggest that the alpine treeline will continue to rise, and that the alpine tundra may disappear if temperatures will increase further. This study not only enhances mechanistic understanding of long-term treeline dynamics, but also highlights the effects of rising temperatures on high-elevation vegetation dynamics. © 2017 John Wiley & Sons Ltd.

  19. Regional climate models downscaling in the Alpine area with multimodel superensemble

    Directory of Open Access Journals (Sweden)

    D. Cane

    2013-05-01

    Full Text Available The climatic scenarios show a strong signal of warming in the Alpine area already for the mid-XXI century. The climate simulations, however, even when obtained with regional climate models (RCMs, are affected by strong errors when compared with observations, due both to their difficulties in representing the complex orography of the Alps and to limitations in their physical parametrization. Therefore, the aim of this work is to reduce these model biases by using a specific post processing statistic technique, in order to obtain a more suitable projection of climate change scenarios in the Alpine area. For our purposes we used a selection of regional climate models (RCMs runs which were developed in the framework of the ENSEMBLES project. They were carefully chosen with the aim to maximise the variety of leading global climate models and of the RCMs themselves, calculated on the SRES scenario A1B. The reference observations for the greater Alpine area were extracted from the European dataset E-OBS (produced by the ENSEMBLES project, which have an available resolution of 25 km. For the study area of Piedmont daily temperature and precipitation observations (covering the period from 1957 to the present were carefully gridded on a 14 km grid over Piedmont region through the use of an optimal interpolation technique. Hence, we applied the multimodel superensemble technique to temperature fields, reducing the high biases of RCMs temperature field compared to observations in the control period. We also proposed the application of a brand new probabilistic multimodel superensemble dressing technique, already applied to weather forecast models successfully, to RCMS: the aim was to estimate precipitation fields, with careful description of precipitation probability density functions conditioned to the model outputs. This technique allowed for reducing the strong precipitation overestimation, arising from the use of RCMs, over the Alpine chain and to

  20. Regional climate models downscaling in the Alpine area with multimodel superensemble

    Science.gov (United States)

    Cane, D.; Barbarino, S.; Renier, L. A.; Ronchi, C.

    2013-05-01

    The climatic scenarios show a strong signal of warming in the Alpine area already for the mid-XXI century. The climate simulations, however, even when obtained with regional climate models (RCMs), are affected by strong errors when compared with observations, due both to their difficulties in representing the complex orography of the Alps and to limitations in their physical parametrization. Therefore, the aim of this work is to reduce these model biases by using a specific post processing statistic technique, in order to obtain a more suitable projection of climate change scenarios in the Alpine area. For our purposes we used a selection of regional climate models (RCMs) runs which were developed in the framework of the ENSEMBLES project. They were carefully chosen with the aim to maximise the variety of leading global climate models and of the RCMs themselves, calculated on the SRES scenario A1B. The reference observations for the greater Alpine area were extracted from the European dataset E-OBS (produced by the ENSEMBLES project), which have an available resolution of 25 km. For the study area of Piedmont daily temperature and precipitation observations (covering the period from 1957 to the present) were carefully gridded on a 14 km grid over Piedmont region through the use of an optimal interpolation technique. Hence, we applied the multimodel superensemble technique to temperature fields, reducing the high biases of RCMs temperature field compared to observations in the control period. We also proposed the application of a brand new probabilistic multimodel superensemble dressing technique, already applied to weather forecast models successfully, to RCMS: the aim was to estimate precipitation fields, with careful description of precipitation probability density functions conditioned to the model outputs. This technique allowed for reducing the strong precipitation overestimation, arising from the use of RCMs, over the Alpine chain and to reproduce well the

  1. Performance of complex snow cover descriptions in a distributed hydrological model system: A case study for the high Alpine terrain of the Berchtesgaden Alps.

    Science.gov (United States)

    Warscher, M; Strasser, U; Kraller, G; Marke, T; Franz, H; Kunstmann, H

    2013-05-01

    [1] Runoff generation in Alpine regions is typically affected by snow processes. Snow accumulation, storage, redistribution, and ablation control the availability of water. In this study, several robust parameterizations describing snow processes in Alpine environments were implemented in a fully distributed, physically based hydrological model. Snow cover development is simulated using different methods from a simple temperature index approach, followed by an energy balance scheme, to additionally accounting for gravitational and wind-driven lateral snow redistribution. Test site for the study is the Berchtesgaden National Park (Bavarian Alps, Germany) which is characterized by extreme topography and climate conditions. The performance of the model system in reproducing snow cover dynamics and resulting discharge generation is analyzed and validated via measurements of snow water equivalent and snow depth, satellite-based remote sensing data, and runoff gauge data. Model efficiency (the Nash-Sutcliffe coefficient) for simulated runoff increases from 0.57 to 0.68 in a high Alpine headwater catchment and from 0.62 to 0.64 in total with increasing snow model complexity. In particular, the results show that the introduction of the energy balance scheme reproduces daily fluctuations in the snowmelt rates that trace down to the channel stream. These daily cycles measured in snowmelt and resulting runoff rates could not be reproduced by using the temperature index approach. In addition, accounting for lateral snow transport changes the seasonal distribution of modeled snowmelt amounts, which leads to a higher accuracy in modeling runoff characteristics.

  2. Hydroclimatic control on suspended sediment dynamics of a regulated Alpine catchment: a conceptual approach

    Directory of Open Access Journals (Sweden)

    A. Costa

    2018-06-01

    including discharge, the HMRC performs better than the traditional rating curve in reproducing SSC seasonality, especially during validation at the daily scale. While erosive rainfall determines the daily variability of SSC and extremes, ice melt generates the highest SSC per unit of runoff and represents the largest contribution to total suspended sediment yield. Finally, we show that the HMRC is capable of simulating climate-driven changes in fine sediment dynamics in Alpine catchments. In fact, HMRC can reproduce the changes in SSC in the past 40 years in the Rhône Basin connected to air temperature rise, even though the simulated changes are more gradual than those observed. The approach presented in this paper, based on the analysis of the hydroclimatic control of suspended sediment concentration, allows the exploration of climate-driven changes in fine sediment dynamics in Alpine catchments. The approach can be applied to any Alpine catchment with a pluvio-glacio-nival hydrological regime and adequate hydroclimatic datasets.

  3. UAS applications in high alpine, snow-covered terrain

    Science.gov (United States)

    Bühler, Y.; Stoffel, A.; Ginzler, C.

    2017-12-01

    Access to snow-covered, alpine terrain is often difficult and dangerous. Hence parameters such as snow depth or snow avalanche release and deposition zones are hard to map in situ with adequate spatial and temporal resolution and with spatial continuous coverage. These parameters are currently operationally measured at automated weather stations and by observer networks. However such isolated point measurements are not able to capture the information spatial continuous and to describe the high spatial variability present in complex mountain topography. Unmanned Aerial Systems (UAS) have the potential to fill this gap by frequently covering selected high alpine areas with high spatial resolution down to ground resolutions of even few millimeters. At the WSL Institute for Snow and Avalanche Research SLF we test different photogrammetric UAS with visual and near infrared bands. During the last three years we were able to gather experience in more than 100 flight missions in extreme terrain. By processing the imagery applying state-of-the-art structure from motion (SfM) software, we were able to accurately document several avalanche events and to photogrammetrically map snow depth with accuracies from 1 to 20 cm (dependent on the flight height above ground) compare to manual snow probe measurements. This was even possible on homogenous snow surfaces with very little texture. A key issue in alpine terrain is flight planning. We need to cover regions at high elevations with large altitude differences (up to 1 km) with high wind speeds (up to 20 m/s) and cold temperatures (down to - 25°C). Only a few UAS are able to cope with these environmental conditions. We will give an overview on our applications of UAS in high alpine terrain that demonstrate the big potential of such systems to acquire frequent, accurate and high spatial resolution geodata in high alpine, snow covered terrain that could be essential to answer longstanding questions in avalanche and snow hydrology

  4. Inventory of the Alpine Flora of Haramosh and Bagrote Valleys (Karakoram Range) District Gilgit, Gilgit-Baltistan, Pakistan

    International Nuclear Information System (INIS)

    Khan, S. W.; Abbas, Q.; Khatoon, S.; Raza, G.; Hussain, A.

    2016-01-01

    Inventorying of plant biodiversity of Haramosh and Bugrote valleys (District Gilgit, Gilgit-Baltistan, Pakistan) was done for fourteen years from 2001- 2014. The fourteen years inventorying revealed a rich plant biodiversity consisting of 232 species belonging to 106 genera and 34 families of flowering plants. The Alpine zone had 18 genera with 4 or more species; Pedicularis with 10 species was the largest genus of this zone, followed by Potentilla and Carex (each with 9 species) and Draba (8 species). Genera containing 9 or 10 species occurred only in Alpine zone. In the Alpine zone, 15 of the larger families were represented by 189 species, forming 81.46 percent of the Alpine flora. Although the highest number of species belonging to these larger families was present in the subalpine zone, but in terms of percentage their contribution was the highest in the Alpine flora. Percentage-wise the contribution of these families gradually increased from Desert zone to Alpine zone, because of their particular distribution patterns. Although the total number of species was the highest in the Subalpine zone, but in the species specific to any one zone, the Alpine zone had the highest number, that is, 96 of the total 232 species of Alpine zone were exclusively found in this zone only. Out of these 96 species specific to the Alpine zone, 53 belonged to such 22 genera that were exclusively found in the Alpine zone only. The Alpine zone was characterized by herbs and low shrubs, with Potentilla species as the dominants. A clear trend of migration of certain species both from lower to higher latitudes and altitudes was observed. The species richness index of Alpine zone however showed increasing trend probably due to species migrations towards the alpine zone. The major threats to the plant biodiversity were recognized as the deforestation and habitat loss due to over-exploitation of species, over-grazing by livestock, and climate changes due to global warming, which were

  5. Working toward integrated models of alpine plant distribution.

    Science.gov (United States)

    Carlson, Bradley Z; Randin, Christophe F; Boulangeat, Isabelle; Lavergne, Sébastien; Thuiller, Wilfried; Choler, Philippe

    2013-10-01

    Species distribution models (SDMs) have been frequently employed to forecast the response of alpine plants to global changes. Efforts to model alpine plant distribution have thus far been primarily based on a correlative approach, in which ecological processes are implicitly addressed through a statistical relationship between observed species occurrences and environmental predictors. Recent evidence, however, highlights the shortcomings of correlative SDMs, especially in alpine landscapes where plant species tend to be decoupled from atmospheric conditions in micro-topographic habitats and are particularly exposed to geomorphic disturbances. While alpine plants respond to the same limiting factors as plants found at lower elevations, alpine environments impose a particular set of scale-dependent and hierarchical drivers that shape the realized niche of species and that require explicit consideration in a modelling context. Several recent studies in the European Alps have successfully integrated both correlative and process-based elements into distribution models of alpine plants, but for the time being a single integrative modelling framework that includes all key drivers remains elusive. As a first step in working toward a comprehensive integrated model applicable to alpine plant communities, we propose a conceptual framework that structures the primary mechanisms affecting alpine plant distributions. We group processes into four categories, including multi-scalar abiotic drivers, gradient dependent species interactions, dispersal and spatial-temporal plant responses to disturbance. Finally, we propose a methodological framework aimed at developing an integrated model to better predict alpine plant distribution.

  6. Semenic Mountains’ alpine skiing area

    Directory of Open Access Journals (Sweden)

    Petru BANIAȘ

    2017-03-01

    Full Text Available The present paper presents, after a short history of alpine skiing which describes apparition, necessity, utility and universality of skiing during time, a comparative study referring to the alpine skiing domain in the Semenic Mountains area. In the paper are also presented general notions about alpine skiing methodology together with an ample description of the plateau area form Semenic Mountains, describing localization and touristic potential. Based on the SWOT analysis made for each slope, was realized a complex analysis of the entire skiing domain, an analysis which includes technical, financial, climatic and environmental aspects, along with an analysis of the marketing policy applied for the specific zone.

  7. Geomorphic determinants of species composition of alpine tundra, Glacier National Park, U.S.A.

    Science.gov (United States)

    George P. Malanson,; Bengtson, Lindsey E.; Fagre, Daniel B.

    2012-01-01

    Because the distribution of alpine tundra is associated with spatially limited cold climates, global warming may threaten its local extent or existence. This notion has been challenged, however, based on observations of the diversity of alpine tundra in small areas primarily due to topographic variation. The importance of diversity in temperature or moisture conditions caused by topographic variation is an open question, and we extend this to geomorphology more generally. The extent to which geomorphic variation per se, based on relatively easily assessed indicators, can account for the variation in alpine tundra community composition is analyzed versus the inclusion of broad indicators of regional climate variation. Visual assessments of topography are quantified and reduced using principal components analysis (PCA). Observations of species cover are reduced using detrended correspondence analysis (DCA). A “best subsets” regression approach using the Akaike Information Criterion for selection of variables is compared to a simple stepwise regression with DCA scores as the dependent variable and scores on significant PCA axes plus more direct measures of topography as independent variables. Models with geographic coordinates (representing regional climate gradients) excluded explain almost as much variation in community composition as models with them included, although they are important contributors to the latter. The geomorphic variables in the model are those associated with local moisture differences such as snowbeds. The potential local variability of alpine tundra can be a buffer against climate change, but change in precipitation may be as important as change in temperature.

  8. Alpine Windharvest: development of information base regarding potentials and the necessary technical, legal and socio-economic conditions for expanding wind energy in the Alpine Space - Digital relief analysis - Abstract of work package 7; Alpine Windharvest: development of information base regarding potentials and the necessary technical, legal and socio-economic conditions for expanding wind energy in the Alpine Space - Digitale Relief-Analyse - Zusammenfassung von Arbeitspaket 7

    Energy Technology Data Exchange (ETDEWEB)

    Schaffner, B.; Cattin, R. [Meteotest, Berne (Switzerland)

    2005-07-01

    This report describes the development work carried out by the Swiss meteorology specialists METEOTEST as part of a project carried out together with the Swiss wind-energy organisation 'Suisse Eole'. The framework for the project is the EU Interreg IIIB Alpine Space Programme, a European Community Initiative Programme funded by the European Regional Development Fund. The project investigated the use of digital relief-analysis. The series of reports describes the development and use of a basic information system to aid the investigation of the technical, legal and socio-economical conditions for the use of wind energy in the alpine area. This report presents a summary of work done on the digital relief analysis used in various stages of the project, its validation and use.

  9. Geochronologic constraints of the uplift and metamorphism along the Alpine Fault, South Island, New Zealand

    International Nuclear Information System (INIS)

    Chamberlain, C.P.; Zeitler, P.K.; Cooper, A.F.

    1995-01-01

    Geochronological studies of pegmatites and Alpine Schist exposed east of the Alpine Fault, South Island, New Zealand, reveal a complex history beginning with magmatism and metamorphism at c. 68 m.y. ago and ending with rapid uplift and exhumation in the last 5 m.y. Pegmatites exposed in the Mataketake Range give conventional U-Pb monazite and SHRIMP ion-probe zircon ages of 68 ± 2.6 Ma and 67.9 ± 2.5 Ma, respectively. Inasmuch as petrologic and isotopic data indicate that the Alpine pegmatites are melts derived from the Alpine Schist, the age of the pegmatites suggests that, at least locally, the high-grade metamorphism is considerably younger than previously assumed. We tentatively suggest that metamorphism, in at least some areas of the Alpine Schist, may be associated with Late Cretaceous transtension rather than resulting from the consequences of collision during the Rangitata Orogeny. 40 Ar/ 39 Ar studies of hornblendes from the Alpine Schist, collected from the Haast River to the Franz Josef Glacier area, reveal highly disturbed spectra. Despite this complexity, these analyses define a systematic decrease in ages both across-strike toward the Alpine Fault (Haast River traverse) and northwards along-strike towards Mt Cook. This pattern of decreasing 40 Ar/ 39 Ar hornblende ages is also observed in lower closure temperature systems such as zircon and apatite fission-track ages. We interpret the decrease in ages toward the fault to be the result of deeper exhumation in the immediate vicinity of the Alpine Fault, whereas we interpret the northward younging of fault-proximal samples to be a result of both more recent and possibly more extensive exhumation than occurred in areas to the south. (author). 55 refs., 4 figs., 2 tabs

  10. How cushion communities are maintained in alpine ecosystems: A review and case study on alpine cushion plant reproduction

    Directory of Open Access Journals (Sweden)

    Jianguo Chen

    2017-08-01

    Full Text Available Cushion species occur in nearly all alpine environments worldwide. In past decades, the adaptive and ecosystem-engineering roles of such highly specialized life forms have been well studied. However, the adaptive strategies responsible for cushion species reproductive success and maintenance in severe alpine habitats remain largely unclear. In this study, we reviewed the current understanding of reproductive strategies and population persistence in alpine cushion species. We then present a preliminary case study on the sexual reproduction of Arenaria polytrichoides (Caryophyllaceae, a typical cushion species inhabiting high elevations of the Himalaya Hengduan Mountains, which is a hotspot for diversification of cushion species. Finally, we highlight the limitations of our current understanding of alpine cushion species reproduction and propose future directions for study.

  11. Geothermal state of the deep Western Alpine Molasse Basin, France-Switzerland

    OpenAIRE

    Chelle-Michou, C; Do Couto, D; Moscariello, A; Renard, Philippe; Rusillon, E

    2018-01-01

    Over the last few years the Western Alpine Molasse Basin (WAMB) has been attracting large institutional, industrial and scientific interest to evaluate the feasibility of geothermal energy production. However, the thermal state of the basin, which is instrumental to the development of such geothermal projects, has remained to date poorly known. Here, we compile and correct temperature measurements (mostly bottom hole temperature) from 26 existing well data mostly acquired during former hydroc...

  12. Relation between extinction and assisted colonization of plants in the arctic-alpine and boreal regions.

    Science.gov (United States)

    Pykälä, Juha

    2017-06-01

    Assisted colonization of vascular plants is considered by many ecologists an important tool to preserve biodiversity threatened by climate change. I argue that assisted colonization may have negative consequences in arctic-alpine and boreal regions. The observed slow movement of plants toward the north has been an argument for assisted colonization. However, these range shifts may be slow because for many plants microclimatic warming (ignored by advocates of assisted colonization) has been smaller than macroclimatic warming. Arctic-alpine and boreal plants may have limited possibilities to disperse farther north or to higher elevations. I suggest that arctic-alpine species are more likely to be driven to extinction because of competitive exclusion by southern species than by increasing temperatures. If so, the future existence of arctic-alpine and boreal flora may depend on delaying or preventing the migration of plants toward the north to allow northern species to evolve to survive in a warmer climate. In the arctic-alpine region, preventing the dispersal of trees and shrubs may be the most important method to mitigate the negative effects of climate change. The purported conservation benefits of assisted colonization should not be used to promote the migration of invasive species by forestry. © 2016 Society for Conservation Biology.

  13. [Effects of altitudes on soil microbial biomass and enzyme activity in alpine-gorge regions.

    Science.gov (United States)

    Cao, Rui; Wu, Fu Zhong; Yang, Wan Qin; Xu, Zhen Feng; Tani, Bo; Wang, Bin; Li, Jun; Chang, Chen Hui

    2016-04-22

    In order to understand the variations of soil microbial biomass and soil enzyme activities with the change of altitude, a field incubation was conducted in dry valley, ecotone between dry valley and mountain forest, subalpine coniferous forest, alpine forest and alpine meadow from 1563 m to 3994 m of altitude in the alpine-gorge region of western Sichuan. The microbial biomass carbon and nitrogen, and the activities of invertase, urease and acid phosphorus were measured in both soil organic layer and mineral soil layer. Both the soil microbial biomass and soil enzyme activities showed the similar tendency in soil organic layer. They increased from 2158 m to 3028 m, then decreased to the lowest value at 3593 m, and thereafter increased until 3994 m in the alpine-gorge region. In contrast, the soil microbial biomass and soil enzyme activities in mineral soil layer showed the trends as, the subalpine forest at 3028 m > alpine meadow at 3994 m > montane forest ecotone at 2158 m > alpine forest at 3593 m > dry valley at 1563 m. Regardless of altitudes, soil microbial biomass and soil enzyme activities were significantly higher in soil organic layer than in mineral soil layer. The soil microbial biomass was significantly positively correlated with the activities of the measured soil enzymes. Moreover, both the soil microbial biomass and soil enzyme activities were significantly positively correlated with soil water content, organic carbon, and total nitrogen. The activity of soil invertase was significantly positively correlated with soil phosphorus content, and the soil acid phosphatase was so with soil phosphorus content and soil temperature. In brief, changes in vegetation and other environmental factors resulting from altitude change might have strong effects on soil biochemical properties in the alpine-gorge region.

  14. Response of alpine vegetation growth dynamics to snow cover phenology on the Tibetan Plateau

    Science.gov (United States)

    Wang, X.; Wu, C.

    2017-12-01

    Alpine vegetation plays a crucial role in global energy cycles with snow cover, an essential component of alpine land cover showing high sensitivity to climate change. The Tibetan Plateau (TP) has a typical alpine vegetation ecosystem and is rich of snow resources. With global warming, the snow of the TP has undergone significant changes that will inevitably affect the growth of alpine vegetation, but observed evidence of such interaction is limited. In particular, a comprehensive understanding of the responses of alpine vegetation growth to snow cover variability is still not well characterized on TP region. To investigate this, we calculated three indicators, the start (SOS) and length (LOS) of growing season, and the maximum of normalized difference vegetation index (NDVImax) as proxies of vegetation growth dynamics from the Moderate Resolution Imaging Spectroradiometer (MODIS) data for 2000-2015. Snow cover duration (SCD) and melt (SCM) dates were also extracted during the same time frame from the combination of MODIS and the Interactive Multi-sensor Snow and Ice Mapping System (IMS) data. We found that the snow cover phenology had a strong control on alpine vegetation growth dynamics. Furthermore, the responses of SOS, LOS and NDVImax to snow cover phenology varied among plant functional types, eco-geographical zones, and temperature and precipitation gradients. The alpine steppes showed a much stronger negative correlation between SOS and SCD, and also a more evidently positive relationship between LOS and SCD than other types, indicating a longer SCD would lead to an earlier SOS and longer LOS. Most areas showed positive correlation between SOS and SCM, while a contrary response was also found in the warm but drier areas. Both SCD and SCM showed positive correlations with NDVImax, but the relationship became weaker with the increase of precipitation. Our findings provided strong evidences between vegetation growth and snow cover phenology, and changes in

  15. Responses of soil CO2 fluxes to short-term experimental warming in alpine steppe ecosystem, Northern Tibet.

    Science.gov (United States)

    Lu, Xuyang; Fan, Jihui; Yan, Yan; Wang, Xiaodan

    2013-01-01

    Soil carbon dioxide (CO2) emission is one of the largest fluxes in the global carbon cycle. Therefore small changes in the size of this flux can have a large effect on atmospheric CO2 concentrations and potentially constitute a powerful positive feedback to the climate system. Soil CO2 fluxes in the alpine steppe ecosystem of Northern Tibet and their responses to short-term experimental warming were investigated during the growing season in 2011. The results showed that the total soil CO2 emission fluxes during the entire growing season were 55.82 and 104.31 g C m(-2) for the control and warming plots, respectively. Thus, the soil CO2 emission fluxes increased 86.86% with the air temperature increasing 3.74°C. Moreover, the temperature sensitivity coefficient (Q 10) of the control and warming plots were 2.10 and 1.41, respectively. The soil temperature and soil moisture could partially explain the temporal variations of soil CO2 fluxes. The relationship between the temporal variation of soil CO2 fluxes and the soil temperature can be described by exponential equation. These results suggest that warming significantly promoted soil CO2 emission in the alpine steppe ecosystem of Northern Tibet and indicate that this alpine ecosystem is very vulnerable to climate change. In addition, soil temperature and soil moisture are the key factors that controls soil organic matter decomposition and soil CO2 emission, but temperature sensitivity significantly decreases due to the rise in temperature.

  16. Intra-articular temperatures of the knee in sports – An in-vivo study of jogging and alpine skiing

    Directory of Open Access Journals (Sweden)

    Cerulli Guiliano

    2008-04-01

    Full Text Available Abstract Background Up to date, no information exists about the intra-articular temperature changes of the knee related to activity and ambient temperature. Methods In 6 healthy males, a probe for intra-articular measurement was inserted into the notch of the right knee. Each subject was jogging on a treadmill in a closed room at 19°C room temperature and skiing in a ski resort at -3°C outside temperature for 60 minutes. In both conditions, temperatures were measured every fifteen minutes intra-articulary and at the skin surface of the knee. A possible influence on joint function and laxity was evaluated before and after activity. Statistical analysis of intra-articular and skin temperatures was done using nonparametric Wilcoxon's sign rank sum test and Mann-Whitney's-U-Test. Results Median intra-articular temperatures increased from 31.4°C before activity by 2.1°C, 4°C, 5.8°C and 6.1°C after 15, 30, 45 and 60 min of jogging (all p ≤ 0.05. Median intra-articular temperatures dropped from 32.2°C before activity by 0.5°C, 1.9°C, 3.6°C and 1.1°C after 15, 30, 45 and 60 min of skiing (all n.s.. After 60 minutes of skiing (jogging, the median intra-articular temperature was 19.6% (8.7% higher than the skin surface temperature at the knee. Joint function and laxity appeared not to be different before and after activity within both groups. Conclusion This study demonstrates different changes of intra-articular and skin temperatures during sports in jogging and alpine skiing and suggests that changes are related to activity and ambient temperature.

  17. Large-displacement, hydrothermal frictional properties of DFDP-1 fault rocks, Alpine Fault, New Zealand: Implications for deep rupture propagation.

    Science.gov (United States)

    Niemeijer, A R; Boulton, C; Toy, V G; Townend, J; Sutherland, R

    2016-02-01

    The Alpine Fault, New Zealand, is a major plate-bounding fault that accommodates 65-75% of the total relative motion between the Australian and Pacific plates. Here we present data on the hydrothermal frictional properties of Alpine Fault rocks that surround the principal slip zones (PSZ) of the Alpine Fault and those comprising the PSZ itself. The samples were retrieved from relatively shallow depths during phase 1 of the Deep Fault Drilling Project (DFDP-1) at Gaunt Creek. Simulated fault gouges were sheared at temperatures of 25, 150, 300, 450, and 600°C in order to determine the friction coefficient as well as the velocity dependence of friction. Friction remains more or less constant with changes in temperature, but a transition from velocity-strengthening behavior to velocity-weakening behavior occurs at a temperature of T  = 150°C. The transition depends on the absolute value of sliding velocity as well as temperature, with the velocity-weakening region restricted to higher velocity for higher temperatures. Friction was substantially lower for low-velocity shearing ( V  Fault rocks at higher temperatures may pose a barrier for rupture propagation to deeper levels, limiting the possible depth extent of large earthquakes. Our results highlight the importance of strain rate in controlling frictional behavior under conditions spanning the classical brittle-plastic transition for quartzofeldspathic compositions.

  18. Soil Fauna Affects Dissolved Carbon and Nitrogen in Foliar Litter in Alpine Forest and Alpine Meadow.

    Science.gov (United States)

    Liao, Shu; Yang, Wanqin; Tan, Yu; Peng, Yan; Li, Jun; Tan, Bo; Wu, Fuzhong

    2015-01-01

    Dissolved organic carbon (DOC) and total dissolved nitrogen (TDN) are generally considered important active biogeochemical pools of total carbon and nitrogen. Many studies have documented the contributions of soil fauna to litter decomposition, but the effects of the soil fauna on labile substances (i.e., DOC and TDN) in litter during early decomposition are not completely clear. Therefore, a field litterbag experiment was carried out from 13th November 2013 to 23rd October 2014 in an alpine forest and an alpine meadow located on the eastern Tibetan Plateau. Litterbags with different mesh sizes were used to provide access to or prohibit the access of the soil fauna, and the concentrations of DOC and TDN in the foliar litter were measured during the winter (the onset of freezing, deep freezing and thawing stage) and the growing season (early and late). After one year of field incubation, the concentration of DOC in the litter significantly decreased, whereas the TDN concentration in the litter increased. Similar dynamic patterns were detected under the effects of the soil fauna on both DOC and TDN in the litter between the alpine forest and the alpine meadow. The soil fauna showed greater positive effects on decreasing DOC concentration in the litter in the winter than in the growing season. In contrast, the dynamics of TND in the litter were related to seasonal changes in environmental factors, rather than the soil fauna. In addition, the soil fauna promoted a decrease in litter DOC/TDN ratio in both the alpine forest and the alpine meadow throughout the first year of decomposition, except for in the late growing season. These results suggest that the soil fauna can promote decreases in DOC and TDN concentrations in litter, contributing to early litter decomposition in these cold biomes.

  19. Seasonal variations in carbon dioxide exchange in an alpine wetland meadow on the Qinghai-Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    L. Zhao

    2010-04-01

    Full Text Available Alpine wetland meadow could functions as a carbon sink due to it high soil organic content and low decomposition. However, the magnitude and dynamics of carbon stock in alpine wetland ecosystems are not well quantified. Therefore, understanding how environmental variables affect the processes that regulate carbon fluxes in alpine wetland meadow on the Qinghai-Tibetan Plateau is critical. To address this issue, Gross Primary Production (GPP, Ecosystem Respiration (Reco, and Net Ecosystem Exchange (NEE were examined in an alpine wetland meadow using the eddy covariance method from October 2003 to December 2006 at the Haibei Research Station of the Chinese Academy of Sciences. Seasonal patterns of GPP and Reco were closely associated with leaf area index (LAI. The Reco showed a positive exponential to soil temperature and relatively low Reco occurred during the non-growing season after a rain event. This result is inconsistent with the result observed in alpine shrubland meadow. In total, annual GPP were estimated at 575.7, 682.9, and 630.97 g C m−2 in 2004, 2005, and 2006, respectively. Meanwhile, the Reco were equal to 676.8, 726.4, 808.2 g C m−2, and thus the NEE were 101.1, 44.0 and 173.2 g C m−2. These results indicated that the alpine wetland meadow was a moderately source of carbon dioxide (CO2. The observed carbon dioxide fluxes in the alpine wetland meadow were higher than other alpine meadow such as Kobresia humilis meadow and shrubland meadow.

  20. Larch dwarf mistletoe not found on alpine larch

    Science.gov (United States)

    Robert L. Mathiasen; Brian W. Geils; Clinton E. Carlson; Frank G. Hawksworth

    1995-01-01

    Reports of larch dwarf mistletoe parasitizing alpine larch are based on two collections of this host/parasite combination made by J.R. Weir in Montana during the early 1900s. Examination of host material from these collections indicates that the host is western larch, not alpine larch as previously reported. Attempts to locate larch dwarf mistletoe on alpine larch were...

  1. Microsatellite Markers for the Chameleon Grasshopper (Kosciuscola tristis (Orthoptera: Acrididae, an Australian Alpine Specialist

    Directory of Open Access Journals (Sweden)

    Ange-Marie Risterucci

    2012-09-01

    Full Text Available A set of polymorphic loci was characterised using an enrichment library for the Australian alpine specialist, the chameleon grasshopper (Kosciuscola tristis, an atypical grasshopper known for its remarkable temperature-controlled colour change. The number of alleles per locus ranged from three to 20 and observed heterozygosity from 0.16 to 0.76. These are the first microsatellite markers for a non-endangered Australian alpine animal and will inform questions of gene flow across the sky islands of this unique and threatened region.

  2. Fine Root Abundance and Dynamics of Stone Pine (Pinus cembra) at the Alpine Treeline Is Not Impaired by Self-shading.

    Science.gov (United States)

    Kubisch, Petra; Leuschner, Christoph; Coners, Heinz; Gruber, Andreas; Hertel, Dietrich

    2017-01-01

    Low temperatures are crucial for the formation of the alpine treeline worldwide. Since soil temperature in the shade of tree canopies is lower than in open sites, it was assumed that self-shading may impair the trees' root growth performance. While experiments with tree saplings demonstrate root growth impairment at soil temperatures below 5-7°C, field studies exploring the soil temperature - root growth relationship at the treeline are missing. We recorded soil temperature and fine root abundance and dynamics in shaded and sun-exposed areas under canopies of isolated Pinus cembra trees at the alpine treeline. In contrast to the mentioned assumption, we found more fine root biomass and higher fine root growth in colder than in warmer soil areas. Moreover, colder areas showed higher fine root turnover and thus lower root lifespan than warmer places. We conclude that P. cembra balances enhanced fine root mortality in cold soils with higher fine root activity and by maintaining higher fine root biomass, most likely as a response to shortage in soil resource supply. The results from our study highlight the importance of in situ measurements on mature trees to understand the fine root response and carbon allocation pattern to the thermal growth conditions at the alpine treeline.

  3. Alpine vegetation communities and the alpine-treeline ecotone boundary in New England as biomonitors for climate change

    Science.gov (United States)

    Kenneth D. Kimball; Douglas M. Weihrauch

    2000-01-01

    This study mapped and analyzed the alpine-treeline ecotone (ATE) boundary and alpine plant communities on the Presidential Range, New Hampshire and Mount Katahdin, Maine. These are sensitive biomonitoring parameters for plant community responses to climatic change. The ATE boundary spans a considerable elevational range, suggesting that shorter growing seasons with...

  4. Seedling Regeneration in the Alpine Treeline Ecotone: Comparison of Wood Microsites and Adjacent Soil Substrates

    Directory of Open Access Journals (Sweden)

    Adelaide Chapman Johnson

    2016-11-01

    Full Text Available Although climate warming is generally expected to facilitate upward advance of forests, conifer seedling regeneration and survival may be hindered by low substrate moisture, high radiation, and both low and high snow accumulation. To better understand substrate-related factors promoting regeneration in the alpine treeline ecotone, this study compared 2 substrates supporting conifer seedlings: rotten downed wood and adjacent soil. Study locations, each with 3 levels of incoming radiation, were randomly selected at forest line–alpine meadow borders in Pacific Northwest wilderness areas extending along an east–west precipitation gradient. Associations among substrate type, seedling density, radiation, site moisture, site temperature, plant water potential, and plant stomatal conductance were assessed. Wood microsites, flush with the ground and supporting Abies spp conifer seedlings, extended up to 20 m into alpine meadows from the forest line. Although wood microsites thawed later in the spring and froze earlier in the fall, they had warmer summer temperatures, greater volumetric water content, and more growing degree hours, and seedlings growing on wood had higher water potentials than seedlings growing on adjacent soil. At drier eastern sites, there was a positive relationship between seedling density and volumetric water content. Further, there was a positive relationship between seedling stomatal conductance and volumetric water content. Our study indicates that in the Pacific Northwest. and likely elsewhere, seedlings benefit from wood microsites, which provide greater water content. Given predictions of increased summer drought in some locations globally, wood microsites at forest line–alpine meadows and forest line–grasslands borders may become increasingly important for successful conifer regeneration.

  5. Semaine alpine 2008 : innover (dans) les Alpes

    OpenAIRE

    Bourdeau, Philippe; Bourdeau, Philippe; Corneloup, Jean; Corneloup, Jean; Finger-Stich, Andréa; Finger-Stich, Andréa; Giraut, Frédéric; Giraut, Frédéric; Kohler, Yann; Kohler, Yann; Macchiavelli, Andrea; Macchiavelli, Andrea; Scheurer, Thomas; Scheurer, Thomas; Ullrich, Aurelia

    2009-01-01

    Ce premier dossier en ligne se penche sur une question de grande actualité : l’innovation, pour interroger les conceptions et mises en œuvre de démarches innovantes dans les contextes montagnards. Ces textes sont issus de la « Semaine alpine », qui s’est déroulée en juin 2008 à l’Argentière-La Bessée, dans les Hautes-Alpes (France). Ces « Semaines alpines », en alternance avec les « Forums alpins », rassemblent tous les deux ans des chercheurs et des acteurs locaux de l’ensemble de l’arc alp...

  6. Glucose homeostasis and cardiovascular disease biomarkers in older alpine skiers

    DEFF Research Database (Denmark)

    Dela, F; Niederseer, David; Patsch, Wolfgang

    2011-01-01

    Alpine skiing and ski training involves elements of static and dynamic training, and may therefore improve insulin sensitivity. Healthy men and women who where beginners/intermediate level of alpine skiing, were studied before (Pre) and immediately after (Post) 12 weeks of alpine ski training. Af...

  7. Climatic change of summer temperature and precipitation in the Alpine region - a statistical-dynamical assessment

    Energy Technology Data Exchange (ETDEWEB)

    Heimann, D.; Sept, V.

    1998-12-01

    Climatic changes in the Alpine region due to increasing greenhouse gas concentrations are assessed by using statistical-dynamical downscaling. The downscaling procedure is applied to two 30-year periods (1971-2000 and 2071-2100, summer months only) of the output of a transient coupled ocean/atmosphere climate scenario simulation. The downscaling results for the present-day climate are in sufficient agreement with observations. The estimated regional climate change during the next 100 years shows a general warming. The mean summer temperatures increase by about 3 to more than 5 Kelvin. The most intense climatic warming is predicted in the western parts of the Alps. The amount of summer precipitation decreases in most parts of central Europe by more than 20 percent. Only over the Adriatic area and parts of eastern central Europe an increase in precipitation is simulated. The results are compared with observed trends and results of regional climate change simulations of other authors. The observed trends and the majority of the simulated trends agree with our results. However, there are also climate change estimates which completely contradict with ours. (orig.) 29 refs.

  8. Transformation of graphite by tectonic and hydrothermal processes in an active plate boundary fault zone, Alpine Fault, New Zealand

    Science.gov (United States)

    Kirilova, Matina; Toy, Virginia; Timms, Nicholas; Halfpenny, Angela; Menzies, Catriona; Craw, Dave; Rooney, Jeremy; Giorgetti, Carolina

    2017-04-01

    Graphite is a material with one of the lowest frictional strengths, with coefficient of friction of 0.1 and thus in natural fault zones it may act as a natural solid lubricant. Graphitization, or the transformation of organic matter (carbonaceous material, or CM) into crystalline graphite, is induced by compositional and structural changes during diagenesis and metamorphism. The supposed irreversible nature of this process has allowed the degree of graphite crystallinity to be calibrated as an indicator of the peak temperatures reached during progressive metamorphism. We examine processes of graphite emplacement and deformation in the Alpine Fault Zone, New Zealand's active continental tectonic plate boundary. Raman spectrometry indicates that graphite in the distal, amphibolite-facies Alpine Schist, which experienced peak metamorphic temperatures up to 640 ◦C, is highly crystalline and occurs mainly along grain boundaries within quartzo-feldspathic domains. The subsequent mylonitisation in the Alpine Fault Zone resulted in progressive reworking of CM under lower temperature conditions (500◦C-600◦C) in a structurally controlled environment, resulting in spatial clustering in lower-strain protomylonites, and further foliation-alignment in higher-strain mylonites. Subsequent brittle deformation of the mylonitised schists resulted in cataclasites that contain over three-fold increase in the abundance of graphite than mylonites. Furthermore, cataclasites contain graphite with two different habits: highly-crystalline, foliated forms that are inherited mylonitic graphite; and lower-crystallinity, less mature patches of finer-grained graphite. The observed graphite enrichment and the occurrence of poorly-organised graphite in the Alpine Fault cataclasites could result from: i) hydrothermal precipitation from carbon-supersaturated fluids; and/or ii) mechanical degradation by structural disordering of mylonitic graphite combined with strain-induced graphite

  9. Spatial distribution and environmental analysis of the alpine flora in the Pyrenees

    Directory of Open Access Journals (Sweden)

    D. Gómez

    2017-09-01

    Full Text Available On the basis of the digital edition of the “Atlas of the vascular flora of the Pyrenees” (www.florapyrenaea. org, the alpine flora of this mountain range is delimited in order to know its diversity and the different patterns of its spatial distribution, along with some other environmental characteristics. The Pyrenean alpine flora is made up of 645 taxa (630 species and 15 subspecies. All the administrative regions harbour more than 60% of the alpine plants, with Catalonia and Aragon reaching the highest values (around 90%. Along the altitudinal gradient, the highest plant diversity is found between 2300 and 2600 m. a. s. l., although 25% of the total alpine flora goes beyond 3000 m. On the other hand, a remarkable number of alpine plants live in the lowlands, and thus more than 300 alpine plants can be found below 1500 m. The average altitude range of the alpine plants is 1369 m, 300 m wider than that observed for the whole Pyrenean flora. Life-forms, habitat distribution and habitat naturalness of alpine plants are significantly different from those of the whole Pyrenean flora. Distribution of abundance categories also shows values of rarity significantly lower among alpine plants than for the whole flora. More than half the Pyrenean endemic plants are present in the alpine flora. High diversity and wide ecological amplitude of the alpine flora must be taken into account either when considering vulnerability of alpine plants facing “global change” or when addressing conservation policies for the whole Pyrenees from a common perspective.

  10. Climate change and mountain Grouse: recent evidences from alpine habitats

    Directory of Open Access Journals (Sweden)

    Brugnoli A

    2013-02-01

    Full Text Available Current climate change, referring as well to the observed rain and temperature patterns as to the increased frequency and intensity of extreme weather conditions, has a deep influence on biotic communities and, in particular, on mountain Grouse. These species show great adaptation to coldness, are highly sedentary and have quite “strict” ecological requirements, when it deals with habitat selection. Moreover, their alpine ranges are dangerously marginal to the main distribution areas, which increases the risk of dramatic changes in occurrence, demography and ecology. However, not all the species will predictably be exposed in the same way to the menace of climate change over the next 50-100 years. This article gives a brief review of the main data acquired in the alpine environment in this matter. It also underlines the utmost need to proceed with research and monitoring activities, in order to effectively adapt and manage conservation strategies on mid-long terms.

  11. Impact of Climate Change on Temperate and Alpine Grasslands in China during 1982–2006

    Directory of Open Access Journals (Sweden)

    Xiangjin Shen

    2015-01-01

    Full Text Available Based on GIMMS NDVI and climate data from 1982 to 2006, this study analyzed the impact of climate change on grassland in China. During the growing season, there were significant effects of precipitation on the growth of all the grassland types (P<0.05, except for meadow vegetation. For the air temperatures, there existed asymmetrical effects of maximum temperature (Tmax and minimum temperature (Tmin on grassland vegetation, especially for the temperate grasslands and alpine steppe. The growing season NDVI correlated negatively with Tmax but positively with Tmin for temperate grasslands. Seasonally, these opposite effects were only observed in summer. For alpine steppe, the growing season NDVI correlated positively with Tmax but negatively with Tmin, and this pattern of asymmetrical responses was only obvious in spring and autumn. Under the background of global asymmetric warming, more attention should be paid to this asymmetric response of grassland vegetation to daytime and night-time warming, especially when we want to predict the productivity of China’s grasslands in the future.

  12. Winter frost resistance of Pinus cembra measured in situ at the alpine timberline as affected by temperature conditions.

    Science.gov (United States)

    Buchner, Othmar; Neuner, Gilbert

    2011-11-01

    Winter frost resistance (WFR), midwinter frost hardening and frost dehardening potential of Pinus cembra L. were determined in situ by means of a novel low-temperature freezing system at the alpine timberline ecotone (1950 m a.s.l., Mt Patscherkofel, Innsbruck, Austria). In situ liquid nitrogen (LN₂)-quenching experiments should check whether maximum WFR of P. cembra belonging to the frost hardiest conifer group, being classified in US Department of Agriculture climatic zone 1, suffices to survive dipping into LN₂ (-196 °C). Viability was assessed in a field re-growth test. Maximum in situ WFR (LT₅₀) of leaves was frost hardening treatment (12 days at -20 °C followed by 3 days at -50 °C) to induce maximum WFR. Temperature treatments applied in the field significantly affected the actual WFR. In January a frost hardening treatment (21 days at -20 °C) led to a significant increase of WFR (buds: -62 °C to frost dehardening (buds: -32.6 °C to -10.2 °C; leaves: -32.7 to -16.4 °C) followed by significantly earlier bud swelling and burst in late winter. Strikingly, both temperature treatments, either increased air temperature (+10.1 °C) or increased soil temperature (+6.5 °C), were similarly effective. This high readiness to frost harden and deharden in winter in the field must be considered to be of great significance for future winter survival of P. cembra. Determination of WFR in field re-growth tests appears to be a valuable tool for critically judging estimates of WFR obtained on detached twigs in an ecological context.

  13. The relative role of dispersal and local interactions for alpine plant community diversity under simulated climate warming

    Energy Technology Data Exchange (ETDEWEB)

    Klanderud, K.; Totland, Oe. [Norwegian Univ. of Life Science, Dept. of Ecology and Natural Resource Management, Aas (Norway)

    2007-08-15

    Most studies on factors determining diversity are conducted in temperate or warm regions, whereas studies in climatically harsh and low productivity areas, such as alpine regions, are rare. We examined the relative roles of seed availability and different biotic and abiotic factors for the diversity of an alpine plant community in southern Norway. Furthermore, because climate warming is predicted to be an important driver of alpine species diversity, we assessed how the relative impacts of dispersal and local interactions on diversity might change under experimental warming (open top chambers, OTCs). Addition of seeds from 27 regional species increased community diversity. The establishment of the species was negatively related both to the diversity of the existing system and the cover of the abundant dwarf shrub Dryas octopetala. These results show that both species dispersal limitation and local biotic interactions are important factors for alpine plant community diversity. Despite relatively harsh environmental conditions and low productivity, competition from the resident vegetation appeared to have a greater role for species establishment and diversity than facilitation and experimental warming. Higher temperature appeared to increase the negative relationship between resident species diversity and species establishment. This may suggest that climate warming can increase the role of interspecific competition for alpine plant community structure, and thus alter the long-term effects of biotic interactions on diversity. (au)

  14. The relationship between soil physical properties and alpine plant diversity on Qinghai-Tibet Plateau

    Directory of Open Access Journals (Sweden)

    Lin Tang

    2015-04-01

    Full Text Available Through a large-scale research, we examined the heterogeneity of soil properties and plant diversity, as well as their relationships across alpine grassland types on Qinghai-Tibet Plateau. The soil pH and EC value increased with the constant deepening of the soil in all the three alpine grassland types which in order of absolute value in every soil layer were alpine desert steppe, alpine steppe and alpine meadow. Among the three grassland types, the alpine meadow possessed the highest SM but the lowest SBD. For plant diversity, alpine meadow was the highest, alpine desert steppe ranked the second and alpine steppe was the last. SM and SBD were the highest influential soil physical properties to species richness, but with opposite effects.

  15. Dendrochronological potential of the alpine shrub Rhododendron nivale on the south-eastern Tibetan Plateau.

    Science.gov (United States)

    Liang, Eryuan; Eckstein, Dieter

    2009-09-01

    Shrubs and dwarf shrubs are wider spread on the Tibetan Plateau than trees and hence offer a unique opportunity to expand the present dendrochronological network into extreme environments beyond the survival limit of trees. Alpine shrublands on the Tibetan Plateau are characterized by rhododendron species. The dendrochronological potential of one alpine rhododendron species and its growth response to the extreme environment on the south-east Tibetan Plateau were investigated. Twenty stem discs of the alpine snowy rhododendron (Rhododendron nivale) were collected close to the tongue of the Zuoqiupu Glacier in south-east Tibet, China. The skeleton plot technique was used for inter-comparison between samples to detect the growth pattern of each stem section. The ring-width chronology was developed by fitting a negative exponential function or a straight line of any slope. Bootstrapping correlations were calculated between the standard chronology and monthly climate data. The wood of snowy rhododendron is diffuse-porous with evenly distributed small-diameter vessels. It has well-defined growth rings. Most stem sections can be visually and statistically cross-dated. The resulting 75-year-long standard ring-width chronology is highly correlated with a timberline fir chronology about 200 km apart, providing a high degree of confidence in the cross-dating. The climate/growth association of alpine snowy rhododendron and of this timberline fir is similar, reflecting an impact of monthly mean minimum temperatures in November of the previous year and in July during the year of ring formation. The alpine snowy rhododendron offers new research directions to investigate the environmental history of the Tibetan Plateau in those regions where up to now there was no chance of applying dendrochronology.

  16. Snowmelt runoff from northern alpine tundra hillslopes: major processes and methods of simulation

    Directory of Open Access Journals (Sweden)

    W. L. Quinton

    2004-01-01

    Full Text Available In northern alpine tundra, large slope gradients, late-lying snow drifts and shallow soils overlying impermeable substrates all contribute to large hillslope runoff volumes during the spring freshet. Understanding the processes and pathways of hillslope runoff in this environment is, therefore, critical to understanding the water cycle within northern alpine tundra ecosystems. This study: (a presents the results of a field study on runoff from a sub-alpine tundra hillslope with a large snow drift during the spring melt period; (b identifies the major runoff processes that must be represented in simulations of snowmelt runoff from sub-alpine tundra hillslopes; (c describes how these processes can be represented in a numerical simulation model; and d compares field measurements with modelled output to validate or refute the conceptual understanding of runoff generation embodied in the process simulations. The study was conducted at Granger Creek catchment, 15 km south of Whitehorse, Yukon Territory, Canada, on a north-facing slope below a late-lying snow drift. For the freshet period, the major processes to be represented in a runoff model include the rate of meltwater release from the late-lying snowdrift, the elevation and thickness of the saturated layer, the magnitude of the soil permeability and its variation with depth. The daily cycle of net all-wave radiation was observed to drive the diurnal pulses of melt water from the drift; this, in turn, was found to control the daily pulses of flow through the hillslope subsurface and in the stream channel. The computed rate of frost table lowering fell within the observed values; however, there was wide variation among the measured frost table depths. Spatial variability in frost table depth would result in spatial variabilities in saturated layer depth and thickness, which would, in turn, produce variations in subsurface flow rates over the slope, including preferential flowpaths. Keywords

  17. [Litter decomposition and soil faunal diversity of two understory plant debris in the alpine timberline ecotone of western Sichuan in a snow cover season].

    Science.gov (United States)

    He, Run-lian; Chen, Ya-mei; Deng, Chang-chun; Yan, Wan-qin; Zhang, Jian; Liu, Yang

    2015-03-01

    In order to understand the relationship between litter decomposition and soil fauna diversity during snow cover season, litterbags with plant debris of Actinothuidium hookeri, Cystopteris montana, two representative understory plants in the alpine timberline ecotone, and their mixed litter were incubated in the dark coniferous forest, timberline and alpine meadow, respectively. After a snow cover season, the mass loss and soil fauna in litterbags were investigated. After decomposition with a snow cover season, alpine meadow showed the highest mass loss of plant debris in comparison with coniferous forest and timberline, and the mass loss of A. hookeri was more significant. The mixture of two plants debris accelerated the mass loss, especially in the timberline. A total of 968 soil invertebrates, which belonged to 5 classes, 10 orders and 35 families, were captured in litterbags. Acarina and Collembola were the dominant groups in plant debris. The numbers of individuals and groups of soil faunal communities in litter of timberline were higher than those of alpine meadow and dark coniferous forest. Canonical correspondence analysis (CCA) indicated that the groups of soil animals were related closely with the average temperature, and endemic species such as Isoptera and Geophilomorpha were observed only in coniferous forest, while Hemiptera and Psocoptera only in.the alpine meadow. The diversity of soil faunal community was more affected by plant debris varieties in the timberline than in the coniferous forest and alpine meadow. Multiple regression analysis indicated that the average temperature and snow depth explained 30.8% of the variation of litter mass loss rate, soil animals explained 8.3%, and altogether explained 34.1%. Snow was one of the most critical factors impacting the decomposition of A. hookeri and C. montana debris in the alpine timberline ecotone.

  18. Validation of Land Surface Temperature from Sentinel-3

    Science.gov (United States)

    Ghent, D.

    2017-12-01

    One of the main objectives of the Sentinel-3 mission is to measure sea- and land-surface temperature with high-end accuracy and reliability in support of environmental and climate monitoring in an operational context. Calibration and validation are thus key criteria for operationalization within the framework of the Sentinel-3 Mission Performance Centre (S3MPC). Land surface temperature (LST) has a long heritage of satellite observations which have facilitated our understanding of land surface and climate change processes, such as desertification, urbanization, deforestation and land/atmosphere coupling. These observations have been acquired from a variety of satellite instruments on platforms in both low-earth orbit and in geostationary orbit. Retrieval accuracy can be a challenge though; surface emissivities can be highly variable owing to the heterogeneity of the land, and atmospheric effects caused by the presence of aerosols and by water vapour absorption can give a bias to the underlying LST. As such, a rigorous validation is critical in order to assess the quality of the data and the associated uncertainties. Validation of the level-2 SL_2_LST product, which became freely available on an operational basis from 5th July 2017 builds on an established validation protocol for satellite-based LST. This set of guidelines provides a standardized framework for structuring LST validation activities. The protocol introduces a four-pronged approach which can be summarised thus: i) in situ validation where ground-based observations are available; ii) radiance-based validation over sites that are homogeneous in emissivity; iii) intercomparison with retrievals from other satellite sensors; iv) time-series analysis to identify artefacts on an interannual time-scale. This multi-dimensional approach is a necessary requirement for assessing the performance of the LST algorithm for the Sea and Land Surface Temperature Radiometer (SLSTR) which is designed around biome

  19. Tree Height-Diameter Relationships in the Alpine Treeline Ecotone Compared with Those in Closed Forests on Changbai Mountain, Northeastern China

    Directory of Open Access Journals (Sweden)

    Xiaoyu Wang

    2017-04-01

    Full Text Available Height-diameter relationship is one of the most important stature characteristics of trees. It will change with climatic conditions because height and diameter growth displays different sensitivities to climatic factors such as temperature. Detecting and understanding changes in the stature of trees growing along altitudinal gradients up to their upper limits can help us to better understand the adaptation strategy of trees under global warming conditions. On Changbai Mountain in northeastern China, height-diameter datasets were collected for 2723 Erman’s birch (Betula ermanii Cham. in the alpine treeline ecotone in 2006 and 2013, and for 888 Erman’s birch, spruce (Picea jezoensis Siebold & Zucc. Carr., larch (Larix olgensis A. Henry, and fir (Abies nephrolepis Trautv. ex Maxim. along an altitudinal gradient below the alpine treeline in 2006. These datasets were utilized to explore both changes in the stature of birch at the alpine treeline over time and variations in tree stature of different tree species across altitudes at a given time point (2006. Results showed that birch saplings (<140 cm in height became stunted while birches with a height of >140 cm became more tapered in the alpine treeline ecotone. The stature of birch along the altitudinal gradient became more tapered from 1700 to 1900 m above see level (a.s.l. and then became more stunted from 1900 to 2050 m a.s.l., with 1900 m a.s.l. being the altitudinal inflection point in this pattern. The treeline birch, due to its great temperature magnitude of distribution, displayed higher stature-plasticity in terms of its height-diameter ratio than the lower elevation species studied. The stature of birch is strongly modulated by altitude-related temperature but also co-influenced by other environmental factors such as soil depth and available water, wind speed, and duration and depth of winter snow cover. The high stature-plasticity of birch makes it fare better than other species to

  20. Increased spring freezing vulnerability for alpine shrubs under early snowmelt.

    Science.gov (United States)

    Wheeler, J A; Hoch, G; Cortés, A J; Sedlacek, J; Wipf, S; Rixen, C

    2014-05-01

    Alpine dwarf shrub communities are phenologically linked with snowmelt timing, so early spring exposure may increase risk of freezing damage during early development, and consequently reduce seasonal growth. We examined whether environmental factors (duration of snow cover, elevation) influenced size and the vulnerability of shrubs to spring freezing along elevational gradients and snow microhabitats by modelling the past frequency of spring freezing events. We sampled biomass and measured the size of Salix herbacea, Vaccinium myrtillus, Vaccinium uliginosum and Loiseleuria procumbens in late spring. Leaves were exposed to freezing temperatures to determine the temperature at which 50% of specimens are killed for each species and sampling site. By linking site snowmelt and temperatures to long-term climate measurements, we extrapolated the frequency of spring freezing events at each elevation, snow microhabitat and per species over 37 years. Snowmelt timing was significantly driven by microhabitat effects, but was independent of elevation. Shrub growth was neither enhanced nor reduced by earlier snowmelt, but decreased with elevation. Freezing resistance was strongly species dependent, and did not differ along the elevation or snowmelt gradient. Microclimate extrapolation suggested that potentially lethal freezing events (in May and June) occurred for three of the four species examined. Freezing events never occurred on late snow beds, and increased in frequency with earlier snowmelt and higher elevation. Extrapolated freezing events showed a slight, non-significant increase over the 37-year record. We suggest that earlier snowmelt does not enhance growth in four dominant alpine shrubs, but increases the risk of lethal spring freezing exposure for less freezing-resistant species.

  1. Climate regulates alpine lake ice cover phenology and aquatic ecosystem structure

    Science.gov (United States)

    Preston, Daniel L.; Caine, Nel; McKnight, Diane M.; Williams, Mark W.; Hell, Katherina; Miller, Matthew P.; Hart, Sarah J.; Johnson, Pieter T.J.

    2016-01-01

    High-elevation aquatic ecosystems are highly vulnerable to climate change, yet relatively few records are available to characterize shifts in ecosystem structure or their underlying mechanisms. Using a long-term dataset on seven alpine lakes (3126 to 3620 m) in Colorado, USA, we show that ice-off dates have shifted seven days earlier over the past 33 years and that spring weather conditions – especially snowfall – drive yearly variation in ice-off timing. In the most well-studied lake, earlier ice-off associated with increases in water residence times, thermal stratification, ion concentrations, dissolved nitrogen, pH, and chlorophyll-a. Mechanistically, low spring snowfall and warm temperatures reduce summer stream flow (increasing lake residence times) but enhance melting of glacial and permafrost ice (increasing lake solute inputs). The observed links among hydrological, chemical, and biological responses to climate factors highlight the potential for major shifts in the functioning of alpine lakes due to forecasted climate change.

  2. Different responses of ecosystem carbon exchange to warming in three types of alpine grassland on the central Qinghai-Tibetan Plateau.

    Science.gov (United States)

    Ganjurjav, Hasbagan; Hu, Guozheng; Wan, Yunfan; Li, Yue; Danjiu, Luobu; Gao, Qingzhu

    2018-02-01

    Climate is a driver of terrestrial ecosystem carbon exchange, which is an important product of ecosystem function. The Qinghai-Tibetan Plateau has recently been subjected to a marked increase in temperature as a consequence of global warming. To explore the effects of warming on carbon exchange in grassland ecosystems, we conducted a whole-year warming experiment between 2012 and 2014 using open-top chambers placed in an alpine meadow, an alpine steppe, and a cultivated grassland on the central Qinghai-Tibetan Plateau. We measured the gross primary productivity, net ecosystem CO 2 exchange (NEE), ecosystem respiration, and soil respiration using a chamber-based method during the growing season. The results show that after 3 years of warming, there was significant stimulation of carbon assimilation and emission in the alpine meadow, but both these processes declined in the alpine steppe and the cultivated grassland. Under warming conditions, the soil water content was more important in stimulating ecosystem carbon exchange in the meadow and cultivated grassland than was soil temperature. In the steppe, the soil temperature was negatively correlated with ecosystem carbon exchange. We found that the ambient soil water content was significantly correlated with the magnitude of warming-induced change in NEE. Under high soil moisture condition, warming has a significant positive effect on NEE, while it has a negative effect under low soil moisture condition. Our results highlight that the NEE in steppe and cultivated grassland have negative responses to warming; after reclamation, the natural meadow would subject to loose more C in warmer condition. Therefore, under future warmer condition, the overextension of cultivated grassland should be avoided and scientific planning of cultivated grassland should be achieved.

  3. Impacts of twenty years of experimental warming on soil carbon, nitrogen, moisture and soil across alpine/subarctic tundra communities

    DEFF Research Database (Denmark)

    M. Alatalo, Juha; K. Jägerbrand, Annika; Juhanson, Jaanis

    2017-01-01

    High-altitude and alpine areas are predicted to experience rapid and substantial increases in future temperature, which may have serious impacts on soil carbon, nutrient and soil fauna. Here we report the impact of 20 years of experimental warming on soil properties and soil mites in three...... contrasting plant communities in alpine/subarctic Sweden. Long-term warming decreased juvenile oribatid mite density, but had no effect on adult oribatids density, total mite density, any major mite group or the most common species. Long-term warming also caused loss of nitrogen, carbon and moisture from...

  4. The onset of alpine pastoral systems in the Eastern Alps

    Science.gov (United States)

    Oeggl, Klaus; Festi, Daniela; Putzer, Andreas

    2015-04-01

    Since the discovery of the Neolithic glacier mummy "Ötzi" in the nival belt of the main Alpine ridge, the onset of alpine pasture is matter of a highly controversial debate both in archaeology and in palaeo-ecology of the Eastern Alps. The implication is that his sojourn in the high-altitudes of the Alps is considered to be connected with pastoral nomadism. Regrettably any archaeological evidence for the existence of such Neolithic alpine pastoral systems is missing up to now and the assumption is based on palynological data only. However, also the palynological record is ambiguous, because pasture indicators in the alpine regions react positive on grazing as well as on fertilization induced by a higher runoff of precipitation. Thus alpine pasture indicators reflect both grazing pressure and climatic change. Anyhow, alpine pastoral systems are a common practice in Alpine animal husbandry, but from an economic point of view such a seasonal vertical transhumance is costly. There are three main reasons for its practice: i) climatic, ii) economic (mainly in connection with population pressure or mining activities), and iii) cultural ideology. In this study we tested the above mentioned reasons in an interdisciplinary study on the beginning of pastoral activities in high altitudes in the central part of the Eastern Alps. This is conducted by palynological analyses of peat deposits situated in the vicinity of the timberline (1600 - 2400 m a.s.l.) combined with archaeological surveys. The investigated sites are located in traditional Alpine transhumance regions and aligned on a transect through the central part of the Eastern Alps. The studies reveal that grazing pressure is reflected since the Bronze Age, which is corroborated by archaeological findings in the vicinity of the investigated sites.

  5. Anterior cruciate ligament injury/reinjury in alpine ski racing

    DEFF Research Database (Denmark)

    Jordan, Matthew J; Aagaard, Per; Herzog, Walter

    2017-01-01

    and return to sport after ACL injury in alpine ski racing. Given that most of the scientific studies on ACL injuries in alpine ski racing have been descriptive, and that very few studies contributed higher level scientific evidence, a nonsystematic narrative review was employed. Three scholarly databases...... were searched for articles on ACL injury or knee injury in alpine ski racing. Studies were classified according to their relevance in relation to epidemiology, etiology, risk factors, and return to sport/reinjury prevention. Alpine ski racers (skiers) were found to be at high risk for knee injuries...... injuries in development-level skiers, there was limited scientific data on ACL injury risk factors among elite skiers. Based on expert opinion, research on injury risk factors should focus on equipment design, course settings/speed, and athlete factors (eg, fitness). While skiers seem to make a successful...

  6. Project SHARE Sustainable Hydropower in Alpine Rivers Ecosystems

    Science.gov (United States)

    Mammoliti Mochet, Andrea

    2010-05-01

    projects. The project openly pursues integrated river management aims (environmental and economic): - define, share and test a decision making framework based on validated methodologies in order to allow public decision makers to take transparent decisions about planning and management of HP concessions, taking account resulting effects on river ecosystems and on all different stakeholders - creation of a technical panel including public decision makers, stakeholders and PPs to promote & transfer the SHARE approach to local, national & transnational level to concretely upgrade the actual standard of problem solving attitude; - classify scenarios of water use optimization, taking into account the different actor needs; - establish a set of generally applicable and comparable indicators & monitoring standards based on transferable guidelines and metrics considering the specific disparities among power stations, diversity of technical approaches and different river ecosystems; - designation and mapping of alpine hydro systems more vulnerable typologies; - designation and mapping of the most convenient sites and typologies of "low impact" new plants; - contribute to the concrete local integration implementation of WFD and RES-e directives. The project partnership embodies different alpine countries & hydrosystems, profiles, status, end users, networks and previous experiences. At the same time the project official observers represent the links with outside the project networks, end users & stakeholders.

  7. Water and CO2 fluxes over semiarid alpine steppe and humid alpine meadow ecosystems on the Tibetan Plateau

    Science.gov (United States)

    Wang, Lei; Liu, Huizhi; Shao, Yaping; Liu, Yang; Sun, Jihua

    2018-01-01

    Based on eddy covariance flux data from July 15, 2014, to December 31, 2015, the water and CO2 fluxes were compared over a semiarid alpine steppe (Bange, Tibetan Plateau) and a humid alpine meadow (Lijiang, Yunnan) on the Tibetan Plateau and its surrounding region. During the wet season, the evaporative fraction (EF) was strongly and linearly correlated with the soil water content (SWC) at Bange because of its sparse green grass cover. In contrast, the correlation between the EF at Lijiang and the SWC and the normalized difference vegetation index (NDVI) was very low because the atmosphere was close to saturation and the EF was relatively constant. In the dry season, the EF at both sites decreased with the SWC. The net ecosystem exchange (NEE) at Bange was largely depressed at noon, while this phenomenon did not occur at Lijiang. The saturated NEE at Bange was 24% of that at Lijiang. The temperature sensitivity coefficient of ecosystem respiration at Bange (1.7) was also much lower than that at Lijiang (3.4). The annual total NEE in 2015 was 21.8 and -230.0 g C m-2 yr-1 at Bange and Lijiang, respectively, and the NEE was tightly controlled by the NDVI at the two sites. The distinct differences in the water and CO2 fluxes at Bange and Lijiang are attributed to the large SWC difference and its effect on vegetation growth.

  8. Statistical Downscaling Of Local Climate In The Alpine Region

    Science.gov (United States)

    Kaspar, Severin; Philipp, Andreas; Jacobeit, Jucundus

    2016-04-01

    The impact of climate change on the alpine region was disproportional strong in the past decades compared to the surrounding areas, which becomes manifest in a higher increase in surface air temperature. Beside the thermal changes also implications for the hydrological cycle may be expected, acting as a very important factor not only for the ecosystem but also for mankind, in the form of water security or considering economical aspects like winter tourism etc. Therefore, in climate impact studies, it is necessary to focus on variables with high influence on the hydrological cycle, for example temperature, precipitation, wind, humidity and radiation. The aim of this study is to build statistical downscaling models which are able to reproduce temperature and precipitation at the mountainous alpine weather stations Zugspitze and Sonnblick and to further project these models into the future to identify possible changes in the behavior of these climate variables and with that in the hydrological cycle. Beside facing a in general very complex terrain in this high elevated regions, we have the advantage of a more direct atmospheric influence on the meteorology of the exposed weather stations from the large scale circulation. Two nonlinear statistical methods are developed to model the station-data series on a daily basis: On the one hand a conditional classification approach was used and on the other hand a model based on artificial neural networks (ANNs) was built. The latter is in focus of this presentation. One of the important steps of developing a new model approach is to find a reliable predictor setup with e.g. informative predictor variables or adequate location and size of the spatial domain. The question is: Can we include synoptic background knowledge to identify an optimal domain for an ANN approach? The yet developed ANN setups and configurations show promising results in downscaling both, temperature (up to 80 % of explained variance) and precipitation (up

  9. Accuracy assessment of a net radiation and temperature index snowmelt model using ground observations of snow water equivalent in an alpine basin

    Science.gov (United States)

    Molotch, N. P.; Painter, T. H.; Bales, R. C.; Dozier, J.

    2003-04-01

    In this study, an accumulated net radiation / accumulated degree-day index snowmelt model was coupled with remotely sensed snow covered area (SCA) data to simulate snow cover depletion and reconstruct maximum snow water equivalent (SWE) in the 19.1-km2 Tokopah Basin of the Sierra Nevada, California. Simple net radiation snowmelt models are attractive for operational snowmelt runoff forecasts as they are computationally inexpensive and have low input requirements relative to physically based energy balance models. The objective of this research was to assess the accuracy of a simple net radiation snowmelt model in a topographically heterogeneous alpine environment. Previous applications of net radiation / temperature index snowmelt models have not been evaluated in alpine terrain with intensive field observations of SWE. Solar radiation data from two meteorological stations were distributed using the topographic radiation model TOPORAD. Relative humidity and temperature data were distributed based on the lapse rate calculated between three meteorological stations within the basin. Fractional SCA data from the Landsat Enhanced Thematic Mapper (5 acquisitions) and the Airborne Visible and Infrared Imaging Spectrometer (AVIRIS) (2 acquisitions) were used to derive daily SCA using a linear regression between acquisition dates. Grain size data from AVIRIS (4 acquisitions) were used to infer snow surface albedo and interpolated linearly with time to derive daily albedo values. Modeled daily snowmelt rates for each 30-m pixel were scaled by the SCA and integrated over the snowmelt season to obtain estimates of maximum SWE accumulation. Snow surveys consisting of an average of 335 depth measurements and 53 density measurements during April, May and June, 1997 were interpolated using a regression tree / co-krig model, with independent variables of average incoming solar radiation, elevation, slope and maximum upwind slope. The basin was clustered into 7 elevation / average

  10. The microbially mediated soil organic carbon loss under degenerative succession in an alpine meadow.

    Science.gov (United States)

    Zhang, Yuguang; Liu, Xiao; Cong, Jing; Lu, Hui; Sheng, Yuyu; Wang, Xiulei; Li, Diqiang; Liu, Xueduan; Yin, Huaqun; Zhou, Jizhong; Deng, Ye

    2017-07-01

    Land-cover change has long been recognized as having marked effect on the amount of soil organic carbon (SOC). However, the microbially mediated processes and mechanisms on SOC are still unclear. In this study, the soil samples in a degenerative succession from alpine meadow to alpine steppe meadow in the Qinghai-Tibetan Plateau were analysed using high-throughput technologies, including Illumina sequencing and geochip functional gene arrays. The soil microbial community structure and diversity were significantly (p carbon degradation genes (e.g., pectin and hemicellulose) was significantly higher in alpine steppe meadow than in alpine meadow, but the relative abundance of soil recalcitrant carbon degradation genes (e.g., chitin and lignin) showed the opposite tendency. The Biolog Ecoplate experiment showed that microbially mediated soil carbon utilization was more active in alpine steppe meadow than in alpine meadow. Consequently, more soil labile carbon might be decomposed in alpine steppe meadow than in alpine meadow. Therefore, the degenerative succession of alpine meadow because of climate change or anthropogenic activities would most likely decrease SOC and nutrients medicated by changing soil microbial community structure and their functional potentials for carbon decomposition. © 2017 John Wiley & Sons Ltd.

  11. Tourism and Water: Themes of the Alpine Convention

    Science.gov (United States)

    Imhof, R.

    2012-04-01

    1) The contribution reflects the personal opinion of the author and does not necessarily reflect the point of view of the Permanent Secretariat. The Alpine Convention is a multilateral framework treaty signed in 1991 by the eight states of the Alpine bow as well as the European Community. Its main objectives are the sustainable development of the Alpine territory and the safeguarding of the interests of the people living within it, embracing the environmental, social and economic dimensions in the broadest sense. In order to achieve its objectives, over the years the Framework Convention has been equipped with a large number of thematic protocols, e.g. on tourism. The overall objective of the Protocol on Tourism, which first came into force in 2002, is to contribute to sustainable development in the Alpine region within the existing institutional framework, by encouraging environmentally-friendly tourism through specific measures and recommendations which take the interests of both the local population and tourists into account. The provisions of the Protocol on Tourism primarily concern tourism management and controlling tourist flows, structural developments such as ski lifts and ski slopes, accommodation and the balanced development of economically weak areas. Guidelines, development plans, sectoral plans have to be adopted at the appropriate territorial level in order to enable to assess the impact of tourism development on, inter alia, water. This extends also to ski slopes developments. For example the production of artificial snow production may be authorized only if the location's hydrological, climatic and ecological conditions allow. Water is listed among the twelve themes in relation to which the Contracting Parties are supposed to take measures and coordinate their policies (Article 2 of the Framework Convention). The Alpine Convention aims to preserve and re-establish healthy water systems, especially keeping waters clean and protecting the natural

  12. Variability and Changes in Climate, Phenology, and Gross Primary Production of an Alpine Wetland Ecosystem

    Directory of Open Access Journals (Sweden)

    Xiaoming Kang

    2016-05-01

    Full Text Available Quantifying the variability and changes in phenology and gross primary production (GPP of alpine wetlands in the Qinghai–Tibetan Plateau under climate change is essential for assessing carbon (C balance dynamics at regional and global scales. In this study, in situ eddy covariance (EC flux tower observations and remote sensing data were integrated with a modified, satellite-based vegetation photosynthesis model (VPM to investigate the variability in climate change, phenology, and GPP of an alpine wetland ecosystem, located in Zoige, southwestern China. Two-year EC data and remote sensing vegetation indices showed that warmer temperatures corresponded to an earlier start date of the growing season, increased GPP, and ecosystem respiration, and hence increased the C sink strength of the alpine wetlands. Twelve-year long-term simulations (2000–2011 showed that: (1 there were significantly increasing trends for the mean annual enhanced vegetation index (EVI, land surface water index (LSWI, and growing season GPP (R2 ≥ 0.59, p < 0.01 at rates of 0.002, 0.11 year−1 and 16.32 g·C·m−2·year−1, respectively, which was in line with the observed warming trend (R2 = 0.54, p = 0.006; (2 the start and end of the vegetation growing season (SOS and EOS experienced a continuous advancing trend at a rate of 1.61 days·year−1 and a delaying trend at a rate of 1.57 days·year−1 from 2000 to 2011 (p ≤ 0.04, respectively; and (3 with increasing temperature, the advanced SOS and delayed EOS prolonged the wetland’s phenological and photosynthetically active period and, thereby, increased wetland productivity by about 3.7–4.2 g·C·m−2·year−1 per day. Furthermore, our results indicated that warming and the extension of the growing season had positive effects on carbon uptake in this alpine wetland ecosystem.

  13. Physiological limitation at alpine treeline: relationships of threshold responses of conifers to their establishment patterns

    Science.gov (United States)

    Germino, M. J.; Lazarus, B.; Castanha, C.; Moyes, A. B.; Kueppers, L. M.

    2014-12-01

    An understanding of physiological limitations to tree establishment at alpine treeline form the basis for predicting how this climate-driven boundary will respond to climate shifts. Most research on this topic has focused on limitations related to carbon balance and growth of trees. Carbon balance could limit survival and establishment primarily through slow-acting, chronic means. We asked whether tree survival and thus establishment patterns reflect control by chronic effects in comparison to acute, threshold responses, such as survival of frost events. Seedling survivorship patterns were compared to thresholds in freezing (temperature causing leaf freezing, or freezing point, FP; and physiological response to freezing) and water status (turgor loss point, TLP; and related physiological adjustments). Subject seedlings were from forest, treeline, and alpine sites in the Alpine Treeline Warming Experiment in Colorado, and included limber and lodgepole pine (a low-elevation species), and Engelmann Spruce. Preliminary results show survival increases with seedling age, but the only corresponding increase in stress acclimation was photosynthetic resistance to freezing and TLP, not FP. Differences in survivorship among the species were not consistent with variation in FP but they generally agreed with variation in photosynthetic resistance to deep freezing and to early-season drought avoidance. Mortality of limber pine increased 35% when minimum temperatures decreased below -9C, which compares with FPs of >-8.6C, and about 1/3 of its mortality occurred during cold/wet events, particularly in the alpine. The other major correlate of mortality is midsummer drying events, as previously reported. Also in limber pine, the TLP for year-old seedlings (-2.5 MPa) corresponded with seasonal-drought mortality. In summary, we show several examples of correspondence in physiological thresholds to mortality events within a species, although the relationships are not strong. Across

  14. [A large-scale accident in Alpine terrain].

    Science.gov (United States)

    Wildner, M; Paal, P

    2015-02-01

    Due to the geographical conditions, large-scale accidents amounting to mass casualty incidents (MCI) in Alpine terrain regularly present rescue teams with huge challenges. Using an example incident, specific conditions and typical problems associated with such a situation are presented. The first rescue team members to arrive have the elementary tasks of qualified triage and communication to the control room, which is required to dispatch the necessary additional support. Only with a clear "concept", to which all have to adhere, can the subsequent chaos phase be limited. In this respect, a time factor confounded by adverse weather conditions or darkness represents enormous pressure. Additional hazards are frostbite and hypothermia. If priorities can be established in terms of urgency, then treatment and procedure algorithms have proven successful. For evacuation of causalities, a helicopter should be strived for. Due to the low density of hospitals in Alpine regions, it is often necessary to distribute the patients over a wide area. Rescue operations in Alpine terrain have to be performed according to the particular conditions and require rescue teams to have specific knowledge and expertise. The possibility of a large-scale accident should be considered when planning events. With respect to optimization of rescue measures, regular training and exercises are rational, as is the analysis of previous large-scale Alpine accidents.

  15. Biomechanical aspects of new techniques in alpine skiing and ski-jumping.

    Science.gov (United States)

    Müller, Erich; Schwameder, Hermann

    2003-09-01

    There have been considerable changes in equipment design and movement patterns in the past few years both in alpine skiing and ski-jumping. These developments have been matched by methods of analysing movements in field conditions. They have yielded new insights into the skills of these specific winter sports. Analytical techniques have included electromyography, kinetic and kinematic methods and computer simulations. Our aim here is to review biomechanical research in alpine skiing and ski-jumping. We present in detail the techniques currently used in alpine skiing (carving technique) and ski-jumping (V-technique), primarily using data from the authors' own research. Finally, we present a summary of the most important results in biomechanical research both in alpine skiing and ski-jumping. This includes an analysis of specific conditions in alpine skiing (type of turn, terrain, snow, speed, etc.) and the effects of equipment, materials and individual-specific abilities on performance, safety and joint loading in ski-jumping.

  16. Alpine Windharvest: development of information base regarding potentials and the necessary technical, legal and socio-economic conditions for expanding wind energy in the Alpine Space - Alpine Space wind map - Modeling approach

    Energy Technology Data Exchange (ETDEWEB)

    Schaffner, B.; Remund, J. [Meteotest, Berne (Switzerland)

    2005-07-01

    This report presents describes the development work carried out by the Swiss meteorology specialists of the company METEOTEST as part of a project carried out together with the Swiss wind-energy organisation 'Suisse Eole'. The framework for the project is the EU Interreg IIIB Alpine Space Programme, a European Community Initiative Programme funded by the European Regional Development Fund. The project investigated the use of digital relief-analysis. The series of reports describes the development and use of a basic information system to aid the investigation of the technical, legal and socio-economical conditions for the use of wind energy in the alpine area. This report discusses two modelling approaches investigated for use in the definition of a wind map for the alpine area. The method chosen and its application are discussed. The various sources of information for input to the model are listed and discussed.

  17. A Spatially Distributed Conceptual Model for Estimating Suspended Sediment Yield in Alpine catchments

    Science.gov (United States)

    Costa, Anna; Molnar, Peter; Anghileri, Daniela

    2017-04-01

    Suspended sediment is associated with nutrient and contaminant transport in water courses. Estimating suspended sediment load is relevant for water-quality assessment, recreational activities, reservoir sedimentation issues, and ecological habitat assessment. Suspended sediment concentration (SSC) along channels is usually reproduced by suspended sediment rating curves, which relate SSC to discharge with a power law equation. Large uncertainty characterizes rating curves based only on discharge, because sediment supply is not explicitly accounted for. The aim of this work is to develop a source-oriented formulation of suspended sediment dynamics and to estimate suspended sediment yield at the outlet of a large Alpine catchment (upper Rhône basin, Switzerland). We propose a novel modelling approach for suspended sediment which accounts for sediment supply by taking into account the variety of sediment sources in an Alpine environment, i.e. the spatial location of sediment sources (e.g. distance from the outlet and lithology) and the different processes of sediment production and transport (e.g. by rainfall, overland flow, snowmelt). Four main sediment sources, typical of Alpine environments, are included in our model: glacial erosion, hillslope erosion, channel erosion and erosion by mass wasting processes. The predictive model is based on gridded datasets of precipitation and air temperature which drive spatially distributed degree-day models to simulate snowmelt and ice-melt, and determine erosive rainfall. A mass balance at the grid scale determines daily runoff. Each cell belongs to a different sediment source (e.g. hillslope, channel, glacier cell). The amount of sediment entrained and transported in suspension is simulated through non-linear functions of runoff, specific for sediment production and transport processes occurring at the grid scale (e.g. rainfall erosion, snowmelt-driven overland flow). Erodibility factors identify different lithological units

  18. Canalization of freeze tolerance in an alpine grasshopper.

    Science.gov (United States)

    Hawes, Timothy C

    2015-10-01

    In the Rock and Pillar Range, New Zealand, the alpine grasshopper, Sigaus australis Hutton, survives equilibrium freezing (EF) all-year round. A comparison of freeze tolerance (FT) in grasshoppers over four austral seasons for a 1 year period finds that: (a) the majority (>70%) of the sample population of grasshoppers survive single freeze-stress throughout the year; (b) exposure to increased freeze stress (multiple freeze-stress events) does not lead to a loss of freeze tolerance; and (c) responses to increased freeze stress reveal seasonal tuning of the FT adaptation to environmental temperatures. The Rock and Pillar sample population provides a clear example of the canalization of the FT adaptation. Seasonal variability in the extent of tolerance of multiple freezing events indicates that physiology is modulated to environmental temperatures by phenotypic plasticity - i.e. the FT adaptation is permanent and adjustable. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Modelling and simulation of floods in alpine catchments equipped with complex hydropower schemes

    OpenAIRE

    Bieri, Martin; Schleiss, Anton; Frankhauser, A.

    2010-01-01

    The simulation of run-off in an alpine catchment area equipped with complex hydropower schemes is presented by the help of an especially developed tool, called Routing System, which can combine hydrological modelling and operation of hydraulic elements. In the hydrological forecasting tool tridimensional rainfall, temperature and evapotranspiration distributions are taken into account for simulating the dominant hydrological processes, as glacier melt, snow pack constitution and melt, soil in...

  20. Minimal erosion of Arctic alpine topography during late Quaternary glaciation

    Science.gov (United States)

    Gjermundsen, Endre F.; Briner, Jason P.; Akçar, Naki; Foros, Jørn; Kubik, Peter W.; Salvigsen, Otto; Hormes, Anne

    2015-10-01

    The alpine topography observed in many mountainous regions is thought to have formed during repeated glaciations of the Quaternary period. Before this time, landscapes had much less relief. However, the spatial patterns and rates of Quaternary exhumation at high latitudes--where cold-based glaciers may protect rather than erode landscapes--are not fully quantified. Here we determine the exposure and burial histories of rock samples from eight summits of steep alpine peaks in northwestern Svalbard (79.5° N) using analyses of 10Be and 26Al concentrations. We find that the summits have been preserved for at least the past one million years. The antiquity of Svalbard’s alpine landscape is supported by the preservation of sediments older than one million years along a fjord valley, which suggests that both mountain summits and low-elevation landscapes experienced very low erosion rates over the past million years. Our findings support the establishment of northwestern Svalbard’s alpine topography during the early Quaternary. We suggest that, as the Quaternary ice age progressed, glacial erosion in the Arctic became inefficient and confined to ice streams, and high-relief alpine landscapes were preserved by minimally erosive glacier armour.

  1. Elevational variation in body-temperature response to immune challenge in a lizard

    Directory of Open Access Journals (Sweden)

    Francisco Javier Zamora-Camacho

    2016-04-01

    Full Text Available Immunocompetence benefits animal fitness by combating pathogens, but also entails some costs. One of its main components is fever, which in ectotherms involves two main types of costs: energy expenditure and predation risk. Whenever those costs of fever outweigh its benefits, ectotherms are expected not to develop fever, or even to show hypothermia, reducing costs of thermoregulation and diverting the energy saved to other components of the immune system. Environmental thermal quality, and therefore the thermoregulation cost/benefit balance, varies geographically. Hence, we hypothesize that, in alpine habitats, immune-challenged ectotherms should show no thermal response, given that (1 hypothermia would be very costly, as the temporal window for reproduction is extremely small, and (2 fever would have a prohibitive cost, as heat acquisition is limited in such habitat. However, in temperate habitats, immune-challenged ectotherms might show a febrile response, due to lower cost/benefit balance as a consequence of a more suitable thermal environment. We tested this hypothesis in Psammodromus algirus lizards from Sierra Nevada (SE Spain, by testing body temperature preferred by alpine and non-alpine lizards, before and after activating their immune system with a typical innocuous pyrogen. Surprisingly, non-alpine lizards responded to immune challenge by decreasing preferential body-temperature, presumably allowing them to save energy and reduce exposure to predators. On the contrary, as predicted, immune-challenged alpine lizards maintained their body-temperature preferences. These results match with increased costs of no thermoregulation with elevation, due to the reduced window of time for reproduction in alpine environment.

  2. Validity, Reliability, and Inertia of Four Different Temperature Capsule Systems.

    Science.gov (United States)

    Bongers, Coen C W G; Daanen, Hein A M; Bogerd, Cornelis P; Hopman, Maria T E; Eijsvogels, Thijs M H

    2018-01-01

    Telemetric temperature capsule systems are wireless, relatively noninvasive, and easily applicable in field conditions and have therefore great advantages for monitoring core body temperature. However, the accuracy and responsiveness of available capsule systems have not been compared previously. Therefore, the aim of this study was to examine the validity, reliability, and inertia characteristics of four ingestible temperature capsule systems (i.e., CorTemp, e-Celsius, myTemp, and VitalSense). Ten temperature capsules were examined for each system in a temperature-controlled water bath during three trials. The water bath temperature gradually increased from 33°C to 44°C in trials 1 and 2 to assess the validity and reliability, and from 36°C to 42°C in trial 3 to assess the inertia characteristics of the temperature capsules. A systematic difference between capsule and water bath temperature was found for CorTemp (0.077°C ± 0.040°C), e-Celsius (-0.081°C ± 0.055°C), myTemp (-0.003°C ± 0.006°C), and VitalSense (-0.017°C ± 0.023°C; P 0.05). Comparable inertia characteristics were found for CorTemp (25 ± 4 s), e-Celsius (21 ± 13 s), and myTemp (19 ± 2 s), whereas the VitalSense system responded more slowly (39 ± 6 s) to changes in water bath temperature (P inertia were observed between capsule systems, an excellent validity, test-retest reliability, and inertia was found for each system between 36°C and 44°C after removal of outliers.

  3. Can riparian vegetation shade mitigate the expected rise in stream temperatures due to climate change during heat waves in a human-impacted pre-alpine river?

    Directory of Open Access Journals (Sweden)

    H. Trimmel

    2018-01-01

    Full Text Available Global warming has already affected European rivers and their aquatic biota, and climate models predict an increase of temperature in central Europe over all seasons. We simulated the influence of expected changes in heat wave intensity during the 21st century on water temperatures of a heavily impacted pre-alpine Austrian river and analysed future mitigating effects of riparian vegetation shade on radiant and turbulent energy fluxes using the deterministic Heat Source model. Modelled stream water temperature increased less than 1.5 °C within the first half of the century. Until 2100, a more significant increase of around 3 °C in minimum, maximum and mean stream temperatures was predicted for a 20-year return period heat event. The result showed clearly that in a highly altered river system riparian vegetation was not able to fully mitigate the predicted temperature rise caused by climate change but would be able to reduce water temperature by 1 to 2 °C. The removal of riparian vegetation amplified stream temperature increases. Maximum stream temperatures could increase by more than 4 °C even in annual heat events. Such a dramatic water temperature shift of some degrees, especially in summer, would indicate a total shift of aquatic biodiversity. The results demonstrate that effective river restoration and mitigation require re-establishing riparian vegetation and emphasize the importance of land–water interfaces and their ecological functioning in aquatic environments.

  4. Can riparian vegetation shade mitigate the expected rise in stream temperatures due to climate change during heat waves in a human-impacted pre-alpine river?

    Science.gov (United States)

    Trimmel, Heidelinde; Weihs, Philipp; Leidinger, David; Formayer, Herbert; Kalny, Gerda; Melcher, Andreas

    2018-01-01

    Global warming has already affected European rivers and their aquatic biota, and climate models predict an increase of temperature in central Europe over all seasons. We simulated the influence of expected changes in heat wave intensity during the 21st century on water temperatures of a heavily impacted pre-alpine Austrian river and analysed future mitigating effects of riparian vegetation shade on radiant and turbulent energy fluxes using the deterministic Heat Source model. Modelled stream water temperature increased less than 1.5 °C within the first half of the century. Until 2100, a more significant increase of around 3 °C in minimum, maximum and mean stream temperatures was predicted for a 20-year return period heat event. The result showed clearly that in a highly altered river system riparian vegetation was not able to fully mitigate the predicted temperature rise caused by climate change but would be able to reduce water temperature by 1 to 2 °C. The removal of riparian vegetation amplified stream temperature increases. Maximum stream temperatures could increase by more than 4 °C even in annual heat events. Such a dramatic water temperature shift of some degrees, especially in summer, would indicate a total shift of aquatic biodiversity. The results demonstrate that effective river restoration and mitigation require re-establishing riparian vegetation and emphasize the importance of land-water interfaces and their ecological functioning in aquatic environments.

  5. Active summer carbon storage for winter persistence in trees at the cold alpine treeline.

    Science.gov (United States)

    Li, Mai-He; Jiang, Yong; Wang, Ao; Li, Xiaobin; Zhu, Wanze; Yan, Cai-Feng; Du, Zhong; Shi, Zheng; Lei, Jingpin; Schönbeck, Leonie; He, Peng; Yu, Fei-Hai; Wang, Xue

    2018-03-12

    The low-temperature limited alpine treeline is one of the most obvious boundaries in mountain landscapes. The question of whether resource limitation is the physiological mechanism for the formation of the alpine treeline is still waiting for conclusive evidence and answers. We therefore examined non-structural carbohydrates (NSC) and nitrogen (N) in treeline trees (TATs) and low-elevation trees (LETs) in both summer and winter in 11 alpine treeline cases ranging from subtropical monsoon to temperate continental climates across Eurasia. We found that tissue N concentration did not decrease with increasing elevation at the individual treeline level, but the mean root N concentration was lower in TATs than in LETs across treelines in summer. The TATs did not have lower tissue NSC concentrations than LETs in summer. However, the present study with multiple tree species across a large geographical scale, for the first time, revealed a common phenomenon that TATs had significantly lower NSC concentration in roots but not in the aboveground tissues than LETs in winter. Compared with LETs, TATs exhibited both a passive NSC storage in aboveground tissues in excess of carbon demand and an active starch storage in roots at the expense of growth reduction during the growing season. This starch accumulation disappeared in winter. Our results highlight some important aspects of the N and carbon physiology in relation to season in trees at their upper limits. Whether or to what extent the disadvantages of winter root NSC and summer root N level of TATs affect the growth of treeline trees and the alpine treeline formation needs to be further studied.

  6. Synoptic climatology evaluation of wind fields in the alpine region

    International Nuclear Information System (INIS)

    Lotteraner, C.

    2009-01-01

    circulations inside the Alpine valleys are taken into consideration. Using a simple cross validation on simulated observations, it is shown that the fingerprint technique applied to wind analyses can increase analysis quality. Also, some case studies with real wind data are presented which confirm this feature, especially on days with weak large-scale pressure gradients and strong incoming solar radiation. (author) [de

  7. Modelling of Aerodynamic Drag in Alpine Skiing

    OpenAIRE

    Elfmark, Ola

    2017-01-01

    Most of the breaking force in the speed disciplines in alpine skiing is caused by the aerodynamic drag, and a better knowledge of the drag force is therefore desirable to gain time in races. In this study a complete database of how the drag area (CDA) changes, with respect to the different body segments, was made and used to explain a complete body motion in alpine skiing. Three experiments were performed in the wind tunnel at NTNU, Trondheim. The database from a full body measurement on an a...

  8. Lithologically controlled detachment strength and steady state since 10 Ma: Exploring the Alpine wedge using critical taper analysis combined with low-temperature thermochronometry

    Science.gov (United States)

    von Hagke, Christoph; Oncken, Onno; Ortner, Hugo; Cederbom, Charlotte

    2014-05-01

    Although evidence for weak detachments underlying foreland thrust belts exists, very little is known about the lateral variations in effective strength, as well as the geological nature of such variations. Using critical taper analysis, we show that a detailed and systematic measurement of surface slope of the Central European Alps reveals variations in strength along the detachment, based on the argument that the Alps are close to the critical state. We show that the basal detachment is very weak near the deformation front but strengthens towards the hinterland. These changes in detachment strength coincide with changes of detachment lithology in the hangingwall and footwall respectively, emphasizing the dominant role of weak shales. The very low strength values we find in shales in the frontal part of the alpine sole detachment are caused partly by slightly elevated pore pressures but may also require additional mechanisms of dynamic weakening. Using the constraints on the present day alpine taper, we investigate the change in taper through time. To this end, we produced new apatite fission track and apatite (U-Th)/He data from the Alpine orogenic front, the Austrian Subalpine Molasse. We combine this data set with existing thermochronometry, and reconstruct the Central Alpine pro-wedge geometry at 10 Ma. We show that the taper of the Central Alps has not changed significantly and presumably remained close to kinematic and mass flux steady state since then. This indicates a feedback between ongoing shortening and erosion at low rates during the Late Neogene to present.

  9. Staying cool: preadaptation to temperate climates required for colonising tropical alpine-like environments

    Directory of Open Access Journals (Sweden)

    Berit Gehrke

    2018-04-01

    Full Text Available Plant species tend to retain their ancestral ecology, responding to temporal, geographic and climatic changes by tracking suitable habitats rather than adapting to novel conditions. Nevertheless, transitions into different environments or biomes still seem to be common. Especially intriguing are the tropical alpine-like areas found on only the highest mountainous regions surrounded by tropical environments. Tropical mountains are hotspots of biodiversity, often with striking degrees of endemism at higher elevations. On these mountains, steep environmental gradients and high habitat heterogeneity within small spaces coincide with astounding species diversity of great conservation value. The analysis presented here shows that the importance of in situ speciation in tropical alpine-like areas has been underestimated. Additionally and contrary to widely held opinion, the impact of dispersal from other regions with alpine-like environments is relatively minor compared to that of immigration from other biomes with a temperate (but not alpine-like climate. This suggests that establishment in tropical alpine-like regions is favoured by preadaptation to a temperate, especially aseasonal, freezing regime such as the cool temperate climate regions in the Tropics. Furthermore, emigration out of an alpine-like environment is generally rare, suggesting that alpine-like environments – at least tropical ones – are species sinks.

  10. A modified MOD16 algorithm to estimate evapotranspiration over alpine meadow on the Tibetan Plateau, China

    Science.gov (United States)

    Chang, Y.; Ding, Y.; Zhao, Q.; Zhang, S.

    2017-12-01

    The accurate estimation of evapotranspiration (ET) is crucial for managing water resources in areas with extreme climates affected by climate change, such as the Tibetan Plateau (TP). The MOD16 ET product has also been validated and applied in many countries with various climates, however, its performance varies under different climates and regions. Several have studied ET based on satellite-based models on the TP. However, only a few studies on the performance of MOD16 in the TP with heterogeneous land cover have been reported. This study proposes an improved algorithm for estimating ET based on a proposed modified MOD16 method over alpine meadow on the TP in China. Wind speed and vegetation height were integrated to estimate aerodynamic resistance, while the temperature and moisture constraint for stomatal conductance were revised based on the technique proposed by Fisher et al. (2008). Moreover, Fisher's method for soil evaporation was introduced to decrease the uncertainty of soil evaporation estimation. Five representative alpine meadow sites on the TP were selected to investigate the performance of the modified algorithm. Comparisons between ET observed using Eddy Covariance (EC) and estimated using both the original method and modified method suggest that the modified algorithm had better performance than the original MOD16 method. This result was achieved considering that the coefficient of determination (R2) increased from 0.28 to 0.70, and the root mean square error (RMSE) decreased from 1.31 to 0.77 mm d-1. The modified algorithm also outperformed on precipitation days compared to non-precipitation days at Suli and Hulugou sites, while it performed well for both non-precipitation and precipitation days at Tanggula site. Comparisons of the 8-day ET estimation using the MOD16 product, original MOD16 method, and modified MOD16 method with observed ET suggest that MOD16 product underestimated ET over the alpine meadow of the TP during the growing season

  11. Evolutionary diversification of cryophilic Grylloblatta species (Grylloblattodea: Grylloblattidae in alpine habitats of California

    Directory of Open Access Journals (Sweden)

    Roderick George K

    2010-06-01

    Full Text Available Abstract Background Climate in alpine habitats has undergone extreme variation during Pliocene and Pleistocene epochs, resulting in repeated expansion and contraction of alpine glaciers. Many cold-adapted alpine species have responded to these climatic changes with long-distance range shifts. These species typically exhibit shallow genetic differentiation over a large geographical area. In contrast, poorly dispersing organisms often form species complexes within mountain ranges, such as the California endemic ice-crawlers (Grylloblattodea: Grylloblattidae: Grylloblatta. The diversification pattern of poorly dispersing species might provide more information on the localized effects of historical climate change, the importance of particular climatic events, as well as the history of dispersal. Here we use multi-locus genetic data to examine the phylogenetic relationships and geographic pattern of diversification in California Grylloblatta. Results Our analysis reveals a pattern of deep genetic subdivision among geographically isolated populations of Grylloblatta in California. Alpine populations diverged from low elevation populations and subsequently diversified. Using a Bayesian relaxed clock model and both uncalibrated and calibrated measurements of time to most recent common ancestor, we reconstruct the temporal diversification of alpine Grylloblatta populations. Based on calibrated relaxed clock estimates, evolutionary diversification of Grylloblatta occurred during the Pliocene-Pleistocene epochs, with an initial dispersal into California during the Pliocene and species diversification in alpine clades during the middle Pleistocene epoch. Conclusions Grylloblatta species exhibit a high degree of genetic subdivision in California with well defined geographic structure. Distinct glacial refugia can be inferred within the Sierra Nevada, corresponding to major, glaciated drainage basins. Low elevation populations are sister to alpine populations

  12. Climate-induced glacier and snow loss imperils alpine stream insects

    Science.gov (United States)

    Giersch, J. Joseph; Hotaling, Scott; Kovach, Ryan; Jones, Leslie A.; Muhlfeld, Clint C.

    2017-01-01

    Climate warming is causing rapid loss of glaciers and snowpack in mountainous regions worldwide. These changes are predicted to negatively impact the habitats of many range-restricted species, particularly endemic, mountaintop species dependent on the unique thermal and hydrologic conditions found only in glacier-fed and snowmelt-driven alpine streams. Though progress has been made, existing understanding of the status, distribution, and ecology of alpine aquatic species, particularly in North America, is lacking, thereby hindering conservation and management programs. Two aquatic insects – the meltwater stonefly Lednia tumana and the glacier stonefly Zapada glacier – were recently proposed for listing under the U.S. Endangered Species Act due to climate-change-induced habitat loss. Using a large dataset (272 streams, 482 total sites) with high-resolution climate and habitat information, we describe the distribution, status, and key environmental features that limit L. tumana and Z. glacier across the northern Rocky Mountains. Lednia tumana was detected in 113 streams (175 sites) within Glacier National Park (GNP) and surrounding areas. The probability of L. tumana occurrence increased with cold stream temperatures and close proximity to glaciers and permanent snowfields. Similarly, densities of L. tumana declined with increasing distance from stream source. Zapada glacier was only detected in 10 streams (20 sites), six in GNP and four in mountain ranges up to ~600 km southwest. Our results show that both L. tumana and Z. glacier inhabit an extremely narrow distribution, restricted to short sections of cold, alpine streams often below glaciers predicted to disappear over the next two decades. Climate warming-induced glacier and snow loss clearly imperils the persistence of L. tumana and Z. glacier throughout their ranges, highlighting the role of mountaintop aquatic invertebrates as sentinels of climate change in mid-latitude regions.

  13. Microstructures Indicate Large Influence of Temperature and Fluid Pressure on the Reactivation of the Alpine Fault, New Zealand

    Science.gov (United States)

    Schuck, B.; Janssen, C.; Schleicher, A.; Toy, V.; Dresen, G.

    2017-12-01

    The transpressional Alpine Fault within New Zealand's South Island is the major structure that accommodates relative motion between the Pacific and the Australian Plates. It has been intensively studied, because it is late in its 291-year seismic cycle (Cochran et al., 2017; doi: 10.1016/j.epsl.2017.02.026), is likely to generate large (i.e. MW > 8) earthquakes, thus presents the biggest seismic hazard in the region. However, because it is severely misoriented in the present-day stress field for reactivation (Boese et al., 2013; doi: 10.1016/j.epsl.2013.06.030), supra-lithostatic fluid-pressures are required for rupture nucleation. We have analyzed microstructures (SEM and TEM), geochemistry (ICP-OES) and mineralogy (XRD) of outcrop samples of the fault core to investigate the influence of fluids on the geomechanical behavior of the fault. Fluid-related alteration is pervasive within 20 m of the principal slip zone (PSZ) (Sutherland et al., 2012; doi: 10.1130/G33614.1), which is an incohesive, cemented and repeatedly reworked fault gouge mostly consisting of a fine-grained matrix composed of comminuted detrital quartz and feldspar as well as authigenic chlorite and calcite. Authigenic phases seal the PSZ for interseismic cross-fault fluid flow and enable fluid pressure to build-up. Notable, smectite, previously considered to significantly influence propagation of Alpine Fault ruptures, is not present in these samples. Undeformed, euhedral chlorite grains suggest that the processes leading to fault sealing are not only active at greater depths but also close to the surface. The absence of smectite and the presence of undeformed chlorite at very shallow depths can be attributed to the fault's high geothermal gradient of > 120 °C km-1 (Sutherland et al., 2012; doi:10.1038/nature22355), which gives temperature conditions unfavorable for smectite to be stable and fostering chlorite growth. A pervasive network of anastomosing calcite veins in the fault core, depicting

  14. Characterization of the shallow groundwater system in an alpine watershed: Handcart Gulch, Colorado, USA

    Science.gov (United States)

    Kahn, Katherine G.; Ge, Shemin; Caine, Jonathan S.; Manning, A.

    2008-01-01

    Water-table elevation measurements and aquifer parameter estimates are rare in alpine settings because few wells exist in these environments. Alpine groundwater systems may be a primary source of recharge to regional groundwater flow systems. Handcart Gulch is an alpine watershed in Colorado, USA comprised of highly fractured Proterozoic metamorphic and igneous rocks with wells completed to various depths. Primary study objectives include determining hydrologic properties of shallow bedrock and surficial materials, developing a watershed water budget, and testing the consistency of measured hydrologic properties and water budget by constructing a simple model incorporating groundwater and surface water for water year 2005. Water enters the study area as precipitation and exits as discharge in the trunk stream or potential recharge for the deeper aquifer. Surficial infiltration rates ranged from 0.1-6.2??0-5 m/s. Discharge was estimated at 1.28??10-3 km3. Numerical modeling analysis of single-well aquifer tests predicted lower specific storage in crystalline bedrock than in ferricrete and colluvial material (6.7??10-5-2.10??0-3 l/m). Hydraulic conductivity in crystalline bedrock was significantly lower than in colluvial and alluvial material (4.3??10-9 -2.0??10-4 m/s). Water budget results suggest that during normal precipitation and temperatures water is available to recharge the deeper groundwater flow system. ?? Springer-Verlag 2007.

  15. Atmospheric deposition as a source of carbon and nutrients to barren, alpine soils of the Colorado Rocky Mountains

    Science.gov (United States)

    Mladenov, N.; Williams, M. W.; Schmidt, S. K.; Cawley, K.

    2012-03-01

    Many alpine areas are experiencing intense deglaciation, biogeochemical changes driven by temperature rise, and changes in atmospheric deposition. There is mounting evidence that the water quality of alpine streams may be related to these changes, including rising atmospheric deposition of carbon (C) and nutrients. Given that barren alpine soils can be severely C limited, we evaluated the magnitude and chemical quality of atmospheric deposition of C and nutrients to an alpine site, the Green Lake 4 catchment in the Colorado Rocky Mountains. Using a long term dataset (2002-2010) of weekly atmospheric wet deposition and snowpack chemistry, we found that volume weighted mean dissolved organic carbon (DOC) concentrations were approximately 1.0 mg L-1and weekly concentrations reached peaks as high at 6-10 mg L-1 every summer. Total dissolved nitrogen concentration also peaked in the summer, whereas total dissolved phosphorus and calcium concentrations were highest in the spring. Relationships among DOC concentration, dissolved organic matter (DOM) fluorescence properties, and nitrate and sulfate concentrations suggest that pollutants from nearby urban and agricultural sources and organic aerosols derived from sub-alpine vegetation may influence high summer DOC wet deposition concentrations. Interestingly, high DOC concentrations were also recorded during "dust-in-snow" events in the spring. Detailed chemical and spectroscopic analyses conducted for samples collected in 2010 revealed that the DOM in many late spring and summer samples was less aromatic and polydisperse and of lower molecular weight than that of winter and fall samples and, therefore, likely to be more bioavailable to microbes in barren alpine soils. Bioavailability experiments with different types of atmospheric C sources are needed to better evaluate the substrate quality of atmospheric C inputs. Our C budget estimates for the Green Lake 4 catchment suggest that atmospheric deposition represents an

  16. Estimation of Biomass Dynamics in Alpine Treeline Ecotone using Airborne Lidar and Repeat Photography

    Science.gov (United States)

    McCaffrey, D. R.; Hopkinson, C.

    2016-12-01

    Historic photographs provide visual records of landscapes which pre-date aerial and satellite observations, but analysis of these photographs has largely been qualitative due to varying spatial scale within an oblique image. Recent technological advances, such as the WSL monoplotting tool, provide the ability to georeference single oblique images, allowing for quantitative spatial analysis of land cover change between historic photographs and contemporary repeat photographs. The WSL monoplotting tool was used to compare alpine land cover change between 12 photographs from a 1914 survey of the West Castle valley (Alberta, Canada; 49.3° N, 114.4° W) and 12 repeat photographs, collected in 2006 by the Mountain Legacy Project. We tested for correlations between land cover shifts over the 92 year observation period and geomorphic controls (e.g. elevation, slope, aspect), with a focus on vegetative change in the alpine treeline ecotone (ATE). A model of above ground biomass was generated using an airborne lidar observation of the valley (2014) and ground validated measurements of tree height, diameter at breast height, and leaf area index from 25 plots (400 m2). By creating a high resolution map of ATE dynamics over a 92 year interval and incorporating a model of above ground biomass, the relative magnitude of anthropogenic, orographic, and climatic controls on ATE can be explored. This research provides a unique opportunity to understand the impact that continued atmospheric warming could have on vegetative boundaries in sensitive alpine systems, such as the eastern slopes of the Rocky Mountains.

  17. Ethnobotany of medicinal plants among the communities of Alpine and Sub-alpine regions of Pakistan.

    Science.gov (United States)

    Kayani, Sadaf; Ahmad, Mushtaq; Sultana, Shazia; Khan Shinwari, Zabta; Zafar, Muhammed; Yaseen, Ghulam; Hussain, Manzoor; Bibi, Tahira

    2015-04-22

    To best of our knowledge it is first quantitative ethno-botanical study from Alpine and Sub-alpine, Western Himalaya of Pakistan. The study aims to report, compare the uses and highlight the ethno-botanical significance of medicinal plants for treatment of various diseases. A total of 290 (278 males and 12 females) informants including 14 Local Traditional Healers (LTHs) were interviewed. Information was collected using semi-structured interviews, analyzed and compared by quantitative ethno-botanical indices such as Informant Consensus Factor (ICF), Relative frequency of citation (RFC), use value (UV), Fidelity Level (FL) and Jaccard index (JI). A total of 125 plant species (Gymnosperms 7 species, Monocotyledons 2 and 116 Di-cotyledons) belonging to 41 families are collected, identified and ethno-botanically assessed. The most dominant family is Ranunculaceae (20 species) followed by Rosaceae (14 species). In diseases treated, gastrointestinal tract (GIT) diseases have highest proportion (27.5%) followed by respiratory diseases (20%) in the mountain communities. The most dominant life form of plants used is herbs (78%) followed by shrubs (19%) while the most commonly used plant parts are leaves (44 reports) followed by underground part, the roots (37 reports). The highest ICF (0.68) is found for ear, nose and eye disease category followed by respiratory disorders (0.46). There are 15 medicinal plants having 100% FL. Use value (UV) and Relative frequency of citation (RFC) range from 0.03 to 0.53 and 0.04 to 0.23 respectively. In comparison, maximum similarity index is found in the studies with JI 19.52 followed by 17.39. Similarity percentage of plant uses range from 1.69% to 19.52% while dissimilarity percentage varies from 0% to 20%. The Alpine and Sub-alpine regions of Pakistan are rich in medicinal plants and still need more research exploration. On the other hand, ethno-botanical knowledge in study areas is decreasing day by day due to high emigration rates

  18. Area burned in alpine treeline ecotones reflects region-wide trends

    Science.gov (United States)

    C. Alina Cansler; Donald McKenzie; Charles B. Halpern

    2016-01-01

    The direct effects of climate change on alpine treeline ecotones – the transition zones between subalpine forest and non-forested alpine vegetation – have been studied extensively, but climate-induced changes in disturbance regimes have received less attention. To determine if recent increases in area burned extend to these higher-elevation landscapes, we analysed...

  19. A simple spatial model exploring positive feedbacks at tropical alpine treelines

    NARCIS (Netherlands)

    Bader, M.; Rietkerk, M.; Bregt, A.K.

    2008-01-01

    Climate change could cause alpine treelines to shift in altitude or to change their spatial pattern, but little is known about the drivers of treeline dynamics and patterning. The position and patterns of tropical alpine treelines are generally attributed to land use, especially burning. Species

  20. Determination of the centre of mass kinematics in alpine skiing using differential global navigation satellite systems.

    Science.gov (United States)

    Gilgien, Matthias; Spörri, Jörg; Chardonnens, Julien; Kröll, Josef; Limpach, Philippe; Müller, Erich

    2015-01-01

    In the sport of alpine skiing, knowledge about the centre of mass (CoM) kinematics (i.e. position, velocity and acceleration) is essential to better understand both performance and injury. This study proposes a global navigation satellite system (GNSS)-based method to measure CoM kinematics without restriction of capture volume and with reasonable set-up and processing requirements. It combines the GNSS antenna position, terrain data and the accelerations acting on the skier in order to approximate the CoM location, velocity and acceleration. The validity of the method was assessed against a reference system (video-based 3D kinematics) over 12 turn cycles on a giant slalom skiing course. The mean (± s) position, velocity and acceleration differences between the CoM obtained from the GNSS and the reference system were 9 ± 12 cm, 0.08 ± 0.19 m · s(-1) and 0.22 ± 1.28 m · s(-2), respectively. The velocity and acceleration differences obtained were smaller than typical differences between the measures of several skiers on the same course observed in the literature, while the position differences were slightly larger than its discriminative meaningful change. The proposed method can therefore be interpreted to be technically valid and adequate for a variety of biomechanical research questions in the field of alpine skiing with certain limitations regarding position.

  1. Snow, ice and water in alpine regions

    International Nuclear Information System (INIS)

    Baumgartner, H.

    2009-01-01

    This article takes a look at how climate change will have a deep impact on alpine regions. The findings discussed at a conference organised by the Swiss Hydrologic Commission are presented and discussed. Flooding incidents that occurred 'once in a century' are now becoming more frequent and were considered at the conference as being an indicator of climate change. Changing hydrological factors are also discussed and the influence of climate factors in alpine regions on the water quantities in the rivers are looked at. Also, the spontaneous emptying of glacial lakes as has already happened in Switzerland and the consequences to be drawn from such incidences are discussed.

  2. Rock glaciers in crystalline catchments: Hidden permafrost-related threats to alpine headwater lakes.

    Science.gov (United States)

    Ilyashuk, Boris P; Ilyashuk, Elena A; Psenner, Roland; Tessadri, Richard; Koinig, Karin A

    2018-04-01

    A global warming-induced transition from glacial to periglacial processes has been identified in mountainous regions around the world. Degrading permafrost in pristine periglacial environments can produce acid rock drainage (ARD) and cause severe ecological damage in areas underlain by sulfide-bearing bedrock. Limnological and paleolimnological approaches were used to assess and compare ARDs generated by rock glaciers, a typical landform of the mountain permafrost domain, and their effects on alpine headwater lakes with similar morphometric features and underlying bedrock geology, but characterized by different intensities of frost action in their catchments during the year. We argue that ARD and its effects on lakes are more severe in the alpine periglacial belt with mean annual air temperatures (MAAT) between -2°C and +3°C, where groundwater persists in the liquid phase for most of the year, in contrast to ARD in the periglacial belt where frost action dominates (MAAT cycle of aquatic organisms should be considered when reconstructing long-term trends in the ecotoxicological state of lakes. © 2017 The Authors. Global Change Biology Published by John Wiley & Sons Ltd.

  3. Activated Fraction Of Black Carbon By Cloud Droplets And Ice Crystals At The High Alpine Site Jungfraujoch (3580 m asl)

    Energy Technology Data Exchange (ETDEWEB)

    Cozic, J.; Mertes, S. [IFT Leipzig (Georgia); Verheggen, B.; Petzold, A. [DLR, Oberpfaffenhofen (Georgia); Weingartner, E.; Baltensperger, U.

    2005-03-01

    Measurements of black carbon (BC) were made in winter and summer 2004 at the high Alpine site Jungfraujoch in order to study the activation of BC into cloud droplets and ice crystals. Main results showed that the activated fraction represents 61% in summer and that for a large temperature range between -25 C and 5 C, the activated BC fraction increases with increasing temperature and increasing liquid water content. (author)

  4. The 'Guetsch' Alpine wind power test site; Alpine Test Site Guetsch. Handbuch und Fachtagung

    Energy Technology Data Exchange (ETDEWEB)

    Cattin, R.

    2008-12-15

    This final report for the Swiss Federal Office of Energy (SFOE) takes a look at the influence of icing-up on the operation of wind turbines in mountainous areas. Within the Swiss research project 'Alpine Test Site Guetsch', extensive icing studies were carried out at the Guetsch site near Andermatt, Switzerland. This document deals with the following subjects: Information about ice formation on structures, in particular with respect to wind turbines, standards and international research activities, wind measurements under icing-up conditions, estimation of the frequency of icing-up conditions, effects of icing-up on wind turbines, ice detection, measures available for de-icing and anti-icing as well as ice throw. A list of factors to be taken into account by the planners and operators of wind turbines in alpine environments is presented.

  5. POPs and other persistent organic compounds in fish from remote alpine lakes in the Grisons, Switzerland

    Energy Technology Data Exchange (ETDEWEB)

    Schmid, P.; Gujer, E.; Zennegg, M. [Swiss Federal Laboratories for Materials Testing and Research (EMPA), Duebendorf (Switzerland); Lanfranchi, M. [Agency for Nature and Environment of the Canton Grisons, Chur (Switzerland)

    2004-09-15

    Global transfer of persistent semivolatile organic compounds, such as persistent organic pollutants (POPs), is effected by long-range atmospheric transport in combination with condensation and volatilization processes. Within the global atmosphere, evaporation in warm latitudes and deposition in cold latitudes leads to a transfer of contaminants towards the poles. The phenomenon of atmospheric migration of semivolatile chemicals, such as PCB and DDT, has been predicted and associated with the term ''global distillation'' by Goldberg, and the model has been extensively reviewed by Mackay and Wania. For comparatively less volatile components such as PCDD/F and PBDE, particle-bound deposition is the dominating transfer mechanism. Therefore, the input of these compounds in remote alpine regions without point sources is controlled by atmospheric deposition (dry and wet) and condensation. For organochlorine compounds, such as pesticides and polychlorinated biphenyls (PCB), it has been shown that accumulation is enhanced by temperaturecontrolled condensation also in alpine regions with low average temperatures. The hydrology of remote alpine lakes is determined by direct atmospheric deposition feeding and feeding with water from the surrounding catchment area, without significant inputs from tributaries or from nearby anthropogenic activities. Fish dwelling in these ecosystems represents an excellent indicator for the long-term input of bioaccumulating contaminants, such as POPs and other persistent organic compounds. In the present study, fish from 7 alpine lakes from the Grisons (Switzerland) situated between 2062 and 2637 m above sea level were investigated. With the exception of Laghetto Moesola which is situated adjacent to a mountain pass road, input from local anthropogenic emissions can be excluded for these lakes.

  6. Snow control on active layer and permafrost in steep alpine rock walls (Aiguille du Midi, 3842 m a.s.l, Mont Blanc massif)

    Science.gov (United States)

    Magnin, Florence; Westermann, Sebastian; Pogliotti, Paolo; Ravanel, Ludovic; Deline, Philip

    2016-04-01

    Permafrost degradation through the thickening of the active layer and the rising temperature at depth is a crucial process of rock wall stability. The ongoing increase in rock falls observed during hot periods in mid-latitude mountain ranges is regarded as a result of permafrost degradation. However, the short-term thermal dynamics of alpine rock walls are misunderstood since they result of complex processes related to the interaction of local climate variables, heterogeneous snow cover and heat transfers. As a consequence steady-state and long-term changes that can be approached with simpler process mainly related to air temperature, solar radiations and heat conduction were the most common dynamics to be studied so far. The effect of snow on the bedrock surface temperature is increasingly investigated and has already been demonstrated to be an essential factor of permafrost distribution. Nevertheless, its effect on the year-to-year changes of the active layer thickness and of the permafrost temperature in steep alpine bedrock has not been investigated yet, partly due to the lack of appropriate data. We explore the role of snow accumulations on the active layer and permafrost thermal regime of steep rock walls of a high-elevated site, the Aiguille du Midi (AdM, 3842 m a.s.l, Mont Blanc massif, Western European Alps) by mean of a multi-methods approach. We first analyse six years of temperature records in three 10-m-deep boreholes. Then we describe the snow accumulation patterns on two rock faces by means of automatically processed camera records. Finally, sensitivity analyses of the active layer thickness and permafrost temperature towards timing and magnitude of snow accumulations are performed using the numerical permafrost model CryoGrid 3. The energy balance module is forced with local meteorological measurements on the AdM S face and validated with surface temperature measurements at the weather station location. The heat conduction scheme is calibrated with

  7. An Embedded Sensor Network for Measuring Elevation Effects on Temperature, Humidity, and Evapotranspiration Within a Tropical Alpine Valley

    Science.gov (United States)

    Hellstrom, R. A.; Mark, B. G.

    2006-12-01

    Conditions of glacier recession in the seasonally dry tropical Peruvian Andes motivates research to better constrain the hydrological balance in alpine valleys. Studies suggest that glaciers in the tropical Andes are particularly sensitive to seasonal humidity flux due to the migration of the Intertropical Convergence Zone. However, there is an outstanding need to better measure and model the spatiotemporal variability of energy and water budgets within pro-glacial valleys. In this context, we introduce a novel embedded network of low- cost, discrete temperature and humidity microloggers and an automatic weather station installed in the Llanganuco valley of the Cordillera Blanca. This paper presents data recorded over a full annual cycle (2004- 2005) and reports on network design and results during the dry and wet seasons. The transect of sensors ranging from about 3500 to 4700 m reveal seasonally characteristic diurnal fluctuations in up-valley lapse rate. A process-based water balance model (Brook90) examines the influence of meteorological forcing on evapotranspiration (ET) rates in the valley. The model results suggest that cloud-free daylight conditions enhances ET during the wet season. ET was insignificant throughout the dry season. In addition, we report on the effects of elevation on ET.

  8. Statistical significant changes in ground thermal conditions of alpine Austria during the last decade

    Science.gov (United States)

    Kellerer-Pirklbauer, Andreas

    2016-04-01

    Longer data series (e.g. >10 a) of ground temperatures in alpine regions are helpful to improve the understanding regarding the effects of present climate change on distribution and thermal characteristics of seasonal frost- and permafrost-affected areas. Beginning in 2004 - and more intensively since 2006 - a permafrost and seasonal frost monitoring network was established in Central and Eastern Austria by the University of Graz. This network consists of c.60 ground temperature (surface and near-surface) monitoring sites which are located at 1922-3002 m a.s.l., at latitude 46°55'-47°22'N and at longitude 12°44'-14°41'E. These data allow conclusions about general ground thermal conditions, potential permafrost occurrence, trend during the observation period, and regional pattern of changes. Calculations and analyses of several different temperature-related parameters were accomplished. At an annual scale a region-wide statistical significant warming during the observation period was revealed by e.g. an increase in mean annual temperature values (mean, maximum) or the significant lowering of the surface frost number (F+). At a seasonal scale no significant trend of any temperature-related parameter was in most cases revealed for spring (MAM) and autumn (SON). Winter (DJF) shows only a weak warming. In contrast, the summer (JJA) season reveals in general a significant warming as confirmed by several different temperature-related parameters such as e.g. mean seasonal temperature, number of thawing degree days, number of freezing degree days, or days without night frost. On a monthly basis August shows the statistically most robust and strongest warming of all months, although regional differences occur. Despite the fact that the general ground temperature warming during the last decade is confirmed by the field data in the study region, complications in trend analyses arise by temperature anomalies (e.g. warm winter 2006/07) or substantial variations in the winter

  9. MAPPING ALPINE VEGETATION LOCATION PROPERTIES BY DENSE MATCHING

    Directory of Open Access Journals (Sweden)

    R. Niederheiser

    2016-06-01

    Full Text Available Highly accurate 3D micro topographic mapping in mountain research demands for light equipment and low cost solutions. Recent developments in structure from motion and dense matching techniques provide promising tools for such applications. In the following, the feasibility of terrestrial photogrammetry for mapping topographic location properties of sparsely vegetated areas in selected European mountain regions is investigated. Changes in species composition at alpine vegetation locations are indicators of climate change consequences, such as the pronounced rise of average temperatures in mountains compared to the global average. Better understanding of climate change effects on plants demand for investigations on a micro-topographic scale. We use professional and consumer grade digital single-lens reflex cameras mapping 288 plots each 3 x 3 m on 18 summits in the Alps and Mediterranean Mountains within the GLORIA (GLobal Observation Research Initiative in Alpine environments network. Image matching tests result in accuracies that are in the order of millimetres in the XY-plane and below 0.5 mm in Z-direction at the second image pyramid level. Reconstructing vegetation proves to be a challenge due to its fine and small structured architecture and its permanent movement by wind during image acquisition, which is omnipresent on mountain summits. The produced 3D point clouds are gridded to 6 mm resolution from which topographic parameters such as slope, aspect and roughness are derived. At a later project stage these parameters will be statistically linked to botanical reference data in order to conclude on relations between specific location properties and species compositions.

  10. Growth and Its Relationship to Individual Genetic Diversity of Mountain Hemlock (Tsuga mertensiana at Alpine Treeline in Alaska: Combining Dendrochronology and Genomics

    Directory of Open Access Journals (Sweden)

    Jeremy S. Johnson

    2017-11-01

    Full Text Available Globally, alpine treelines are characterized as temperature-limited environments with strong controls on tree growth. However, at local scales spatially heterogeneous environments generally have more variable impacts on individual patterns of tree growth. In addition to the landscape spatial heterogeneity there is local variability in individual tree genetic diversity (level of individual heterozygosity. It has been hypothesized that higher individual heterozygosity will result in more consistent patterns of growth. In this article, we combine genomics and dendrochronology to explore the relationship between individual genetic diversity and tree growth at a mountain hemlock (Tsuga mertensiana Bong. Carr alpine treeline on the Kenai Peninsula, Alaska, USA. We correlated average observed individual heterozygosity with average tree-ring width and variance in tree-ring width within individuals to test the hypothesis that trees with higher individual heterozygosity will also have more consistent growth patterns, suggesting that they may be more resilient to climate and environmental fluctuations at the alpine treeline. Our results showed that there was no significant relationship between tree growth and individual heterozygosity. However, there was a significant positive relationship between average tree-ring width and variance in tree-ring width implying that overall, fast growing trees in stressful environments, such as the alpine treeline, grow unstably regardless of the level of individual heterozygosity.

  11. Clay mineral formation and fabric development in the DFDP-1B borehole, central Alpine Fault, New Zealand

    International Nuclear Information System (INIS)

    Schleicher, A.M.; Sutherland, R.; Townend, J.; Toy, V.G.; Van der Pluijm, B.A.

    2015-01-01

    Clay minerals are increasingly recognised as important controls on the state and mechanical behaviour of fault systems in the upper crust. Samples retrieved by shallow drilling from two principal slip zones within the central Alpine Fault, South Island, New Zealand, offer an excellent opportunity to investigate clay formation and fluid-rock interaction in an active fault zone. Two shallow boreholes, DFDP-1A (100.6 m deep) and DFDP-1B (151.4 m) were drilled in Phase 1 of the Deep Fault Drilling Project (DFDP-1) in 2011. We provide a mineralogical and textural analysis of clays in fault gouge extracted from the Alpine Fault. Newly formed smectitic clays are observed solely in the narrow zones of fault gouge in drill core, indicating that localised mineral reactions are restricted to the fault zone. The weak preferred orientation of the clay minerals in the fault gouge indicates minimal strain-driven modification of rock fabrics. While limited in extent, our results support observations from surface outcrops and faults systems elsewhere regarding the key role of clays in fault zones and emphasise the need for future, deeper drilling into the Alpine Fault in order to understand correlative mineralogies and fabrics as a function of higher temperature and pressure conditions. (author).

  12. Influence of Slope-Scale Snowmelt on Catchment Response Simulated With the Alpine3D Model

    Science.gov (United States)

    Brauchli, Tristan; Trujillo, Ernesto; Huwald, Hendrik; Lehning, Michael

    2017-12-01

    Snow and hydrological modeling in alpine environments remains challenging because of the complexity of the processes affecting the mass and energy balance. This study examines the influence of snowmelt on the hydrological response of a high-alpine catchment of 43.2 km2 in the Swiss Alps during the water year 2014-2015. Based on recent advances in Alpine3D, we examine how snow distributions and liquid water transport within the snowpack influence runoff dynamics. By combining these results with multiscale observations (snow lysimeter, distributed snow depths, and streamflow), we demonstrate the added value of a more realistic snow distribution at the onset of melt season. At the site scale, snowpack runoff is well simulated when the mass balance errors are corrected (R2 = 0.95 versus R2 = 0.61). At the subbasin scale, a more heterogeneous snowpack leads to a more rapid runoff pulse originating in the shallower areas while an extended melting period (by a month) is caused by snowmelt from deeper areas. This is a marked improvement over results obtained using a traditional precipitation interpolation method. Hydrological response is also improved by the more realistic snowpack (NSE of 0.85 versus 0.74), even though calibration processes smoothen out the differences. The added value of a more complex liquid water transport scheme is obvious at the site scale but decreases at larger scales. Our results highlight not only the importance but also the difficulty of getting a realistic snowpack distribution even in a well-instrumented area and present a model validation from multiscale experimental data sets.

  13. Snow cover dynamics and water balance in complex high alpine terrain

    Science.gov (United States)

    Warscher, Michael; Kraller, Gabriele; Kunstmann, Harald; Strasser, Ulrich; Franz, Helmut

    2010-05-01

    The water balance in high alpine regions in its full complexity is so far insufficiently understood. High altitudinal gradients, a strong variability of meteorological variables in time and space, complex hydrogeological situations, unquantified lateral snow transport processes and heterogenous snow cover dynamics result in high uncertainties in the quantification of the water balance. To achieve interpretable modeling results we have complemented the deterministic hydrological model WaSiM-ETH with the high-alpine specific snow model AMUNDSEN. The integration of the new snow module was done to improve the modeling of water fluxes influenced by the dynamics of the snow cover, which greatly affect the water cycle in high alpine regions. To enhance the reproduction of snow deposition and ablation processes, the new approach calculates the energy balance of the snow cover considering the terrain-dependent radiation fluxes, the interaction between tree canopy and snow cover as well as lateral snow transport processes. The test site for our study is the Berchtesgaden National Park which is characterized by an extreme topography with mountain ranges covering an altitude from 607 to 2713 m.a.s.l. About one quarter of the investigated catchment area, which comprises 433 km² in total, is terrain steeper than 35°. Due to water soluble limestone being predominant in the region, a high number of subsurface water pathways (karst) exist. The results of several tracer experiments and extensive data of spring observations provide additional information to meet the challenge of modeling the unknown subsurface pathways and the complex groundwater system of the region. The validation of the new snow module is based on a dense network of meteorological stations which have been adapted to measure physical properties of the snow cover like snow water equivalent and liquid water content. We will present first results which show that the integration of the new snow module generates a

  14. Impact of climatic change on alpine ecosystems: inference and prediction

    Directory of Open Access Journals (Sweden)

    Nigel G. Yoccoz

    2011-01-01

    Full Text Available Alpine ecosystems will be greatly impacted by climatic change, but other factors, such as land use and invasive species, are likely to play an important role too. Climate can influence ecosystems at several levels. We describe some of them, stressing methodological approaches and available data. Climate can modify species phenology, such as flowering date of plants and hatching date in insects. It can also change directly population demography (survival, reproduction, dispersal, and therefore species distribution. Finally it can effect interactions among species – snow cover for example can affect the success of some predators. One characteristic of alpine ecosystems is the presence of snow cover, but surprisingly the role played by snow is relatively poorly known, mainly for logistical reasons. Even if we have made important progress regarding the development of predictive models, particularly so for distribution of alpine plants, we still need to set up observational and experimental networks which properly take into account the variability of alpine ecosystems and of their interactions with climate.Les écosystèmes alpins vont être grandement influencés par les changements climatiques à venir, mais d’autres facteurs, tels que l’utilisation des terres ou les espèces invasives, pourront aussi jouer un rôle important. Le climat peut influencer les écosystèmes à différents niveaux, et nous en décrivons certains, en mettant l’accent sur les méthodes utilisées et les données disponibles. Le climat peut d’abord modifier la phénologie des espèces, comme la date de floraison des plantes ou la date d’éclosion des insectes. Il peut ensuite affecter directement la démographie des espèces (survie, reproduction, dispersion et donc à terme leur répartition. Il peut enfin agir sur les interactions entre espèces – le couvert neigeux par exemple modifie le succès de certains prédateurs. Une caractéristique des

  15. Measurements concerning the immission load in the Alpine region with passive samplers

    International Nuclear Information System (INIS)

    Kirchner, M.; Suppan, P.

    1994-02-01

    This project deals with measurements concerning the nuisance situation in various areas of the Alpine region using selected passive collectors for ozone and NO 2 . In a first partial step (phase I) a comparative experiment, building on a pilot test, with the use of different passive collectors in sites in the Alpine region was carried through. In a second stage of the project (Phase II) two types of passive collectors were used at suitable altitude profiles in the Alpine region to measure ozone levels. In this way, more detailed knowledge on the vertical distribution of ozone in areas with a varied orography was to be obtained. The study is a joint project of numerous scientific tasks forces from several countries and a number of institutions participating in the 'ARGE ALP' working group of Alpine countries. Results of the first project phase are reported. (orig./KW) [de

  16. Climatic warming strengthens a positive feedback between alpine shrubs and fire.

    Science.gov (United States)

    Camac, James S; Williams, Richard J; Wahren, Carl-Henrik; Hoffmann, Ary A; Vesk, Peter A

    2017-08-01

    Climate change is expected to increase fire activity and woody plant encroachment in arctic and alpine landscapes. However, the extent to which these increases interact to affect the structure, function and composition of alpine ecosystems is largely unknown. Here we use field surveys and experimental manipulations to examine how warming and fire affect recruitment, seedling growth and seedling survival in four dominant Australian alpine shrubs. We found that fire increased establishment of shrub seedlings by as much as 33-fold. Experimental warming also doubled growth rates of tall shrub seedlings and could potentially increase their survival. By contrast, warming had no effect on shrub recruitment, postfire tussock regeneration, or how tussock grass affected shrub seedling growth and survival. These findings indicate that warming, coupled with more frequent or severe fires, will likely result in an increase in the cover and abundance of evergreen shrubs. Given that shrubs are one of the most flammable components in alpine and tundra environments, warming is likely to strengthen an existing feedback between woody species abundance and fire in these ecosystems. © 2017 John Wiley & Sons Ltd.

  17. The role of solar UV radiation in the ecology of alpine lakes.

    Science.gov (United States)

    Sommaruga, R

    2001-09-01

    Solar ultraviolet radiation (UVR, 290-400 nm) is a crucial environmental factor in alpine lakes because of the natural increase of the UVR flux with elevation and the high water transparency of these ecosystems. The ecological importance of UVR, however, has only recently been recognized. This review, examines the general features of alpine lakes regarding UVR, summarizes what is known about the role of solar UVR in the ecology of alpine lakes, and identifies future research directions. Unlike the pattern observed in most lowland lakes, variability of UV attenuation in alpine lakes is poorly explained by differences in dissolved organic carbon (DOC) concentrations, and depends mainly on optical characteristics (absorption) of the chromophoric dissolved organic matter (CDOM). Within the water column of lakes with low DOC concentrations (0.2-0.4 mg l(-1)), UV attenuation is influenced by phytoplankton whose development at depth (i.e. the deep chlorophyll maximum) causes important changes in UV attenuation. Alpine aquatic organisms have developed a number of strategies to minimize UV damage. The widespread synthesis or bioaccumulation of different compounds that directly or indirectly absorb UV energy is one such strategy. Although most benthic and planktonic primary producers and crustacean zooplankton are well adapted to high intensities of solar radiation, heterotrophic protists, bacteria, and viruses seem to be particularly sensitive to UVR. Understanding the overall impact of UVR on alpine lakes would need to consider synergistic and antagonistic processes resulting from the pronounced climatic warming, which have the potential to modify the UV underwater climate and consequently the stress on aquatic organisms.

  18. Estimating Forest Carbon Stock in Alpine and Arctic Ecotones of the Urals

    Directory of Open Access Journals (Sweden)

    V. A. Usoltsev

    2014-10-01

    assessing the income part of the carbon cycle in forests of alpine and arctic tree communities of the Ural region, as well as when validating the results of simulation experiments on evaluation of the carbon depositing capacity of forests.

  19. Seedling recruitment of forb species under experimental microhabitats in alpine grassland

    International Nuclear Information System (INIS)

    Li, S. S.; Yu, L.; Lin, W. G.; Pingi, T. F.

    2015-01-01

    Which factors limit plant seedling recruitment in alpine meadow of the Qinghai-Tibetan Plateau (QTP), China? This study examined the relative influence of seed mass and microsites (resulted from grazing disturbance) on field seedling emergence and survival of nineteen alpine herbaceous species with a range of traits in QTP. Seed mass had significant effects on seedling emergence and survival eliminating influence of light and nutrient variances among these species. The larger-seed species had more advantageous than the smaller-seed species in seedling survival, but it was disadvatage for seedling emergence, especially under high nutrient availability and low light intensity conditions. Light had obvious effects on seedling survival, but less effects on seedling emergence for these species. Moreover, nutrient and light treatments altered the regression relationships of seed mass and seedling emergence and survival and the order of significances was L25>L50>L100>L10>L4. These results suggested that seed mass may restrict seedling recruitment processes, however, light and nutrient availability all have significant effects on seedling emergence and survival for these alpine species. Moderate light intensity was propitious to seedling emergence and survival in alpine grassland. This suggests that ecological factors in alpine grassland provide a stochastic influence on different seed-mass species. These trends may help to explain why many small-seeded species of Asteraceae and Gramineae tend to be more abundant in disturbed habitats. (author)

  20. Dairy cattle on Norwegian alpine rangelands – grazing preferences and milk quality

    NARCIS (Netherlands)

    Sickel, H; Abrahamsen, R K; Eldegard, K; Lunnan, T; Norderhaug, A; Petersen, M.A.; Sickel, M.; Steenhuisen, F.; Ohlson, M.

    2014-01-01

    The results from the study ‘Effects of vegetation and grazing preferences on the quality of alpine dairy products’ will be presented. The main objective of the project was to investigate the connections bet - ween alpine rangeland vegetation, landscape use and grazing preferences of free ranging

  1. Pathogenic Yersinia enterocolitica O:3 isolated from a hunted wild alpine ibex.

    Science.gov (United States)

    Joutsen, S; Sarno, E; Fredriksson-Ahomaa, M; Cernela, N; Stephan, R

    2013-03-01

    Occurrence of Yersinia spp. in wild ruminants was studied and the strains were characterized to get more information on the epidemiology of enteropathogenic Yersinia in the wildlife. In total, faecal samples of 77 red deer, 60 chamois, 55 roe deer and 27 alpine ibex were collected during 3 months of the hunting season in 2011. The most frequently identified species was Y. enterocolitica found in 13%, 10%, 4% and 2% of roe deer, red deer, alpine ibex and chamois, respectively. Interestingly, one Y. enterocolitica O:3 strain, isolated from an alpine ibex, carried the important virulence genes located on the virulence plasmid (yadA and virF) and in the chromosome (ail, hreP, myfA and ystA). Most of the Y. enterocolitica strains belonged to biotype 1A of which 14 were ystB positive. Further studies are needed to clarify the importance of alpine ibex as a reservoir of pathogenic Y. enterocolitica.

  2. Innovation in the plural of the alpine cre-actors

    Directory of Open Access Journals (Sweden)

    Andréa Finger-Stich

    2009-06-01

    Full Text Available The capacity to innovate for a sustainable development of alpine territories cannot depend only on economic, legal and political conditions defined by the State at national and international levels. It depends also on local conditions that situate historically and geographically the actors in a continuity of social and ecological relationships. This approach highlights the collective – thus organisational – dimensions of the innovation process, including the imagination, the development, the implementation and even the diffusion of a new practice. Our point of view is that for contributing to the sustainable development of the Alps, innovations need to change the ecological, political, social and cultural relationships engaging the actors in these territories. This change affects as much the object territory as the subject actor of the territory. This is why innovating in the Alps means also innovating the Alps and the alpine actors (Cosalp, 2008. Based on a research about local people’s participation in the management of alpine communal forests, the article shows the importance of local interactions involving actors of diverse occupation, gender, age and origins1.La capacité d’innovation pour un développement durable des territoires alpins ne peut dépendre uniquement de conditions économiques, légales et politiques définies par les Etats aux échelles nationale et internationale. Elle dépend aussi de conditions locales, qui situent historiquement et géographiquement les acteurs dans une continuité de relations sociales et écologiques. Cette perspective accentue l’importance de la dimension collective, donc organisationnelle, du processus d’innovation, allant de l’imagination, puis au développement, à la réalisation – voire la diffusion – d’une nouvelle pratique. Le point de vue de cet article est qu’une innovation, pour contribuer au développement durable des Alpes, doit changer les relations

  3. L’innovation au pluriel des cré-acteurs alpins

    Directory of Open Access Journals (Sweden)

    Andréa Finger-Stich

    2009-06-01

    Full Text Available La capacité d’innovation pour un développement durable des territoires alpins ne peut dépendre uniquement de conditions économiques, légales et politiques définies par les Etats aux échelles nationale et internationale. Elle dépend aussi de conditions locales, qui situent historiquement et géographiquement les acteurs dans une continuité de relations sociales et écologiques. Cette perspective accentue l’importance de la dimension collective, donc organisationnelle, du processus d’innovation, allant de l’imagination, puis au développement, à la réalisation – voire la diffusion – d’une nouvelle pratique. Le point de vue de cet article est qu’une innovation, pour contribuer au développement durable des Alpes, doit changer les relations écologique, politique, sociale et culturelle, qui engagent les acteurs du territoire. Ce changement affecte tant l’objet territoire que le sujet acteur du territoire. C’est pourquoi, innover dans les Alpes revient aussi à innover les Alpes et les acteurs alpins(Cosalp, 2008. Sur la base d’une recherche sur la participation des populations locales dans la gestion de forêts communales alpines, l’article relève l’importance des interactions locales impliquant les acteurs d’occupations, genres, âges et origines divers1.The capacity to innovate for a sustainable development of alpine territories cannot depend only on economic, legal and political conditions defined by the State at national and international levels. It depends also on local conditions that situate historically and geographically the actors in a continuity of social and ecological relationships. This approach highlights the collective - thus organisational - dimensions of the innovation process, including the imagination, the development, the implementation and even the diffusion of a new practice. Our point of view is that for contributing to the sustainable development of the Alps, innovations need to

  4. Ice barriers promote supercooling and prevent frost injury in reproductive buds, flowers and fruits of alpine dwarf shrubs throughout the summer.

    Science.gov (United States)

    Kuprian, Edith; Briceño, Verónica F; Wagner, Johanna; Neuner, Gilbert

    2014-10-01

    Over-wintering reproductive buds of many woody plants survive frost by supercooling. The bud tissues are isolated from acropetally advancing ice by the presence of ice barriers that restrict ice growth. Plants living in alpine environments also face the risk of ice formation in summer months. Little knowledge exists, how reproductive structures of woody alpine plants are protected from frost injury during episodic summer frosts. In order to address this question, frost resistance of three common dwarf shrubs, Calluna vulgaris , Empetrum hermaphroditum and Loiseleuria procumbens was measured and ice formation and propagation were monitored in twigs bearing reproductive shoots during various stages of reproductive development (bud, anthesis, and fruit) throughout the alpine summer. Results indicated that, in the investigated species, ice barriers were present at all reproductive stages, isolating the reproductive shoots from ice advancing from the subtending vegetative shoot. Additionally, in the reproductive stems ice nucleating agents that are active at warm, sub-zero temperatures, were absent. The ice barriers were 100% effective, with the exception of L. procumbens , where in 13% of the total observations, the ice barrier failed. The ice barriers were localized at the base of the pedicel, at the anatomical junction of the vegetative and reproductive shoot. There, structural aspects of the tissue impede or prevent ice from advancing from the frozen stem into the pedicel of the reproductive shoot. Under the experimental conditions used in this study, ice nucleation initially occurred in the stem of the vegetative shoot at species-specific mean temperatures in the range of -4.7 to -5.8 °C. Reproductive shoots, however, remained supercooled and ice free down to a range of -7.2 to -18.2 °C or even below -22 °C, the lowest temperature applied in the study. This level of supercooling is sufficient to prevent freezing of reproductive structures at the lowest air

  5. Uranium-series dating of fossil bones from alpine caves

    International Nuclear Information System (INIS)

    Leitner-Wild, E.; Steffan, I.

    1993-01-01

    During the course of an investigation of fossil cave bear populations the uranium-series method for absolute age determination has been applied to bone material. The applicability of the method to bone samples from alpine caves is demonstrated by the concordance of U/Th and U/Pa ages and cross-checks with the radiocarbon method. Stratigraphic agreement between bone ages and carbonate speleothem ages also indicates the potential of the uranium-series method as a suitable tool for the age determination of fossil bones from alpine cave environments. (Author)

  6. Transient thermal effects in Alpine permafrost

    Directory of Open Access Journals (Sweden)

    J. Noetzli

    2009-04-01

    Full Text Available In high mountain areas, permafrost is important because it influences the occurrence of natural hazards, because it has to be considered in construction practices, and because it is sensitive to climate change. The assessment of its distribution and evolution is challenging because of highly variable conditions at and below the surface, steep topography and varying climatic conditions. This paper presents a systematic investigation of effects of topography and climate variability that are important for subsurface temperatures in Alpine bedrock permafrost. We studied the effects of both, past and projected future ground surface temperature variations on the basis of numerical experimentation with simplified mountain topography in order to demonstrate the principal effects. The modeling approach applied combines a distributed surface energy balance model and a three-dimensional subsurface heat conduction scheme. Results show that the past climate variations that essentially influence present-day permafrost temperatures at depth of the idealized mountains are the last glacial period and the major fluctuations in the past millennium. Transient effects from projected future warming, however, are likely larger than those from past climate conditions because larger temperature changes at the surface occur in shorter time periods. We further demonstrate the accelerating influence of multi-lateral warming in steep and complex topography for a temperature signal entering the subsurface as compared to the situation in flat areas. The effects of varying and uncertain material properties (i.e., thermal properties, porosity, and freezing characteristics on the subsurface temperature field were examined in sensitivity studies. A considerable influence of latent heat due to water in low-porosity bedrock was only shown for simulations over time periods of decades to centuries. At the end, the model was applied to the topographic setting of the Matterhorn

  7. A kinematic and kinetic study of alpine skiing technique in slalom

    OpenAIRE

    Reid, Robert C.

    2010-01-01

    Avhandling (doktorgrad) - Norges idrettshøgskole, 2010. Despite a large body of lay and professional literature covering numerous aspects of alpine skiing technique, only a limited number of published scientific investigations have examined the relationship between skier technical and tactical characteristics and racing performance. As a consequence, our scientific understanding of how the underlying mechanics of alpine ski racing technique relate to performance is surprisin...

  8. High solar radiation hinders tree regeneration above the alpine treeline in northern Ecuador

    NARCIS (Netherlands)

    Bader, M.Y.; Geloof, I. van; Rietkerk, M.G.

    2007-01-01

    Many tropical alpine treelines lie below their climatic potential, because of natural or anthropogenic causes. Forest extension above the treeline depends on the ability of trees to establish in the alpine environment. This ability may be limited by different factors, such as low

  9. Energy Consumption and Greenhouse Gas Emissions Resulting From Tourism Travel in an Alpine Setting

    Directory of Open Access Journals (Sweden)

    Rainer Unger

    2016-11-01

    Full Text Available Tourism—with its social, economic, and ecological dimensions—can be an important driver of sustainable development of alpine communities. Tourism is essential for local people's incomes and livelihoods, but it can also have a major impact on the local environment, landscape aesthetics, and (mainly through tourist transport global climate change. A project currently underway is developing the Austrian mountain municipality of Alpbach into a role model for competitive and sustainable year-round alpine tourism using an integrated and spatially explicit approach that considers energy demand and supply related to housing, infrastructure, and traffic in the settlement and the skiing area. As the first outcome of the project, this article focuses on the development of the Model of Alpine Tourism and Transportation, a geographic information system–based tool for calculating, in detail, energy consumption and greenhouse gas emissions resulting from travel to a single alpine holiday destination. Analysis results show that it is crucial to incorporate both direct and indirect energy use and emissions as each contributes significantly to the climate impact of travel. The study fills a research gap in carbon impact appraisal studies of tourism transport in the context of alpine tourism at the destination level. Our findings will serve as a baseline for the development of comprehensive policies and agendas promoting the transformation toward sustainable alpine tourism.

  10. Increasing alpine transit traffic through Switzerland will considerably enhance high altitude alpine pollutant levels

    Energy Technology Data Exchange (ETDEWEB)

    Prevot, A S.H.; Dommen, J; Furger, M; Graber, W K [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    Within the EU-Project VOTALP (Vertical Ozone Transports in the Alps), we have shown that deep alpine valleys like the Mesolcina Valley very efficiently transport air out of the polluted valley up to altitudes between 2000 and near 4000 m asl (above sea level). Pollutants emitted in these valleys are very efficiently transported up to high altitudes. (author) 2 figs., 1 tab., 2 refs.

  11. Climate change and alpine stream biology

    DEFF Research Database (Denmark)

    Hotaling, Scott; Finn, Debra S.; Joseph Giersch, J.

    2017-01-01

    micro- to macroscopic organisms and genes to communities. Herein, we describe the current state of alpine stream biology from an organism-focused perspective. We begin by reviewing seven standard and emerging approaches that combine to form the current state of the discipline. We follow with a call...

  12. Anterior cruciate ligament injury/reinjury in alpine ski racing: a narrative review

    Science.gov (United States)

    Jordan, Matthew J; Aagaard, Per; Herzog, Walter

    2017-01-01

    The purpose of the present review was to: 1) provide an overview of the current understanding on the epidemiology, etiology, risk factors, and prevention methods for anterior cruciate ligament (ACL) injury in alpine ski racing; and 2) provide an overview of what is known pertaining to ACL reinjury and return to sport after ACL injury in alpine ski racing. Given that most of the scientific studies on ACL injuries in alpine ski racing have been descriptive, and that very few studies contributed higher level scientific evidence, a nonsystematic narrative review was employed. Three scholarly databases were searched for articles on ACL injury or knee injury in alpine ski racing. Studies were classified according to their relevance in relation to epidemiology, etiology, risk factors, and return to sport/reinjury prevention. Alpine ski racers (skiers) were found to be at high risk for knee injuries, and ACL tears were the most frequent diagnosis. Three primary ACL injury mechanism were identified that involved tibial internal rotation and anteriorly directed shear forces from ski equipment and the environment. While trunk muscle strength imbalance and genetics were found to be predictive of ACL injuries in development-level skiers, there was limited scientific data on ACL injury risk factors among elite skiers. Based on expert opinion, research on injury risk factors should focus on equipment design, course settings/speed, and athlete factors (eg, fitness). While skiers seem to make a successful recovery following ACL injury, there may be persistent neuromuscular deficits. Future research efforts should be directed toward prospective studies on ACL injury/reinjury prevention in both male and female skiers and toward the effects of knee injury on long-term health outcomes, such as the early development of osteoarthritis. International collaborations may be necessary to generate sufficient statistical power for ACL injury/reinjury prevention research in alpine ski racing

  13. Facilitation among plants in alpine environments in the face of climate change

    Directory of Open Access Journals (Sweden)

    Fabien eAnthelme

    2014-08-01

    Full Text Available While there is a large consensus that plant–plant interactions are a crucial component of the response of plant communities to the effects of climate change, available data remain scarce, particularly in alpine systems. This represents an important obstacle to making consistent predictions about the future of plant communities. Here, we review current knowledge on the effects of climate change on facilitation among alpine plant communities and propose directions for future research. In established alpine communities, while warming seemingly generates a net facilitation release, earlier snowmelt may increase facilitation. Some nurse plants are able to buffer microenvironmental changes in the long term and may ensure the persistence of other alpine plants through local migration events. For communities migrating to higher elevations, facilitation should play an important role in their reorganization because of the harsher environmental conditions. In particular, the absence of efficient nurse plants might slow down upward migration, possibly generating chains of extinction. Facilitation–climate change relationships are expected to shift along latitudinal gradients because (1 the magnitude of warming is predicted to vary along these gradients, and (2 alpine environments are significantly different at low vs. high latitudes. Data on these expected patterns are preliminary and thus need to be tested with further studies on facilitation among plants in alpine environments that have thus far not been considered. From a methodological standpoint, future studies will benefit from the spatial representation of the microclimatic environment of plants to predict their response to climate change. Moreover, the acquisition of long-term data on the dynamics of plant–plant interactions, either through permanent plots or chronosequences of glacial recession, may represent powerful approaches to clarify the relationship between plant interactions and

  14. Facilitation among plants in alpine environments in the face of climate change.

    Science.gov (United States)

    Anthelme, Fabien; Cavieres, Lohengrin A; Dangles, Olivier

    2014-01-01

    While there is a large consensus that plant-plant interactions are a crucial component of the response of plant communities to the effects of climate change, available data remain scarce, particularly in alpine systems. This represents an important obstacle to making consistent predictions about the future of plant communities. Here, we review current knowledge on the effects of climate change on facilitation among alpine plant communities and propose directions for future research. In established alpine communities, while warming seemingly generates a net facilitation release, earlier snowmelt may increase facilitation. Some nurse plants are able to buffer microenvironmental changes in the long term and may ensure the persistence of other alpine plants through local migration events. For communities migrating to higher elevations, facilitation should play an important role in their reorganization because of the harsher environmental conditions. In particular, the absence of efficient nurse plants might slow down upward migration, possibly generating chains of extinction. Facilitation-climate change relationships are expected to shift along latitudinal gradients because (1) the magnitude of warming is predicted to vary along these gradients, and (2) alpine environments are significantly different at low vs. high latitudes. Data on these expected patterns are preliminary and thus need to be tested with further studies on facilitation among plants in alpine environments that have thus far not been considered. From a methodological standpoint, future studies will benefit from the spatial representation of the microclimatic environment of plants to predict their response to climate change. Moreover, the acquisition of long-term data on the dynamics of plant-plant interactions, either through permanent plots or chronosequences of glacial recession, may represent powerful approaches to clarify the relationship between plant interactions and climate change.

  15. Abiotic and biotic controls of spatial pattern at alpine treeline

    Science.gov (United States)

    Malanson, George P.; Xiao, Ningchuan; Alftine, K.J.; Bekker, Mathew; Butler, David R.; Brown, Daniel G.; Cairns, David M.; Fagre, Daniel; Walsh, Stephen J.

    2000-01-01

    At alpine treeline, trees and krummholz forms affect the environment in ways that increase their growth and reproduction. We assess the way in which these positive feedbacks combine in spatial patterns to alter the environment in the neighborhood of existing plants. The research is significant because areas of alpine tundra are susceptible to encroachment by woody species as climate changes. Moreover, understanding the general processes of plant invasion is important. The importance of spatial pattern has been recognized, but the spatial pattern of positive feedbacks per se has not been explored in depth. We present a linked set of models of vegetation change at an alpine forest-tundra ecotone. Our aim is to create models that are as simple as possible in order to test specific hypotheses. We present results from a model of the resource averaging hypothesis and the positive feedback switch hypothesis of treelines. We compare the patterns generated by the models to patterns observed in fine scale remotely sensed data.

  16. Alpine treeline and timberline dynamics during the Holocene in the Northern Romanian Carpathians

    Directory of Open Access Journals (Sweden)

    Anca GEANTĂ

    2014-11-01

    Full Text Available High altitude environments (treeline and alpine communities are particularly sensitive to climate changes, disturbances and land-use changes due to their limited tolerance and adaptability range, habitat fragmentation and habitat restriction. The current and future climate warming is anticipated to shift the tree- and timberlines upwards thus affecting alpine plant communities and causing land-cover change and fragmentation of alpine habitats. An upslope movement of some trees, shrubs and cold adapted alpine herbs as a response to the current climate warming has already been noted in many montane and subalpine regions.Four Holocene peat and lacustrine sediment sequences located between 1670 and 1918 m a.s.l. (Fig.1, in the Rodna Mountains (Northern Romania, Eastern Carpathians are used with the aim to determine: i the sensitivity of high mountain habitats to climate, fire and land use changes; ii tree- and timberline shifts: and iii the influence of landscape topography on trees and shrubs.

  17. RCCS Experiments and Validation for High Temperature Gas-Cooled Reactor

    International Nuclear Information System (INIS)

    Chang Oh; Cliff Davis; Goon C. Park

    2007-01-01

    A reactor cavity cooling system (RCCS), an air-cooled helical coil RCCS unit immersed in the water pool, was proposed to overcome the disadvantages of the weak cooling ability of air-cooled RCCS and the complex structure of water-cooled RCCS for the high temperature gas-cooled reactor (HTGR). An experimental apparatus was constructed to investigate the various heat transfer phenomena in the water pool type RCCS, such as the natural convection of air inside the cavity, radiation in the cavity, the natural convection of water in the water pool and the forced convection of air in the cooling pipe. The RCCS experimental results were compared with published correlations. The CFX code was validated using data from the air-cooled portion of the RCCS. The RELAP5 code was validated using measured temperatures from the reactor vessel and cavity walls

  18. Atmospheric deposition as a source of carbon and nutrients to an alpine catchment of the Colorado Rocky Mountains

    Science.gov (United States)

    Mladenov, N.; Williams, M. W.; Schmidt, S. K.; Cawley, K.

    2012-08-01

    Many alpine areas are experiencing deglaciation, biogeochemical changes driven by temperature rise, and changes in atmospheric deposition. There is mounting evidence that the water quality of alpine streams may be related to these changes, including rising atmospheric deposition of carbon (C) and nutrients. Given that barren alpine soils can be severely C limited, atmospheric deposition sources may be an important source of C and nutrients for these environments. We evaluated the magnitude of atmospheric deposition of C and nutrients to an alpine site, the Green Lake 4 catchment in the Colorado Rocky Mountains. Using a long-term dataset (2002-2010) of weekly atmospheric wet deposition and snowpack chemistry, we found that volume weighted mean dissolved organic carbon (DOC) concentrations were 1.12 ± 0.19 mg l-1, and weekly concentrations reached peaks as high at 6-10 mg l-1 every summer. Total dissolved nitrogen concentration also peaked in the summer, whereas total dissolved phosphorus and calcium concentrations were highest in the spring. To investigate potential sources of C in atmospheric deposition, we evaluated the chemical quality of dissolved organic matter (DOM) and relationships between DOM and other solutes in wet deposition. Relationships between DOC concentration, fluorescence, and nitrate and sulfate concentrations suggest that pollutants from nearby urban and agricultural sources and organic aerosols derived from sub-alpine vegetation may influence high summer DOC wet deposition concentrations. Interestingly, high DOC concentrations were also recorded during "dust-in-snow" events in the spring, which may reflect an association of DOM with dust. Detailed chemical and spectroscopic analyses conducted for samples collected in 2010 revealed that the DOM in many late spring and summer samples was less aromatic and polydisperse and of lower molecular weight than that of winter and fall samples. Our C budget estimates for the Green Lake 4 catchment

  19. Introgression from domestic goat generated variation at the major histocompatibility complex of Alpine ibex.

    Directory of Open Access Journals (Sweden)

    Christine Grossen

    2014-06-01

    Full Text Available The major histocompatibility complex (MHC is a crucial component of the vertebrate immune system and shows extremely high levels of genetic polymorphism. The extraordinary genetic variation is thought to be ancient polymorphisms maintained by balancing selection. However, introgression from related species was recently proposed as an additional mechanism. Here we provide evidence for introgression at the MHC in Alpine ibex (Capra ibex ibex. At a usually very polymorphic MHC exon involved in pathogen recognition (DRB exon 2, Alpine ibex carried only two alleles. We found that one of these DRB alleles is identical to a DRB allele of domestic goats (Capra aegagrus hircus. We sequenced 2489 bp of the coding and non-coding regions of the DRB gene and found that Alpine ibex homozygous for the goat-type DRB exon 2 allele showed nearly identical sequences (99.8% to a breed of domestic goats. Using Sanger and RAD sequencing, microsatellite and SNP chip data, we show that the chromosomal region containing the goat-type DRB allele has a signature of recent introgression in Alpine ibex. A region of approximately 750 kb including the DRB locus showed high rates of heterozygosity in individuals carrying one copy of the goat-type DRB allele. These individuals shared SNP alleles both with domestic goats and other Alpine ibex. In a survey of four Alpine ibex populations, we found that the region surrounding the DRB allele shows strong linkage disequilibria, strong sequence clustering and low diversity among haplotypes carrying the goat-type allele. Introgression at the MHC is likely adaptive and introgression critically increased MHC DRB diversity in the genetically impoverished Alpine ibex. Our finding contradicts the long-standing view that genetic variability at the MHC is solely a consequence of ancient trans-species polymorphism. Introgression is likely an underappreciated source of genetic diversity at the MHC and other loci under balancing selection.

  20. Introgression from Domestic Goat Generated Variation at the Major Histocompatibility Complex of Alpine Ibex

    Science.gov (United States)

    Grossen, Christine; Keller, Lukas; Biebach, Iris; Croll, Daniel

    2014-01-01

    The major histocompatibility complex (MHC) is a crucial component of the vertebrate immune system and shows extremely high levels of genetic polymorphism. The extraordinary genetic variation is thought to be ancient polymorphisms maintained by balancing selection. However, introgression from related species was recently proposed as an additional mechanism. Here we provide evidence for introgression at the MHC in Alpine ibex (Capra ibex ibex). At a usually very polymorphic MHC exon involved in pathogen recognition (DRB exon 2), Alpine ibex carried only two alleles. We found that one of these DRB alleles is identical to a DRB allele of domestic goats (Capra aegagrus hircus). We sequenced 2489 bp of the coding and non-coding regions of the DRB gene and found that Alpine ibex homozygous for the goat-type DRB exon 2 allele showed nearly identical sequences (99.8%) to a breed of domestic goats. Using Sanger and RAD sequencing, microsatellite and SNP chip data, we show that the chromosomal region containing the goat-type DRB allele has a signature of recent introgression in Alpine ibex. A region of approximately 750 kb including the DRB locus showed high rates of heterozygosity in individuals carrying one copy of the goat-type DRB allele. These individuals shared SNP alleles both with domestic goats and other Alpine ibex. In a survey of four Alpine ibex populations, we found that the region surrounding the DRB allele shows strong linkage disequilibria, strong sequence clustering and low diversity among haplotypes carrying the goat-type allele. Introgression at the MHC is likely adaptive and introgression critically increased MHC DRB diversity in the genetically impoverished Alpine ibex. Our finding contradicts the long-standing view that genetic variability at the MHC is solely a consequence of ancient trans-species polymorphism. Introgression is likely an underappreciated source of genetic diversity at the MHC and other loci under balancing selection. PMID:24945814

  1. Climate change links fate of glaciers and an endemic alpine invertebrate

    Science.gov (United States)

    Muhlfeld, Clint C.; Giersch, J. Joseph; Hauer, F. Richard; Pederson, Gregory T.; Luikart, Gordon; Peterson, Douglas P.; Downs, Christopher C.; Fagre, Daniel B.

    2011-01-01

    Climate warming in the mid- to high-latitudes and high-elevation mountainous regions is occurring more rapidly than anywhere else on Earth, causing extensive loss of glaciers and snowpack. However, little is known about the effects of climate change on alpine stream biota, especially invertebrates. Here, we show a strong linkage between regional climate change and the fundamental niche of a rare aquatic invertebrate—themeltwater stonefly Lednia tumana—endemic toWaterton- Glacier International Peace Park, Canada and USA. L. tumana has been petitioned for listing under the U.S. Endangered Species Act due to climate-change-induced glacier loss, yet little is known on specifically how climate impacts may threaten this rare species and many other enigmatic alpine aquatic species worldwide. During 14 years of research, we documented that L. tumana inhabits a narrow distribution, restricted to short sections (∼500 m) of cold, alpine streams directly below glaciers, permanent snowfields, and springs. Our simulation models suggest that climate change threatens the potential future distribution of these sensitive habitats and persistence of L. tumana through the loss of glaciers and snowfields. Mountaintop aquatic invertebrates are ideal early warning indicators of climate warming in mountain ecosystems. Research on alpine invertebrates is urgently needed to avoid extinctions and ecosystem change.

  2. Stacking and metamorphism of continuous segments of subducted lithosphere in a high-pressure wedge: The example of Alpine Corsica (France)

    Science.gov (United States)

    Vitale Brovarone, Alberto; Beyssac, Olivier; Malavieille, Jacques; Molli, Giancarlo; Beltrando, Marco; Compagnoni, Roberto

    2013-01-01

    Alpine Corsica consists of a stack of variably metamorphosed units of continental and Tethys-derived rocks. It represents an excellent example of high-pressure (HP) orogenic belt, such as the Western Alps, exposed over a small and accessible area. Compared to the Western Alps, the geology of Alpine Corsica is poorly unraveled. During the 1970s-80s, based on either lithostratigraphic or metamorphic field observations, various classifications of the belt have been proposed, but these classifications have been rarely matched together. Furthermore, through time, the internal complexity of large domains has been progressively left aside in the frame of large-scale geodynamic reconstructions. As a consequence, major open questions on the internal structure of the belt have remained unsolved. Apart from a few local studies, Alpine Corsica has not benefited of modern developments in petrology and basin research. This feature results in several uncertainties when combining lithostratigraphic and metamorphic patterns and, consequently, in the definition of an exhaustive architecture of the belt. In this paper we provide a review on the geology of Alpine Corsica, paying particular attention to the available lithostratigraphic and metamorphic classifications of the metamorphic terranes. These data are completed by a new and exhaustive metamorphic dataset obtained by means of thermometry based on Raman Spectroscopy of Carbonaceous Material (RSCM). This technique provides reliable insights on the peak temperature of the metamorphic history for CM-bearing metasediments. A detailed metamorphic characterization of metasediments, which have been previously largely ignored due to retrogression or to the lack of diagnostic mineralogy, is thus obtained and fruitfully coupled with the available lithostratigraphic data. Nine main tectono-metamorphic units are defined, from subgreenschist (ca. 280-300 °C) to the lawsonite-eclogite-facies (ca. 500-550 °C) condition. These units are

  3. The validity of tympanic and exhaled breath temperatures for core temperature measurement

    International Nuclear Information System (INIS)

    Flouris, Andreas D; Cheung, Stephen S

    2010-01-01

    We examined the efficacy of tympanic (T ty ) and exhaled breath (T X ) temperatures as indices of rectal temperature (T re ) by applying heat (condition A) and cold (condition B) in a dynamic A-B-A-B sequence. Fifteen healthy adults (8 men; 7 women; 24.9 ± 4.6 years) volunteered. Following a 15 min baseline period, participants entered a water tank maintained at 42 °C water temperature and passively rested until their T re increased by 0.5 °C above baseline. Thereafter, they entered a different water tank maintained at 12 °C water temperature until their T re decreased by 0.5 °C below baseline. This procedure was repeated twice (i.e. A-B-A-B). T ty demonstrated moderate response delays to the repetitive changes in thermal balance, whereas T X and T re responded relatively fast. Both T ty and T X correlated significantly with T re (P < 0.05). Linear regression models were used to predict T re based on T ty and T X . The predicted values from both models correlated significantly with T re (P < 0.05) and followed the changes in T re during the A-B-A-B thermal protocol. While some mean differences with T re were observed (P < 0.05), the 95% limits of agreement were acceptable for both models. It is concluded that the calculated models based on tympanic and exhaled breath temperature are valid indicators of core temperature. (note)

  4. Moisture rivals temperature in limiting photosynthesis by trees establishing beyond their cold-edge range limit under ambient and warmed conditions.

    Science.gov (United States)

    Moyes, Andrew B; Germino, Matthew J; Kueppers, Lara M

    2015-09-01

    Climate change is altering plant species distributions globally, and warming is expected to promote uphill shifts in mountain trees. However, at many cold-edge range limits, such as alpine treelines in the western United States, tree establishment may be colimited by low temperature and low moisture, making recruitment patterns with warming difficult to predict. We measured response functions linking carbon (C) assimilation and temperature- and moisture-related microclimatic factors for limber pine (Pinus flexilis) seedlings growing in a heating × watering experiment within and above the alpine treeline. We then extrapolated these response functions using observed microclimate conditions to estimate the net effects of warming and associated soil drying on C assimilation across an entire growing season. Moisture and temperature limitations were each estimated to reduce potential growing season C gain from a theoretical upper limit by 15-30% (c. 50% combined). Warming above current treeline conditions provided relatively little benefit to modeled net assimilation, whereas assimilation was sensitive to either wetter or drier conditions. Summer precipitation may be at least as important as temperature in constraining C gain by establishing subalpine trees at and above current alpine treelines as seasonally dry subalpine and alpine ecosystems continue to warm. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  5. Validation of Temperature Histories for Structural Steel Welds Using Estimated Heat-Affected-Zone Edges

    Science.gov (United States)

    2016-10-12

    Metallurgy , 2nd Ed., John Wiley & Sons, Inc., 2003. DOI: 10.1002/0471434027. 2. O. Grong, Metallurgical Modelling of Welding , 2ed., Materials Modelling...Naval Research Laboratory Washington, DC 20375-5320 NRL/MR/6394--16-9690 Validation of Temperature Histories for Structural Steel Welds Using...PAGES 17. LIMITATION OF ABSTRACT Validation of Temperature Histories for Structural Steel Welds Using Estimated Heat-Affected-Zone Edges S.G. Lambrakos

  6. Biomechanical factors influencing the performance of elite Alpine ski racers.

    Science.gov (United States)

    Hébert-Losier, Kim; Supej, Matej; Holmberg, Hans-Christer

    2014-04-01

    Alpine ski racing is a popular international winter sport that is complex and challenging from physical, technical, and tactical perspectives. Despite the vast amount of scientific literature focusing on this sport, including topical reviews on physiology, ski-snow friction, and injuries, no review has yet addressed the biomechanics of elite alpine ski racers and which factors influence performance. In World Cup events, winning margins are often mere fractions of a second and biomechanics may well be a determining factor in podium place finishes. The aim of this paper was to systematically review the scientific literature to identify the biomechanical factors that influence the performance of elite alpine ski racers, with an emphasis on slalom, giant slalom, super-G, and downhill events. Four electronic databases were searched using relevant medical subject headings and key words, with an additional manual search of reference lists, relevant journals, and key authors in the field. Articles were included if they addressed human biomechanics, elite alpine skiing, and performance. Only original research articles published in peer-reviewed journals and in the English language were reviewed. Articles that focused on skiing disciplines other than the four of primary interest were excluded (e.g., mogul, ski-cross and freestyle skiing). The articles subsequently included for review were quality assessed using a modified version of a validated quality assessment checklist. Data on the study population, design, location, and findings relating biomechanics to performance in alpine ski racers were extracted from each article using a standard data extraction form. A total of 12 articles met the inclusion criteria, were reviewed, and scored an average of 69 ± 13% (range 40-89%) upon quality assessment. Five of the studies focused on giant slalom, four on slalom, and three on downhill disciplines, although these latter three articles were also relevant to super-G events

  7. Validity of Devices That Assess Body Temperature During Outdoor Exercise in the Heat

    OpenAIRE

    Casa, Douglas J; Becker, Shannon M; Ganio, Matthew S; Brown, Christopher M; Yeargin, Susan W; Roti, Melissa W; Siegler, Jason; Blowers, Julie A; Glaviano, Neal R; Huggins, Robert A; Armstrong, Lawrence E; Maresh, Carl M

    2007-01-01

    Context: Rectal temperature is recommended by the National Athletic Trainers' Association as the criterion standard for recognizing exertional heat stroke, but other body sites commonly are used to measure temperature. Few authors have assessed the validity of the thermometers that measure body temperature at these sites in athletic settings.

  8. Characterisation of alpine skis

    OpenAIRE

    Wikerman, Fredrik

    2016-01-01

    Skiing is a fast and competitive sport where skiers must push their performance limit to win medals, the di↵erence can be within hundreds of a second. Therefore, technical improvements are essential for assisting in the skier’s improvement. This thesis project is a joint project between KTH and the Swedish Ski Association and Swedish Ski Team with the purpose of obtaining a better understanding of the structural properties of alpine skis, aiming to improve the individual selection process of ...

  9. Increasing Carbon Loss from Snow-Scoured Alpine Tundra in the Colorado Rocky Mountains: An Indicator of Climate Change?

    Science.gov (United States)

    Knowles, J. F.; Blanken, P.; Williams, M. W.; Lawrence, C. R.

    2015-12-01

    We used the eddy covariance method to continuously measure the net ecosystem exchange of carbon dioxide for seven years from a snow-scoured alpine tundra meadow on Niwot Ridge in Colorado, USA that may be underlain by sporadic permafrost. On average, the alpine tundra was a net annual source of 232 g C m-2 to the atmosphere, and the source strength of this ecosystem increased over the length of the seven year period due to both reduced carbon uptake during the growing season and increased respiration throughout the winter. To constrain the contribution of permafrost degradation to observed carbon emissions, we also measured the radiocarbon content of actively cycling, occluded, and mineral soil carbon pools across a meso-scale soil moisture and (possible) permafrost gradient within this meadow, as well as the seasonal radiocarbon content of soil respiration. These data suggest that wintertime soil respiration is limited to patches of wet meadow tundra that may be associated with permafrost. Furthermore, soil respiration from one of these locations indicates preferential turnover of a relatively slow cycling carbon pool during the winter. Given that summer air temperatures and positive degree days have been increasing on Niwot Ridge since the middle of the 20th century, this research suggests that an alpine tundra permafrost-respiration feedback to climate change, similar to that observed in arctic tundra ecosystems, may be currently underway.

  10. Fragile areas in the Alpine region: a reading between innovation and marginality

    Directory of Open Access Journals (Sweden)

    Federica Corrado

    2010-05-01

    Full Text Available The paper proposes a reading and description of fragile Alpine areas that overturns the conventional standpoint, according to which marginality is often synonymous with handicap. The paper starts form a different point of view, able to recognize specific local potentialities that can still be activated with a specific creative effort. The reading regards fragile Alpine areas in the Provinces of Turin and Cuneo and is based on an empirical analysis of the actions underlying current micro-territorial innovative development trends.Cet article propose une lecture et une description des territoires alpins fragiles, en jetant un autre regard, où le concept de fragilité est associé à celui de handicap, c’est-à-dire un autre regard sur l’identification des potentiels locaux spécifiques qui peuvent être encore activés à travers une force créatrice propre aux Alpes. La lecture est effectuée en fonction des territoires alpins fragiles qui font partie des provinces de Turin et Coni et se base sur une analyse empirique des initiatives qui enclenchent en quelque façon des dynamiques micro-territoriales de développement innovant.

  11. Estimating the snowfall limit in alpine and pre-alpine valleys: A local evaluation of operational approaches

    Science.gov (United States)

    Fehlmann, Michael; Gascón, Estíbaliz; Rohrer, Mario; Schwarb, Manfred; Stoffel, Markus

    2018-05-01

    The snowfall limit has important implications for different hazardous processes associated with prolonged or heavy precipitation such as flash floods, rain-on-snow events and freezing precipitation. To increase preparedness and to reduce risk in such situations, early warning systems are frequently used to monitor and predict precipitation events at different temporal and spatial scales. However, in alpine and pre-alpine valleys, the estimation of the snowfall limit remains rather challenging. In this study, we characterize uncertainties related to snowfall limit for different lead times based on local measurements of a vertically pointing micro rain radar (MRR) and a disdrometer in the Zulg valley, Switzerland. Regarding the monitoring, we show that the interpolation of surface temperatures tends to overestimate the altitude of the snowfall limit and can thus lead to highly uncertain estimates of liquid precipitation in the catchment. This bias is much smaller in the Integrated Nowcasting through Comprehensive Analysis (INCA) system, which integrates surface station and remotely sensed data as well as outputs of a numerical weather prediction model. To reduce systematic error, we perform a bias correction based on local MRR measurements and thereby demonstrate the added value of such measurements for the estimation of liquid precipitation in the catchment. Regarding the nowcasting, we show that the INCA system provides good estimates up to 6 h ahead and is thus considered promising for operational hydrological applications. Finally, we explore the medium-range forecasting of precipitation type, especially with respect to rain-on-snow events. We show for a selected case study that the probability for a certain precipitation type in an ensemble-based forecast is more persistent than the respective type in the high-resolution forecast (HRES) of the European Centre for Medium Range Weather Forecasts Integrated Forecasting System (ECMWF IFS). In this case study, the

  12. Evaluation of storage and filtration protocols for alpine/subalpine lake water quality samples

    Science.gov (United States)

    John L. Korfmacher; Robert C. Musselman

    2007-01-01

    Many government agencies and other organizations sample natural alpine and subalpine surface waters using varying protocols for sample storage and filtration. Simplification of protocols would be beneficial if it could be shown that sample quality is unaffected. In this study, samples collected from low ionic strength waters in alpine and subalpine lake inlets...

  13. Identification and climatology of Alpine pumping from a regional climate simulation

    Directory of Open Access Journals (Sweden)

    Maximilian eGraf

    2016-02-01

    Full Text Available The thermally driven circulation between the European Alps and the alpine foreland - named Alpine pumping – occurs regularly under clear and calm weather conditions. While previous studies focused on the impact of Alpine pumping on moist convection and transport of air pollutants, this study was motivated by its ventilation effect for Munich, located about 50 km north of the Alps in undulating and only slightly inclined terrain, where local thermal circulations are weak. Hourly data from a reanalysis driven regional climate simulation with COSMO-CLM model for the period 1989 to 2008 were analysed to identify days with Alpine pumping and to determine the mean diurnal characteristics of this regional thermal circulation. Four literature derived combinations of meteorological criteria were tested to identify days favorable for Alpine pumping from COSMO-CLM results. The first criterion selects days with a daily sum of solar radiation ≥20 MJ/m2 and has been used in an earlier observational study. On average 60 d/y are fulfilling the criterion in the model simulation, which compares well to the 67 d/y determined from observations. The other three criteria combinations consider a maximum wind velocity at 850 hPa, a maximum daily precipitation sum, and/or a maximum mean cloud cover. The mean annual number of selected days is lower for these criteria combinations and ranges between 20 and 52. Diurnal wind reversals occur on 77 to 81% of the selected days, depending on the criteria combinationThe daily solar radiation sum of 20 MJ/m2 is only exceeded during April to September, while days satisfying the criteria combinations without the radiation threshold occur all year round. In agreement with observations, the simulated regional thermally driven wind field extends up to ~100 km north of the Alps with average near-surface wind speeds of 0.5-1.5 m/s in the Munich area. With increasing distance from the Alps, the diurnal cycle of Alpine pumping is

  14. Impacts of changes in vegetation cover on soil water heat coupling in an alpine meadow of the Qinghai-Tibet Plateau, China

    Directory of Open Access Journals (Sweden)

    W. Genxu

    2009-03-01

    Full Text Available Alpine meadow is one of the most widespread grassland types in the permafrost regions of the Qinghai-Tibet Plateau, and the transmission of coupled soil water heat is one of the most crucial processes influencing cyclic variations in the hydrology of frozen soil regions, especially under different vegetation covers. The present study assesses the impact of changes in vegetation cover on the coupling of soil water and heat in a permafrost region. Soil moisture (θv, soil temperature (Ts, soil heat content, and differences in θvTs coupling were monitored on a seasonal and daily basis under three different vegetation covers (30, 65, and 93% on both thawed and frozen soils. Regression analysis of θv vs. Ts plots under different levels of vegetation cover indicates that soil freeze-thaw processes were significantly affected by the changes in vegetation cover. The decrease in vegetation cover of an alpine meadow reduced the difference between air temperature and ground temperatureTa−s, and it also resulted in a decrease in Ts at which soil froze, and an increase in the temperature at which it thawed. This was reflected in a greater response of soil temperature to changes in air temperature (Ta. For ΔTa−s outside the range of −0.1 to 1.0°C, root zone soil-water temperatures showed a significant increase with increasing ΔTa−s; however, the magnitude of this relationship was dampened with increasing vegetation cover. At the time of maximum water content in the thawing season, the soil temperature decreased with increasing vegetation. Changes in vegetation cover also led to variations in θvTs coupling. With the increase in vegetation cover, the surface heat flux decreased. Soil heat storage at 20 cm in

  15. Alpine dams

    Directory of Open Access Journals (Sweden)

    Alain Marnezy

    2009-03-01

    Full Text Available Les barrages-réservoirs de montagne ont été réalisés initialement dans les Alpes pour répondre à la demande d’énergie en période hivernale. Une certaine diversification des usages de l’eau s’est ensuite progressivement développée, en relation avec le développement touristique des collectivités locales. Aujourd’hui, la participation des ouvrages d’Électricité De France à la production de neige de culture représente une nouvelle étape. Dans les régions où les aménagements hydroélectriques sont nombreux, les besoins en eau pour la production de neige peuvent être résolus par prélèvements à partir des adductions EDF. Les gestionnaires de stations échappent ainsi aux inconvénients liés à la construction et à la gestion des « retenues collinaires ». Cette évolution, qui concerne déjà quelques régions alpines comme la haute Maurienne ou le Beaufortin, apparaît comme une forme renouvelée d’intégration territoriale de la ressource en eau.Mountain reservoirs were initially built in the Alps to meet energy needs in the winter. A certain diversification in the uses of water then gradually developed, related to tourism development in the local communities. Today, the use of facilities belonging to EDF (French Electricity Authority to provide water for winter resorts to make artificial snow represents a new phase. By taking water from EDF resources to supply snow-making equipment, resort managers are thus able to avoid the problems related to the construction and management of small headwater dams. This new orientation in the use of mountain water resources already affects a number of alpine regions such as the Upper Maurienne valley and Beaufortain massif and represents a renewed form of the territorial integration of water resources.

  16. Is the alpine divide becoming more permeable to biological invasions? - Insights on the invasion and establishment of the Walnut Husk Fly, Rhagoletis completa (Diptera: Tephritidae) in Switzerland.

    Science.gov (United States)

    Aluja, M; Guillén, L; Rull, J; Höhn, H; Frey, J; Graf, B; Samietz, J

    2011-08-01

    The Walnut Husk Fly, Rhagoletis completa Cresson (Diptera: Tephritidae), is native to North America (Midwestern US and north-eastern Mexico) and has invaded several European countries in the past decades by likely crossing the alpine divide separating most parts of Switzerland from Italy. Here, we determined its current distribution in Switzerland by sampling walnuts (Juglans regia L.) in ecologically and climatically distinct regions along potential invasion corridors. R. completa was found to be firmly established in most low altitude areas of Switzerland where walnuts thrive, but notably not a single parasitoid was recovered from any of the samples. Infested fruit was recovered in 42 of the 71 localities that were surveyed, with mean fruit infestation rate varying greatly among sites. The incidence of R. completa in Switzerland is closely related to meteorological mean spring temperature patterns influencing growing season length, but not to winter temperatures, reflecting survival potential during hibernation. Importantly, areas in which the fly is absent correspond with localities where the mean spring temperatures fall below 7°C. Historical data records show that the natural cold barrier around the Alpine divide in the central Swiss Alps corresponding to such minimal temperatures has shrunk significantly from a width of more than 40 km before 1990 to around 20 km after 2000. We hypothesize on possible invasion/expansion routes along alpine valleys, dwell on distribution patterns in relation to climate, and outline future research needs as the incursion of R. completa into Switzerland; and, more recently, other European countries, such as Germany, Austria, France and Slovenia, represent an example of alien species that settle first in the Mediterranean Basin and from there become invasive by crossing the Alps.

  17. Recent Relationships of Tree Establishment and Climate in Alpine Treelines of the Rocky Mountains

    Science.gov (United States)

    Germino, M. J.; Graumlich, L. J.; Maher, E. J.

    2007-12-01

    Changes in the forest structure of alpine-forest or treeline boundaries may be a significant climate response of mountainous regions in the near future. A particularly important point of climate sensitivity for treelines is the initial survival and establishment of tree seedlings - a demographic bottleneck that may be particularly suited to early detection of treeline responses to climate change. However, concise information on climate sensitivity of seedling establishment has come primarily from direct observations of seedlings over short time periods encompassing a few years. Dendrochronological approaches have revealed tree establishment patterns at more extensive time scales of decades to millenia, but at coarser temporal resolutions. Climate variations that most directly affect initial tree seedling establishment occur at annual or smaller time scales, and climate for seedlings is modulated by landscape factors such as neighboring plant cover. Our objective was to assess climate sensitivity of tree establishment at treeline at these finer temporal and spatial scales, with consideration of treeline features that alter the climate for seedlings. Our approach combined direct observations of seedling emergence and survival with dendrochronology of older seedlings and saplings that were still small and young enough (less than 25 years and 20 cm height) to allow detecting the year of establishment and associated factors. Surveys for subject seedlings and saplings were performed for 2 years across the gradient from forest into treeline alpine in the Beartooth, Teton, and Medicine Bow mountains of Wyoming USA. No seedlings or saplings were detected above the highest elevation adult trees or krummholz, but there were up to 0.3 seedlings per square meter in subalpine meadows close to forest (within the timberline zone) where changes in tree abundance appear possible in future decades. Correlations of establishment and summer temperature ranged from weak in whitebark

  18. Little Ice Age climate reconstruction from ensemble reanalysis of Alpine glacier fluctuations

    Directory of Open Access Journals (Sweden)

    M. P. Lüthi

    2014-04-01

    Full Text Available Mountain glaciers sample a combination of climate fields – temperature, precipitation and radiation – by accumulation and melting of ice. Flow dynamics acts as a transfer function that maps volume changes to a length response of the glacier terminus. Long histories of terminus positions have been assembled for several glaciers in the Alps. Here I analyze terminus position histories from an ensemble of seven glaciers in the Alps with a macroscopic model of glacier dynamics to derive a history of glacier equilibrium line altitude (ELA for the time span 400–2010 C.E. The resulting climatic reconstruction depends only on records of glacier variations. The reconstructed ELA history is similar to recent reconstructions of Alpine summer temperature and Atlantic Multidecadal Oscillation (AMO index, but bears little resemblance to reconstructed precipitation variations. Most reconstructed low-ELA periods coincide with large explosive volcano eruptions, hinting at a direct effect of volcanic radiative cooling on mass balance. The glacier advances during the LIA, and the retreat after 1860, can thus be mainly attributed to temperature and volcanic radiative cooling.

  19. Paleomagnetism and the alpine tectonics of Eurasia

    NARCIS (Netherlands)

    Raven, Th.

    1964-01-01

    The following paper by Gregor and Zijderveld is the first of a series planned to report results of paleomagnetic investigations in the Alpine area from Italy to the Himalayas. These investigations are carried out in close collaboration between the well-equipped paleomagnetic laboratory of

  20. Characterization of culturable heterotrophic bacteria in hydrocarbon-contaminated soil from an alpine former military site.

    Science.gov (United States)

    Zhang, Dechao; Margesin, Rosa

    2014-06-01

    We characterized the culturable, heterotrophic bacterial community in soil collected from a former alpine military site contaminated with petroleum hydrocarbons. The physiologically active eubacterial community, as revealed by fluorescence-in situ-hybridization, accounted for 14.9 % of the total (DAPI-stained) bacterial community. 4.0 and 1.2 % of the DAPI-stained cells could be attributed to culturable, heterotrophic bacteria able to grow at 20 and 10 °C, respectively. The majority of culturable bacterial isolates (23/28 strains) belonged to the Proteobacteria with a predominance of Alphaproteobacteria. The remaining isolates were affiliated with the Firmicutes, Actinobacteria and Bacteroidetes. Five strains could be identified as representatives of novel species. Characterization of the 28 strains demonstrated their adaptation to the temperature and nutrient conditions prevailing in the studied soil. One-third of the strains was able to grow at subzero temperatures (-5 °C). Studies on the effect of temperature on growth and lipase production with two selected strains demonstrated their low-temperature adaptation.

  1. The consequences of elevated CO² and land use in alpine ecosystems

    OpenAIRE

    Inauen, Nicole

    2014-01-01

    The consequences of elevated CO2 and land use in alpine ecosystems This PhD thesis addresses two main aspects of Global Change and their impacts on alpine vegetation and eco-hydrology, (1) the steadily increasing concentration of CO2 in the atmosphere as well as (2) land use and its current decline across the Alps. Current and future rises of atmospheric CO2 concentration are commonly expected to stimulate photosynthesis and to reduce carbon limitation of plant growth. Whether this hypoth...

  2. Identifying key conservation threats to Alpine birds through expert knowledge

    Science.gov (United States)

    Pedrini, Paolo; Brambilla, Mattia; Rolando, Antonio; Girardello, Marco

    2016-01-01

    Alpine biodiversity is subject to a range of increasing threats, but the scarcity of data for many taxa means that it is difficult to assess the level and likely future impact of a given threat. Expert opinion can be a useful tool to address knowledge gaps in the absence of adequate data. Experts with experience in Alpine ecology were approached to rank threat levels for 69 Alpine bird species over the next 50 years for the whole European Alps in relation to ten categories: land abandonment, climate change, renewable energy, fire, forestry practices, grazing practices, hunting, leisure, mining and urbanization. There was a high degree of concordance in ranking of perceived threats among experts for most threat categories. The major overall perceived threats to Alpine birds identified through expert knowledge were land abandonment, urbanization, leisure and forestry, although other perceived threats were ranked highly for particular species groups (renewable energy and hunting for raptors, hunting for gamebirds). For groups of species defined according to their breeding habitat, open habitat species and treeline species were perceived as the most threatened. A spatial risk assessment tool based on summed scores for the whole community showed threat levels were highest for bird communities of the northern and western Alps. Development of the approaches given in this paper, including addressing biases in the selection of experts and adopting a more detailed ranking procedure, could prove useful in the future in identifying future threats, and in carrying out risk assessments based on levels of threat to the whole bird community. PMID:26966659

  3. Identifying key conservation threats to Alpine birds through expert knowledge

    Directory of Open Access Journals (Sweden)

    Dan E. Chamberlain

    2016-02-01

    Full Text Available Alpine biodiversity is subject to a range of increasing threats, but the scarcity of data for many taxa means that it is difficult to assess the level and likely future impact of a given threat. Expert opinion can be a useful tool to address knowledge gaps in the absence of adequate data. Experts with experience in Alpine ecology were approached to rank threat levels for 69 Alpine bird species over the next 50 years for the whole European Alps in relation to ten categories: land abandonment, climate change, renewable energy, fire, forestry practices, grazing practices, hunting, leisure, mining and urbanization. There was a high degree of concordance in ranking of perceived threats among experts for most threat categories. The major overall perceived threats to Alpine birds identified through expert knowledge were land abandonment, urbanization, leisure and forestry, although other perceived threats were ranked highly for particular species groups (renewable energy and hunting for raptors, hunting for gamebirds. For groups of species defined according to their breeding habitat, open habitat species and treeline species were perceived as the most threatened. A spatial risk assessment tool based on summed scores for the whole community showed threat levels were highest for bird communities of the northern and western Alps. Development of the approaches given in this paper, including addressing biases in the selection of experts and adopting a more detailed ranking procedure, could prove useful in the future in identifying future threats, and in carrying out risk assessments based on levels of threat to the whole bird community.

  4. Seismic anisotropy in the vicinity of the Alpine fault, New Zealand, estimated by seismic interferometry

    Science.gov (United States)

    Takagi, R.; Okada, T.; Yoshida, K.; Townend, J.; Boese, C. M.; Baratin, L. M.; Chamberlain, C. J.; Savage, M. K.

    2016-12-01

    We estimate shear wave velocity anisotropy in shallow crust near the Alpine fault using seismic interferometry of borehole vertical arrays. We utilized four borehole observations: two sensors are deployed in two boreholes of the Deep Fault Drilling Project in the hanging wall side, and the other two sites are located in the footwall side. Surface sensors deployed just above each borehole are used to make vertical arrays. Crosscorrelating rotated horizontal seismograms observed by the borehole and surface sensors, we extracted polarized shear waves propagating from the bottom to the surface of each borehole. The extracted shear waves show polarization angle dependence of travel time, indicating shear wave anisotropy between the two sensors. In the hanging wall side, the estimated fast shear wave directions are parallel to the Alpine fault. Strong anisotropy of 20% is observed at the site within 100 m from the Alpine fault. The hanging wall consists of mylonite and schist characterized by fault parallel foliation. In addition, an acoustic borehole imaging reveals fractures parallel to the Alpine fault. The fault parallel anisotropy suggest structural anisotropy is predominant in the hanging wall, demonstrating consistency of geological and seismological observations. In the footwall side, on the other hand, the angle between the fast direction and the strike of the Alpine fault is 33-40 degrees. Since the footwall is composed of granitoid that may not have planar structure, stress induced anisotropy is possibly predominant. The direction of maximum horizontal stress (SHmax) estimated by focal mechanisms of regional earthquakes is 55 degrees of the Alpine fault. Possible interpretation of the difference between the fast direction and SHmax direction is depth rotation of stress field near the Alpine fault. Similar depth rotation of stress field is also observed in the SAFOD borehole at the San Andreas fault.

  5. U-Pb thermochronology of rutile from Alpine Corsica: constraints on the thermal evolution of the European margin during Jurassic continental breakup

    Science.gov (United States)

    Ewing, T. A.; Beltrando, M.; Müntener, O.

    2017-12-01

    U-Pb thermochronology of rutile can provide valuable temporal constraints on the exhumation history of the lower crust, given its moderate closure temperature and the occurrence of rutile in appropriate lithologies. We present an example from Alpine Corsica, in which we investigate the thermal evolution of the distal European margin during Jurassic continental rifting that culminated in the opening of the Alpine Tethys ocean. The Belli Piani unit of the Santa Lucia nappe (Corsica) experienced minimal Alpine overprint and bears a striking resemblance to the renowned Ivrea Zone lower crustal section (Italy). At its base, a 2-4 km thick gabbroic complex contains slivers of granulite facies metapelites that represent Permian lower crust. Zr-in-rutile temperatures and U-Pb ages were determined for rutile from three metapelitic slivers from throughout the Mafic Complex. High Zr-in-rutile temperatures of 850-950 °C corroborate textural evidence for rutile formation during Permian granulite facies metamorphism. Lower Zr-in-rutile temperatures of 750-800 °C in a few grains are partly associated with elongate strings of rutile within quartz ribbons, which record recrystallisation of some rutile during high-temperature shearing. Zr thermometry documents that both crystallisation and re-crystallisation of rutile occurred above the closure temperature of Pb in rutile, such that the U-Pb system can be expected to record cooling ages uncomplicated by re-crystallisation. Our new high-precision single-spot LA-ICPMS U-Pb dates are highly consistent between and within samples. The three samples gave ages from 160 ± 1 Ma to 161 ± 2 Ma, with no other age populations detected. The new data indicate that the Santa Lucia lower crust last cooled through 550-650 °C at 160 Ma, coeval with the first formation of oceanic crust in the Tethys. The new data are compared to previous depth profiling rutile U-Pb data for the Belli Piani unit1, and exploited to cast light on the tectonothermal

  6. Enzymatic milk clotting activity in artichoke (Cynara scolymus) leaves and alpine thistle (Carduus defloratus) flowers. Immobilization of alpine thistle aspartic protease.

    Science.gov (United States)

    Esposito, Marilena; Di Pierro, Prospero; Dejonghe, Winnie; Mariniello, Loredana; Porta, Raffaele

    2016-08-01

    Two different milk clotting enzymes, belonging to the aspartic protease family, were extracted from both artichoke leaves and alpine thistle flowers, and the latter was covalently immobilized by using a polyacrylic support containing polar epoxy groups. Our findings showed that the alpine thistle aspartic protease was successfully immobilized at pH 7.0 on Immobeads IB-150P beads and that, under these experimental conditions, an immobilization yield of about 68% and a recovery of about 54% were obtained. Since the enzyme showed an optimal pH of 5.0, a value very similar to the one generally used for milk clotting during cheese making, and exhibited a satisfactory stability over time, the use of such immobilized vegetable rennet for the production of novel dairy products is suggested. Copyright © 2016. Published by Elsevier Ltd.

  7. Effect of degradation intensity on grassland ecosystem services in the alpine region of Qinghai-Tibetan Plateau, China.

    Directory of Open Access Journals (Sweden)

    Lu Wen

    Full Text Available The deterioration of alpine grassland has great impact on ecosystem services in the alpine region of Qinghai-Tibetan Plateau. However, the effect of grassland degradation on ecosystem services and the consequence of grassland deterioration on economic loss still remains a mystery. So, in this study, we assessed four types of ecosystem services following the Millennium Ecosystem Assessment classification, along a degradation gradient. Five sites of alpine grassland at different levels of degradation were investigated in Guoluo Prefecture of Qinghai Province, China. The species composition, aboveground biomass, soil total organic carbon (TOC, and soil total nitrogen (TN were tested to evaluate major ecological services of the alpine grassland. We estimated the value of primary production, carbon storage, nitrogen recycling, and plant diversity. The results show the ecosystem services of alpine grassland varied along the degradation gradient. The ecosystem services of degraded grassland (moderate, heavy and severe were all significantly lower than non-degraded grassland. Interestingly, the lightly degraded grassland provided more economic benefit from carbon maintenance and nutrient sequestration compared to non-degraded. Due to the destruction of the alpine grassland, the economic loss associated with decrease of biomass in 2008 was $198/ha. Until 2008, the economic loss caused by carbon emissions and nitrogen loss on severely degraded grassland was up to $8 033/ha and $13 315/ha, respectively. Urgent actions are required to maintain or promote the ecosystem services of alpine grassland in the Qinghai-Tibetan Plateau.

  8. Effect of degradation intensity on grassland ecosystem services in the alpine region of Qinghai-Tibetan Plateau, China.

    Science.gov (United States)

    Wen, Lu; Dong, Shikui; Li, Yuanyuan; Li, Xiaoyan; Shi, Jianjun; Wang, Yanlong; Liu, Demei; Ma, Yushou

    2013-01-01

    The deterioration of alpine grassland has great impact on ecosystem services in the alpine region of Qinghai-Tibetan Plateau. However, the effect of grassland degradation on ecosystem services and the consequence of grassland deterioration on economic loss still remains a mystery. So, in this study, we assessed four types of ecosystem services following the Millennium Ecosystem Assessment classification, along a degradation gradient. Five sites of alpine grassland at different levels of degradation were investigated in Guoluo Prefecture of Qinghai Province, China. The species composition, aboveground biomass, soil total organic carbon (TOC), and soil total nitrogen (TN) were tested to evaluate major ecological services of the alpine grassland. We estimated the value of primary production, carbon storage, nitrogen recycling, and plant diversity. The results show the ecosystem services of alpine grassland varied along the degradation gradient. The ecosystem services of degraded grassland (moderate, heavy and severe) were all significantly lower than non-degraded grassland. Interestingly, the lightly degraded grassland provided more economic benefit from carbon maintenance and nutrient sequestration compared to non-degraded. Due to the destruction of the alpine grassland, the economic loss associated with decrease of biomass in 2008 was $198/ha. Until 2008, the economic loss caused by carbon emissions and nitrogen loss on severely degraded grassland was up to $8 033/ha and $13 315/ha, respectively. Urgent actions are required to maintain or promote the ecosystem services of alpine grassland in the Qinghai-Tibetan Plateau.

  9. An Investigation of the Impacts of Climate and Environmental Change on Alpine Lakes in the Uinta Mountains, Utah

    Science.gov (United States)

    Moser, K. A.; Hundey, E. J.; Porinchu, D. F.

    2007-12-01

    Aquatic systems in alpine and sub-alpine areas of the western United States are potentially impacted by atmospheric pollution and climate change. Because these mountainous regions are an important water resource for the western United States, it is critical to monitor and protect these systems. The Uinta Mountains are an east- west trending mountain range located on the border between Utah, Wyoming and Colorado and downwind of the Wasatch Front, Utah, which is characterized by a rapidly expanding population, as well as mining and industry. This alpine area provides water to many areas in Utah, and contributes approximately nine percent of the water supply to the Upper Colorado River. Our research is focused on determining the impacts of climate change and pollution on alpine lakes in the Uinta Mountains. The results presented here are based on limnological measurements made at 64 Uinta Mountain lakes spanning a longitude gradient of one degree and an elevation gradient of 3000 feet. At each lake maximum depth, conductivity, salinity, pH, Secchi depth, temperature, alkalinity, and concentrations of major anions, cations and trace metals were measured. Principal Components Analysis (PCA) was performed to determine relationships between these variables and to examine the variability of the values of these variables. Our results indicate that steep climate gradients related to elevation and longitude result in clear differences in limnological properties of the study sites, with high elevation lakes characterized by greater amounts of nitrate and nitrite compared to low elevation sites. As well, diatoms in these lakes indicate that many high elevation sites are mesotrophic to eutrophic, which is unexpected for such remote aquatic ecosystems. We hypothesize that elevated nitrate and nitrite levels at high elevation sites are related to atmospherically derived nitrogen, but are being exacerbated relative to lower elevation sites by greater snow cover and reduced plant

  10. Human behaviour towards climatic change during the 4th millennium BC in the Swiss Alpine forelands

    DEFF Research Database (Denmark)

    Karg, Sabine

    Human behaviour towards climatic change during the 4th millennium BC in the Swiss Alpine forelands.......Human behaviour towards climatic change during the 4th millennium BC in the Swiss Alpine forelands....

  11. Responses of Ecosystem CO2 Fluxes to Short-Term Experimental Warming and Nitrogen Enrichment in an Alpine Meadow, Northern Tibet Plateau

    Science.gov (United States)

    Shi, Peili; Jiang, Jing; Song, Minghua; Xiong, Dingpeng; Ma, Weiling; Fu, Gang; Zhang, Xianzhou; Shen, Zhenxi

    2013-01-01

    Over the past decades, the Tibetan Plateau has experienced pronounced warming, yet the extent to which warming will affect alpine ecosystems depends on how warming interacts with other influential global change factors, such as nitrogen (N) deposition. A long-term warming and N manipulation experiment was established to investigate the interactive effects of warming and N deposition on alpine meadow. Open-top chambers were used to simulate warming. N addition, warming, N addition × warming, and a control were set up. In OTCs, daytime air and soil temperature were warmed by 2.0°C and 1.6°C above ambient conditions, but soil moisture was decreased by 4.95 m3 m−3. N addition enhanced ecosystem respiration (Reco); nevertheless, warming significantly decreased Reco. The decline of Reco resulting from warming was cancelled out by N addition in late growing season. Our results suggested that N addition enhanced Reco by increasing soil N availability and plant production, whereas warming decreased Reco through lowering soil moisture, soil N supply potential, and suppression of plant activity. Furthermore, season-specific responses of Reco indicated that warming and N deposition caused by future global change may have complicated influence on carbon cycles in alpine ecosystems. PMID:24459432

  12. The Alpine loop of the tethys zone

    NARCIS (Netherlands)

    Bemmelen, R.W. van

    The Alpine loop in Europe results from semi-autochthonous crustal movements which are restricted to the mobile Tethys zone. Its evolution cannot be explained by a uniform northward drift and push of the African continent; it has to be sought, in the first place, in geodynamic processes occurring in

  13. Climate-driven speedup of alpine treeline forest growth in the Tianshan Mountains, Northwestern China.

    Science.gov (United States)

    Qi, Zhaohuan; Liu, Hongyan; Wu, Xiuchen; Hao, Qian

    2015-02-01

    Forest growth is sensitive to interannual climatic change in the alpine treeline ecotone (ATE). Whether the alpine treeline ecotone shares a similar pattern of forest growth with lower elevational closed forest belt (CFB) under changing climate remains unclear. Here, we reported an unprecedented acceleration of Picea schrenkiana forest growth since 1960s in the ATE of Tianshan Mountains, northwestern China by a stand-total sampling along six altitudinal transects with three plots in each transect: one from the ATE between the treeline and the forest line, and the other two from the CFB. All the sampled P. schrenkiana forest patches show a higher growth speed after 1960 and, comparatively, forest growth in the CFB has sped up much slower than that in the ATE. The speedup of forest growth at the ATE is mainly accounted for by climate factors, with increasing temperature suggested to be the primary driver. Stronger water deficit as well as more competition within the CFB might have restricted forest growth there more than that within the ATE, implying biotic factors were also significant for the accelerated forest growth in the ATE, which should be excluded from simulations and predictions of warming-induced treeline dynamics. © 2014 John Wiley & Sons Ltd.

  14. Anterior cruciate ligament injury/reinjury in alpine ski racing: a narrative review

    Directory of Open Access Journals (Sweden)

    Jordan MJ

    2017-03-01

    Full Text Available Matthew J Jordan,1 Per Aagaard,2 Walter Herzog1 1Human Performance Laboratory, The University of Calgary, Calgary, AB, Canada; 2Department of Sports Science and Clinical Biomechanics, SDU Muscle Research Cluster (SMRC, University of Southern Denmark, Odense M, Denmark Abstract: The purpose of the present review was to: 1 provide an overview of the current understanding on the epidemiology, etiology, risk factors, and prevention methods for anterior cruciate ligament (ACL injury in alpine ski racing; and 2 provide an overview of what is known pertaining to ACL reinjury and return to sport after ACL injury in alpine ski racing. Given that most of the scientific studies on ACL injuries in alpine ski racing have been descriptive, and that very few studies contributed higher level scientific evidence, a nonsystematic narrative review was employed. Three scholarly databases were searched for articles on ACL injury or knee injury in alpine ski racing. Studies were classified according to their relevance in relation to epidemiology, etiology, risk factors, and return to sport/reinjury prevention. Alpine ski racers (skiers were found to be at high risk for knee injuries, and ACL tears were the most frequent diagnosis. Three primary ACL injury mechanism were identified that involved tibial internal rotation and anteriorly directed shear forces from ski equipment and the environment. While trunk muscle strength imbalance and genetics were found to be predictive of ACL injuries in development-level skiers, there was limited scientific data on ACL injury risk factors among elite skiers. Based on expert opinion, research on injury risk factors should focus on equipment design, course settings/speed, and athlete factors (eg, fitness. While skiers seem to make a successful recovery following ACL injury, there may be persistent neuromuscular deficits. Future research efforts should be directed toward prospective studies on ACL injury/reinjury prevention in both

  15. Growth responses of low-alpine dwarf-shrub heath species to nitrogen deposition and management

    International Nuclear Information System (INIS)

    Britton, Andrea J.; Fisher, Julia M.

    2008-01-01

    Nitrogen deposition is a continuing problem in European alpine regions. We hypothesised that, despite climatic limitations, low-alpine Calluna heathland would respond to nitrogen addition with increased shoot growth and flowering and that fire and grazing would modify responses. In a five-year study, 0-50 kg N ha -1 y -1 were added, combined with burning (+/-) and clipping (+/-). Calluna vulgaris responded with increased shoot extension, but effects on flowering were variable. Burning enhanced the positive effect of nitrogen addition and negative effects of clipping. Sub-dominant shrubs generally did not respond to nitrogen. C. vulgaris shoot extension was stimulated by nitrogen addition of 10 kg N ha -1 y -1 (above background) supporting suggestions that alpine heathlands are sensitive to low levels of nitrogen deposition. Increased C. vulgaris growth could negatively impact on important lichen components of this vegetation through increased shading and competition. Climatic factors constrain productivity in this community, but do not prevent rapid responses to nitrogen deposition by some species. - Low levels of N deposition increase productivity in alpine dwarf-shrub heath despite strong climatic constraints

  16. Preserved Organic Matter in the Alpine Tethyan Ocean Continental Transition (Totalp unit, Eastern Swiss Alps)

    Science.gov (United States)

    Mateeva, T.; Wolff, G. A.; Kusznir, N.; Wheeler, J.; Manatschal, G.

    2015-12-01

    Observations at hydrothermal systems in modern ocean settings suggest that methane produced by serpentinization can support methanotrophic bio-systems. An important question is whether such bio-systems are localised or are more pervasive in their association with serpentinized mantle in the subsurface. This has implications for the global importance of the hidden sub-surface bio-systems, the fate of methane and the carbon cycle. The Totalp unit, a remnant of a former Ocean Continent Transition (OCT) exposed in Alps of Eastern Switzerland, has been chosen to investigate the presence or absence of methanotrophic biosystems within serpentinized exhumed mantle in the Alpine Tethyan margin. The Totalp unit is made of serpentinized mantle and ophicalcites overlain by Upper Jurassic to Lower Cretaceous post-rift sediments. The Totalp unit has undergone little Alpine deformation and only a low-grade metamorphic overprint (serpentinized peridotite, ophicalcite and post-rift sediments contain hydrocarbons in the form of n-alkanes in the range C20 - C40; isoprenoids, for example pristane and phytane are present in sediments. The organic biological marker distribution is consistent with the temperature history of the OCT (i.e.lower maximum temperature than 200°C). First results from Totalp show evidence for preservation of marine organic matter in the serpentinized mantle and overlying sediments, although there is no evidence that any organic matter is generated from methanotrophic bio-systems. Nevertheless, focussing on Tethyan hydrothermal systems and preserved hydrocarbons will be critical in understanding whether methanotrophic biomarkers can be preserved and if so whether the methane originated from serpentenization.

  17. The use of invertebrates as indicators of environmental change in alpine rivers and lakes

    International Nuclear Information System (INIS)

    Khamis, K.; Hannah, D.M.; Brown, L.E.; Tiberti, R.; Milner, A.M.

    2014-01-01

    In alpine regions climatic change will alter the balance between water sources (rainfall, ice-melt, snowmelt, and groundwater) for aquatic systems, particularly modifying the relative contributions of meltwater, groundwater and rain to both rivers and lakes. While these changes are expected to have implications for alpine aquatic ecosystems, little is known about potential ecological tipping points and associated indicator taxa. We examined changes in biotic communities along a gradient of glacier influence for two study systems: (1) a stream network in the French Pyrénées; and (2) a network of lakes in the Italian Alps, with the aim of identifying potential indicator taxa (macroinvertebrates and zooplankton) of glacier retreat in these environments. To assess parallels in biotic responses across streams and lakes, both primary data and findings from other publications were synthesised. Using TITAN (Threshold Indicator Taxa ANalysis) changes in community composition of river taxa were identified at thresholds of < 5.1% glacier cover and < 66.6% meltwater contribution. Below these thresholds the loss of cold stenothermic benthic invertebrate taxa, Diamesa spp. and the Pyrenean endemic Rhyacophila angelieri was apparent. Some generalist taxa including Protonemura sp., Perla grandis, Baetis alpinus, Rhithrogena loyolaea and Microspectra sp. increased when glacier cover was < 2.7% and < 52% meltwater. Patterns were not as distinct for the alpine lakes, due to fewer sampling sites; however, Daphnia longispina grp. and the benthic invertebrate groups Plectopera and Planaria were identified as potential indicator taxa. While further work is required to assess potential indicator taxa for alpine lake systems, findings from alpine river systems were consistent between methods for assessing glacier influence (meltwater contribution/glacier cover). Hence, it is clear that TITAN could become a useful management tool, enabling: (i) the identification of taxa particularly

  18. The use of invertebrates as indicators of environmental change in alpine rivers and lakes

    Energy Technology Data Exchange (ETDEWEB)

    Khamis, K.; Hannah, D.M. [School of Geography Earth and Environmental Science, University of Birmingham, Birmingham B15 2TT (United Kingdom); Brown, L.E. [School of Geography/water@leeds, University of Leeds, Woodhouse Lane, Leeds LS2 9JT (United Kingdom); Tiberti, R. [DSTA, Dipartimento di Scienze della Terra e dell' Ambiente, University of Pavia, Via Ferrata 9, 27100 Pavia (Italy); Alpine Wildlife Research Centre, Gran Paradiso National Park, Degioz 11, I-1101 Valsavarenche, Aosta (Italy); Milner, A.M., E-mail: a.m.milner@bham.ac.uk [School of Geography Earth and Environmental Science, University of Birmingham, Birmingham B15 2TT (United Kingdom); Institute of Arctic Biology, University of Alaska, Fairbanks, AK 99775 (United States)

    2014-09-15

    In alpine regions climatic change will alter the balance between water sources (rainfall, ice-melt, snowmelt, and groundwater) for aquatic systems, particularly modifying the relative contributions of meltwater, groundwater and rain to both rivers and lakes. While these changes are expected to have implications for alpine aquatic ecosystems, little is known about potential ecological tipping points and associated indicator taxa. We examined changes in biotic communities along a gradient of glacier influence for two study systems: (1) a stream network in the French Pyrénées; and (2) a network of lakes in the Italian Alps, with the aim of identifying potential indicator taxa (macroinvertebrates and zooplankton) of glacier retreat in these environments. To assess parallels in biotic responses across streams and lakes, both primary data and findings from other publications were synthesised. Using TITAN (Threshold Indicator Taxa ANalysis) changes in community composition of river taxa were identified at thresholds of < 5.1% glacier cover and < 66.6% meltwater contribution. Below these thresholds the loss of cold stenothermic benthic invertebrate taxa, Diamesa spp. and the Pyrenean endemic Rhyacophila angelieri was apparent. Some generalist taxa including Protonemura sp., Perla grandis, Baetis alpinus, Rhithrogena loyolaea and Microspectra sp. increased when glacier cover was < 2.7% and < 52% meltwater. Patterns were not as distinct for the alpine lakes, due to fewer sampling sites; however, Daphnia longispina grp. and the benthic invertebrate groups Plectopera and Planaria were identified as potential indicator taxa. While further work is required to assess potential indicator taxa for alpine lake systems, findings from alpine river systems were consistent between methods for assessing glacier influence (meltwater contribution/glacier cover). Hence, it is clear that TITAN could become a useful management tool, enabling: (i) the identification of taxa particularly

  19. Biological consequences of earlier snowmelt from desert dust deposition in alpine landscapes.

    Science.gov (United States)

    Steltzer, Heidi; Landry, Chris; Painter, Thomas H; Anderson, Justin; Ayres, Edward

    2009-07-14

    Dust deposition to mountain snow cover, which has increased since the late 19(th) century, accelerates the rate of snowmelt by increasing the solar radiation absorbed by the snowpack. Snowmelt occurs earlier, but is decoupled from seasonal warming. Climate warming advances the timing of snowmelt and early season phenological events (e.g., the onset of greening and flowering); however, earlier snowmelt without warmer temperatures may have a different effect on phenology. Here, we report the results of a set of snowmelt manipulations in which radiation-absorbing fabric and the addition and removal of dust from the surface of the snowpack advanced or delayed snowmelt in the alpine tundra. These changes in the timing of snowmelt were superimposed on a system where the timing of snowmelt varies with topography and has been affected by increased dust loading. At the community level, phenology exhibited a threshold response to the timing of snowmelt. Greening and flowering were delayed before seasonal warming, after which there was a linear relationship between the date of snowmelt and the timing of phenological events. Consequently, the effects of earlier snowmelt on phenology differed in relation to topography, which resulted in increasing synchronicity in phenology across the alpine landscape with increasingly earlier snowmelt. The consequences of earlier snowmelt from increased dust deposition differ from climate warming and include delayed phenology, leading to synchronized growth and flowering across the landscape and the opportunity for altered species interactions, landscape-scale gene flow via pollination, and nutrient cycling.

  20. Effects of floral morphology on flower temperature increment in alpine plants%高山植物花形态特征对花温度积累的影响

    Institute of Scientific and Technical Information of China (English)

    张国鹏; 杨明柳; 程贤训; 孟丽华

    2017-01-01

    Low temperature of alpine environment would limits the development of reproductive organs and pollination process, and thus flower structures that increase the temperatures within flowers and inflorescence will protect anthers and ovules from the low temperature and then increase the reproductive success.In this study, we investigated the flower and leaf temperature of 64 alpine plants with an infrared camera equipped with a macro-lens, and then calculated the flower temperature increment (FTI) by subtracting the leaf temperature from the temperature of the reproductive organs.Based on these data, we examined the effects of phylogeny, flowers size, symmetry and color on the FTI.Our result showed that the phylogenetic signal of FTI among different species was weak, indicating that FTI among different species might result from the various demands to temperature, independent of phylogenetic relationship.Furthermore, FTI increased with the increase of flower size, and FTI increased more quickly in zygomorphic flower than in actinomorphic flowers, but the effects of symmetry and color on the averaged FTI were minor across all species.Our results suggest that the differences in FTI are great among different species, but the contribution of FTI on plant reproductive success need to be clarified in future researches.%高山生态系统的低温环境不利于植物繁殖器官的发育和传粉过程,因此能改善花内或花序温度的结构对植物繁殖具有积极意义.该研究利用红外测温仪测量了高寒草甸中64种植物的花温度和叶温度以计算花温度积累,并检测了系统发育、花大小、花对称方式和花大小对花温度积累的影响.结果表明:所测量的64种植物种类,花部温度均高于叶部温度.花温度积累的系统发育信号较弱,表明

  1. Model-Based Attribution of High-Resolution Streamflow Trends in Two Alpine Basins of Western Austria

    Directory of Open Access Journals (Sweden)

    Christoph Kormann

    2016-02-01

    Full Text Available Several trend studies have shown that hydrological conditions are changing considerably in the Alpine region. However, the reasons for these changes are only partially understood and trend analyses alone are not able to shed much light. Hydrological modelling is one possible way to identify the trend drivers, i.e., to attribute the detected streamflow trends, given that the model captures all important processes causing the trends. We modelled the hydrological conditions for two alpine catchments in western Austria (a large, mostly lower-altitude catchment with wide valley plains and a nested high-altitude, glaciated headwater catchment with the distributed, physically-oriented WaSiM-ETH model, which includes a dynamical glacier module. The model was calibrated in a transient mode, i.e., not only on several standard goodness measures and glacier extents, but also in such a way that the simulated streamflow trends fit with the observed ones during the investigation period 1980 to 2007. With this approach, it was possible to separate streamflow components, identify the trends of flow components, and study their relation to trends in atmospheric variables. In addition to trends in annual averages, highly resolved trends for each Julian day were derived, since they proved powerful in an earlier, data-based attribution study. We were able to show that annual and highly resolved trends can be modelled sufficiently well. The results provide a holistic, year-round picture of the drivers of alpine streamflow changes: Higher-altitude catchments are strongly affected by earlier firn melt and snowmelt in spring and increased ice melt throughout the ablation season. Changes in lower-altitude areas are mostly caused by earlier and lower snowmelt volumes. All highly resolved trends in streamflow and its components show an explicit similarity to the local temperature trends. Finally, results indicate that evapotranspiration has been increasing in the lower

  2. Argon and fission track dating of Alpine metamorphism and basement exhumation in the Sopron Mts. (Eastern Alps, Hungary): thermochronology or mineral growth?

    International Nuclear Information System (INIS)

    Balogh, K.; Dunkl, I.

    2005-01-01

    The crystalline basement rocks of the Sopron Mountains are the easternmost and most isolated outcrops of the Austroalpine basement of the Eastern Alps. Ar/Ar and K/Ar dating of phengitic mica indicates that the Eoalpine high-pressure metamorphism of the area occurred between 76 and 71 Ma. Short-lived metamorphism is characterized by fluid-poor conditions. Fluid circulation was mostly restricted to shear zones, thus the degree of Alpine overprint has an extreme spatial variation. In several metamorphic slices Variscan mineral assemblages have been preserved and biotite yielded Variscan and Permo-Triassic Ar ages. Different mineral and isotope thermometers (literature data) yielded temperatures of 500-600 o C for the peak of Alpine metamorphism in the Sopron Mountains, but muscovite and biotite do not show complete argon resetting. Thus, we consider this crystalline area as a well constrained natural test site, which either indicates considerably high closure temperatures (around 550 o C) for Ar in muscovite and biotite in a dry metamorphic environment, or which is suitable for testing the widely applied methods of temperature estimations under disequilibrium conditions. Apatite fission track results and their thermal modeling, together with structural, mineralogical and sedimentological observations, allows the identification of a post-metamorphic, Eocene hydrothermal event and Late Miocene-Pliocene sediment burial of the crystalline rocks of the Sopron Mountains. (author)

  3. Temperature Response of a Small Mountain Stream to Thunderstorm Cloud-Cover: Application of DTS Fiber-Optic Temperature Sensing

    Science.gov (United States)

    Thayer, D.; Klatt, A. L.; Miller, S. N.; Ohara, N.

    2014-12-01

    From a hydrologic point of view, the critical zone in alpine areas contains the first interaction of living systems with water which will flow to streams and rivers that sustain lowland biomes and human civilization. A key to understanding critical zone functions is understanding the flow of energy, and we can measure temperature as a way of looking at energy transfer between related systems. In this study we installed a Distributed Temperature Sensor (DTS) and fiber-optic cable in a zero-order stream at 9,000 ft in the Medicine Bow National Forest in southern Wyoming. We measured the temperature of the stream for 17 days from June 29 to July 16; the first 12 days were mostly sunny with occasional afternoon storms, and the last 5 experienced powerful, long-lasting storms for much of the day. The DTS measurements show a seasonal warming trend of both minimum and maximum stream temperature for the first 12 days, followed by a distinct cooling trend for the five days that experienced heavy storm activity. To gain insights into the timing and mechanisms of energy flow through the critical zone systems, we analyzed the timing of stream temperature change relative to solar short-wave radiation, and compared the stream temperature temporal response to the temporal response of soil temperature adjacent to the stream. Since convective thunderstorms are a dominant summer weather pattern in sub-alpine regions in the Rocky Mountains, this study gives us further insight into interactions of critical zone processes and weather in mountain ecosystems.

  4. Representing the effects of alpine grassland vegetation cover on the simulation of soil thermal dynamics by ecosystem models applied to the Qinghai-Tibetan Plateau

    Science.gov (United States)

    Yi, S.; Li, N.; Xiang, B.; Wang, X.; Ye, B.; McGuire, A.D.

    2013-01-01

    Soil surface temperature is a critical boundary condition for the simulation of soil temperature by environmental models. It is influenced by atmospheric and soil conditions and by vegetation cover. In sophisticated land surface models, it is simulated iteratively by solving surface energy budget equations. In ecosystem, permafrost, and hydrology models, the consideration of soil surface temperature is generally simple. In this study, we developed a methodology for representing the effects of vegetation cover and atmospheric factors on the estimation of soil surface temperature for alpine grassland ecosystems on the Qinghai-Tibetan Plateau. Our approach integrated measurements from meteorological stations with simulations from a sophisticated land surface model to develop an equation set for estimating soil surface temperature. After implementing this equation set into an ecosystem model and evaluating the performance of the ecosystem model in simulating soil temperature at different depths in the soil profile, we applied the model to simulate interactions among vegetation cover, freeze-thaw cycles, and soil erosion to demonstrate potential applications made possible through the implementation of the methodology developed in this study. Results showed that (1) to properly estimate daily soil surface temperature, algorithms should use air temperature, downward solar radiation, and vegetation cover as independent variables; (2) the equation set developed in this study performed better than soil surface temperature algorithms used in other models; and (3) the ecosystem model performed well in simulating soil temperature throughout the soil profile using the equation set developed in this study. Our application of the model indicates that the representation in ecosystem models of the effects of vegetation cover on the simulation of soil thermal dynamics has the potential to substantially improve our understanding of the vulnerability of alpine grassland ecosystems to

  5. Alpine Windharvest: development of information base regarding potentials and the necessary technical, legal and socio-economic conditions for expanding wind energy in the Alpine Space - Digital relief analysis - Abstract of work package 7

    Energy Technology Data Exchange (ETDEWEB)

    Schaffner, B.; Cattin, R. [Meteotest, Berne (Switzerland)

    2005-07-01

    This report presents an abstract of the development work carried out by the Swiss meteorology specialists METEOTEST as part of a project carried out together with the Swiss wind-energy organisation 'Suisse Eole'. The framework for the project is the EU Interreg IIIB Alpine Space Programme, a European Community Initiative Programme funded by the European Regional Development Fund. The project investigated the use of digital relief-analysis. The series of reports describes the development and use of a basic information system to aid the investigation of the technical, legal and socio-economical conditions for the use of wind energy in the alpine area. This report presents an abstract of the work done as part of the Work Package 7 of the Alpine Windharvest project.

  6. Alpine snow cover in a changing climate: a regional climate model perspective

    Science.gov (United States)

    Steger, Christian; Kotlarski, Sven; Jonas, Tobias; Schär, Christoph

    2013-08-01

    An analysis is presented of an ensemble of regional climate model (RCM) experiments from the ENSEMBLES project in terms of mean winter snow water equivalent (SWE), the seasonal evolution of snow cover, and the duration of the continuous snow cover season in the European Alps. Two sets of simulations are considered, one driven by GCMs assuming the SRES A1B greenhouse gas scenario for the period 1951-2099, and the other by the ERA-40 reanalysis for the recent past. The simulated SWE for Switzerland for the winters 1971-2000 is validated against an observational data set derived from daily snow depth measurements. Model validation shows that the RCMs are capable of simulating the general spatial and seasonal variability of Alpine snow cover, but generally underestimate snow at elevations below 1,000 m and overestimate snow above 1,500 m. Model biases in snow cover can partly be related to biases in the atmospheric forcing. The analysis of climate projections for the twenty first century reveals high inter-model agreement on the following points: The strongest relative reduction in winter mean SWE is found below 1,500 m, amounting to 40-80 % by mid century relative to 1971-2000 and depending upon the model considered. At these elevations, mean winter temperatures are close to the melting point. At higher elevations the decrease of mean winter SWE is less pronounced but still a robust feature. For instance, at elevations of 2,000-2,500 m, SWE reductions amount to 10-60 % by mid century and to 30-80 % by the end of the century. The duration of the continuous snow cover season shows an asymmetric reduction with strongest shortening in springtime when ablation is the dominant factor for changes in SWE. We also find a substantial ensemble-mean reduction of snow reliability relevant to winter tourism at elevations below about 1,800 m by mid century, and at elevations below about 2,000 m by the end of the century.

  7. A GLOBAL TWO-TEMPERATURE CORONA AND INNER HELIOSPHERE MODEL: A COMPREHENSIVE VALIDATION STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Jin, M.; Manchester, W. B.; Van der Holst, B.; Gruesbeck, J. R.; Frazin, R. A.; Landi, E.; Toth, G.; Gombosi, T. I. [Atmospheric Oceanic and Space Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Vasquez, A. M. [Instituto de Astronomia y Fisica del Espacio (CONICET-UBA) and FCEN (UBA), CC 67, Suc 28, Ciudad de Buenos Aires (Argentina); Lamy, P. L.; Llebaria, A.; Fedorov, A., E-mail: jinmeng@umich.edu [Laboratoire d' Astrophysique de Marseille, Universite de Provence, Marseille (France)

    2012-01-20

    The recent solar minimum with very low activity provides us a unique opportunity for validating solar wind models. During CR2077 (2008 November 20 through December 17), the number of sunspots was near the absolute minimum of solar cycle 23. For this solar rotation, we perform a multi-spacecraft validation study for the recently developed three-dimensional, two-temperature, Alfven-wave-driven global solar wind model (a component within the Space Weather Modeling Framework). By using in situ observations from the Solar Terrestrial Relations Observatory (STEREO) A and B, Advanced Composition Explorer (ACE), and Venus Express, we compare the observed proton state (density, temperature, and velocity) and magnetic field of the heliosphere with that predicted by the model. Near the Sun, we validate the numerical model with the electron density obtained from the solar rotational tomography of Solar and Heliospheric Observatory/Large Angle and Spectrometric Coronagraph C2 data in the range of 2.4 to 6 solar radii. Electron temperature and density are determined from differential emission measure tomography (DEMT) of STEREO A and B Extreme Ultraviolet Imager data in the range of 1.035 to 1.225 solar radii. The electron density and temperature derived from the Hinode/Extreme Ultraviolet Imaging Spectrometer data are also used to compare with the DEMT as well as the model output. Moreover, for the first time, we compare ionic charge states of carbon, oxygen, silicon, and iron observed in situ with the ACE/Solar Wind Ion Composition Spectrometer with those predicted by our model. The validation results suggest that most of the model outputs for CR2077 can fit the observations very well. Based on this encouraging result, we therefore expect great improvement for the future modeling of coronal mass ejections (CMEs) and CME-driven shocks.

  8. The 'Alpine Windharvest' project - Overview; Projekt Alpine Windharvest - Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Schaffner, B.; Kunz, S. [Suisse Eole, Meteotest, Berne (Switzerland)

    2005-07-01

    This short introduction forms part of a final report for the Swiss Federal Office of Energy (SFOE) that presents the results of a project carried out by the Swiss wind-energy organisation 'Suisse Eole' and the meteorology specialists of the company METEOTEST. The project investigated the use of digital relief-analysis and formed part of a European wind-energy project that investigated the technical, legal and socio-economical aspects of the use of wind energy. The work-package 7 included the identification of wind-energy areas using comparative Geographic Information System (GIS) methods. An overview is provided of the wind-energy potential in the whole of the alpine region and five areas in which measurements are to be made, including GIS analyses, are defined.

  9. Recent crustal movements and geophysical interpretation of geodynamic processes in the Alpine mountain belt

    Science.gov (United States)

    Gubler, E.; Kahle, H. G.

    It is a well-known fact that the surface phenomena of global plate tectonics are most convincingly seen and felt along the boundaries of the moving lithospheric plates. These boundaries are morphologically expressed as mild-ocean ridges or as subduction zones such as deep sea trenches or Himalayan/Alpine fold belts, the latter of which are the subject of this paper. On a global scale, there are kinematic models giving an idea of what kind of rates can be expected. This is due to the fact that magnetic sea floor spreading anomalies are missing in the Alpine environment. On the other hand, the structure and kinematics of the Apulian microplate are of major interest to Switzerland because its northern boundary seems to be formed by the Alpine chain. In Switzerland there are some 14 special study groups actively working in this field of geodynamics. This paper is restricted to the geodetic and gravity studies. With emphasis on the assumed northern boundary of the Apulian microplate, the kinematics of relative plate movements in the Alpine area were investigated. A simplified tectonic map of this region is shown.

  10. Contrasting shrub species respond to early summer temperatures leading to correspondence of shrub growth patterns

    Science.gov (United States)

    Weijers, Stef; Pape, Roland; Löffler, Jörg; Myers-Smith, Isla H.

    2018-03-01

    The Arctic-alpine biome is warming rapidly, resulting in a gradual replacement of low statured species by taller woody species in many tundra ecosystems. In northwest North America, the remotely sensed normalized difference vegetation index (NDVI), suggests an increase in productivity of the Arctic and alpine tundra and a decrease in productivity of boreal forests. However, the responses of contrasting shrub species growing at the same sites to climate drivers remain largely unexplored. Here, we test growth, climate, and NDVI relationships of two contrasting species: the expanding tall deciduous shrub Salix pulchra and the circumarctic evergreen dwarf shrub Cassiope tetragona from an alpine tundra site in the Pika valley in the Kluane Region, southwest Yukon Territories, Canada. We found that annual growth variability of both species at this site is strongly driven by early summer temperatures, despite their contrasting traits and habitats. Shrub growth chronologies for both species were correlated with the regional climate signal and showed spatial correspondence with interannual variation in NDVI in surrounding alpine and Arctic regions. Our results suggest that early summer warming represents a common driver of vegetation change for contrasting shrub species growing in different habitats in the same alpine environments.

  11. Developing the remote sensing-based water environmental model for monitoring alpine river water environment over Plateau cold zone

    Science.gov (United States)

    You, Y.; Wang, S.; Yang, Q.; Shen, M.; Chen, G.

    2017-12-01

    Alpine river water environment on the Plateau (such as Tibetan Plateau, China) is a key indicator for water security and environmental security in China. Due to the complex terrain and various surface eco-environment, it is a very difficult to monitor the water environment over the complex land surface of the plateau. The increasing availability of remote sensing techniques with appropriate spatiotemporal resolutions, broad coverage and low costs allows for effective monitoring river water environment on the Plateau, particularly in remote and inaccessible areas where are lack of in situ observations. In this study, we propose a remote sense-based monitoring model by using multi-platform remote sensing data for monitoring alpine river environment. In this study some parameterization methodologies based on satellite remote sensing data and field observations have been proposed for monitoring the water environmental parameters (including chlorophyll-a concentration (Chl-a), water turbidity (WT) or water clarity (SD), total nitrogen (TN), total phosphorus (TP), and total organic carbon (TOC)) over the china's southwest highland rivers, such as the Brahmaputra. First, because most sensors do not collect multiple observations of a target in a single pass, data from multiple orbits or acquisition times may be used, and varying atmospheric and irradiance effects must be reconciled. So based on various types of satellite data, at first we developed the techniques of multi-sensor data correction, atmospheric correction. Second, we also built the inversion spectral database derived from long-term remote sensing data and field sampling data. Then we have studied and developed a high-precision inversion model over the southwest highland river backed by inversion spectral database through using the techniques of multi-sensor remote sensing information optimization and collaboration. Third, take the middle reaches of the Brahmaputra river as the study area, we validated the key

  12. Generic Regional Development Strategies from Local Stakeholders' Scenarios - an Alpine Village Experience

    Directory of Open Access Journals (Sweden)

    Wolfgang Loibl

    2010-09-01

    Full Text Available The article discusses the participatory elaboration of strategies for sustainable regional development in an Alpine tourist region in Austria to cope with global change effects evolving locally, considering climate change, economic change as well as (local societal change. Local stakeholders in an Alpine village in the Montafon region contributed in workshops to achieve the final results: participant teams conducted system analyses of the regional system to explore key elements of the region. Narrative scenarios described possible positive and negative development trends and indicated the critical issues controlling future development; 3D-images of landscape transition simulations show the consequences of certain development directions. Alternative development directions supported the local stakeholders to elaborate regional development strategies. In the end, the scientist team derived generic strategies for Alpine regions based on the locally developed strategy bundle. The article presents the intention, progress and outcome of the participatory approach and elaborates the potential to derive generic strategies from local ones and discusses the possibly occurring conflicts regarding cross-scale transfers of these local strategies. Overall, tourism was seen as a key element for future regional development, which can on the one hand derogate Alpine regions and is on the other hand threatened by climate change and diminution of landscape attractiveness. The suggested development strategies will help to cope with global change issues mitigating the negative consequences on the local society and environment.

  13. A multi-objective approach to improve SWAT model calibration in alpine catchments

    Science.gov (United States)

    Tuo, Ye; Marcolini, Giorgia; Disse, Markus; Chiogna, Gabriele

    2018-04-01

    Multi-objective hydrological model calibration can represent a valuable solution to reduce model equifinality and parameter uncertainty. The Soil and Water Assessment Tool (SWAT) model is widely applied to investigate water quality and water management issues in alpine catchments. However, the model calibration is generally based on discharge records only, and most of the previous studies have defined a unique set of snow parameters for an entire basin. Only a few studies have considered snow observations to validate model results or have taken into account the possible variability of snow parameters for different subbasins. This work presents and compares three possible calibration approaches. The first two procedures are single-objective calibration procedures, for which all parameters of the SWAT model were calibrated according to river discharge alone. Procedures I and II differ from each other by the assumption used to define snow parameters: The first approach assigned a unique set of snow parameters to the entire basin, whereas the second approach assigned different subbasin-specific sets of snow parameters to each subbasin. The third procedure is a multi-objective calibration, in which we considered snow water equivalent (SWE) information at two different spatial scales (i.e. subbasin and elevation band), in addition to discharge measurements. We tested these approaches in the Upper Adige river basin where a dense network of snow depth measurement stations is available. Only the set of parameters obtained with this multi-objective procedure provided an acceptable prediction of both river discharge and SWE. These findings offer the large community of SWAT users a strategy to improve SWAT modeling in alpine catchments.

  14. Assessing the protection function of Alpine forest ecosystems using BGC modelling theory

    Science.gov (United States)

    Pötzelsberger, E.; Hasenauer, H.; Petritsch, R.; Pietsch, S. A.

    2009-04-01

    The purpose of this study was to assess the protection function of forests in Alpine areas by modelling the flux dynamics (water, carbon, nutrients) within a watershed as they may depend on the vegetation pattern and forest management impacts. The application case for this study was the catchment Schmittenbach, located in the province of Salzburg. Data available covered the hydrology (rainfall measurements from 1981 to 1998 and runoff measurements at the river Schmittenbach from 1981 to 2005), vegetation dynamics (currently 69% forest, predominantly Norway Spruce). The method of simulating the forest growth and water outflow was validated. For simulations of the key ecosystem processes (e.g. photosynthesis, carbon and nitrogen allocation in the different plant parts, litter fall, mineralisation, tree water uptake, transpiration, rainfall interception, evaporation, snow accumulation and snow melt, outflow of spare water) the biogeochemical ecosystem model Biome-BGC was applied. Relevant model extensions were the tree species specific parameter sets and the improved thinning regime. The model is sensitive to site characteristics and needs daily weather data and information on the atmospheric composition, which makes it sensitive to higher CO2-levels and climate change. For model validation 53 plots were selected covering the full range of site quality and stand age. Tree volume and soil was measured and compared with the respective model results. The outflow for the watershed was predicted by combining the simulated forest-outflow (derived from plot-outflow) with the outflow from the non-forest area (calculated with a fixed outflow/rainfall coefficient (OC)). The analysis of production and water related model outputs indicated that mechanistic modelling can be used as a tool to assess the performance of Alpine protection forests. The Water Use Efficiency (WUE), the ratio of Net primary production (NPP) and Transpiration, was found the highest for juvenile stands (

  15. Climate change and its impacts on vegetation distribution and net primary productivity of the alpine ecosystem in the Qinghai-Tibetan Plateau.

    Science.gov (United States)

    Gao, Qingzhu; Guo, Yaqi; Xu, Hongmei; Ganjurjav, Hasbagen; Li, Yue; Wan, Yunfan; Qin, Xiaobo; Ma, Xin; Liu, Shuo

    2016-06-01

    Changes in climate have caused impacts on ecosystems on all continents scale, and climate change is also projected to be a stressor on most ecosystems even at the rate of low- to medium-range warming scenarios. Alpine ecosystem in the Qinghai-Tibetan Plateau is vulnerable to climate change. To quantify the climate change impacts on alpine ecosystems, we simulated the vegetation distribution and net primary production in the Qinghai-Tibetan Plateau for three future periods (2020s, 2050s and 2080s) using climate projection for RCPs (Representative Concentration Pathways) RCP4.5 and RCP8.5 scenarios. The modified Lund-Potsdam-Jena Dynamic Global Vegetation Model (LPJ model) was parameter and test to make it applicable to the Qinghai-Tibetan Plateau. Climate projections that were applied to LPJ model in the Qinghai-Tibetan Plateau showed trends toward warmer and wetter conditions. Results based on climate projections indicated changes from 1.3°C to 4.2°C in annual temperature and changes from 2% to 5% in annual precipitation. The main impacts on vegetation distribution was increase in the area of forests and shrubs, decrease in alpine meadows which mainly replaced by shrubs which dominated the eastern plateau, and expanding in alpine steppes to the northwest dominated the western and northern plateau. The NPP was projected to increase by 79% and 134% under the RCP4.5 and RCP8.5. The projected NPP generally increased about 200gC·m(-2)·yr(-1) in most parts of the plateau with a gradual increase from the eastern to the western region of the Qinghai-Tibetan Plateau at the end of this century. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Exploring the Potential of Aerial Photogrammetry for 3d Modelling of High-Alpine Environments

    Science.gov (United States)

    Legat, K.; Moe, K.; Poli, D.; Bollmannb, E.

    2016-03-01

    High-alpine areas are subject to rapid topographic changes, mainly caused by natural processes like glacial retreat and other geomorphological processes, and also due to anthropogenic interventions like construction of slopes and infrastructure in skiing resorts. Consequently, the demand for highly accurate digital terrain models (DTMs) in alpine environments has arisen. Public administrations often have dedicated resources for the regular monitoring of glaciers and natural hazard processes. In case of glaciers, traditional monitoring encompasses in-situ measurements of area and length and the estimation of volume and mass changes. Next to field measurements, data for such monitoring programs can be derived from DTMs and digital ortho photos (DOPs). Skiing resorts, on the other hand, require DTMs as input for planning and - more recently - for RTK-GNSS supported ski-slope grooming. Although different in scope, the demand of both user groups is similar: high-quality and up-to-date terrain data for extended areas often characterised by difficult accessibility and large elevation ranges. Over the last two decades, airborne laser scanning (ALS) has replaced photogrammetric approaches as state-of-the-art technology for the acquisition of high-resolution DTMs also in alpine environments. Reasons include the higher productivity compared to (manual) stereo-photogrammetric measurements, canopy-penetration capability, and limitations of photo measurements on sparsely textured surfaces like snow or ice. Nevertheless, the last few years have shown strong technological advances in the field of aerial camera technology, image processing and photogrammetric software which led to new possibilities for image-based DTM generation even in alpine terrain. At Vermessung AVT, an Austrian-based surveying company, and its subsidiary Terra Messflug, very promising results have been achieved for various projects in high-alpine environments, using images acquired by large-format digital

  17. Les barrages alpins

    Directory of Open Access Journals (Sweden)

    Alain Marnezy

    2009-03-01

    Full Text Available Les barrages-réservoirs de montagne ont été réalisés initialement dans les Alpes pour répondre à la demande d’énergie en période hivernale. Une certaine diversification des usages de l’eau s’est ensuite progressivement développée, en relation avec le développement touristique des collectivités locales. Aujourd’hui, la participation des ouvrages d’Électricité De France à la production de neige de culture représente une nouvelle étape. Dans les régions où les aménagements hydroélectriques sont nombreux, les besoins en eau pour la production de neige peuvent être résolus par prélèvements à partir des adductions EDF. Les gestionnaires de stations échappent ainsi aux inconvénients liés à la construction et à la gestion des « retenues collinaires ». Cette évolution, qui concerne déjà quelques régions alpines comme la haute Maurienne ou le Beaufortin, apparaît comme une forme renouvelée d’intégration territoriale de la ressource en eau.Mountain reservoirs were initially built in the Alps to meet energy needs in the winter. A certain diversification in the uses of water then gradually developed, related to tourism development in the local communities. Today, the use of facilities belonging to EDF (French Electricity Authority to provide water for winter resorts to make artificial snow represents a new phase. By taking water from EDF resources to supply snow-making equipment, resort managers are thus able to avoid the problems related to the construction and management of small headwater dams. This new orientation in the use of mountain water resources already affects a number of alpine regions such as the Upper Maurienne valley and Beaufortain massif and represents a renewed form of the territorial integration of water resources.

  18. Vascular plant flora of the alpine zone in the southern Rocky Mountains, U.S.A

    Science.gov (United States)

    James F. Fowler; B. E. Nelson; Ronald L. Hartman

    2014-01-01

    Field detection of changes in occurrence, distribution, or abundance of alpine plant species is predicated on knowledge of which species are in specific locations. The alpine zone of the Southern Rocky Mountain Region has been systematically inventoried by the staff and floristics graduate students from the Rocky Mountain Herbarium over the last 27 years. It is...

  19. Seasonality in the alpine water logistic system on a regional basis

    Science.gov (United States)

    Vanham, D.; Fleischhacker, E.; Rauch, W.

    2007-08-01

    In this study the water logistic system is defined as the interaction of the subsystems water resources, water supply and water demand in terms of water flow. The analysis of a water balance in alpine regions is strongly influenced by both temporal and spatial seasonal fluctuations within these elements, the latter due to the vertical dimension of mountainous areas. Therefore the determination of different seasons plays a key role within the assessment of alpine water logistic systems. In most studies a water balance for a certain region is generated on an annual, monthly or classic 4-seasonal basis. This paper presents a GIS-based multi criteria method to determine an optimal winter and summer period, taking into account different water demand stakeholders, alpine hydrology and the characteristic present day water supply infrastructure of the Alps. Technical snow-making and (winter) tourism were identified as the two major seasonal water demand stakeholders in the study area, which is the Kitzbueheler region in the Austrian Alps. Based upon the geographical datasets mean snow cover start and end date, winter was defined as the period from December to March, and summer as the period from April to November.

  20. The Swiss Alpine Glacier's Response to the '2°C Target

    Science.gov (United States)

    Salzmann, Nadine; Machguth, Horst

    2010-05-01

    The "2°C target" for global warming (relative to pre-industrial level) became a main focus in the climate change debate since the UN Climate Change Conference in Copenhagen (COP15) in December 2009 at the latest. While this target implies to be a ‘clear' goal for politicians and decision makers, the effective impacts that a global mean air temperature increase of 2°C has on natural and human systems on regional to local scales remain complex. So far, most impact studies use only relative and static 2°C delta change approaches. Here, however, we use results from latest climate model outputs an take into account the warming that has already occurred in a specific region. Global warming is not equally distributed around the globe. Observations show that during the last century air temperature trends significantly differ between regions. In Switzerland, for example, air temperature has increased about twice as much as the global mean during the last century. In glacierised mountain regions, where glaciers represent an important source for fresh water and control a great part of the hydrological cycle, the retreat or disappearance of glaciers as a consequence of climatic changes will have major socio-economical consequences on the people living there and the adjacent lowland. A trend to negative glacier mass balances is observed and well documented for many mountain ranges all over the world. Based on climate model projections it is very likely that this trend continues or even accelerates. Here, we make an effort to assess the impact of a global 2°C (that is about 4°C for Switzerland) air temperature increase compared to pre-industrial conditions for the Swiss Alpine glaciers. We use 12 homogenised long-term climate observations to define the warming that has already taken place. The ‘remaining' temperature increase up to the level of 2°C, is based on results from a selection of Regional Climate Model results that have been simulated in the recently finished

  1. Validity of Devices That Assess Body Temperature During Outdoor Exercise in the Heat

    Science.gov (United States)

    Casa, Douglas J; Becker, Shannon M; Ganio, Matthew S; Brown, Christopher M; Yeargin, Susan W; Roti, Melissa W; Siegler, Jason; Blowers, Julie A; Glaviano, Neal R; Huggins, Robert A; Armstrong, Lawrence E; Maresh, Carl M

    2007-01-01

    Context: Rectal temperature is recommended by the National Athletic Trainers' Association as the criterion standard for recognizing exertional heat stroke, but other body sites commonly are used to measure temperature. Few authors have assessed the validity of the thermometers that measure body temperature at these sites in athletic settings. Objective: To assess the validity of commonly used temperature devices at various body sites during outdoor exercise in the heat. Design: Observational field study. Setting: Outdoor athletic facilities. Patients or Other Participants: Fifteen men and 10 women (age = 26.5 ± 5.3 years, height = 174.3 ± 11.1 cm, mass = 72.73 ± 15.95 kg, body fat = 16.2 ± 5.5%). Intervention(s): We simultaneously tested inexpensive and expensive devices orally and in the axillary region, along with measures of aural, gastrointestinal, forehead, temporal, and rectal temperatures. Temporal temperature was measured according to the instruction manual and a modified method observed in medical tents at local road races. We also measured forehead temperatures directly on the athletic field (other measures occurred in a covered pavilion) where solar radiation was greater. Rectal temperature was the criterion standard used to assess the validity of all other devices. Subjects' temperatures were measured before exercise, every 60 minutes during 180 minutes of exercise, and every 20 minutes for 60 minutes of postexercise recovery. Temperature devices were considered invalid if the mean bias (average difference between rectal temperature and device temperature) was greater than ±0.27°C (±0.5°F). Main Outcome Measure(s): Temperature from each device at each site and time point. Results: Mean bias for the following temperatures was greater than the allowed limit of ±0.27°C (±0.5°F): temperature obtained via expensive oral device (−1.20°C [−2.17°F]), inexpensive oral device (−1.67°C [−3.00°F]), expensive axillary device (−2.58°C [−4

  2. A modified MOD16 algorithm to estimate evapotranspiration over alpine meadow on the Tibetan Plateau, China

    Science.gov (United States)

    Chang, Yaping; Qin, Dahe; Ding, Yongjian; Zhao, Qiudong; Zhang, Shiqiang

    2018-06-01

    The long-term change of evapotranspiration (ET) is crucial for managing water resources in areas with extreme climates, such as the Tibetan Plateau (TP). This study proposed a modified algorithm for estimating ET based on the MOD16 algorithm on a global scale over alpine meadow on the TP in China. Wind speed and vegetation height were integrated to estimate aerodynamic resistance, while the temperature and moisture constraints for stomatal conductance were revised based on the technique proposed by Fisher et al. (2008). Moreover, Fisher's method for soil evaporation was adopted to reduce the uncertainty in soil evaporation estimation. Five representative alpine meadow sites on the TP were selected to investigate the performance of the modified algorithm. Comparisons were made between the ET observed using the Eddy Covariance (EC) and estimated using both the original and modified algorithms. The results revealed that the modified algorithm performed better than the original MOD16 algorithm with the coefficient of determination (R2) increasing from 0.26 to 0.68, and root mean square error (RMSE) decreasing from 1.56 to 0.78 mm d-1. The modified algorithm performed slightly better with a higher R2 (0.70) and lower RMSE (0.61 mm d-1) for after-precipitation days than for non-precipitation days at Suli site. Contrarily, better results were obtained for non-precipitation days than for after-precipitation days at Arou, Tanggula, and Hulugou sites, indicating that the modified algorithm may be more suitable for estimating ET for non-precipitation days with higher accuracy than for after-precipitation days, which had large observation errors. The comparisons between the modified algorithm and two mainstream methods suggested that the modified algorithm could produce high accuracy ET over the alpine meadow sites on the TP.

  3. Carbon sequestration in Himalaya's alpine meadows: Mitigating cropping encroachment on pastures in Northern Pakistan

    OpenAIRE

    Rueff, Henri; Syed Rehman, Aziz; Rahim, Inam; Maselli, Daniel; Nafees, Mohammad; Wiesmann, Urs

    2011-01-01

    Rangelands store about 30% of the world’s carbon and support over 120 million pastoralists globally. Adjusting the management of remote alpine pastures bears a substantial climate change mitigation potential that can provide livelihood support for marginalized pastoralists through carbon payment. Landless pastoralists in Northern Pakistan seek higher income by cropping potatoes and peas over alpine pastures. However, tilling steep slopes without terracing exposes soil to erosion. Moreover, yi...

  4. A new approach for surveying the Alpine Salamander (Salamandra atra in Austria

    Directory of Open Access Journals (Sweden)

    Ursula Reinthaler-Lottermoser

    2010-12-01

    Full Text Available The Alpine Salamander is a small pitch black amphibian which is endemic to the European Alps and the Dinarides. It is strictly protected according to the European FFH guidelines. Despite its central role in the alpine ecosystem our actual published record in Austria is small. In order to resolve this shortcoming our project explores its distribution in Austria. It uses a participatory and community based approach to gather data. Everybody can enter and look at Alpine Salamander observations on our website www.alpensalamander.eu. This approach also allows us to establish an “oral history” of Salamander observations in the past 50 years by conducting interviews in the local community. Since July 2009 the website and salamander report database are online. From the actual data (more than 5600 records we already obtained an overview about the present distribution and data quality. The data are an excellent basis for detailed scientific studies on these remarkable amphibians. With this new and highly interactive approach science and education are combined to initiate protection measures with the public.

  5. Continuous recording of seismic signals in Alpine permafrost

    Science.gov (United States)

    Hausmann, H.; Krainer, K.; Staudinger, M.; Brückl, E.

    2009-04-01

    Over the past years various geophysical methods were applied to study the internal structure and the temporal variation of permafrost whereof seismic is of importance. For most seismic investigations in Alpine permafrost 24-channel equipment in combination with long data and trigger cables is used. Due to the harsh environment source and geophone layouts are often limited to 2D profiles. With prospect for future 3D-layouts we introduce an alternative of seismic equipment that can be used for several applications in Alpine permafrost. This study is focussed on controlled and natural source seismic experiments in Alpine permafrost using continuous data recording. With recent data from an ongoing project ("Permafrost in Austria") we will highlight the potential of the used seismic equipment for three applications: (a) seismic permafrost mapping of unconsolidated sediments, (b) seismic tomography in rock mass, and (c) passive seismic monitoring of rock falls. Single recording units (REFTEK 130, 6 channels) are used to continuously record the waveforms of both the seismic signals and a trigger signal. The combination of a small number of recording units with different types of geophones or a trigger allow numerous applications in Alpine permafrost with regard to a high efficiency and flexible seismic layouts (2D, 3D, 4D). The efficiency of the light and robust seismic equipment is achieved by the simple acquisition and the flexible and fast deployment of the (omni-directional) geophones. Further advantages are short (data and trigger) cables and the prevention of trigger errors. The processing of the data is aided by 'Seismon' which is an open source software project based on Matlab® and MySQL (see SM1.0). For active-source experiments automatic stacking of the seismic signals is implemented. For passive data a program for automatic detection of events (e.g. rock falls) is available which allows event localization. In summer 2008 the seismic equipment was used for the

  6. Classification of the eastern alpine vegetation of Lesotho | Morris ...

    African Journals Online (AJOL)

    Five vegetation communities in the alpine catchment of Lesotho were identified by hierarchical classification of the botanical composition data. Discriminant analysis indicated that these communities occupy particular topographic positions. The community-environmental relationships identified in this study were similar to ...

  7. Quantitative ecological relationships in the alpine grassland of ...

    African Journals Online (AJOL)

    A survey, based on 56 000 points at 102 sampling sites in the Tsehlanyane valley of the Oxbow (Madibamatso) Dam catchment in the alpine grassland of Lesotho, indicates that the area is generally in good condition. Physiographic and floristic criteria were measured and the association between pairs of criteria statistically ...

  8. Alpine Skiing With total knee ArthroPlasty (ASWAP)

    DEFF Research Database (Denmark)

    Kristensen, M.; Pötzelsberger, B.; Scheiber, P.

    2015-01-01

    We investigated the effect of alpine skiing for 12 weeks on skeletal muscle characteristics and biomarkers of glucose homeostasis and cardiovascular risk factors. Twenty-three patients with a total knee arthroplasty (TKA) were studied 2.9 ± 0.9 years (mean ± SD) after the operation. Fourteen...

  9. Lake surface water temperatures of European Alpine lakes (1989-2013) based on the Advanced Very High Resolution Radiometer (AVHRR) 1 km data set

    Science.gov (United States)

    Riffler, M.; Wunderle, S.

    2014-05-01

    Lake water temperature (LWT) is an important driver of lake ecosystems and it has been identified as an indicator of climate change. Thus, the Global Climate Observing System (GCOS) lists LWT as an Essential Climate Variable (ECV). Although for some European lakes long in situ time series of LWT do exist, many lakes are not observed or only on a non-regular basis making these observations insufficient for climate monitoring. Satellite data can provide the information needed. However, only few satellite sensors offer the possibility to analyse time series which cover 25 years or more. The Advanced Very High Resolution Radiometer (AVHRR) is among these and has been flown as a heritage instrument for almost 35 years. It will be carried on for at least ten more years finally offering a unique opportunity for satellite-based climate studies. Herein we present a satellite-based lake surface water temperature (LSWT) data set for European (pre-alpine) water bodies based on the extensive AVHRR 1 km data record (1989-2013) of the Remote Sensing Research Group at the University of Bern. It has been compiled out of AVHRR/2 (NOAA-07, -09, -11, -14) and AVHRR/3 (NOAA-16, -17, -18, -19 and Metop-A) data. The high accuracy needed for climate related studies requires careful pre-processing and consideration of the atmospheric state. Especially data from NOAA-16 and prior satellites were prone to noise, e.g., due to transmission errors or fluctuations in the instrument's thermal state. This has resulted in partly corrupted thermal calibration data and may cause errors of up to several Kelvin in the final resulting LSWT. Thus, a multi-stage correction scheme has been applied to the data to minimize these artefacts. The LSWT retrieval is based on a simulation-based scheme making use of the Radiative Transfer for TOVS (RTTOV) Version 10 together with operational analysis and reanalysis data from the European Centre for Medium Range Weather Forecasts. The resulting LSWTs were

  10. 78 FR 28273 - Alpine Investors IV SBIC, LP; Notice Seeking Exemption Under Section 312 of the Small Business...

    Science.gov (United States)

    2013-05-14

    ... SMALL BUSINESS ADMINISTRATION [License No. 09/09-0461] Alpine Investors IV SBIC, LP; Notice... hereby given that Alpine Investors IV SBIC, LP, 3 Embarcadero Center, Suite 2330, San Francisco, CA, a...'') Rules and [[Page 28274

  11. Glacial refugia, recolonization patterns and diversification forces in Alpine-endemic Megabunus harvestmen.

    Science.gov (United States)

    Wachter, Gregor A; Papadopoulou, Anna; Muster, Christoph; Arthofer, Wolfgang; Knowles, L Lacey; Steiner, Florian M; Schlick-Steiner, Birgit C

    2016-06-01

    The Pleistocene climatic fluctuations had a huge impact on all life forms, and various hypotheses regarding the survival of organisms during glacial periods have been postulated. In the European Alps, evidence has been found in support of refugia outside the ice shield (massifs de refuge) acting as sources for postglacial recolonization of inner-Alpine areas. In contrast, evidence for survival on nunataks, ice-free areas above the glacier, remains scarce. Here, we combine multivariate genetic analyses with ecological niche models (ENMs) through multiple timescales to elucidate the history of Alpine Megabunus harvestmen throughout the ice ages, a genus that comprises eight high-altitude endemics. ENMs suggest two types of refugia throughout the last glacial maximum, inner-Alpine survival on nunataks for four species and peripheral refugia for further four species. In some geographic regions, the patterns of genetic variation are consistent with long-distance dispersal out of massifs de refuge, repeatedly coupled with geographic parthenogenesis. In other regions, long-term persistence in nunataks may dominate the patterns of genetic divergence. Overall, our results suggest that glacial cycles contributed to allopatric diversification in Alpine Megabunus, both within and at the margins of the ice shield. These findings exemplify the power of ENM projections coupled with genetic analyses to identify hypotheses about the position and the number of glacial refugia and thus to evaluate the role of Pleistocene glaciations in driving species-specific responses of recolonization or persistence that may have contributed to observed patterns of biodiversity. © 2016 John Wiley & Sons Ltd.

  12. Identifying the Relative Contributions of Climate and Grazing to Both Direction and Magnitude of Alpine Grassland Productivity Dynamics from 1993 to 2011 on the Northern Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    Yunfei Feng

    2017-02-01

    Full Text Available Alpine grasslands on the Tibetan Plateau are claimed to be sensitive and vulnerable to climate change and human disturbance. The mechanism, direction and magnitude of climatic and anthropogenic influences on net primary productivity (NPP of various alpine pastures remain under debate. Here, we simulated the potential productivity (with only climate variables being considered as drivers; NPPP and actual productivity (based on remote sensing dataset including both climate and anthropogenic drivers; NPPA from 1993 to 2011. We denoted the difference between NPPP and NPPA as NPPpc to quantify how much forage can be potentially consumed by livestock. The actually consumed productivity (NPPac by livestock were estimated based on meat production and daily forage consumption per standardized sheep unit. We hypothesized that the gap between NPPpc and NPPac (NPPgap indicates the direction of vegetation dynamics, restoration or degradation. Our results show that growing season precipitation rather than temperature significantly relates with NPPgap, although warming was significant for the entire study region while precipitation only significantly increased in the northeastern places. On the Northern Tibetan Plateau, 69.05% of available alpine pastures showed a restoration trend with positive NPPgap, and for 58.74% of alpine pastures, stocking rate is suggested to increase in the future because of the positive mean NPPgap and its increasing trend. This study provides a potential framework for regionally regulating grazing management with aims to restore the degraded pastures and sustainable management of the healthy pastures on the Tibetan Plateau.

  13. A half century of change in alpine treeline patterns at Glacier National Park, Montana, U.S.A.

    Science.gov (United States)

    Klasner, F.L.; Fagre, D.B.

    2002-01-01

    Using sequential aerial photography, we identified changes in the spatial distribution of subalpine fir (Abies lasiocarpa) habitat at the alpine treeline ecotone. Six 40-ha study sites in the McDonald Creek drainage of Glacier National Park contained subalpine fir forests that graded into alpine tundra. Over a 46-yr period, altitudinal changes in the location of alpine treeline ecotone were not observed. However, over this 46-yr period the area of krummholz, patch-forest, and continuous canopy forest increased by 3.4%, and tree density increased within existing patches of krummholz and patch-forest. Change in subalpine fir vegetation patterns within 100 m of trails was also compared to areas without trails. Within 100 m of trails, the number of small, discrete krummholz stands increased compared to areas without trails, but there was no significant change in total krummholz area. We used historical terrestrial photography to expand the period (to 70 yr) considered. This photography supported the conclusions that a more abrupt ecotone transition developed from forest to tundra at alpine treeline, that tree density within forested areas increased, and that krummholz became fragmented along trails. This local assessment of fine-grained change in the alpine treeline ecotone provides a comparative base for looking at ecotone change in other mountain regions throughout the world.

  14. [Nitrogen bio-cycle in the alpine tundra ecosystem of Changbai Mountain and its comparison with arctic tundra].

    Science.gov (United States)

    Wei, Jing; Zhao, Jing-zhu; Deng, Hong-bing; Wu, Gang; Hao, Ying-jie; Shang, Wen-yan

    2005-03-01

    The nitrogen bio-cycle was discussed in the alpine tundra ecosystem of Changbai Mountain through compartment model. The alpine tundra of Changbai Mountain was compared with Arctic tundra by the common ratio of genus and species in this paper. It was found that the 89.3% of genus and 58.6% of species was the common between Changbai alpine tundra and Arctic tundra while 95.5% of lichen genus and 58.7% lichen species, 82.1% of moss genus and 76.3% of moss species, 93.1% of vascular bundle genus and 40.5% of vascular bundle species were the common, respectively, which made vegetation type or community to be similar between Changbai alpine tundra and Arctic tundra. The total storage of nitrogen was 65220.6 t in the vegetation-plant system of Changbai Mountain, of which soil pool amounted to 99.3%. The nitrogen storage of each compartment was as follows: the vegetation pool, litterfall pool and soil pool were 237.4 t, 145.3 t and 64837.9 t respectively. The transferable amounts of nitrogen were 131.7 t x a(-1), 58 t/a and 73.7 t x a(-1) in the aboveground plant, belowground root system and litterfall of alpine tundra ecosystem of Changbai Mountain.

  15. Potential of cold-adapted microorganisms for bioremediation of oil-polluted Alpine soils

    International Nuclear Information System (INIS)

    Margesin, R.

    2000-01-01

    The environmental contamination by organic pollutants is a widespread problem in all climates. The most widely distributed pollution can be attributed to oil contamination. Bioremediation methods can provide efficient, inexpensive and environmentally safe cleanup tools. The role of cold-adapted microorganisms for the bioremediation of experimentally and chronically oil-contaminated Alpine soils was evaluated in the studies described. The results demonstrated that there is a considerable potential for oil bioremediation in Alpine soils. Oil biodegradation can be significantly enhanced by biostimulation (inorganic nutrient supply), but a complete oil elimination is not possible by employing biological decontamination alone. (Author)

  16. Hydrologic response to valley-scale structure in alpine headwaters

    Science.gov (United States)

    Weekes, Anne A.; Torgersen, Christian E.; Montgomery, David R.; Woodward, Andrea; Bolton, Susan M.

    2015-01-01

    Few systematic studies of valley-scale geomorphic drivers of streamflow regimes in complex alpine headwaters have compared response between catchments. As a result, little guidance is available for regional-scale hydrological research and monitoring efforts that include assessments of ecosystem function. Physical parameters such as slope, elevation range, drainage area and bedrock geology are often used to stratify differences in streamflow response between sampling sites within an ecoregion. However, these metrics do not take into account geomorphic controls on streamflow specific to glaciated mountain headwaters. The coarse-grained nature of depositional features in alpine catchments suggests that these landforms have little water storage capacity because hillslope runoff moves rapidly just beneath the rock mantle before emerging in fluvial networks. However, recent studies show that a range of depositional features, including talus slopes, protalus ramparts and 'rock-ice' features may have more storage capacity than previously thought.

  17. Phosphate sorption characteristics of European alpine soils

    Czech Academy of Sciences Publication Activity Database

    Kaňa, Jiří; Kopáček, Jiří; Camarero, L.; Garcia-Pausas, J.

    2011-01-01

    Roč. 75, č. 3 (2011), s. 862-870 ISSN 0361-5995 R&D Projects: GA ČR(CZ) GA526/09/0567; GA AV ČR(CZ) KJB600960907 Grant - others:EU EMERGE(CZ) EVK1-CT-1999-00032 Institutional research plan: CEZ:AV0Z60170517 Keywords : phosphate sorption * alpine soil s * acidification Subject RIV: DJ - Water Pollution ; Quality Impact factor: 1.979, year: 2011

  18. A comparison of Alpine emissions to forest soil and spruce needle loads for persistent organic pollutants (POPs)

    Energy Technology Data Exchange (ETDEWEB)

    Belis, C.A., E-mail: claudio.belis@jrc.ec.europa.e [Regional Agency for Environmental Protection of Lombardia (Italy); Offenthaler, I.; Uhl, M.; Nurmi-Legat, J. [Umweltbundesamt GmbH (Austria); Bassan, R. [Regional Agency for Environmental Prevention and Protection of Veneto (Italy); Jakobi, G.; Kirchner, M. [Helmholtz Zentrum Muenchen, German Research Centre for Environment and Health (Germany); Knoth, W. [German Federal Environmental Agency (Germany); Kraeuchi, N. [WSL Swiss Federal Institute for Forest, Snow and Landscape Research (Switzerland); Levy, W. [Helmholtz Zentrum Muenchen, German Research Centre for Environment and Health (Germany); Magnani, T. [Regional Agency for Environmental Protection of Lombardia (Italy); Moche, W. [Umweltbundesamt GmbH (Austria); Schramm, K.-W. [Regional Agency for Environmental Prevention and Protection of Veneto (Italy); Simoncic, P. [Slovenian Forestry Institute (Slovenia); Weiss, P. [Umweltbundesamt GmbH (Austria)

    2009-12-15

    The project MONARPOP analysed the concentrations of semivolatile organic compounds (SVOCs) in two important sink compartments, needles of Norway spruce (Picea abies [L.] Karst.) and forest soil from 40 remote Alpine forest sites in Austria, Germany, Italy, Slovenia and Switzerland. In the present study the load of PCDD/F, PCB, PBDE, PAH, HCB, HCH and DDT in the Alps calculated on the basis of measured data are compared with their estimated emissions in the Alpine region. It comes out that the masses of the studied pollutants stored in the forests are higher than the corresponding emissions in the Alpine area indicating that the Alps are a sink for POPs advected from surrounding areas. It is assumed that local emissions of PCDD/F and PAH deriving from biomass burning are probably underestimated and that the pool of these pollutants in the forests represents the accumulation over some decades. - The loads of POPs in the Alps are higher than their emissions in the Alpine region.

  19. Exploring the patterns of alpine vegetation of Eastern Bhutan: a case study from the Merak Himalaya.

    Science.gov (United States)

    Jamtsho, Karma; Sridith, Kitichate

    2015-01-01

    A survey was conducted from March to September 2012 along the altitudinal gradient of the Jomokungkhar trail in the Merak Himalaya of Sakteng Wildlife Sanctuary to study the floristic compositions and the patterns of alpine vegetation of Eastern Bhutan. The vegetation of the sampled plots is classified into five types of communities based on the hierarchical cluster analysis at similarity index 63% viz., (1) Riverine Community; (2) Abies-Rhododendron Woodland Community; (3) Juniperus Scrub Community; (4) Rhododendron Krummholz and (5) Alpine Meadow, based on the floristic compositions. In addition, it was noticed that the fragile alpine environment of the Merak Himalaya has high plant diversity and important plants that are susceptible to the anthropogenic pressures.

  20. Cryospheric Change Impacts on Alpine Hydrology: Combining Model With Observations in the Upper Reaches of Hei River, China

    Science.gov (United States)

    Li, X.; Chen, R.; Wang, G.; Liu, J.; Yang, Y.; Han, C.; Song, Y.; Liu, Z.; Kang, E.

    2017-12-01

    Cryospheric change impacts largely on alpine hydrology but they are still unclear owing to rare observations and suitable models in the Western Cold Regions of China (WCRC), where many large rivers including almost inland rivers originate and some of them flow to adjacent countries. The upstream of the inland river provides nearly almost water resources to the arid mid-downstream areas, such as the Hei River. Based on the long term field observation in WCRC, a Cryospheric Basin Hydrological Model (CBHM) was created to evaluate the cryospheric impacts on streamflow in the upper reaches of Hei river (UHR), and relationships between Cryosphere and streamflow were further discussed by using measured data. The NorESM1-ME were chosen to project future streamflow under scenarios RCP2.6, RCP4.5 and RCP8.5. The monthly basin runoff in UHR was simulated with a coefficient of efficiency about 0.93 and 0.94, and a mass balance error about 2.5% and -0.2% during the calibration period from 1960 to 1990 and validation period from 1991 to 2013, respectively. The CBHM results were then well validated by measured evapotranspiration (ET), soil temperature, glacier area, water balance of land covers etc. in UHR. It found that the moraine-talus region was the major runoff contribution (60.5%) area though its area proportion was only about 20%, whereas the total runoff contribution of meadow and grassland was only about 27% but their area ratio was about 70% in UHR. Glacier and snow cover contributed 3.5% and 25.4% fresh water in average to streamflow during 1960 to 2013 in HUR. Owing to the increased air temperature (2.9 oC/54a) and precipitation (69.2 mm/54a) in the past 54 years, glacial and snow melting runoff increased 9.8% and 12.1%, respectively. The air temperature rise decreased and brought forward the snowmelt flood peak, and increased the winter flow due to permafrost degradation in UHR. Glaciers would disappear in the near future owing to its small size and increasing air

  1. Technical Note: Seasonality in alpine water resources management - a regional assessment

    Science.gov (United States)

    Vanham, D.; Fleischhacker, E.; Rauch, W.

    2008-01-01

    Alpine regions are particularly affected by seasonal variations in water demand and water availability. Especially the winter period is critical from an operational point of view, as being characterised by high water demands due to tourism and low water availability due to the temporal storage of precipitation as snow and ice. The clear definition of summer and winter periods is thus an essential prerequisite for water resource management in alpine regions. This paper presents a GIS-based multi criteria method to determine the winter season. A snow cover duration dataset serves as basis for this analysis. Different water demand stakeholders, the alpine hydrology and the present day water supply infrastructure are taken into account. Technical snow-making and (winter) tourism were identified as the two major seasonal water demand stakeholders in the study area, which is the Kitzbueheler region in the Austrian Alps. Based upon different geographical datasets winter was defined as the period from December to March, and summer as the period from April to November. By determining potential regional water balance deficits or surpluses in the present day situation and in future, important management decisions such as water storage and allocation can be made and transposed to the local level.

  2. Complex responses of spring alpine vegetation phenology to snow cover dynamics over the Tibetan Plateau, China.

    Science.gov (United States)

    Wang, Siyuan; Wang, Xiaoyue; Chen, Guangsheng; Yang, Qichun; Wang, Bin; Ma, Yuanxu; Shen, Ming

    2017-09-01

    Snow cover dynamics are considered to play a key role on spring phenological shifts in the high-latitude, so investigating responses of spring phenology to snow cover dynamics is becoming an increasingly important way to identify and predict global ecosystem dynamics. In this study, we quantified the temporal trends and spatial variations of spring phenology and snow cover across the Tibetan Plateau by calibrating and analyzing time series of the NOAA AVHRR-derived normalized difference vegetation index (NDVI) during 1983-2012. We also examined how snow cover dynamics affect the spatio-temporal pattern of spring alpine vegetation phenology over the plateau. Our results indicated that 52.21% of the plateau experienced a significant advancing trend in the beginning of vegetation growing season (BGS) and 34.30% exhibited a delaying trend. Accordingly, the snow cover duration days (SCD) and snow cover melt date (SCM) showed similar patterns with a decreasing trend in the west and an increasing trend in the southeast, but the start date of snow cover (SCS) showed an opposite pattern. Meanwhile, the spatial patterns of the BGS, SCD, SCS and SCM varied in accordance with the gradients of temperature, precipitation and topography across the plateau. The response relationship of spring phenology to snow cover dynamics varied within different climate, terrain and alpine plant community zones, and the spatio-temporal response patterns were primarily controlled by the long-term local heat-water conditions and topographic conditions. Moreover, temperature and precipitation played a profound impact on diverse responses of spring phenology to snow cover dynamics. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Increased stem density and competition may diminish the positive effects of warming at alpine treeline.

    Science.gov (United States)

    Wang, Yafeng; Pederson, Neil; Ellison, Aaron M; Buckley, Hannah L; Case, Bradley S; Liang, Eryuan; Julio Camarero, J

    2016-07-01

    The most widespread response to global warming among alpine treeline ecotones is not an upward shift, but an increase in tree density. However, the impact of increasing density on interactions among trees at treeline is not well understood. Here, we test if treeline densification induced by climatic warming leads to increasing intraspecific competition. We mapped and measured the size and age of Smith fir trees growing in two treelines located in the southeastern Tibetan Plateau. We used spatial point-pattern and codispersion analyses to describe the spatial association and covariation among seedlings, juveniles, and adults grouped in 30-yr age classes from the 1860s to the present. Effects of competition on tree height and regeneration were inferred from bivariate mark-correlations. Since the 1950s, a rapid densification occurred at both sites in response to climatic warming. Competition between adults and juveniles or seedlings at small scales intensified as density increased. Encroachment negatively affected height growth and further reduced recruitment around mature trees. We infer that tree recruitment at the studied treelines was more cold-limited prior to 1950 and shifted to a less temperature-constrained regime in response to climatic warming. Therefore, the ongoing densification and encroachment of alpine treelines could alter the way climate drives their transitions toward subalpine forests. © 2016 by the Ecological Society of America.

  4. Effects of Soil Temperature and Moisture on Soil Respiration on the Tibetan Plateau.

    Science.gov (United States)

    Bao, Xiaoying; Zhu, Xiaoxue; Chang, Xiaofeng; Wang, Shiping; Xu, Burenbayin; Luo, Caiyun; Zhang, Zhenhua; Wang, Qi; Rui, Yichao; Cui, Xiaoying

    2016-01-01

    Understanding of effects of soil temperature and soil moisture on soil respiration (Rs) under future warming is critical to reduce uncertainty in predictions of feedbacks to atmospheric CO2 concentrations from grassland soil carbon. Intact cores with roots taken from a full factorial, 5-year alpine meadow warming and grazing experiment in the field were incubated at three different temperatures (i.e. 5, 15 and 25°C) with two soil moistures (i.e. 30 and 60% water holding capacity (WHC)) in our study. Another experiment of glucose-induced respiration (GIR) with 4 h of incubation was conducted to determine substrate limitation. Our results showed that high temperature increased Rs and low soil moisture limited the response of Rs to temperature only at high incubation temperature (i.e. 25°C). Temperature sensitivity (Q10) did not significantly decrease over the incubation period, suggesting that substrate depletion did not limit Rs. Meanwhile, the carbon availability index (CAI) was higher at 5°C compared with 15 and 25°C incubation, but GIR increased with increasing temperature. Therefore, our findings suggest that warming-induced decrease in Rs in the field over time may result from a decrease in soil moisture rather than from soil substrate depletion, because warming increased root biomass in the alpine meadow.

  5. [Soil hydrolase characteristics in late soil-thawing period in subalpine/alpine forests of west Sichuan].

    Science.gov (United States)

    Tan, Bo; Wu, Fu-Zhong; Yang, Wan-Qin; Yu, Sheng; Yang, Yu-Lian; Wang, Ao

    2011-05-01

    Late soil-thawing period is a critical stage connecting winter and growth season. The significant temperature fluctuation at this stage might have strong effects on soil ecological processes. In order to understand the soil biochemical processes at this stage in the subalpine/alpine forests of west Sichuan, soil samples were collected from the representative forests including primary fir forest, fir and birch mixed forest, and secondary fir forest in March 5-April 25, 2009, with the activities of soil invertase, urease, and phosphatase (neutral, acid and alkaline phosphatases) measured. In soil frozen period, the activities of the three enzymes in test forests still kept relatively higher. With the increase of soil temperature, the activities of hydrolases at the early stage of soil-thawing decreased rapidly after a sharp increase, except for neutral phosphatease. Thereafter, there was an increase in the activities of urease and phosphatase. Relative to soil mineral layer, soil organic layer had higher hydrolase activity in late soil-thawing period, and showed more obvious responses to the variation of soil temperature.

  6. A comparative phylogeographic study reveals discordant evolutionary histories of alpine ground beetles (Coleoptera, Carabidae).

    Science.gov (United States)

    Weng, Yi-Ming; Yang, Man-Miao; Yeh, Wen-Bin

    2016-04-01

    Taiwan, an island with three major mountain ranges, provides an ideal topography to study mountain-island effect on organisms that would be diversified in the isolation areas. Glaciations, however, might drive these organisms to lower elevations, causing gene flow among previously isolated populations. Two hypotheses have been proposed to depict the possible refugia for alpine organisms during glaciations. Nunatak hypothesis suggests that alpine species might have stayed in situ in high mountain areas during glaciations. Massif de refuge, on the other hand, proposes that alpine species might have migrated to lower ice-free areas. By sampling five sympatric carabid species of Nebria and Leistus, and using two mitochondrial genes and two nuclear genes, we evaluated the mountain-island effect on alpine carabids and tested the two proposed hypotheses with comparative phylogeographic method. Results from the phylogenetic relationships, network analysis, lineage calibration, and genetic structure indicate that the deep divergence among populations in all L. smetanai, N. formosana, and N. niitakana was subjected to long-term isolation, a phenomenon in agreement with the nunatak hypothesis. However, genetic admixture among populations of N. uenoiana and some populations of L. nokoensis complex suggests that gene flow occurred during glaciations, as a massif de refuge depicts. The speciation event in N. niitakana is estimated to have occurred before 1.89 million years ago (Mya), while differentiation among isolated populations in N. niitakana, N. formosana, L. smetanai, and L. nokoensis complex might have taken place during 0.65-1.65 Mya. While each of the alpine carabids arriving in Taiwan during different glaciation events acquired its evolutionary history, all of them had confronted the existing mountain ranges.

  7. Identification of groundwater nitrate sources in pre-alpine catchments: a multi-tracer approach

    Science.gov (United States)

    Stoewer, Myriam; Stumpp, Christine

    2014-05-01

    Porous aquifers in pre-alpine areas are often used as drinking water resources due to their good water quality status and water yield. Maintaining these resources requires knowledge about possible sources of pollutants and a sustainable management practice in groundwater catchment areas. Of particular interest in agricultural areas, like in pre-alpine regions, is limiting nitrate input as main groundwater pollutant. Therefore, the objective of the presented study is i) to identify main nitrate sources in a pre-alpine groundwater catchment with current low nitrate concentration using stable isotopes of nitrate (d18O and d15N) and ii) to investigate seasonal dynamics of nitrogen compounds. The groundwater catchment areas of four porous aquifers are located in Southern Germany. Most of the land use is organic grassland farming as well as forestry and residential area. Thus, potential sources of nitrate mainly are mineral fertilizer, manure/slurry, leaking sewage system and atmospheric deposition of nitrogen compounds. Monthly freshwater samples (precipitation, river water and groundwater) are analysed for stable isotope of water (d2H, d18O), the concentration of major anions and cations, electrical conductivity, water temperature, pH and oxygen. In addition, isotopic analysis of d18O-NO3- and d15N-NO3- for selected samples is carried out using the denitrifier method. In general, all groundwater samples were oxic (10.0±2.6mg/L) and nitrate concentrations were low (0.2 - 14.6mg/L). The observed nitrate isotope values in the observation area compared to values from local precipitation, sewage, manure and mineral fertilizer as well as to data from literature shows that the nitrate in freshwater samples is of microbial origin. Nitrate derived from ammonium in fertilizers and precipitation as well as from soil nitrogen. It is suggested that a major potential threat to the groundwater quality is ammonia and ammonium at a constant level mainly from agriculture activities as

  8. Global Validation of MODIS Atmospheric Profile-Derived Near-Surface Air Temperature and Dew Point Estimates

    Science.gov (United States)

    Famiglietti, C.; Fisher, J.; Halverson, G. H.

    2017-12-01

    This study validates a method of remote sensing near-surface meteorology that vertically interpolates MODIS atmospheric profiles to surface pressure level. The extraction of air temperature and dew point observations at a two-meter reference height from 2001 to 2014 yields global moderate- to fine-resolution near-surface temperature distributions that are compared to geographically and temporally corresponding measurements from 114 ground meteorological stations distributed worldwide. This analysis is the first robust, large-scale validation of the MODIS-derived near-surface air temperature and dew point estimates, both of which serve as key inputs in models of energy, water, and carbon exchange between the land surface and the atmosphere. Results show strong linear correlations between remotely sensed and in-situ near-surface air temperature measurements (R2 = 0.89), as well as between dew point observations (R2 = 0.77). Performance is relatively uniform across climate zones. The extension of mean climate-wise percent errors to the entire remote sensing dataset allows for the determination of MODIS air temperature and dew point uncertainties on a global scale.

  9. Coupled cryoconite ecosystem structure-function relationships are revealed by comparing bacterial communities in alpine and Arctic glaciers

    DEFF Research Database (Denmark)

    Edwards, Arwyn; Mur, Luis A. J.; Girdwood, Susan E.

    2014-01-01

    Cryoconite holes are known as foci of microbial diversity and activity on polar glacier surfaces, but are virtually unexplored microbial habitats in alpine regions. In addition, whether cryoconite community structure reflects ecosystem functionality is poorly understood. Terminal restriction...... revealed Proteobacteria were particularly abundant, with Cyanobacteria likely acting as ecosystem engineers in both alpine and Arctic cryoconite communities. However, despite these generalities, significant differences in bacterial community structures, compositions and metabolomes are found between alpine...... fragment length polymorphism and Fourier transform infrared metabolite fingerprinting of cryoconite from glaciers in Austria, Greenland and Svalbard demonstrated cryoconite bacterial communities are closely correlated with cognate metabolite fingerprints. The influence of bacterial-associated fatty acids...

  10. Semen quality and concentration of soluble proteins in the seminal plasma of Alpine bucks Semen quality and concentration of soluble proteins in the seminal plasma of Alpine bucks

    Directory of Open Access Journals (Sweden)

    Simone Eliza Facione Guimarães

    2010-06-01

    Full Text Available It was aimed to study the in vitro seminal quality analyzed by complementary tests and to compare them with physical, morphological and biochemical aspects of male goat semen of the Alpine breed. This experiment took place at the Federal University of Viçosa, situated at 20º45’ S latitude and 42º51’ W longitude, Southwest of Brazil. It was done during the summer months of January and February, and three adult male goats of the Alpine breed were used in intensive conditions. The semen was collected by artificial vagina method. In all semen samples (45 ejaculates, after the physical and morphological analysis, the hiposmotic test was done. In 24 ejaculates, it were done thermo-resistance test, and in 21 ejaculates it were determined the concentration of total soluble proteins in seminal plasma. The male goats presented difference in the semen physical and morphological aspects, in the hiposmotic test and thermo-resistance test, but they did not presented difference in total soluble proteins concentration in seminal plasma. Results of the slow thermo-resistance test and hiposmotic test were positively correlated (r = 0.60. It was concluded, according to our results, that the concentration of total soluble proteins in seminal plasma can not be used as a parameter to predict the seminal quality of Alpine bucks.It was aimed to study the in vitro seminal quality analyzed by complementary tests and to compare them with physical, morphological and biochemical aspects of male goat semen of the Alpine breed. This experiment took place at the Federal University of Viçosa, situated at 20º45’ S latitude and 42º51’ W longitude, Southwest of Brazil. It was done during the summer months of January and February, and three adult male goats of the Alpine breed were used in intensive conditions. The semen was collected by artificial vagina method. In all semen samples (45 ejaculates, after the physical and morphological analysis, the hiposmotic test

  11. Geochemistry of the triassic-Jurassic alpine continental deposits: origin and geodynamic implications

    International Nuclear Information System (INIS)

    Poinssot, Ch.; Goffe, B.; Toulhoat, P.

    1997-01-01

    Mid-Triassic to mid-Jurassic Alpine continental deposits are known all along the former Brianconnais peninsula. They constitutes small karstic pockets on the thick Triassic calcareous series and their chemistry evolves between bauxites s.s. and aluminous argilites. Most of them were deeply buried during the Alpine orogenesis as recorded by HP-LT metamorphism. Only the deposits of the Pre-Alps were submitted to lower PT conditions (diagenesis-anchizone boundary) during their incorporation in the thrust wedge of the 'Prealpes Medianes'. These formations are known for containing traces of light elements (Li, F) and heavy elements (Zn, REE...). In order to understand the possible origin of these elements, we studied the geochemistry (major and trace elements) of two representative deposits, one in Vanoise which underwent a HP-LT metamorphism, the other one in the Pre-Alps, which was only submitted to diagenesis. Trace elements patterns allow us to preclude an autochthonous origin for these formations as well as the intervention of metasomatism, and demonstrate a granitic origin. Moreover, discrimination diagrams for granites indicate an obvious alkaline granitic origin for these deposits. In the framework of the Alpine palaeogeography, we then discuss the possible granitic sources. Two main sources can be invoked: either a Brianconnais s.s. formation (crystalline or sediments), which supposes a more intense erosion as classically admitted, or more distant sources such as the Corso-Sardinian alkaline acid-rocks, which supposes a complex palaeo-hydrography. This confirms the sedimentary origin of the light elements in these rocks and precludes the intervention of light elements-rich hydrothermal fluids migrating through Alpine metamorphic units. (author)

  12. Temperature, precipitation and biotic interactions as determinants of tree seedling recruitment across the tree line ecotone.

    Science.gov (United States)

    Tingstad, Lise; Olsen, Siri Lie; Klanderud, Kari; Vandvik, Vigdis; Ohlson, Mikael

    2015-10-01

    Seedling recruitment is a critical life history stage for trees, and successful recruitment is tightly linked to both abiotic factors and biotic interactions. In order to better understand how tree species' distributions may change in response to anticipated climate change, more knowledge of the effects of complex climate and biotic interactions is needed. We conducted a seed-sowing experiment to investigate how temperature, precipitation and biotic interactions impact recruitment of Scots pine (Pinus sylvestris) and Norway spruce (Picea abies) seedlings in southern Norway. Seeds were sown into intact vegetation and experimentally created gaps. To study the combined effects of temperature and precipitation, the experiment was replicated across 12 sites, spanning a natural climate gradient from boreal to alpine and from sub-continental to oceanic. Seedling emergence and survival were assessed 12 and 16 months after sowing, respectively, and above-ground biomass and height were determined at the end of the experiment. Interestingly, very few seedlings were detected in the boreal sites, and the highest number of seedlings emerged and established in the alpine sites, indicating that low temperature did not limit seedling recruitment. Site precipitation had an overall positive effect on seedling recruitment, especially at intermediate precipitation levels. Seedling emergence, establishment and biomass were higher in gap plots compared to intact vegetation at all temperature levels. These results suggest that biotic interactions in the form of competition may be more important than temperature as a limiting factor for tree seedling recruitment in the sub- and low-alpine zone of southern Norway.

  13. Australian Alps: Kosciuszko, Alpine and Namadgi National Parks (Second Edition

    Directory of Open Access Journals (Sweden)

    Nicole Porter

    2017-02-01

    Full Text Available Reviewed: Australian Alps: Kosciuszko, Alpine and Namadgi National Parks (Second Edition By Deidre Slattery. Clayton South, Australia: CSIRO Publishing, 2015. xvii + 302 pp. AU$ 45.00, US$ 35.95. ISBN 978-1-486-30171-3.

  14. Climate control on sulphate and nitrate concentrations in alpine streams of Northern Italy along a nitrogen saturation gradient

    Directory of Open Access Journals (Sweden)

    M. Rogora

    2008-03-01

    Full Text Available The role of meteorology, hydrology and atmospheric deposition on the temporal pattern of SO4 and NO3 concentrations was investigated for three streams draining alpine catchments in Northern Italy.

    The study sites lie on a gradient of atmospheric fluxes of SO4 and NO3 (from about 50 to 80 meq m−2 y−1, and from 40 to 90 meq m−2 y−1, respectively. As a consequence of the increasing N input, the three catchments are also representative of aggrading levels of N saturation. Different methods of statistical analysis were applied to monthly data for the period 1997–2005 to identify which variables (temperature, precipitation, hydrology, SO4 and NO3 deposition were the main predictors of water chemistry and its change in time. Hydrological changes and snow cover proved to be the main confounding factors in the response to atmospheric deposition in the River Masino catchment. Its particular characteristics (small catchment area, rapid flushing during runoff and thin soil cover meant that this site responded without a significant delay to SO4 deposition decrease. It also showed a clear seasonal pattern of NO3 concentration, in response to hydrology and biological uptake in the growing season.

    The selected driving variables failed to model the water chemistry at the other study sites. Nevertheless, temperature, especially extreme values, turned out to be important in both SO4 and NO3 export from the catchments. This result might be largely explained by the effect of warm periods on temperature-dependent processes such as mineralization, nitrification and S desorption.

    Our findings suggest that surface waters in the alpine area will be extremely sensitive to a climate warming scenario: higher temperatures and increasing frequency of drought could exacerbate the effects

  15. MILK COAGULATION PROPERTIES OF CATTLE BREEDS REARED IN ALPINE AREA

    Directory of Open Access Journals (Sweden)

    Giulio Visentin

    2015-09-01

    Full Text Available The aim of the present study was to apply mid-infrared spectroscopy prediction models developed for milk coagulation properties (MCP to a spectral dataset of 123,240 records collected over a 2-year period in the Alpine area, and to investigate sources of variation of the predicted MCP. Mixed linear models included fixed effects of breed, month and year of sampling, days in milk, parity, and the interactions between the main effects. Random effects were herd nested within breed, cow nested within breed, and the residual. All fixed effects were significant (P<0.05 in explaining the variation of MCP. In particular, milk clotting characteristics varied significantly among breeds, and local Alpine Grey breed exhibited the most favourable processing characteristics. Milk coagulation properties varied across lactation and were at their worst after the peak.

  16. Hydrological Response of Alpine Wetlands to Climate Warming in the Eastern Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    Wenjiang Zhang

    2016-04-01

    Full Text Available Alpine wetlands in the Tibetan Plateau (TP play a crucial role in the regional hydrological cycle due to their strong influence on surface ecohydrological processes; therefore, understanding how TP wetlands respond to climate change is essential for projecting their future condition and potential vulnerability. We investigated the hydrological responses of a large TP wetland complex to recent climate change, by combining multiple satellite observations and in-situ hydro-meteorological records. We found different responses of runoff production to regional warming trends among three basins with similar climate, topography and vegetation cover but different wetland proportions. The basin with larger wetland proportion (40.1% had a lower mean runoff coefficient (0.173 ± 0.006, and also showed increasingly lower runoff level (−3.9% year−1, p = 0.002 than the two adjacent basins. The satellite-based observations showed an increasing trend of annual non-frozen period, especially in the wetland-dominated region (2.64 day·year−1, p < 0.10, and a strong extension of vegetation growing-season (0.26–0.41 day·year−1, p < 0.10. Relatively strong increasing trends in evapotranspiration (ET (~1.00 mm·year−1, p < 0.01 and the vertical temperature gradient above ground surface (0.043 °C·year−1, p < 0.05 in wetland-dominant areas were documented from satellite-based ET observations and weather station records. These results indicate recent surface drying and runoff reduction of alpine wetlands, and their potential vulnerability to degradation with continued climate warming.

  17. Seasonal and interannual dynamics of soil microbial biomass and available nitrogen in an alpine meadow in the eastern part of Qinghai-Tibet Plateau, China

    Science.gov (United States)

    Xu, Bo; Wang, Jinniu; Wu, Ning; Wu, Yan; Shi, Fusun

    2018-01-01

    Soil microbial activity varies seasonally in frozen alpine soils during cold seasons and plays a crucial role in available N pool accumulation in soil. The intra- and interannual patterns of microbial and nutrient dynamics reflect the influences of changing weather factors, and thus provide important insights into the biogeochemical cycles and ecological functions of ecosystems. We documented the seasonal and interannual dynamics of soil microbial and available N in an alpine meadow in the eastern part of Qinghai-Tibet Plateau, China, between April 2011 and October 2013. Soil was collected in the middle of each month and analyzed for water content, microbial biomass C (MBC) and N (MBN), dissolved organic C and N, and inorganic N. Soil microbial community composition was measured by the dilution-plate method. Fungi and actinomycetes dominated the microbial community during the nongrowing seasons, and the proportion of bacteria increased considerably during the early growing seasons. Trends of consistently increasing MBC and available N pools were observed during the nongrowing seasons. MBC sharply declined during soil thaw and was accompanied by a peak in available N pool. Induced by changes in soil temperatures, significant shifts in the structures and functions of microbial communities were observed during the winter-spring transition and largely contributed to microbial reduction. The divergent seasonal dynamics of different N forms showed a complementary nutrient supply pattern during the growing season. Similarities between the interannual dynamics of microbial biomass and available N pools were observed, and soil temperature and water conditions were the primary environmental factors driving interannual fluctuations. Owing to the changes in climate, seasonal soil microbial activities and nutrient supply patterns are expected to change further, and these changes may have crucial implications for the productivity and biodiversity of alpine ecosystems.

  18. Soil bacterial and fungal diversity differently correlated with soil biochemistry in alpine grassland ecosystems in response to environmental changes

    Science.gov (United States)

    Zhang, Yong; Dong, Shikui; Gao, Qingzhu; Liu, Shiliang; Ganjurjav, Hasbagan; Wang, Xuexia; Su, Xukun; Wu, Xiaoyu

    2017-03-01

    To understand effects of soil microbes on soil biochemistry in alpine grassland ecosystems under environmental changes, we explored relationships between soil microbial diversity and soil total nitrogen, organic carbon, available nitrogen and phosphorus, soil microbial biomass and soil enzyme activities in alpine meadow, alpine steppe and cultivated grassland on the Qinghai-Tibetan plateau under three-year warming, enhanced precipitation and yak overgrazing. Soil total nitrogen, organic carbon and NH4-N were little affected by overgrazing, warming or enhanced precipitation in three types of alpine grasslands. Soil microbial biomass carbon and phosphorus along with the sucrase and phosphatase activities were generally stable under different treatments. Soil NO3-N, available phosphorus, urease activity and microbial biomass nitrogen were increased by overgrazing in the cultivated grassland. Soil bacterial diversity was positively correlated with, while soil fungal diversity negatively with soil microbial biomass and enzyme activities. Soil bacterial diversity was negatively correlated with, while soil fungal diversity positively with soil available nutrients. Our findings indicated soil bacteria and fungi played different roles in affecting soil nutrients and microbiological activities that might provide an important implication to understand why soil biochemistry was generally stable under environmental changes in alpine grassland ecosystems.

  19. New P-T and U-Pb constraints on Alpine Schist metamorphism in south Westland, New Zealand

    International Nuclear Information System (INIS)

    Scott, J.M.; Auer, A.; Muhling, J.R.; Czertowicz, T.A.; Cooper, A.F.; Billia, M.A.; Kennedy, A.K.

    2015-01-01

    Metamorphic mineral compositions of a staurolite-bearing greyschist from the middle reaches of the Moeraki River valley in south Westland reveal peak equilibration at c. 558±50 degrees C and c. 6.1±1.2 kbar. Two c. 83 Ma U-Pb monazite age populations from the cores of monazite-apatite-allanite-epidote corona structures in mylonitised schists from near Fox Glacier confirm that Alpine Schist metamorphism occurred during the Late Cretaceous. The published spread in Late Cretaceous metamorphic ages indicates that metamorphism was diachronous or was a protracted event. Further dating is required to pin down the cryptic transition into the Jurassic-Early Cretaceous metamorphosed Otago Schist, but the Alpine Schist must extend at least 11 km east of the Alpine Fault in south Westland and overprint the suture between the Pounamu and Rakaia terranes. The P-T-t results imply that the Late Cretaceous crust represented by portions of the Alpine Schist was probably of similar thickness to that beneath the Southern Alps today, but with dehydration and partial melting occurring near the base. The crust under Westland and Otago may be dry and therefore strong. (author).

  20. Experimental effects of herbivore density on above-ground plant biomass in an alpine grassland ecosystem

    OpenAIRE

    Austrheim, Gunnar; Speed, James David Mervyn; Martinsen, Vegard; Mulder, Jan; Mysterud, Atle

    2014-01-01

    Herbivores may increase or decrease aboveground plant productivity depending on factors such as herbivore density and habitat productivity. The grazing optimization hypothesis predicts a peak in plant production at intermediate herbivore densities, but has rarely been tested experimentally in an alpine field setting. In an experimental design with three densities of sheep (high, low, and no sheep), we harvested aboveground plant biomass in alpine grasslands prior to treatment and after five y...

  1. The validity of Actiwatch2 and SenseWear armband compared against polysomnography at different ambient temperature conditions

    Directory of Open Access Journals (Sweden)

    Mirim Shin

    2015-01-01

    Full Text Available There were no validation studies on portable sleep devices under different ambient temperature, thus this study evaluated the validity of wrist Actiwatch2 (AW2 or SenseWear armband (SWA against polysomnography (PSG in different ambient temperatures. Nine healthy young participants (6 males, aged 23.3±4.1 y underwent nine nights of study at ambient temperature of 17 °C, 22 °C and 29 °C in random order, after an adaptation night. They wore the AW2 and SWA while being monitored for PSG simultaneously. A linear mixed model indicated that AW2 is valid for sleep onset latency (SOL, total sleep time (TST and sleep efficiency (SE but significantly overestimated wake after sleep onset (WASO at 17 °C and 22 °C. SWA is valid for WASO, TST and SE at these temperatures, but severely underestimates SOL. However, at 29 °C, SWA significantly overestimated WASO and underestimated TST and SE. Bland–Altman plots showed small biases with acceptable limits of agreement (LoA for AW2 whereas, small biases and relatively wider LoA for most sleep variables were observed in SWA. The kappa statistic showed a moderate sleep–wake epoch agreement, with a high sensitivity but poor specificity; wake detection remains suboptimal. AW2 showed small biases for most of sleep variables at all temperature conditions, except for WASO. SWA is reliable for measures of TST, WASO and SE at 17–22 °C but not at 29 °C, and SOL approximates that of PSG only at 29 °C, thus caution is needed when monitoring sleep at different temperatures, especially in home sleep studies, in which temperature conditions are more variable.

  2. Quantifying the role of mantle forcing, crustal shortening and exogenic forcing on exhumation of the North Alpine Foreland Basin

    Science.gov (United States)

    von Hagke, C.; Luijendijk, E.; Hindle, D.

    2017-12-01

    In contrast to the internal zones of orogens, where the stacking of thrust sheets can overwhelm more subtle signals, foreland basins can record long-wavelength subsidence or uplift signals caused by mantle processes. We use a new and extensive compilation of geological and thermochronology data from the North Alpine Foreland Basin to understand the dynamics of foreland basins and their interaction with surface and geodynamic processes. We quantify cooling and exhumation rates in the basin by combining published and new vitrinite reflectance, apatite fission track and U-Th/He data with a new inverse burial and thermal history model, pybasin. No correlation is obvious between inferred cooling and exhumation rates and elevation, relief or tectonics. Uncertainty analysis shows that thermochronometers can be explained by cooling starting as early as the Miocene or as late as the Pleistocene. We compare derived temperature histories to exhumation estimates based on the retro-deformation of Molasse basin and the Jura mountains, and to exhumation caused by drainage reorganization and incision. Drainage reorganization can explain at most 25% of the observed cooling rates in the basin. Tectonic transport of the basin's sediments over the inclined basement of the alpine foreland as the Jura mountains shortened can explain part of the cooling signal in the western part of the basin. However, overall a substantial amount of cooling and exhumation remains unexplained by known tectonic and surface processes. Our results document basin wide exhumation that may be related to slab roll-back or other lithospheric processes. We suggest that new (U-Th)/He data from key areas close to the Alpine front may provide better constraints on the timing of exhumation.

  3. Effects of Cryospheric Change on Alpine Hydrology: Combining a Model With Observations in the Upper Reaches of the Hei River, China

    Science.gov (United States)

    Chen, R.; Wang, G.; Yang, Y.; Liu, J.; Han, C.; Song, Y.; Liu, Z.; Kang, E.

    2018-04-01

    Cryospheric changes have great effects on alpine hydrology, but these effects are still unclear owing to rare observations and suitable models in the western cold regions of China. Based on long-term field observations in the western cold regions of China, a cryospheric basin hydrological model was proposed to evaluate the cryospheric effects on streamflow in the upper Hei River basin (UHR), and the relationship between the cryosphere and streamflow was further discussed with measured data. The Norwegian Earth System Model outputs were chosen to project future streamflow under scenarios Representative Concentration Pathways (RCP)2.6, RCP4.5, and RCP8.5. The cryospheric basin hydrological model results were well validated by the measured precipitation, streamflow, evapotranspiration, soil temperature, glacier and snow cover area, and the water balance of land cover in the UHR. The moraine-talus region contributed most of the runoff (60%), even though it made up only about 20% of the area. On average, glacier and snow cover, respectively, contributed 3.5% and 25.4% of the fresh water to the streamflow in the UHR between 1960 and 2013. Because of the increased air temperature (2.9°C/54a) and precipitation (69.2 mm/54a) over the past 54 years, glacial and snowmelt runoff increased by 9.8% and 12.1%, respectively. The increase in air temperature brought forward the snowmelt flood peak and increased the winter flow due to permafrost degradation. Glaciers may disappear in the near future because of their small size, but snowmelt would increase due to increases in snowfall in the higher mountainous areas, and the basin runoff would increase slightly in the future.

  4. Preserved organic matter in the Serpentinized Ocean-Continent Transition of Alpine Tethys

    Science.gov (United States)

    Mateeva, T.; Wolff, G. A.; Kusznir, N.; Manatschal, G.; Wheeler, J.

    2017-12-01

    Serpentinization occurs at slow-spreading ocean ridges and magma-poor rifted continental margins. At modern hydrothermal vents, serpentinization has been observed to support hydrogen-driven microbial environments including methanotrophic biosystems. An important question is: "Are such bio-systems locally restricted to hydrothermal vents or are they more pervasive, being linked with the exhumation of serpentinized mantle at the seafloor?" Fieldwork sampling of km scale exposures of orogenically exhumed serpentinized mantle in the Alps allows 3D mantle sampling that is not possible at ocean ridges and provides an opportunity to investigate the organic matter in an ophiolite sequence relative to the seafloor. Samples from the fossil Tethyan OCT, exhumed during Alpine collisional orogeny, have been examined for the presence or absence of biomarkers typical of methanotrophy within serpentinized exhumed mantle. Samples from the Totalp unit, Tasna nappe and Platta unit of the Eastern Swiss Alps and Chenaillet in the Western Alps from the Tethyan magma-poor OCT were selected for analysis because they have little Alpine deformation and underwent only low-grade Alpine metamorphism. Hand specimens and cores taken from these locations have been analysed to search for the presence or absence of biomarkers in the serpentinite and its overlying lithologies. Thin sections of samples from these OCT locations reveal multiple serpentinization events and calcification phases. All the lithologies sampled show the presence of hydrocarbons such as n-alkanes, low molecular weight polynuclear aromatic hydrocarbons (PAHs, of mixed petrogenic and pyrogenic source), hopanes, steranes (of marine origin), and branched alkanes (pristane and phytane, non-specific marine origin). The identifiable biomarkers and the isotopic data are consistent with organic matter of a marine origin and do not provide any evidence for a methanotrophic bio-system. It is noteworthy that basement mantle rocks still

  5. Development of Safety Analysis Codes and Experimental Validation for a Very High Temperature Gas-Cooled Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Chang, H. Oh, PhD; Cliff Davis; Richard Moore

    2004-11-01

    The very high temperature gas-cooled reactors (VHTGRs) are those concepts that have average coolant temperatures above 900 degrees C or operational fuel temperatures above 1250 degrees C. These concepts provide the potential for increased energy conversion efficiency and for high-temperature process heat application in addition to power generation and nuclear hydrogen generation. While all the High Temperature Gas Cooled Reactor (HTGR) concepts have sufficiently high temperatures to support process heat applications, such as desalination and cogeneration, the VHTGR's higher temperatures are suitable for particular applications such as thermochemical hydrogen production. However, the high temperature operation can be detrimental to safety following a loss-of-coolant accident (LOCA) initiated by pipe breaks caused by seismic or other events. Following the loss of coolant through the break and coolant depressurization, air from the containment will enter the core by molecular diffusion and ultimately by natural convection, leading to oxidation of the in-core graphite structures and fuel. The oxidation will release heat and accelerate the heatup of the reactor core. Thus, without any effective countermeasures, a pipe break may lead to significant fuel damage and fission product release. The Idaho National Engineering and Environmental Laboratory (INEEL) has investigated this event for the past three years for the HTGR. However, the computer codes used, and in fact none of the world's computer codes, have been sufficiently developed and validated to reliably predict this event. New code development, improvement of the existing codes, and experimental validation are imperative to narrow the uncertaninty in the predictions of this type of accident. The objectives of this Korean/United States collaboration are to develop advanced computational methods for VHTGR safety analysis codes and to validate these computer codes.

  6. Petrophysical, Geochemical, and Hydrological Evidence for Extensive Fracture-Mediated Fluid and Heat Transport in the Alpine Fault's Hanging-Wall Damage Zone

    Science.gov (United States)

    Townend, John; Sutherland, Rupert; Toy, Virginia G.; Doan, Mai-Linh; Célérier, Bernard; Massiot, Cécile; Coussens, Jamie; Jeppson, Tamara; Janku-Capova, Lucie; Remaud, Léa.; Upton, Phaedra; Schmitt, Douglas R.; Pezard, Philippe; Williams, Jack; Allen, Michael John; Baratin, Laura-May; Barth, Nicolas; Becroft, Leeza; Boese, Carolin M.; Boulton, Carolyn; Broderick, Neil; Carpenter, Brett; Chamberlain, Calum J.; Cooper, Alan; Coutts, Ashley; Cox, Simon C.; Craw, Lisa; Eccles, Jennifer D.; Faulkner, Dan; Grieve, Jason; Grochowski, Julia; Gulley, Anton; Hartog, Arthur; Henry, Gilles; Howarth, Jamie; Jacobs, Katrina; Kato, Naoki; Keys, Steven; Kirilova, Martina; Kometani, Yusuke; Langridge, Rob; Lin, Weiren; Little, Tim; Lukacs, Adrienn; Mallyon, Deirdre; Mariani, Elisabetta; Mathewson, Loren; Melosh, Ben; Menzies, Catriona; Moore, Jo; Morales, Luis; Mori, Hiroshi; Niemeijer, André; Nishikawa, Osamu; Nitsch, Olivier; Paris, Jehanne; Prior, David J.; Sauer, Katrina; Savage, Martha K.; Schleicher, Anja; Shigematsu, Norio; Taylor-Offord, Sam; Teagle, Damon; Tobin, Harold; Valdez, Robert; Weaver, Konrad; Wiersberg, Thomas; Zimmer, Martin

    2017-12-01

    Fault rock assemblages reflect interaction between deformation, stress, temperature, fluid, and chemical regimes on distinct spatial and temporal scales at various positions in the crust. Here we interpret measurements made in the hanging-wall of the Alpine Fault during the second stage of the Deep Fault Drilling Project (DFDP-2). We present observational evidence for extensive fracturing and high hanging-wall hydraulic conductivity (˜10-9 to 10-7 m/s, corresponding to permeability of ˜10-16 to 10-14 m2) extending several hundred meters from the fault's principal slip zone. Mud losses, gas chemistry anomalies, and petrophysical data indicate that a subset of fractures intersected by the borehole are capable of transmitting fluid volumes of several cubic meters on time scales of hours. DFDP-2 observations and other data suggest that this hydrogeologically active portion of the fault zone in the hanging-wall is several kilometers wide in the uppermost crust. This finding is consistent with numerical models of earthquake rupture and off-fault damage. We conclude that the mechanically and hydrogeologically active part of the Alpine Fault is a more dynamic and extensive feature than commonly described in models based on exhumed faults. We propose that the hydrogeologically active damage zone of the Alpine Fault and other large active faults in areas of high topographic relief can be subdivided into an inner zone in which damage is controlled principally by earthquake rupture processes and an outer zone in which damage reflects coseismic shaking, strain accumulation and release on interseismic timescales, and inherited fracturing related to exhumation.

  7. Seasonal inorganic nitrogen release in alpine lakes on the Colorado western slope

    Science.gov (United States)

    Inyan, B.I.; Williams, M.W.; Tonnessen, K.; Turk, J.T.; Campbell, D.H.

    1998-01-01

    In the Rocky Mountains, the association of increases in acidic deposition with increased atmospheric loading of sulfate and direct changes in surface water chemistry has been well established. The importance, though, of increased nitrogen (N) deposition in the episodic acidification of alpine lakes and N saturation in alpine ecosystems is only beginning to be documented. In alpine areas of the Colorado Front Range, modest loadings of N in deposition have been associated with leakage of N to surface waters. On the Colorado western slope, however, no leakage of N to surface waters has been reported. A 1995 study that included early season under-ice water samples that were not available in earlier studies showed that there is, in fact, N leakage to surface waters in some western slope basins. Under-ice nitrate (NO3-) concentrations were as high as 10.5 ??q L-1, and only decreased to detection limits in September. Landscape type appears to be important in leakage of N to surface waters, which is associated with basins having steep slopes, thin soils, and large amounts of exposed bedrock. NO3- leakage compounds the existing sensitivity to episodic acidification from low acid neutralizing capacity (ANC), which is less than 40 ??eq L-1 in those basins.

  8. Site-specific landslide assessment in Alpine area using a reliable integrated monitoring system

    Science.gov (United States)

    Romeo, Saverio; Di Matteo, Lucio; Kieffer, Daniel Scott

    2016-04-01

    Rockfalls are one of major cause of landslide fatalities around the world. The present work discusses the reliability of integrated monitoring of displacements in a rockfall within the Alpine region (Salzburg Land - Austria), taking into account also the effect of the ongoing climate change. Due to the unpredictability of the frequency and magnitude, that threatens human lives and infrastructure, frequently it is necessary to implement an efficient monitoring system. For this reason, during the last decades, integrated monitoring systems of unstable slopes were widely developed and used (e.g., extensometers, cameras, remote sensing, etc.). In this framework, Remote Sensing techniques, such as GBInSAR technique (Groung-Based Interferometric Synthetic Aperture Radar), have emerged as efficient and powerful tools for deformation monitoring. GBInSAR measurements can be useful to achieve an early warning system using surface deformation parameters as ground displacement or inverse velocity (for semi-empirical forecasting methods). In order to check the reliability of GBInSAR and to monitor the evolution of landslide, it is very important to integrate different techniques. Indeed, a multi-instrumental approach is essential to investigate movements both in surface and in depth and the use of different monitoring techniques allows to perform a cross analysis of the data and to minimize errors, to check the data quality and to improve the monitoring system. During 2013, an intense and complete monitoring campaign has been conducted on the Ingelsberg landslide. By analyzing both historical temperature series (HISTALP) recorded during the last century and those from local weather stations, temperature values (Autumn-Winter, Winter and Spring) are clearly increased in Bad Hofgastein area as well as in Alpine region. As consequence, in the last decades the rockfall events have been shifted from spring to summer due to warmer winters. It is interesting to point out that

  9. Carbon dioxide concentration in caves and soils in an alpine setting: implications for speleothem fabrics and their palaeoclimate significance

    Science.gov (United States)

    Borsato, Andrea; Frisia, Silvia; Miorandi, Renza

    2015-04-01

    Carbon dioxide concentration in soils controls carbonate dissolution, soil CO2 efflux to the atmosphere, and CO2 transfer to the subsurface that lead, ultimately, to speleothem precipitation. Systematic studies on CO2 concentration variability in soil and caves at regional scale are, however, few. Here, the systematic investigation of CO2 concentration in caves and soils in a temperate, Alpine region along a 2,100 m altitudinal range transect, which corresponds to a mean annual temperature (MAT) range of 12°C is presented. Soil pCO2 is controlled by the elevation and MAT and exhibits strong seasonality, which follows surface air temperature with a delay of about a month. The aquifer pCO2, by contrast, is fairly constant throughout the year, and it is primarily influenced by summer soil pCO2. Cave CO2 concentration is a balance between the CO2 influx and CO2 efflux, where the efflux is controlled by the cave ventilation, which is responsible for low pCO2 values recorded in most of the caves with respect to soil levels. Carbon dioxide in the innermost part of the studied caves exhibits a clear seasonal pattern. Thermal convection is the most common mechanism causing higher ventilation and low cave air pCO2 levels during the winter season: this promotes CO2 degassing and higher supersaturation in the drip water and, eventually, higher speleothem growth rates during winter. The combined influence of three parameters - dripwater pCO2, dripwater Ca content, and cave air pCO2 - all related to the infiltration elevation and MAT directly controls calcite supersaturation in dripwater. Four different altitudinal belts are then defined, which reflect temperature-dependent saturation state of dripwaters. These belts broadly correspond to vegetation zones: the lower montane (100 to 800 m asl), the upper montane (800 to 1600 m asl), the subalpine (1600 to 2200 m asl) and the Alpine (above 2200 m asl). Each altitudinal belt is characterised by different calcite fabrics, which can

  10. Distribution and diversity of Arctic-Alpine species in the Balkans

    DEFF Research Database (Denmark)

    Stevanovic, Vladimir; Vukojicic, Snezana; Sinzar-Sekulic, Jasmina

    2009-01-01

    The distributions of 77 Arctic-Alpine species in the Balkans are mapped and the centers of their richness and diversity presented. Within the Dinaric Alps these are Mts Vranica, Durmitor, and Prokletije; in the Scardo-Pindhic mountains, Šarplanina-Rudoka-Korab form a continuous chain...

  11. Alpine glacial topography and the rate of rock column uplift

    DEFF Research Database (Denmark)

    Pedersen, Vivi Kathrine; Egholm, D.L.; Nielsen, S.B.

    2010-01-01

    The present study investigates the influence of alpine glacial erosion on the morphology and relief distribution of mountain regions associated with varying rock column uplift rates. We take a global approach and analyse the surface area distribution of all mountain regions affected by glacial er...

  12. [Contribution of soil fauna to litter decomposition of Abies faxoniana and Rhododendron lapponicum across an alpine timberline ecotone in Western Sichuan, China.

    Science.gov (United States)

    Wang, Li Feng; He, Run Lian; Yang, Lin; Chen, Ya Mei; Liu, Yang; Zhang, Jian

    2016-11-18

    Soil fauna is an important biological factor in regulation litter decomposition. In order to quantify the contributions of soil fauna to the mass losses of litter of two dominant species fir (Abies faxoniana) and rhododendron (Rhododendron lapponicum) in the alpine timberline ecotone (coniferous forest-timberline-alpine meadow) of western Sichuan, China, a field litterbag experiment was conducted from May 2013 to November 2014. Samples of air-dried leaf litter were placed in nylon litterbags of two different mesh sizes, i.e. 3.00 mm (with the soil animals) and 0.04 mm (excluded the soil animals). The results showed that the decomposition rate of A. faxoniana (k: 0.209-0.243) was higher than that of R. lapponicum (k: 0.173-0.189) across the timberline ecotone. Soil fauna had significant contributions to litter decomposition of two species, the contributions of soil fauna to mass loss showed a decreasing trend with increasing altitude. From the coniferous forest to the alpine meadow, the mass losses caused by soil fauna for the fir litter accounted for 15.2%, 13.2% and 9.8%, respectively and that for the rhododendron litter accounted for 20.1%, 17.5% and 12.4%, respectively. Meanwhile, the daily average contributions caused by soil fauna for the fir and rhododendron litter decomposition accounted for 0.17%, 0.13%, 0.12% and 0.26%, 0.25%, 0.23%, respectively. Relatively, soil fauna had more influence on alpine rhododendron decomposition. Two-way ANOVA showed that species, altitude and their interaction had significant impact on the litter mass loss and decomposition rate caused by soil fauna. The daily average contribution caused by soil fauna for the fir and rhododendron litter decomposition accounted for 0.25% and 0.44% in the first growing season, then 0.10% and 0.19% in the second growing season, both were higher than that of snow-covered season (0.07% and 0.12%). Regression analysis showed that the environmental factors (daily average temperature, freezing and

  13. Metabolic Profiling of Alpine and Ecuadorian Lichens

    Directory of Open Access Journals (Sweden)

    Verena K. Mittermeier

    2015-10-01

    Full Text Available Non-targeted 1H-NMR methods were used to determine metabolite profiles from crude extracts of Alpine and Ecuadorian lichens collected from their natural habitats. In control experiments, the robustness of metabolite detection and quantification was estimated using replicate measurements of Stereocaulon alpinum extracts. The deviations in the overall metabolite fingerprints were low when analyzing S. alpinum collections from different locations or during different annual and seasonal periods. In contrast, metabolite profiles observed from extracts of different Alpine and Ecuadorian lichens clearly revealed genus- and species-specific profiles. The discriminating functions determining cluster formation in principle component analysis (PCA were due to differences in the amounts of genus-specific compounds such as sticticin from the Sticta species, but also in the amounts of ubiquitous metabolites, such as sugar alcohols or trehalose. However, varying concentrations of these metabolites from the same lichen species e.g., due to different environmental conditions appeared of minor relevance for the overall cluster formation in PCA. The metabolic clusters matched phylogenetic analyses using nuclear ribosomal DNA (nrDNA internal transcribed spacer (ITS sequences of lichen mycobionts, as exemplified for the genus Sticta. It can be concluded that NMR-based non-targeted metabolic profiling is a useful tool in the chemo-taxonomy of lichens. The same approach could also facilitate the discovery of novel lichen metabolites on a rapid and systematical basis.

  14. Climate signal in d13C of wood lignin methoxyl groups from high-elevation alpine larch trees

    Science.gov (United States)

    Reichelmann, Dana; Greule, Markus; Treydte, Kerstin; Keppler, Frank; Esper, Jan

    2015-04-01

    Tree-rings of high alpine larch trees (Larix decidua) were investigated by a recently established method that measures d13C values of the wood lignin methoxyl groups (Greule et al. 2009). The resulting d13C time series were tested for their potential as a climate proxy. For this 37 larch trees were sampled at the tree line near Simplon Village (Southern Switzerland). They were analysed for their tree-ring width (TRW) and from five individuals d13C of the wood lignin methoxyl groups (d13Cmethoxyl) were measured at annual resolution from 1971-2009 and at pentadal resolution from 1747-2009. The d13Cmethoxyl chronologies were corrected for the anthropogenic change in atmospheric CO2 concentration and its decreasing d13C value. Further, the physiological response of the trees to these atmospheric changes was corrected using the flexible correction factor approach of Treydte et al. (2009), which minimise the residuals with the target climate data. This approach results in the highest so far reported correction factors of 0.032 - 0.036‰/ppmv CO2, which are explained by a low water-use efficiency of deciduous larch. The climate response of the new d13Cmethoxyl proxy shows a significant correlation of 0.75 for the annually and 0.87 for the pentadally resolved data with June to August temperatures. TRW shows also significant correlations with June to August temperatures, but they are lower than the correlations observed for the d13Cmethoxyl chronologies. These results indicate the potential of d13Cmethoxyl chronologies as a summer temperature proxy from high-elevation alpine trees with an even stronger signal than reported from earlier published tree-ring width and maximum latewood density temperature reconstructions. References: Greule, M., Mosandl, A., Hamilton, J.T.G., Keppler, F., 2009. A simple rapid method to precisely determine 13C/12C ratios of plant methoxyl groups. Rapid Communications in Mass Spectrometry, 23(11): 1710-1714. Treydte, K.S., Frank, D.C., Saurer, M

  15. Methods for measuring arctic and alpine shrub growth: A review

    NARCIS (Netherlands)

    Myers-Smith, I.H.; Hallinger, M.; Blok, D.; Sass-Klaassen, U.G.W.; Rayback, S.A.

    2015-01-01

    Shrubs have increased in abundance and dominance in arctic and alpine regions in recent decades. This often dramatic change, likely due to climate warming, has the potential to alter both the structure and function of tundra ecosystems. The analysis of shrub growth is improving our understanding of

  16. Aortic Dissection Type A in Alpine Skiers

    Directory of Open Access Journals (Sweden)

    Thomas Schachner

    2013-01-01

    Full Text Available Patients and Methods. 140 patients with aortic dissection type A were admitted for cardiac surgery. Seventy-seven patients experienced their dissection in the winter season (from November to April. We analyzed cases of ascending aortic dissection associated with alpine skiing. Results. In 17 patients we found skiing-related aortic dissections. Skiers were taller (180 (172–200 cm versus 175 (157–191 cm, and heavier (90 (68–125 kg versus 80 (45–110 kg, than nonskiers. An extension of aortic dissection into the aortic arch, the descending thoracic aorta, and the abdominal aorta was found in 91%, 74%, and 69%, respectively, with no significant difference between skiers and nonskiers. Skiers experienced RCA ostium dissection requiring CABG in 17.6% while this was true for 5% of nonskiers (. Hospital mortality of skiers was 6% versus 13% in nonskiers (. The skiers live at an altitude of 170 (0–853 m.a.s.l. and experience their dissection at 1602 (1185–3105; m.a.s.l. In 82% symptom start was during recreational skiing without any trauma. Conclusion. Skiing associated aortic dissection type A is usually nontraumatic. The persons affected live at low altitudes and practice an outdoor sport at unusual high altitude at cold temperatures. Postoperative outcome is good.

  17. ALPINE VEGETATION ECOTONE DYNAMICS IN GANGOTRI CATCHMENT USING REMOTE SENSING TECHNIQUES

    Directory of Open Access Journals (Sweden)

    C. P. Singh

    2012-09-01

    Full Text Available Analysis of the satellite imagery reveals two different perspectives of the vegetation ecotone dynamics in Gangotri catchment. On one hand, there is evidence of upward shift in the alpine tree and vegetation ecotone over three decades. On the other hand, there has been densification happening at the past treeline. The time series fAPAR data of two decades from NOAA-AVHRR confirms the greening trend in the area. The density of trees in Chirbasa has gone up whereas in Bhojbasa there is no significant change in NDVI but the number of groves has increased. Near Gaumukh the vegetal activity has not shown any significant change. We found that the treeline extracted from satellite imagery has moved up about 327±80m and other vegetation line has moved up about 401±77m in three decades. The vertical rate of treeline shift is found to be 11m/yr with reference to 1976 treeline; however, this can be 5m/yr if past toposheet records (1924 – 45 are considered as reliable reference. However, the future IPCC scenario based bioclimatic fundamental niche modelling of the Betula utilis (a surrogate to alpine treeline suggests that treeline could be moving upward with an average rate of 3m/yr. This study not only confirms that there is an upward shift of vegetation in the alpine zone of Himalayas, but also indicate that old vegetation ecotones have grown denser

  18. In Review (Geology): Alpine Landscape Evolution Dominated by Cirque Retreat

    Science.gov (United States)

    Oskin, Michael; Burbank, Doug

    2005-01-01

    Despite the abundance in alpine terrain of glacially dissected landscapes, the magnitude and geometry of glacial erosion can rarely be defined. In the eastern Kyrgyz Range, a widespread unconformity exhumed as a geomorphic surface provides a regional datum with which to calibrate erosion. As tectonically driven surface uplift has progressively pushed this surface into the zone of ice accumulation, glacial erosion has overprinted the landscape. With as little as 500 m of incision into rocks underlying the unconformity, distinctive glacial valleys display their deepest incision adjacent to cirque headwalls. The expansion of north-facing glacial cirques at the expense of south-facing valleys has driven the drainage divide southwards at rates up to 2 to 3 times the rate of valley incision. Existing ice-flux-based glacial erosion rules incompletely model expansion of glacial valleys via cirque retreat into the low-gradient unconformity remnants. Local processes that either directly sap cirque headwalls or inhibit erosion down-glacier appear to control, at least initially, alpine landscape evolution.

  19. Experimental validation of error in temperature measurements in thin walled ductile iron castings

    DEFF Research Database (Denmark)

    Pedersen, Karl Martin; Tiedje, Niels Skat

    2007-01-01

    An experimental analysis has been performed to validate the measurement error of cooling curves measured in thin walled ductile cast iron. Specially designed thermocouples with Ø0.2 mm thermocouple wire in Ø1.6 mm ceramic tube was used for the experiments. Temperatures were measured in plates...

  20. Overlapping Leaves Covering Flowers in the Alpine Species Eriophyton wallichii (Lamiaceae: Key Driving Factors and Their Potential Impact on Pollination.

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    De-Li Peng

    Full Text Available Extrafloral structures are supposed to have evolved to protect flowers from harsh physical environments but might have effects on pollination. Overlapping leaves cover flowers in Eriophyton wallichii, an alpine perennial endemic to the Himalaya-Hengduan Mountains. In previous study, it has showed that these extrafloral leaves can protect interior flowers from temperature fluctuations caused by drastic solar radiation fluctuations, but these leaves may also protect interior flowers from rain wash and UVB damage, and we do not know which one is the main function. In this study, we investigated whether rain and UVB protection are the main functions of overlapping leaves covering flowers and their potential impact on pollination. We first measured the intensities of UVB radiation in open air, beneath leaves and corollas, and then examined pollen susceptibility to different intensities of UVB and rain in the laboratory to estimate whether corollas per se protect interior pollen from UVB and rain damage. We also carried out pollination treatments and observed pollinator visitation of flowers with and without leaves in the field to assess whether the overlapping leaves covering flowers impair pollinator attraction. Our results showed that (1 water and strong UVB significantly decreased pollen germinability, but corollas per se could protect pollen from UVB and rain damage; (2 no autonomous self-pollination and apomixis occurred, and pollinators were essential for the reproduction of E. wallichii; however, flower coverage by overlapping leaves did not limit pollination. We suggested that rain and UVB protection was not the main function of overlapping leaves covered flowers, given that this protection can be provided by corollas per se. Alternatively, this extrafloral structure in E. wallichii may have evolved in response to extreme high temperatures associated with the strong solar radiation fluctuations. This indicates that, even in alpine plants

  1. Simulating the influence of snow surface processes on soil moisture dynamics and streamflow generation in an alpine catchment

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    N. Wever

    2017-08-01

    Full Text Available The assessment of flood risks in alpine, snow-covered catchments requires an understanding of the linkage between the snow cover, soil and discharge in the stream network. Here, we apply the comprehensive, distributed model Alpine3D to investigate the role of soil moisture in the predisposition of the Dischma catchment in Switzerland to high flows from rainfall and snowmelt. The recently updated soil module of the physics-based multilayer snow cover model SNOWPACK, which solves the surface energy and mass balance in Alpine3D, is verified against soil moisture measurements at seven sites and various depths inside and in close proximity to the Dischma catchment. Measurements and simulations in such terrain are difficult and consequently, soil moisture was simulated with varying degrees of success. Differences between simulated and measured soil moisture mainly arise from an overestimation of soil freezing and an absence of a groundwater description in the Alpine3D model. Both were found to have an influence in the soil moisture measurements. Using the Alpine3D simulation as the surface scheme for a spatially explicit hydrologic response model using a travel time distribution approach for interflow and baseflow, streamflow simulations were performed for the discharge from the catchment. The streamflow simulations provided a closer agreement with observed streamflow when driving the hydrologic response model with soil water fluxes at 30 cm depth in the Alpine3D model. Performance decreased when using the 2 cm soil water flux, thereby mostly ignoring soil processes. This illustrates that the role of soil moisture is important to take into account when understanding the relationship between both snowpack runoff and rainfall and catchment discharge in high alpine terrain. However, using the soil water flux at 60 cm depth to drive the hydrologic response model also decreased its performance, indicating that an optimal soil depth to include in

  2. Leaf waxes of slow-growing alpine and fast-growing lowland Poa species: inherent differences and responses to UV-B radiation

    International Nuclear Information System (INIS)

    Pilon, J.J.; Lambers, H.; Baas, W.; Tosserams, M.; Rozema, J.; Atkin, O.K.

    1999-01-01

    We investigated whether alpine and lowland Poa species exhibit inherent differences in leaf cuticular waxes, leaf UV absorbing compounds and/or growth responses to UV-B treatment. All plants were grown hydroponically in a growth cabinet (constant 20°; 14 hr photoperiod; 520 μmol photons m −2 s −1 PAR). Two alpine (P. fawcettiae and P. costiniana), one sub-alpine (P. alpina) and three temperate lowland species (P. pratensis, P. compressa and P. trivialis) were grown under conditions without UV radiation for 36 days. In a subsequent experiment, four Poa species (P. costiniana, P. alpina, P. compressa and P. trivialis) were also exposed for 21 days to UV-B/(UV-A) radiation ('UV-B treatment') that resulted in daily UV-B radiation of 7.5 kJ m −2 day −1 , with control plants being grown without UV-B ('UV-A control treatment'). All treatments were carried out in the same growth cabinet. There was no altitudinal trend regarding wax concentrations per unit leaf area, when the six species grown under UV-less conditions, were compared at similar developmental stage (20–30 g shoot fresh mass). However, large differences in cuticular wax chemical composition were observed between the alpine and lowland species grown under UV-less conditions. For example, a single primary alcohol was present in the waxes of the lowland and sub-alpine species (C 26 H 53 OH), but was virtually absent in the alpine species. Although alkanes were present in all six species (primarily C 29 H 60 and C 31 H 64 ), the proportion of total wax present as alkanes was highest in the alpine species. Aldehydes were only present in the waxes of the alpine species. Conversely, substantial amounts of triterpenoids were mainly present in the three lowland species (squalene and lupeol were the dominant forms). The proportion of total wax present as long-chain esters (LCE-s) was similar in all six species grown in the absence of UV radiation. Acetates were observed only in the wax of

  3. Strong Regionality and Dominance of Anaerobic Bacterial Taxa Characterize Diazotrophic Bacterial Communities of the Arcto-Alpine Plant Species Oxyria digyna and Saxifraga oppositifolia

    Directory of Open Access Journals (Sweden)

    Manoj Kumar

    2017-10-01

    Full Text Available Arctic and alpine biomes are most often strongly nitrogen-limited, and hence biological nitrogen fixation is a strong driver of these ecosystems. Both biomes are characterized by low temperatures and short growing seasons, but they differ in seasonality of solar radiation and in soil water balance due to underlying permafrost in the Arctic. Arcto-alpine plant species are well-adapted to the low temperatures that prevail in their habitats, and plant growth is mainly limited by the availability of nutrients, in particular nitrogen, due to slow mineralization. Nitrogen fixing bacteria are likely important for plant growth in these habitats, but very little is known of these bacteria or forces shaping their communities. In this study, we characterized the potential nitrogen fixing bacterial (PNFB communities associated with two arcto-alpine pioneer plant species, Oxyria digyna (mountain sorrel and Saxifraga oppositifolia (blue saxifrage, in three climate regions. Both of these plants readily colonize low nutrient mineral soils. Our goal was to investigate how climate (region and, on the other hand, host plant and plant species shape these communities. To our knowledge, this is the first comprehensive study describing PNFB communities associated with pioneer plants in different arcto-alpine biomes. Replicate samples were taken from two arctic regions, Kilpisjärvi and Ny-Ålesund, and one alpine region, Mayrhofen. In these, the PNFB communities in the bulk and rhizosphere soils and the plant endospheres were characterized by nifH-targeted PCR and massive parallel sequencing. The data revealed strong effects of climatic region on the dominating nitrogen fixers. Specifically, nifH sequences related to Geobacter (δ-Proteobacteria were present in high relative abundances in the nitrogen-fixing communities in the Mayrhofen and Kilpisjärvi regions, while members of the Clostridiales prevailed in the Kilpisjärvi and Ny-Ålesund regions. The bulk and

  4. Strong Regionality and Dominance of Anaerobic Bacterial Taxa Characterize Diazotrophic Bacterial Communities of the Arcto-Alpine Plant Species Oxyria digyna and Saxifraga oppositifolia.

    Science.gov (United States)

    Kumar, Manoj; van Elsas, Jan Dirk; Nissinen, Riitta

    2017-01-01

    Arctic and alpine biomes are most often strongly nitrogen-limited, and hence biological nitrogen fixation is a strong driver of these ecosystems. Both biomes are characterized by low temperatures and short growing seasons, but they differ in seasonality of solar radiation and in soil water balance due to underlying permafrost in the Arctic. Arcto-alpine plant species are well-adapted to the low temperatures that prevail in their habitats, and plant growth is mainly limited by the availability of nutrients, in particular nitrogen, due to slow mineralization. Nitrogen fixing bacteria are likely important for plant growth in these habitats, but very little is known of these bacteria or forces shaping their communities. In this study, we characterized the potential nitrogen fixing bacterial (PNFB) communities associated with two arcto-alpine pioneer plant species, Oxyria digyna (mountain sorrel) and Saxifraga oppositifolia (blue saxifrage), in three climate regions. Both of these plants readily colonize low nutrient mineral soils. Our goal was to investigate how climate (region) and, on the other hand, host plant and plant species shape these communities. To our knowledge, this is the first comprehensive study describing PNFB communities associated with pioneer plants in different arcto-alpine biomes. Replicate samples were taken from two arctic regions, Kilpisjärvi and Ny-Ålesund, and one alpine region, Mayrhofen. In these, the PNFB communities in the bulk and rhizosphere soils and the plant endospheres were characterized by nifH -targeted PCR and massive parallel sequencing. The data revealed strong effects of climatic region on the dominating nitrogen fixers. Specifically, nifH sequences related to Geobacter (δ- Proteobacteria ) were present in high relative abundances in the nitrogen-fixing communities in the Mayrhofen and Kilpisjärvi regions, while members of the Clostridiales prevailed in the Kilpisjärvi and Ny-Ålesund regions. The bulk and rhizosphere soil

  5. Brightness Temperature and Soil Moisture Validation at Different Scales During the SMOS Validation Campaign in the Rur and Erft Catchments, Germany

    DEFF Research Database (Denmark)

    Montzka, Carsten; Bogena, Heye R.; Weihermüller, Lutz

    2013-01-01

    The European Space Agency's Soil Moisture and Ocean Salinity (SMOS) satellite was launched in November 2009 and delivers now brightness temperature and soil moisture products over terrestrial areas on a regular three-day basis. In 2010, several airborne campaigns were conducted to validate the SMOS......-band Microwave Emission of the Biosphere model. Measurements of the airborne L-band sensors EMIRAD and HUT-2D on-board a Skyvan aircraft as well as ground-based mobile measurements performed with the truck mounted JÜLBARA L-band radiometer were analyzed for calibration of the simulated brightness temperature...

  6. Integrating the EMPD with an Alpine altitudinal training set to reconstruct climate variables in Holocene pollen records from high-altitude peat bogs

    Science.gov (United States)

    Furlanetto, Giulia; Badino, Federica; Brunetti, Michele; Champvillair, Elena; De Amicis, Mattia; Maggi, Valter; Pini, Roberta; Ravazzi, Cesare; Vallé, Francesca

    2016-04-01

    Temperatures and precipitation are the main environmental factors influencing vegetation and pollen production. Knowing the modern climate optima and tolerances of those plants represented in fossil assemblages and assuming that the relationships between plants and climate in the past are not dissimilar from the modern ones, fossil pollen records offer many descriptors to reconstruct past climate variables. The aim of our work is to investigate the potential of high-altitude pollen records from an Alpine peat bog (TBValter, close to the Ruitor Glacier, Western Italian Alps) for quantitative paleoclimate estimates. The idea behind is that high-altitude ecosystems are more sensitive to climate changes, especially to changes in July temperatures that severely affect the timberline ecotone. Meantime, we met with difficulties when considering the factors involved in pollen dispersal over a complex altitudinal mountain pattern, such as the Alps. We used the EMPD-European Modern Pollen Database (Davis et al., 2013) as modern training set to be compared with our high-altitude fossil site. The EMPD dataset is valuable in that it provides a large geographic coverage of main ecological and climate gradients (at sub-continental scale) but lacks in sampling of altitudinal gradients and high-altitude sites in the Alps. We therefore designed an independent altitudinal training set for the alpine valley hosting our fossil site. 27 sampling plots were selected along a 1700m-elevational transect. In a first step, each plot was provided with (i) 3 moss polsters collected following the guidelines provided by Cañellas-Boltà et al. (2009) and analyzed separately to account for differences in pollen deposition at small scale, (ii) morphometrical parameters obtained through a high-resolution DEM, and (iii) temperature and precipitation were estimated by means of weighted linear regression of the meteorological variable versus elevation, locally evaluated for each site (Brunetti et al

  7. A soil moisture and temperature network for SMOS validation in Western Denmark

    DEFF Research Database (Denmark)

    Bircher, Simone; Skou, Niels; Jensen, K. H.

    2011-01-01

    The Soil Moisture and Ocean Salinity Mission (SMOS) acquires surface soil moisture data globally, and thus product validation for a range of climate and environmental conditions across continents is a crucial step. For this purpose, a soil moisture and temperature network of Decagon ECH2O 5TE...... SMOS pixel (44 × 44 km), which is representative of the land surface conditions of the catchment and with minimal impact from open water (2) arrangement of three network clusters along the precipitation gradient, and (3) distribution of the stations according to respective fractions of classes...... representing the prevailing environmental conditions. Overall, measured moisture and temperature patterns could be related to the respective land cover and soil conditions. Texture-dependency of the 0–5 cm soil moisture measurements was demonstrated. Regional differences in 0–5 cm soil moisture, temperature...

  8. Treeline proximity alters an alpine plant-herbivore interaction.

    Science.gov (United States)

    Illerbrun, Kurt; Roland, Jens

    2011-05-01

    Rising treeline threatens the size and contiguity of alpine meadows worldwide. As trees encroach into previously open habitat, the movement and population dynamics of above-treeline alpine species may be disrupted. This process is well documented in studies of the Rocky Mountain apollo butterfly (Parnassius smintheus). However, subtler consequences of treeline rise remain poorly understood. In this study, we examine whether treeline proximity affects feeding behaviour of P. smintheus larvae, due to altered habitat affecting the distribution and availability of their host plant, lance-leaved stonecrop (Sedum lanceolatum). Understanding differential larval exploitation of food resources in relation to the treeline is an important step in predicting the consequences of continued treeline rise. Parnassius smintheus larvae feed more intensively on S. lanceolatum away from the treeline despite the relative paucity of hosts in these areas, and despite higher fitness penalties associated with the plant's herbivory-induced chemical defenses. Sedum lanceolatum growing near the treeline is less attractive, and therefore represents a less significant resource for P. smintheus larvae than its abundance might imply. If treeline rise continues, we suggest that this pattern of altered resource exploitation may represent a mechanism by which larvae are adversely affected even while adult movement among and within meadows appears sufficient for maintaining population health, and total host availability seems ample.

  9. Evaluating the Contributions of Atmospheric Deposition of Carbon and Other Nutrients to Nitrification in Alpine Environments

    Science.gov (United States)

    Oldani, K. M.; Mladenov, N.; Williams, M. W.

    2013-12-01

    The Colorado Front Range of the Rocky Mountains contains undeveloped, barren soils, yet in this environment there is strong evidence for a microbial role in increased nitrogen (N) export. Barren soils in alpine environments are severely carbon-limited, which is the main energy source for microbial activity and sustenance of life. It has been shown that atmospheric deposition can contain high amounts of organic carbon (C). Atmospheric pollutants, dust events, and biological aerosols, such as bacteria, may be important contributors to the atmospheric organic C load. In this stage of the research we evaluated seasonal trends in the chemical composition and optical spectroscopic (fluorescence and UV-vis absorbance) signatures of snow, wet deposition, and dry deposition in an alpine environment at Niwot Ridge in the Rocky Mountains of Colorado to obtain a better understanding of the sources and chemical character of atmospheric deposition. Our results reveal a positive trend between dissolved organic carbon concentrations and calcium, nitrate and sulfate concentrations in wet and dry deposition, which may be derived from such sources as dust and urban air pollution. We also observed the presence of seasonally-variable fluorescent components that may be attributed to fluorescent pigments in bacteria. These results are relevant because atmospheric inputs of carbon and other nutrients may influence nitrification in barren, alpine soils and, ultimately, the export of nitrate to alpine watersheds.

  10. High resolution climate scenarios for snowmelt modelling in small alpine catchments

    Science.gov (United States)

    Schirmer, M.; Peleg, N.; Burlando, P.; Jonas, T.

    2017-12-01

    Snow in the Alps is affected by climate change with regard to duration, timing and amount. This has implications with respect to important societal issues as drinking water supply or hydropower generation. In Switzerland, the latter received a lot of attention following the political decision to phase out of nuclear electricity production. An increasing number of authorization requests for small hydropower plants located in small alpine catchments was observed in the recent years. This situation generates ecological conflicts, while the expected climate change poses a threat to water availability thus putting at risk investments in such hydropower plants. Reliable high-resolution climate scenarios are thus required, which account for small-scale processes to achieve realistic predictions of snowmelt runoff and its variability in small alpine catchments. We therefore used a novel model chain by coupling a stochastic 2-dimensional weather generator (AWE-GEN-2d) with a state-of-the-art energy balance snow cover model (FSM). AWE-GEN-2d was applied to generate ensembles of climate variables at very fine temporal and spatial resolution, thus providing all climatic input variables required for the energy balance modelling. The land-surface model FSM was used to describe spatially variable snow cover accumulation and melt processes. The FSM was refined to allow applications at very high spatial resolution by specifically accounting for small-scale processes, such as a subgrid-parametrization of snow covered area or an improved representation of forest-snow processes. For the present study, the model chain was tested for current climate conditions using extensive observational dataset of different spatial and temporal coverage. Small-scale spatial processes such as elevation gradients or aspect differences in the snow distribution were evaluated using airborne LiDAR data. 40-year of monitoring data for snow water equivalent, snowmelt and snow-covered area for entire

  11. Permafrost collapse shifts alpine tundra to a carbon source but reduces N2O and CH4 release on the northern Qinghai-Tibetan Plateau

    Science.gov (United States)

    Mu, C.

    2017-12-01

    Important unknowns remain about how abrupt permafrost collapse (thermokarst) affects carbon balance and greenhouse gas flux, limiting our ability to predict the magnitude and timing of the permafrost carbon feedback. We measured monthly, growing-season fluxes of CO2, CH4, and N2O at a large thermokarst feature in alpine tundra on the northern Qinghai-Tibetan Plateau (QTP). Thermokarst formation disrupted plant growth and soil hydrology, shifting the ecosystem from a growing-season carbon sink to a weak source, but decreasing feature-level CH4 and N2O flux. Temperature-corrected ecosystem respiration from decomposing permafrost soil was 2.7 to 9.5-fold higher than in similar features from Arctic and Boreal regions, suggesting that warmer and dryer conditions on the northern QTP could accelerate carbon decomposition following permafrost collapse. N2O flux was similar to the highest values reported for Arctic ecosystems, and was 60% higher from exposed mineral soil on the feature floor, confirming Arctic observations of coupled nitrification and denitrification in collapsed soils. Q10 values for respiration were typically over 4, suggesting high temperature sensitivity of thawed carbon. Taken together, these results suggest that QTP permafrost carbon in alpine tundra is highly vulnerable to mineralization following thaw, and that N2O production could be an important non-carbon permafrost climate feedback.

  12. The alpine cushion plant Silene acaulis as foundation species: a bug's-eye view to facilitation and microclimate.

    Directory of Open Access Journals (Sweden)

    Olivia Molenda

    Full Text Available Alpine ecosystems are important globally with high levels of endemic and rare species. Given that they will be highly impacted by climate change, understanding biotic factors that maintain diversity is critical. Silene acaulis is a common alpine nurse plant shown to positively influence the diversity and abundance of organisms--predominantly other plant species. The hypothesis that cushion or nurse plants in general are important to multiple trophic levels has been proposed but rarely tested. Alpine arthropod diversity is also largely understudied worldwide, and the plant-arthropod interactions reported are mostly negative, that is,. herbivory. Plant and arthropod diversity and abundance were sampled on S. acaulis and at paired adjacent microsites with other non-cushion forming vegetation present on Whistler Mountain, B.C., Canada to examine the relative trophic effects of cushion plants. Plant species richness and abundance but not Simpson's diversity index was higher on cushion microsites relative to other vegetation. Arthropod richness, abundance, and diversity were all higher on cushion microsites relative to other vegetated sites. On a microclimatic scale, S. acaulis ameliorated stressful conditions for plants and invertebrates living inside it, but the highest levels of arthropod diversity were observed on cushions with tall plant growth. Hence, alpine cushion plants can be foundation species not only for other plant species but other trophic levels, and these impacts are expressed through both direct and indirect effects associated with altered environmental conditions and localized productivity. Whilst this case study tests a limited subset of the membership of alpine animal communities, it clearly demonstrates that cushion-forming plant species are an important consideration in understanding resilience to global changes for many organisms in addition to other plants.

  13. The validity of wireless iButtons® and thermistors for human skin temperature measurement

    International Nuclear Information System (INIS)

    Smith, A D Harper; Walsh, N P; Crabtree, D R; Bilzon, J L J

    2010-01-01

    Skin temperature is a fundamental variable in human thermo-physiology, and yet skin temperature measurement remains impractical in most free-living, exercise and clinical settings, using currently available hard-wired methods. The purpose of this study was to compare wireless iButtons® and hard-wired thermistors for human skin temperature measurement. In the first of two investigations, iButtons® and thermistors monitored temperature in a controlled water bath (range: 10–40 °C) and were referenced against a certified, mercury thermometer. In the second investigation, eight healthy males completed three randomized trials (ambient temperature = 10 °C, 20 °C and 30 °C) while both devices recorded skin temperature at rest (in low and high wind velocities) and during cycle-ergometry exercise. The results are as follows; Investigation 1: both devices displayed very high validity correlation with the reference thermometer (r > 0.999). Prior to correction, the mean bias was +0.121 °C for iButtons® and +0.045 °C for thermistors. Upon calibration correction the mean bias for iButtons® and thermistors was not significantly different from zero bias. Interestingly, the typical error of the estimate of iButtons® (0.043 °C) was 1.5 times less than that of thermistors (0.062 °C), demonstrating iButtons'® lower random error. Investigation 2: the offset between iButton® and thermistor readings was generally consistent across conditions; however, thermistor responses gave readings that were always closer to ambient temperature than those given by iButtons®, suggesting potential thermistor drift towards environmental conditions. Mean temperature differences between iButtons® and thermistors during resting trials ranged from 0.261 °C to 1.356 °C. Mean temperature differences between iButtons® and thermistors during exercise were 0.989 °C (ambient temperature = 10 °C), 0.415 °C (ambient temperature = 20 °C) and 0.318 °C (ambient temperature = 30 °C). Observed

  14. Checking the validity of Busquet's ionization temperature with detailed collisional radiative models.

    Science.gov (United States)

    Klapisch, M.; Bar-Shalom, A.

    1997-12-01

    Busquet's RADIOM model for effective ionization temperature Tz is an appealing and simple way to introduce non LTE effects in hydrocodes. The authors report checking the validity of RADIOM in the optically thin case by comparison with two collisional radiative models, MICCRON (level-by-level) for C and Al and SCROLL (superconfiguration- by-superconfiguration) for Lu and Au. MICCRON is described in detail. The agreement between the average ion charge >ZBusquet is very good in most cases. There is however room for improvement when the departure from LTE is more pronounced for heavy atoms and for emissivity. Improvement appears possible because the concept of ionization temperature seems to hold in a broader range of parameters.

  15. Microstructures imply cataclasis and authigenic mineral formation control geomechanical properties of New Zealand's Alpine Fault

    Science.gov (United States)

    Schuck, B.; Janssen, C.; Schleicher, A. M.; Toy, V. G.; Dresen, G.

    2018-05-01

    The Alpine Fault is capable of generating large (MW > 8) earthquakes and is the main geohazard on South Island, NZ, and late in its 250-291-year seismic cycle. To minimize its hazard potential, it is indispensable to identify and understand the processes influencing the geomechanical behavior and strength-evolution of the fault. High-resolution microstructural, mineralogical and geochemical analyses of the Alpine Fault's core demonstrate wall rock fragmentation, assisted by mineral dissolution, and cementation resulting in the formation of a fine-grained principal slip zone (PSZ). A complex network of anastomosing and mutually cross-cutting calcite veins implies that faulting occurred during episodes of dilation, slip and sealing. Fluid-assisted dilatancy leads to a significant volume increase accommodated by vein formation in the fault core. Undeformed euhedral chlorite crystals and calcite veins that have cut footwall gravels demonstrate that these processes occurred very close to the Earth's surface. Microstructural evidence indicates that cataclastic processes dominate the deformation and we suggest that powder lubrication and grain rolling, particularly influenced by abundant nanoparticles, play a key role in the fault core's velocity-weakening behavior rather than frictional sliding. This is further supported by the absence of smectite, which is reasonable given recently measured geothermal gradients of more than 120 °C km-1 and the impermeable nature of the PSZ, which both limit the growth of this phase and restrict its stability to shallow depths. Our observations demonstrate that high-temperature fluids can influence authigenic mineral formation and thus control the fault's geomechanical behavior and the cyclic evolution of its strength.

  16. A deposition record of inorganic ions from a high-alpine glacier

    Energy Technology Data Exchange (ETDEWEB)

    Huber, T. [Bern Univ. (Switzerland); Bruetsch, S.; Gaeggeler, H.W.; Schotterer, U.; Schwikowski, M. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-09-01

    The lowest five metres of an ice core from a high-alpine glacier (Colle Gnifetti, Monte Rosa massif, 4450m a.s.l., Switzerland) were analysed for ammonium, calcium, chloride, magnesium, nitrate, potassium, sodium, and sulphate by ion chromatography. (author) 1 fig., 3 refs.

  17. Modelling channel incision and alpine hillslope development using laser altimetry data

    NARCIS (Netherlands)

    Anders, N.S.; Seijmonsbergen, A.C.; Bouten, W.

    2009-01-01

    This paper presents a new approach to simulate drainage basin evolution and demonstrates that high resolution elevation data can be used as useful tool for a dynamic simulation of Alpine landscape development, in which channel incision is incorporated in high spatial detail. A vector channel

  18. Increasing temperature reduces the coupling between available nitrogen and phosphorus in soils of Chinese grasslands

    Science.gov (United States)

    Geng, Yan; Baumann, Frank; Song, Chao; Zhang, Mi; Shi, Yue; Kühn, Peter; Scholten, Thomas; He, Jin-Sheng

    2017-03-01

    Changes in climatic conditions along geographical gradients greatly affect soil nutrient cycling processes. Yet how climate regimes such as changes in temperature influence soil nitrogen (N) and phosphorus (P) concentrations and their stoichiometry is not well understood. This study investigated the spatial pattern and variability of soil N and P availability as well as their coupling relationships at two soil layers (0-10 and 10-20 cm) along a 4000-km climate transect in two grassland biomes of China, the Inner Mongolian temperate grasslands and the Tibetan alpine grasslands. Our results found that in both grasslands, from cold to warm sites the amounts of soil total N, total P and available P all decreased. By contrast, the amount of available N was positively related to mean annual temperature in the Tibetan grasslands. Meanwhile, with increasing temperature ratio of available N to P significantly increased but the linear relationship between them was considerably reduced. Thus, increasing temperature may not only induce a stoichiometric shift but also loose the coupling between available N and P. This N-P decoupling under warmer conditions was more evident in the Tibetan alpine grasslands where P limitation might become more widespread relative to N as temperatures continue to rise.

  19. Influence of climate on alpine stream chemistry and water sources

    Science.gov (United States)

    Foks, Sydney; Stets, Edward; Singha, Kamini; Clow, David W.

    2018-01-01

    The resilience of alpine/subalpine watersheds may be viewed as the resistance of streamflow or stream chemistry to change under varying climatic conditions, which is governed by the relative size (volume) and transit time of surface and subsurface water sources. Here, we use end‐member mixing analysis in Andrews Creek, an alpine stream in Rocky Mountain National Park, Colorado, from water year 1994 to 2015, to explore how the partitioning of water sources and associated hydrologic resilience change in response to climate. Our results indicate that four water sources are significant contributors to Andrews Creek, including snow, rain, soil water, and talus groundwater. Seasonal patterns in source‐water contributions reflected the seasonal hydrologic cycle, which is driven by the accumulation and melting of seasonal snowpack. Flushing of soil water had a large effect on stream chemistry during spring snowmelt, despite making only a small contribution to streamflow volume. Snow had a large influence on stream chemistry as well, contributing large amounts of water with low concentrations of weathering products. Interannual patterns in end‐member contributions reflected responses to drought and wet periods. Moderate and significant correlations exist between annual end‐member contributions and regional‐scale climate indices (the Palmer Drought Severity Index, the Palmer Hydrologic Drought Index, and the Modified Palmer Drought Severity Index). From water year 1994 to 2015, the percent contribution from the talus‐groundwater end member to Andrews Creek increased an average of 0.5% per year (p < 0.0001), whereas the percent contributions from snow plus rain decreased by a similar amount (p = 0.001). Our results show how water and solute sources in alpine environments shift in response to climate variability and highlight the role of talus groundwater and soil water in providing hydrologic resilience to the system.

  20. The relative age effect and the influence on performance in youth alpine ski racing.

    Science.gov (United States)

    Müller, Lisa; Hildebrandt, Carolin; Raschner, Christian

    2015-03-01

    The relative age effect (RAE), which refers to an over representation of athletes born early in a selection year, recently was proven to be present in alpine skiing. However, it was not made apparent whether the RAE exists as early as at the youngest level of youth ski racing at national level, nor whether the relative age influences racing performance. As a consequence, the purpose of the present study was twofold: first, to examine the extent of the RAE and second, to assess the influence the relative age has on the overall performance at the youngest levels of youth ski racing. The study included the investigation of 1,438 participants of the Austrian Kids Cup and 1,004 participants of the Teenager Cup at the provincial level, as well as 250 finalists of the Kids Cup and 150 finalists of the Teenager Cup at the national level. Chi²-tests revealed a highly significant RAE already at the youngest level of youth ski racing (Kids Cup) at both the provincial and national levels. There are not again favorably selected the relatively older athletes from the first into the second level of youth ski racing (Teenager Cup). Among the athletes of the Kids Cup, the relative age quarter distribution differed highly significantly from the distribution of the total sample with an over representation of relatively older athletes by comparison taking the top three positions. The data revealed that relative age had a highly significant influence on performance. This study demonstrated that the RAE poses a problem as early as the youngest level of youth ski racing, thereby indicating that many young talented kids are discriminated against, diminishing any chance they might have of becoming elite athletes despite their talents and efforts. The RAE influences not only the participation rate in alpine skiing, but also the performances. As a result, changes in the talent development system are imperative. Key pointsThe relative age influences not only the participation in youth ski

  1. Snow effects on alpine vegetation in the Qinghai-Tibetan Plateau

    Science.gov (United States)

    Wang, Kun; Zhang, Li; Qiu, Yubao; Ji, Lei; Tian, Feng; Wang, Cuizhen; Wang, Zhiyong

    2013-01-01

    Understanding the relationships between snow and vegetation is important for interpretation of the responses of alpine ecosystems to climate changes. The Qinghai-Tibetan Plateau is regarded as an ideal area due to its undisturbed features with low population and relatively high snow cover. We used 500 m Moderate Resolution Imaging Spectroradiometer (MODIS) datasets during 2001–2010 to examine the snow–vegetation relationships, specifically, (1) the influence of snow melting date on vegetation green-up date and (2) the effects of snow cover duration on vegetation greenness. The results showed that the alpine vegetation responded strongly to snow phenology (i.e., snow melting date and snow cover duration) over large areas of the Qinghai-Tibetan Plateau. Snow melting date and vegetation green-up date were significantly correlated (p growth was influenced by different seasonal snow cover durations (SCDs) in different regions. Generally, the December–February and March–May SCDs played a significantly role in vegetation growth, both positively and negatively, depending on different water source regions. Snow's positive impact on vegetation was larger than the negative impact.

  2. Seasonal dynamics and micro-climatic preference of two Alpine endemic hypogean beetles

    Directory of Open Access Journals (Sweden)

    Stefano Mammola

    2015-09-01

    Full Text Available Hypogean beetles generally live in stable environments, characterized by constant temperature and high relative humidity. Changes in the underground microclimatic conditions generally induce local migrations of the beetles through the hypogean environment in search of suitable microhabitats. We studied the seasonal dynamics and the micro-climatic preference of two Alpine endemic hypogean beetles - Sphodropsis ghilianii (Coleoptera, Carabidae and Dellabeffaella roccae (Coleoptera, Cholevidae - in the hypogean complex of Pugnetto (Graian Alps, Italy. We surveyed the two species for one year, using baited pitfall traps and measuring temperature and humidity along the two main caves. We used logistic regression mixed models (GLMMs to relate the presence of the two species to several variables, namely microclimate (seasonality, temperature, and humidity, subjacency and cave length. In addition, we tested the attractive power of the bait on the two species. The thermic optimum for S. ghilianii was found to be around 7°C, with an increasing probability of finding the species in the vicinity of the cave entrance during summer, autumn and spring. The species migrates inside the cave in winter, in response to the drop in the mean daily temperature and in the relative humidity occurring in the outer parts of the cave. On the contrary, D. roccae showed a significant preference for the deeper sections of the cave, characterized by an almost constant temperature of 9°C in air saturated with water vapour. Males and females individuals of both species were found to be equally affected by the environmental variables included in the analysis. We also provided information on the life history of the two species and methodological insights about the use of the bait in the traps

  3. Temporal variations of perfluoroalkyl substances and polybrominated diphenyl ethers in alpine snow

    International Nuclear Information System (INIS)

    Kirchgeorg, Torben; Dreyer, Annekatrin; Gabrieli, Jacopo; Kehrwald, Natalie; Sigl, Michael; Schwikowski, Margit

    2013-01-01

    The occurrence and temporal variation of 18 perfluoroalkyl substances (PFASs) and 8 polybrominated diphenyl ethers (PBDEs) in the European Alps was investigated in a 10 m shallow firn core from Colle Gnifetti in the Monte Rosa Massif (4455 m above sea level). The firn core encompasses the years 1997–2007. Firn core sections were analyzed by liquid chromatography–tandem mass spectrometry (PFASs) and gas chromatography–mass spectrometry (PBDEs). We detected 12 PFASs and 8 PBDEs in the firn samples. Perfluorobutanoic acid (PFBA; 0.3–1.8 ng L −1 ) and perfluorooctanoic acid (PFOA; 0.2–0.6 ng L −1 ) were the major PFASs while BDE 99 ( −1 ) and BDE 47 (n.d.–2.6 ng L −1 ) were the major PBDEs. This study demonstrates the occurrence of PFASs and PBDEs in the European Alps and provides the first evidence that PFASs compositions may be changing to PFBA-dominated compositions. -- Highlights: •PFASs and PBDEs were detected in low ng L −1 concentrations in an Alpine firn core. •BDE 47, BDE 99 and BDE 209 are the dominating PBDEs. •PFOA, PFNA and PFBA are the major PFASs. •We demonstrate a change in the PFASs composition. •Atmospheric degradation of volatile precursor might be the main source for >C8 PFCAs. -- PFAS and PBDE concentrations in European Alpine snow provide information about the occurrence, accumulation and recent changes of these persistent organic pollutants in Alpine regions

  4. Soil microbial responses to climate warming in Northern Andean alpine ecosystems

    Science.gov (United States)

    Gallery, R. E.; Lasso, E.

    2017-12-01

    The historically cooler temperatures and waterlogged soils of tropical alpine grasslands (páramo) have resulted in low decomposition rates and a large buildup of organic matter, making páramo one of the most important carbon sinks in tropical biomes. The climatic factors that favored the carbon accumulation are changing, and as a result páramo could play a disproportionate role in driving climate feedbacks through increased carbon released from these large soil carbon stores. Open top chamber warming experiments were established in the Colombian Andes in 2016 to quantify the magnitude of climate change on carbon balance and identify microbial and plant traits that regulate these impacts. Two focal sites differ in mean annual temperature, precipitation, and plant community richness. Heterotrophic respiration (RH,) was measured from soil cores incubated at temperatures representing current and projected warming. The warming effect on RH was sensitive to soil moisture, which could reflect shifts in microbial community composition and/or extracellular enzyme production or efficiency as soils dry. Bacterial, archaeal, and fungal communities in ambient and warmed plots were measured through high-throughput amplicon sequencing of the 16S rRNA and ITS1 rRNA gene regions. Communities showed strong spatial structuring both within and among páramo, reflecting the topographic heterogeneity of these ecosystems. Significant differences in relative abundance of dominant microbial taxa between páramo could be largely explained by soil bulk density, water holding capacity, and non-vascular plant cover. Phototrophs common to anoxic soils (e.g., Rhodospirillaceae, Hyphomicrobiaceae) were abundant. Taxa within Euryarchaeota were recovered, suggesting methanogenesis potential. Exploration of the magnitude and temperature sensitivity of methane flux is needed in these seasonally anoxic soils whose dynamics could have significant implications for the global climate system.

  5. Alien roadside species more easily invade alpine than lowland plant communities in a subarctic mountain ecosystem.

    Directory of Open Access Journals (Sweden)

    Jonas J Lembrechts

    Full Text Available Effects of roads on plant communities are not well known in cold-climate mountain ecosystems, where road building and development are expected to increase in future decades. Knowledge of the sensitivity of mountain plant communities to disturbance by roads is however important for future conservation purposes. We investigate the effects of roads on species richness and composition, including the plant strategies that are most affected, along three elevational gradients in a subarctic mountain ecosystem. We also examine whether mountain roads promote the introduction and invasion of alien plant species from the lowlands to the alpine zone. Observations of plant community composition were made together with abiotic, biotic and anthropogenic factors in 60 T-shaped transects. Alpine plant communities reacted differently to road disturbances than their lowland counterparts. On high elevations, the roadside species composition was more similar to that of the local natural communities. Less competitive and ruderal species were present at high compared with lower elevation roadsides. While the effects of roads thus seem to be mitigated in the alpine environment for plant species in general, mountain plant communities are more invasible than lowland communities. More precisely, relatively more alien species present in the roadside were found to invade into the surrounding natural community at high compared to low elevations. We conclude that effects of roads and introduction of alien species in lowlands cannot simply be extrapolated to the alpine and subarctic environment.

  6. Alien roadside species more easily invade alpine than lowland plant communities in a subarctic mountain ecosystem.

    Science.gov (United States)

    Lembrechts, Jonas J; Milbau, Ann; Nijs, Ivan

    2014-01-01

    Effects of roads on plant communities are not well known in cold-climate mountain ecosystems, where road building and development are expected to increase in future decades. Knowledge of the sensitivity of mountain plant communities to disturbance by roads is however important for future conservation purposes. We investigate the effects of roads on species richness and composition, including the plant strategies that are most affected, along three elevational gradients in a subarctic mountain ecosystem. We also examine whether mountain roads promote the introduction and invasion of alien plant species from the lowlands to the alpine zone. Observations of plant community composition were made together with abiotic, biotic and anthropogenic factors in 60 T-shaped transects. Alpine plant communities reacted differently to road disturbances than their lowland counterparts. On high elevations, the roadside species composition was more similar to that of the local natural communities. Less competitive and ruderal species were present at high compared with lower elevation roadsides. While the effects of roads thus seem to be mitigated in the alpine environment for plant species in general, mountain plant communities are more invasible than lowland communities. More precisely, relatively more alien species present in the roadside were found to invade into the surrounding natural community at high compared to low elevations. We conclude that effects of roads and introduction of alien species in lowlands cannot simply be extrapolated to the alpine and subarctic environment.

  7. Evapotranspiration partitioning in the highest alpine meadow zones through in-situ chamber and dual stable water isotope approaches

    Science.gov (United States)

    Cui, J.; Tian, L.

    2017-12-01

    Understanding plant functionality within the water cycles of grassland ecosystems is crucial for obtaining both regional water balance and plant adaptability in the context of ongoing climate change. The transpiration to evapotranspiration ratio (T/ET) is an indicator of plant's contribution to ecosystem water cycle. In this study, we used high-frequency laser spectroscopy (L2130-i), three custom-built chambers, and eddy covariance techniques, to constrain the role played by plants in evapotranspiration over an alpine meadow ecosystem in the central Tibetan Plateau (TP). Three different sizes of chambers are used to direct measure the isotopic compositions in evapotranspiration (δET), evaporation (δE) and transpiration (δT). The consistent T/ET between δ18O and δD manifests that chamber and dual isotope tracers are robust methods to estimate T/ET in alpine meadow zone. Sensitivity analysis shows that the isotopic composition of evapotranspiration is the main contributor to, and the uncertainty source for, the T/ET estimate. The influence of meteorological and biotic factors on T/ET is also discussed. The results from this study indicate that plants play an important role in the water cycles of alpine meadow ecosystems despite the sparse distribution of plant cover. We also synthesized the published T/ET data over the entire TP region, and found a good relation between T/ET and leaf area index (LAI). Moreover, soil water content played some role in controlling T/ET beyond the LAI in arid/semiarid regions such as the TP. More than half of the TP is covered by grassland, but its low biomass and shallow rooting depth make it very vulnerable to climate change variables such as air temperature warming and variations in precipitation. Given the crucial role played by plants in an ecosystem's water cycle, any variations in grassland cover are likely to exert a critical impact on the regional hydrological cycle, and even the regional climate.

  8. Aortic Dissection Type A in Alpine Skiers

    Science.gov (United States)

    Schachner, Thomas; Fischler, Nikolaus; Dumfarth, Julia; Bonaros, Nikolaos; Krapf, Christoph; Schobersberger, Wolfgang; Grimm, Michael

    2013-01-01

    Patients and Methods. 140 patients with aortic dissection type A were admitted for cardiac surgery. Seventy-seven patients experienced their dissection in the winter season (from November to April). We analyzed cases of ascending aortic dissection associated with alpine skiing. Results. In 17 patients we found skiing-related aortic dissections. Skiers were taller (180 (172–200) cm versus 175 (157–191) cm, P = 0.008) and heavier (90 (68–125) kg versus 80 (45–110) kg, P = 0.002) than nonskiers. An extension of aortic dissection into the aortic arch, the descending thoracic aorta, and the abdominal aorta was found in 91%, 74%, and 69%, respectively, with no significant difference between skiers and nonskiers. Skiers experienced RCA ostium dissection requiring CABG in 17.6% while this was true for 5% of nonskiers (P = 0.086). Hospital mortality of skiers was 6% versus 13% in nonskiers (P = 0.399). The skiers live at an altitude of 170 (0–853) m.a.s.l. and experience their dissection at 1602 (1185–3105; P < 0.001) m.a.s.l. In 82% symptom start was during recreational skiing without any trauma. Conclusion. Skiing associated aortic dissection type A is usually nontraumatic. The persons affected live at low altitudes and practice an outdoor sport at unusual high altitude at cold temperatures. Postoperative outcome is good. PMID:23971024

  9. Modeling validation and control analysis for controlled temperature and humidity of air conditioning system.

    Science.gov (United States)

    Lee, Jing-Nang; Lin, Tsung-Min; Chen, Chien-Chih

    2014-01-01

    This study constructs an energy based model of thermal system for controlled temperature and humidity air conditioning system, and introduces the influence of the mass flow rate, heater and humidifier for proposed control criteria to achieve the controlled temperature and humidity of air conditioning system. Then, the reliability of proposed thermal system model is established by both MATLAB dynamic simulation and the literature validation. Finally, the PID control strategy is applied for controlling the air mass flow rate, humidifying capacity, and heating, capacity. The simulation results show that the temperature and humidity are stable at 541 sec, the disturbance of temperature is only 0.14 °C, 0006 kg(w)/kg(da) in steady-state error of humidity ratio, and the error rate is only 7.5%. The results prove that the proposed system is an effective controlled temperature and humidity of an air conditioning system.

  10. Modeling Validation and Control Analysis for Controlled Temperature and Humidity of Air Conditioning System

    Directory of Open Access Journals (Sweden)

    Jing-Nang Lee

    2014-01-01

    Full Text Available This study constructs an energy based model of thermal system for controlled temperature and humidity air conditioning system, and introduces the influence of the mass flow rate, heater and humidifier for proposed control criteria to achieve the controlled temperature and humidity of air conditioning system. Then, the reliability of proposed thermal system model is established by both MATLAB dynamic simulation and the literature validation. Finally, the PID control strategy is applied for controlling the air mass flow rate, humidifying capacity, and heating, capacity. The simulation results show that the temperature and humidity are stable at 541 sec, the disturbance of temperature is only 0.14°C, 0006 kgw/kgda in steady-state error of humidity ratio, and the error rate is only 7.5%. The results prove that the proposed system is an effective controlled temperature and humidity of an air conditioning system.

  11. Collembola at three alpine subarctic sites resistant to twenty years of experimental warming

    Czech Academy of Sciences Publication Activity Database

    Alatalo, J.M.; Jägerbrand, A.K.; Čuchta, Peter

    2015-01-01

    Roč. 5, December (2015), s. 18161 ISSN 2045-2322 Institutional support: RVO:60077344 Keywords : Collembola * alpine subarctic sites * experimental warming Subject RIV: EH - Ecology, Behaviour Impact factor: 5.228, year: 2015

  12. Alpine crossroads or origin of genetic diversity? Comparative phylogeography of two sympatric microgastropod species.

    Directory of Open Access Journals (Sweden)

    Alexander M Weigand

    Full Text Available The Alpine Region, constituting the Alps and the Dinaric Alps, has played a major role in the formation of current patterns of biodiversity either as a contact zone of postglacial expanding lineages or as the origin of genetic diversity. In our study, we tested these hypotheses for two widespread, sympatric microgastropod taxa--Carychium minimum O.F. Müller, 1774 and Carychium tridentatum (Risso, 1826 (Gastropoda, Eupulmonata, Carychiidae--by using COI sequence data and species potential distribution models analyzed in a statistical phylogeographical framework. Additionally, we examined disjunct transatlantic populations of those taxa from the Azores and North America. In general, both Carychium taxa demonstrate a genetic structure composed of several differentiated haplotype lineages most likely resulting from allopatric diversification in isolated refugial areas during the Pleistocene glacial periods. However, the genetic structure of Carychium minimum is more pronounced, which can be attributed to ecological constraints relating to habitat proximity to permanent bodies of water. For most of the Carychium lineages, the broader Alpine Region was identified as the likely origin of genetic diversity. Several lineages are endemic to the broader Alpine Region whereas a single lineage per species underwent a postglacial expansion to (recolonize previously unsuitable habitats, e.g. in Northern Europe. The source populations of those expanding lineages can be traced back to the Eastern and Western Alps. Consequently, we identify the Alpine Region as a significant 'hot-spot' for the formation of genetic diversity within European Carychium lineages. Passive dispersal via anthropogenic means best explains the presence of transatlantic European Carychium populations on the Azores and in North America. We conclude that passive (anthropogenic transport could mislead the interpretation of observed phylogeographical patterns in general.

  13. Growth and reproduction of the alpine grasshopper Miramella alpina feeding on CO2-enriched dwarf shrubs at treeline.

    Science.gov (United States)

    Asshoff, Roman; Hättenschwiler, Stephan

    2005-01-01

    The consequences for plant-insect interactions of atmospheric changes in alpine ecosystems are not well understood. Here, we tested the effects of elevated CO(2) on leaf quality in two dwarf shrub species (Vaccinium myrtillus and V. uliginosum) and the response of the alpine grasshopper (Miramella alpina) feeding on these plants in a field experiment at the alpine treeline (2,180 m a.s.l.) in Davos, Switzerland. Relative growth rates (RGR) of M. alpina nymphs were lower when they were feeding on V. myrtillus compared to V. uliginosum, and were affected by elevated CO(2) depending on plant species and nymph developmental stage. Changes in RGR correlated with CO(2)-induced changes in leaf water, nitrogen, and starch concentrations. Elevated CO(2) resulted in reduced female adult weight irrespective of plant species, and prolonged development time on V. uliginosum only, but there were no significant differences in nymphal mortality. Newly molted adults of M. alpina produced lighter eggs and less secretion (serving as egg protection) under elevated CO(2). When grasshoppers had a choice among four different plant species grown either under ambient or elevated CO(2), V. myrtillus and V. uliginosum consumption increased under elevated CO(2) in females while it decreased in males compared to ambient CO(2)-grown leaves. Our findings suggest that rising atmospheric CO(2) distinctly affects leaf chemistry in two important dwarf shrub species at the alpine treeline, leading to changes in feeding behavior, growth, and reproduction of the most important insect herbivore in this system. Changes in plant-grasshopper interactions might have significant long-term impacts on herbivore pressure, community dynamics and ecosystem stability in the alpine treeline ecotone.

  14. The GRETA project: the contribution of near-surface geothermal energy for the energetic self-sufficiency of Alpine regions

    Directory of Open Access Journals (Sweden)

    Alessandro Casasso

    2017-03-01

    Full Text Available The Alpine regions are deeply involved in the challenge set by climate change, which is a threat for their environment and for important economic activities such as tourism. The heating and cooling of buildings account for a major share of the total primary energy consumption in Europe, and hence the energy policies should focus on this sector to achieve the greenhouse gas reduction targets set by international agreements. Geothermal heat pump is one of the least carbon-intensive technologies for the heating and cooling of buildings. It exploits the heat stored within the ground, a local renewable energy source which is widely available across the Alpine territory. Nevertheless, it has been little considered by European policies and cooperation projects. GRETA (near-surface Geothermal REsources in the Territory of the Alpine space is a cooperation project funded by the EU INTERREG-Alpine Space program, aiming at demonstrating the potential of shallow geothermal energy and to foster its integration into energy planning instruments. It started in December 2015 and will last three years, involving 12 partners from Italy, France, Switzerland, Germany, Austria, and Slovenia. In this paper, the project is presented, along with the results of the first year of work.

  15. Les territoires fragiles dans la région alpine : une proposition de lecture entre innovation et marginalité

    Directory of Open Access Journals (Sweden)

    Federica Corrado

    2010-05-01

    Full Text Available Cet article propose une lecture et une description des territoires alpins fragiles, en jetant un autre regard, où le concept de fragilité est associé à celui de handicap, c’est-à-dire un autre regard sur l’identification des potentiels locaux spécifiques qui peuvent être encore activés à travers une force créatrice propre aux Alpes. La lecture est effectuée en fonction des territoires alpins fragiles qui font partie des provinces de Turin et Coni et se base sur une analyse empirique des initiatives qui enclenchent en quelque façon des dynamiques micro-territoriales de développement innovant.The paper proposes a reading and description of fragile Alpine areas that overturns the conventional standpoint, according to which marginality is often synonymous with handicap. The paper starts form a different point of view, able to recognize specific local potentialities that can still be activated with a specific creative effort. The reading regards fragile Alpine areas in the Provinces of Turin and Cuneo and is based on an empirical analysis of the actions underlying current micro-territorial innovative development trends.

  16. Development of safety analysis codes and experimental validation for a very high temperature gas-cooled reactor Final report

    Energy Technology Data Exchange (ETDEWEB)

    Chang Oh

    2006-03-01

    The very high-temperature gas-cooled reactor (VHTR) is envisioned as a single- or dual-purpose reactor for electricity and hydrogen generation. The concept has average coolant temperatures above 9000C and operational fuel temperatures above 12500C. The concept provides the potential for increased energy conversion efficiency and for high-temperature process heat application in addition to power generation. While all the High Temperature Gas Cooled Reactor (HTGR) concepts have sufficiently high temperature to support process heat applications, such as coal gasification, desalination or cogenerative processes, the VHTR’s higher temperatures allow broader applications, including thermochemical hydrogen production. However, the very high temperatures of this reactor concept can be detrimental to safety if a loss-of-coolant accident (LOCA) occurs. Following the loss of coolant through the break and coolant depressurization, air will enter the core through the break by molecular diffusion and ultimately by natural convection, leading to oxidation of the in-core graphite structure and fuel. The oxidation will accelerate heatup of the reactor core and the release of toxic gasses (CO and CO2) and fission products. Thus, without any effective countermeasures, a pipe break may lead to significant fuel damage and fission product release. Prior to the start of this Korean/United States collaboration, no computer codes were available that had been sufficiently developed and validated to reliably simulate a LOCA in the VHTR. Therefore, we have worked for the past three years on developing and validating advanced computational methods for simulating LOCAs in a VHTR. Research Objectives As described above, a pipe break may lead to significant fuel damage and fission product release in the VHTR. The objectives of this Korean/United States collaboration were to develop and validate advanced computational methods for VHTR safety analysis. The methods that have been developed are now

  17. Development of safety analysis codes and experimental validation for a very high temperature gas-cooled reactor Final report

    International Nuclear Information System (INIS)

    Chang Oh

    2006-01-01

    The very high-temperature gas-cooled reactor (VHTR) is envisioned as a single- or dual-purpose reactor for electricity and hydrogen generation. The concept has average coolant temperatures above 900 C and operational fuel temperatures above 1250 C. The concept provides the potential for increased energy conversion efficiency and for high-temperature process heat application in addition to power generation. While all the High Temperature Gas Cooled Reactor (HTGR) concepts have sufficiently high temperature to support process heat applications, such as coal gasification, desalination or cogenerative processes, the VHTR's higher temperatures allow broader applications, including thermochemical hydrogen production. However, the very high temperatures of this reactor concept can be detrimental to safety if a loss-of-coolant accident (LOCA) occurs. Following the loss of coolant through the break and coolant depressurization, air will enter the core through the break by molecular diffusion and ultimately by natural convection, leading to oxidation of the in-core graphite structure and fuel. The oxidation will accelerate heatup of the reactor core and the release of toxic gases (CO and CO2) and fission products. Thus, without any effective countermeasures, a pipe break may lead to significant fuel damage and fission product release. Prior to the start of this Korean/United States collaboration, no computer codes were available that had been sufficiently developed and validated to reliably simulate a LOCA in the VHTR. Therefore, we have worked for the past three years on developing and validating advanced computational methods for simulating LOCAs in a VHTR. Research Objectives As described above, a pipe break may lead to significant fuel damage and fission product release in the VHTR. The objectives of this Korean/United States collaboration were to develop and validate advanced computational methods for VHTR safety analysis. The methods that have been developed are now

  18. Dating the past 7000 years of major earthquakes on the Alpine Fault, New Zealand

    International Nuclear Information System (INIS)

    Clark, KJ.; Biasi, G.

    2009-01-01

    The Alpine Fault, New Zealand, is a major plate boundary fault that accommodates two thirds of the motion between the Australian and Pacific plates. The Hokuri Stream locality at the southern end of the Alpine Fault has the potential to contain a long record of earthquakes. The field component of this study involved the description, measurement and sampling of multiple river bank outcrops of the Hokuri sedimentary sequence. Sampling was undertaken by two approaches: discrete sediment sampling and continuous push-core sampling. Radiocarbon samples were processed at the Rafter Radiocarbon Laboratory, New Zealand. 123 samples were dated and the most commonly dated organic fractions were individual leaves, reeds, and seeds. 15 refs., 6 figs.

  19. The evolution of dwarf shrubs in alpine environments: a case study of Alchemilla in Africa.

    Science.gov (United States)

    Gehrke, Berit; Kandziora, Martha; Pirie, Michael D

    2016-01-01

    Alpine and arctic environments worldwide, including high mountains, are dominated by short-stature woody plants (dwarf shrubs). This conspicuous life form asserts considerable influence on local environmental conditions above the treeline, creating its own microhabitat. This study reconstructs the evolution of dwarf shrubs in Alchemilla in the African tropical alpine environment, where they represent one of the largest clades and are among the most common and abundant plants. Different phylogenetic inference methods were used with plastid and nuclear DNA sequence markers, molecular dating (BEAST and RelTime), analyses of diversification rate shifts (MEDUSA and BAMM) and ancestral character and area reconstructions (Mesquite). It is inferred that African Alchemilla species originated following long-distance dispersal to tropical East Africa, but that the evolution of dwarf shrubs occurred in Ethiopia and in tropical East Africa independently. Establishing a timeframe is challenging given inconsistencies in age estimates, but it seems likely that they originated in the Pleistocene, or at the earliest in the late Miocene. The adaptation to alpine-like environments in the form of dwarf shrubs has apparently not led to enhanced diversification rates. Ancestral reconstructions indicate reversals in Alchemilla from plants with a woody base to entirely herbaceous forms, a transition that is rarely reported in angiosperms. Alchemilla is a clear example of in situ tropical alpine speciation. The dwarf shrub life form typical of African Alchemilla has evolved twice independently, further indicating its selective advantage in these harsh environments. However, it has not influenced diversification, which, although recent, was not rapid. © The Author 2015. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  20. Alpine treeline of western North America: linking organism-to-landscape dynamics.

    Science.gov (United States)

    George P. Malanson; David R. Butler; Daniel B. Fagre; Stephen J. Walsh; Diana F. Tomback; Lori D. Daniels; Lynn M. Resler; William K. Smith; Daniel J. Weiss; David L. Peterson; Andrew G. Bunn; Christopher A. Hiemstra; Daniel Liptzin; Patrick S. Bourgeron; Zehao Shen; Constance I. Millar

    2007-01-01

    Although the ecological dynamics of the alpine treeline ecotone are influenced by climate, it is an imperfect indicator of climate change. Mechanistic processes that shape the ecotone—seed rain, seed germination, seedling establishment and subsequent tree growth form, or, conversely tree diebackdepend on microsite patterns. Growth forms affect wind...

  1. Study on Viscoelastic Deformation Monitoring Index of an RCC Gravity Dam in an Alpine Region Using Orthogonal Test Design

    Directory of Open Access Journals (Sweden)

    Yaoying Huang

    2018-01-01

    Full Text Available The main objective of this study is to present a method of determining viscoelastic deformation monitoring index of a Roller-compacted concrete (RCC gravity dam in an alpine region. By focusing on a modified deformation monitoring model considering frost heave and back analyzed mechanical parameters of the dam, the working state of viscoelasticity for the dam is illustrated followed by an investigation and designation of adverse load cases using orthogonal test method. Water pressure component is then calculated by finite element method, while temperature, time effect, and frost heave components are obtained through deformation statistical model considering frost heave. The viscoelastic deformation monitoring index is eventually determined by small probability and maximum entropy methods. The results show that (a with the abnormal probability 1% the dam deformation monitoring index for small probability and maximum entropy methods is 23.703 mm and 22.981 mm, respectively; thus the maximum measured displacement of the dam is less than deformation monitoring index, which indicates that the dam is currently in a state of safety operation and (b the obtained deformation monitoring index using orthogonal test method is more accurate due to the full consideration of more random factors; the method gained from this study will likely be of use to diagnose the working state for those RCC dams in alpine regions.

  2. Modelling mass movement susceptibility for Alpine infrastructure in the Karavank Mountains (Austria/Slovenia)

    Science.gov (United States)

    Bauer, C.; Kern, K.; Lieb, G. K.

    2012-12-01

    that an individual falling rock can reach any place in the area situated inside a cone of given aperture. In contrast, for modelling debris flows, a multiple flow directions method was used to calculate potential pathways and velocities. The method is implemented as a random walk in conjunction with a Monte Carlo approach (using 1000 iterations). Both models were calibrated with field observation data (e.g. GPS measurements) and in addition, model results were validated with high resolution aerial photographs. By overlaying the modelling results with road and trail network information, susceptibility maps were created. These maps clearly show that large parts of the existing Alpine infrastructure are potentially affected by the modelled processes. Therefore, the resulting susceptibility maps provide as a useful tool to indicate areas prone to rockfall and debris flow as well as for the maintenance of the road and trail networks.

  3. A Retrospective Analysis of Concurrent Pathology in ACL-Reconstructed Knees of Elite Alpine Ski Racers

    DEFF Research Database (Denmark)

    Jordan, Matthew J; Doyle-Baker, Patricia; Heard, Mark

    2017-01-01

    /chondral surgery, 60% of meniscal tears and 80% of chondral lesions had worsened since the time of primary ACLR. CONCLUSION: Concurrent injury was common in this group of elite ski racers. Primary ACL tears were typically accompanied by lateral compartment chondral lesions and complex meniscal tears that worsened...... over time. ACL/MCL tears were the most common multiligament injury pattern.......BACKGROUND: Anterior cruciate ligament (ACL) tear is the most frequent injury in alpine ski racing, and there is a high prevalence of ACL reinjury. Limited data exist on the concurrent pathology with primary ACL tears in elite alpine ski racers and the magnitude of injury progression after primary...

  4. New Constraints for Tectono-Thermal Alpine Evolution of the Pyrenees: Combining Zircon Fission-Track and (U-Th)/He Analyses with Raman Spectrometry and In-Situ K-Ar Geochronology

    Science.gov (United States)

    Waldner, M.; Bellahsen, N.; Mouthereau, F.; Pik, R.; Bernet, M.; Scaillet, S.; Rosenberg, C.

    2017-12-01

    The pyrenean range was formed by the convergence of European and Iberian plates following the inversion of the Mesozoic rifting in the north of Pyrenees. In the Axial Zone, the collision caused an antiformal nappe-stacking of tectonic units. Recent studies pointed out the importance of pre-collision structural and thermal inheritance that may play a major role for orogeny such as: 1) Paleozoic Variscan inheritance; 2) Mesozoic rift-related high geothermal gradients, which are maintained during the onset of convergence in the North Pyrenean Zone. From a mineralogical point of view, pre-collision feldspars have been destabilized and influenced the development of alpine phyllonite in brittle-ductile conditions which suggests a weak crustal behavior during the formation of the orogenic wedge. Our aim is to get a better understanding of alpine deformation and exhumation by coupling different thermochronological, geochronological and thermometric methods. We document the thermal evolution of each tectonic unit by using low-temperature thermochronometers (Zircon Fission Tracks, U-Th/He on zircons including laser ablation profiles). Our data on vertical profiles combined to existing dataset on apatite allows to model alpine exhumation across the Axial zone. Structural observations through alpine thrusts coupled to geochronology (in situ K/Ar on phengites), Raman and chlorite-phengite thermo(baro)metry provide new key data to unravel the alpine evolution of the Pyrenees. According to preliminary ZFT results on granite massifs in the central part of Pyrenean Axial zone (near ECORS profile), exhumation ages potentially indicates a migration of exhumation towards the south. Exhumation ages of the northern massifs seems to have preserved the North Pyrenean Cretaceous rift evolution. Further south, the onset of exhumation is as old as Paleocene, which precedes the Eocene ages of the literature. The low burial estimated in the northern massifs may indicate a high thermal gradient

  5. Impact of the Chernobyl fallout in the alpine environment

    International Nuclear Information System (INIS)

    Gastberger, M.; Lettner, H.; Hofmann, W.; Pohl-Rueling, J.; Steinhaeusler, N.F.; Hubmer, A.

    1997-01-01

    In Austria the alpine regions received the highest fallout contamination, showing a very inhomogeneous spatial distribution of the surface deposition. About half of the national territory is within alpine regions, which are very different in times of underlying bedrock and soil characteristic. Since this is the controlling factor for the radionuclide uptake of the vegetation, it is crucial for the long-term effects of radioactive fallout. Different studies have been carried out in the Province of Salzburg (area: 7154 km 2 ) over the past ten years, addressing a broad spectrum of issues, such as: measurement of the spatial distribution of the fallout, research in monitoring techniques comparison of theoretical calculations with actual in vivo-measurements of nuclide uptake by man for different population groups, and the investigation of biological effects. When considering the radioecological effects of the Chernobyl fallout a distinction has to be made between the short-term effects immediately following the fallout and the long-term effects. While the short term effects are controlled by the physical characteristics of the fallout, similar for the whole region, the long-term effects are more determined by the radioecological properties of the environments affected which are much more variable than the fallout-characteristics

  6. Estimation of Alpine Skier Posture Using Machine Learning Techniques

    Directory of Open Access Journals (Sweden)

    Bojan Nemec

    2014-10-01

    Full Text Available High precision Global Navigation Satellite System (GNSS measurements are becoming more and more popular in alpine skiing due to the relatively undemanding setup and excellent performance. However, GNSS provides only single-point measurements that are defined with the antenna placed typically behind the skier’s neck. A key issue is how to estimate other more relevant parameters of the skier’s body, like the center of mass (COM and ski trajectories. Previously, these parameters were estimated by modeling the skier’s body with an inverted-pendulum model that oversimplified the skier’s body. In this study, we propose two machine learning methods that overcome this shortcoming and estimate COM and skis trajectories based on a more faithful approximation of the skier’s body with nine degrees-of-freedom. The first method utilizes a well-established approach of artificial neural networks, while the second method is based on a state-of-the-art statistical generalization method. Both methods were evaluated using the reference measurements obtained on a typical giant slalom course and compared with the inverted-pendulum method. Our results outperform the results of commonly used inverted-pendulum methods and demonstrate the applicability of machine learning techniques in biomechanical measurements of alpine skiing.

  7. Geochemistry and petrography of the MacAlpine Hills lunar meteorites

    Science.gov (United States)

    Lindstrom, Marilyn M.; Mckay, David S.; Wentworth, Susan J.; Martinez, Rene R.; Mittlefehldt, David W.; Wang, Ming-Sheng; Lipschutz, Michael E.

    1991-01-01

    MacAlpine Hills 88104 and 88105, anorthositic lunar meteorites recovered form the same area in Antartica, are characterized. Petrographic studies show that MAC88104/5 is a polymict breccia dominated by impact melt clasts. It is better classified as a fragmental breccia than a regolith breccia. The bulk composition is ferroan and highly aluminous (Al2O3-28 percent).

  8. A review of reactor physics uncertainties and validation requirements for the modular high-temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    Baxter, A.M.; Lane, R.K.; Hettergott, E.; Lefler, W.

    1991-01-01

    The important, safety-related, physics parameters for the low-enriched Modular High-Temperature gas-Cooled Reactor (MHTGR) such as control rod worth, shutdown margins, temperature coefficients, and reactivity worths, are considered, and estimates are presented of the uncertainties in the calculated values of these parameters. The basis for the uncertainty estimate in several of the important calculated parameters is reviewed, including the available experimental data used in obtaining these estimates. Based on this review, the additional experimental data needed to complete the validation of the methods used to calculate these parameters is presented. The role of benchmark calculations in validating MHTGR reactor physics data is also considered. (author). 10 refs, 5 figs, 3 tabs

  9. Analytical solutions for recession analyses of sloping aquifers - applicability on relict rock glaciers in alpine catchments

    Science.gov (United States)

    Pauritsch, Marcus; Birk, Steffen; Hergarten, Stefan; Kellerer-Pirklbauer, Andreas; Winkler, Gerfried

    2014-05-01

    Rock glaciers as aquifer systems in alpine catchments may strongly influence the hydrological characteristics of these catchments. Thus, they have a high impact on the ecosystem and potential natural hazards such as for example debris flow. Therefore, knowledge of the hydrodynamic processes, internal structure and properties of these aquifers is important for resource management and risk assessment. The investigation of such aquifers often turns out to be expensive and technically complicated because of their strongly limited accessibility. Analytical solutions of discharge recession provide a quick and easy way to estimate aquifer parameters. However, due to simplifying assumptions the validity of the interpretation is often questionable. In this study we compared results of an analytical solution of discharge recessions with results based on a numerical model. This was done in order to analyse the range of uncertainties and the applicability of the analytical method in alpine catchment areas. The research area is a 0.76 km² large catchment in the Seckauer Tauern Range, Austria. The dominant aquifer in this catchment is a rock glacier, namely the Schöneben Rock Glacier. This relict rock glacier (i.e. containing no permafrost at present) covers an area of 0.11 km² and is drained by one spring at the rock glacier front. The rock glacier consists predominantly of gneissic sediments (mainly coarse-grained, blocky at the surface) and extends from 1720 to 1905 m a.s.l.. Discharge of the rock glacier spring is automatically measured since 2002. Electric conductivity and water temperature is monitored since 2008. An automatic weather station was installed in 2011 in the central part of the catchment. Additionally data of geophysical surveys (refraction seismic and ground penetrating radar) have been used to analyse the base slope and inner structure of the rock glacier. The measured data are incorporated into a numerical model implemented in MODFLOW. The numerical

  10. Growth of Gypsophila paniculata According to the Pruning Time and Ridge Position in Sub-alpine Area

    International Nuclear Information System (INIS)

    Cheong, D.C.; Lim, H.C.; Song, Y.J.; Park, H.B.

    2008-01-01

    This study was carried out to investigate the growth of Gypsophila paniculata affected by pruning time (July 10, July 18, and July 25) and ridge position (middle or window side) under south-north oriented plastic house in sub-alpine area. The average night temperature was similar between the two ridges, but the average day temperature and soil temperature were higher at the middle ridge; particularly, there was distinct difference after late October. Also the accumulative solar radiation was higher at the middle ridge than the window side ridge owing to the shading by neighboring plastic house and the structure of plastic house. The root activity, photosynthetic rate and transpiration rate of plants surveyed in late October were inclined to be more increased at the middle than the window side ridge. The flowering traits at the pruning time of July 10 and July 18 were similar between the two ridges, but the flower malformation rate was higher at the middle ridge. On the other hand, in case of the pruning time of July 25, the blooming was advanced by 13 days, and the flowering traits such as flower stalk length and branch number were better; also, the flower malformation and rosette formation rate decreased at the middle ridge, because of its higher air and soil temperature and the accumulative solar radiation

  11. Validation of SCALE for High Temperature Gas-Cooled Reactors Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ilas, Germina [ORNL; Ilas, Dan [ORNL; Kelly, Ryan P [ORNL; Sunny, Eva E [ORNL

    2012-08-01

    This report documents verification and validation studies carried out to assess the performance of the SCALE code system methods and nuclear data for modeling and analysis of High Temperature Gas-Cooled Reactor (HTGR) configurations. Validation data were available from the International Handbook of Evaluated Reactor Physics Benchmark Experiments (IRPhE Handbook), prepared by the International Reactor Physics Experiment Evaluation Project, for two different HTGR designs: prismatic and pebble bed. SCALE models have been developed for HTTR, a prismatic fuel design reactor operated in Japan and HTR-10, a pebble bed reactor operated in China. The models were based on benchmark specifications included in the 2009, 2010, and 2011 releases of the IRPhE Handbook. SCALE models for the HTR-PROTEUS pebble bed configuration at the PROTEUS critical facility in Switzerland have also been developed, based on benchmark specifications included in a 2009 IRPhE draft benchmark. The development of the SCALE models has involved a series of investigations to identify particular issues associated with modeling the physics of HTGRs and to understand and quantify the effect of particular modeling assumptions on calculation-to-experiment comparisons.

  12. Experimental soil warming shifts the fungal community composition at the alpine treeline.

    Science.gov (United States)

    Solly, Emily F; Lindahl, Björn D; Dawes, Melissa A; Peter, Martina; Souza, Rômulo C; Rixen, Christian; Hagedorn, Frank

    2017-07-01

    Increased CO 2 emissions and global warming may alter the composition of fungal communities through the removal of temperature limitation in the plant-soil system, faster nitrogen (N) cycling and changes in the carbon (C) allocation of host plants to the rhizosphere. At a Swiss treeline featuring Larix decidua and Pinus uncinata, the effects of multiple years of CO 2 enrichment and experimental soil warming on the fungal community composition in the organic horizons were analysed using 454-pyrosequencing of ITS2 amplicons. Sporocarp production and colonization of ectomycorrhizal root tips were investigated in parallel. Fungal community composition was significantly altered by soil warming, whereas CO 2 enrichment had little effect. Tree species influenced fungal community composition and the magnitude of the warming responses. The abundance of ectomycorrhizal fungal taxa was positively correlated with N availability, and ectomycorrhizal taxa specialized for conditions of high N availability proliferated with warming, corresponding to considerable increases in inorganic N in warmed soils. Traits related to N utilization are important in determining the responses of ectomycorrhizal fungi to warming in N-poor cold ecosystems. Shifts in the overall fungal community composition in response to higher temperatures may alter fungal-driven processes with potential feedbacks on ecosystem N cycling and C storage at the alpine treeline. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  13. Bacteria and pelagic food webs in Pristine alpine lakes (Retezat Mountains, Romania)

    Czech Academy of Sciences Publication Activity Database

    Straškrábová, Viera; Cogalniceanu, D.; Nedoma, Jiří; Parpala, L.; Postolache, C.; Tudorancea, C.; Vadineanu, A.; Valcu, C. M.; Zinevici, V.

    2006-01-01

    Roč. 3, - (2006), s. 1-10 ISSN 1841-7051 Grant - others:EC(XE) EVK1-CT-1999-00032; EC(XE) GOCE-CT-2003-505298 Institutional research plan: CEZ:AV0Z60170517 Keywords : alpine lakes * pelagic bacteria * chlorophyll * zooplankton Subject RIV: EH - Ecology, Behaviour

  14. PV plants for Alpine huts: Installation and operating experience at seven ENEL plants

    International Nuclear Information System (INIS)

    Belli, G.; Iliceto, A.; Previ, A.

    1988-01-01

    The problem of supplying electric power to isolated users far from the electricity distribution grid is one of general interest. Such consumers are nowadays generally supplied with electricity produced by small diesel generator-sets, and only recently have photovoltaic arrays and wind-turbines offered an alternative to the internal combustion engine. ENEL, as a State-owned electricity utility, is interested in the development of this particular application of renewable energy sources. Enlarging a low-voltage distribution network to connect consumers whose power requirements are extremely low (about 1000 kWh/year) may, in certain conditions, be uneconomical, both for the utility, which has to absorb most of the expense involved in construction and maintenance, and for the consumer himself. The paper reports the design criteria, the tests and the problems encountered in electrifying seven alpine huts belonging to CAI (Italian Alpine Club)

  15. The Alpine-Carpathian-Dinaridic orogenic system: correlation and evolution of tectonic units

    NARCIS (Netherlands)

    Schmid, S.M.; Bernoulli, D.; Fügenschuh, B.; Matenco, L.C.; Schefer, S.; Schuster, R.; Tischler, M.; Ustaszewski, K.

    2008-01-01

    A correlation of tectonic units of the Alpine-Carpathian-Dinaridic system of orogens, including the substrate of the Pannonian and Transylvanian basins, is presented in the form of a map. Combined with a series of crustal-scale cross sections this correlation of tectonic units yields a clearer

  16. The validity, reliability, and utility of the iButton® for measurement of body temperature circadian rhythms in sleep/wake research.

    Science.gov (United States)

    Hasselberg, Michael J; McMahon, James; Parker, Kathy

    2013-01-01

    Changes in core body temperature due to heat transfer through the skin have a major influence on sleep regulation. Traditional measures of skin temperature are often complicated by extensive wiring and are not practical for use in normal living conditions. This review describes studies examining the reliability, validity and utility of the iButton®, a wireless peripheral thermometry device, in sleep/wake research. A review was conducted of English language literature on the iButton as a measure of circadian body temperature rhythms associated with the sleep/wake cycle. Seven studies of the iButtton as a measure of human body temperature were included. The iButton was found to be a reliable and valid measure of body temperature. Its application to human skin was shown to be comfortable and tolerable with no significant adverse reactions. Distal skin temperatures were negatively correlated with sleep/wake activity, and the temperature gradient between the distal and proximal skin (DPG) was identified as an accurate physiological correlate of sleep propensity. Methodological issues included site of data logger placement, temperature masking factors, and temperature data analysis. The iButton is an inexpensive, wireless data logger that can be used to obtain a valid measurement of human skin temperature. It is a practical alternative to traditional measures of circadian rhythms in sleep/wake research. Further research is needed to determine the utility of the iButton in vulnerable populations, including those with neurodegenerative disorders and memory impairment and pediatric populations. Copyright © 2011 Elsevier B.V. All rights reserved.

  17. Nitrogen-15 natural abundance of different soil N pools as a tool for assessing N transformation processes in alpine soils

    Science.gov (United States)

    Makarov, Mikhail; Malysheva, Tatiana; Tiunov, Alexei; Kadulin, Maxim; Maslov, Mikhail

    2017-04-01

    Nitrogen availability, net N mineralization, nitrification and 15N natural abundance of total soil N and small soil N pools (N-NH4+, N-NO3-, DON and microbial biomass N) were studied in a toposequence of alpine ecosystems in the Northern Caucasus. The toposequence was represented by (1) low productive alpine lichen heath (ALH) of the wind-exposed ridge and upper slope; (2) more productive Festuca varia grassland (FG) of the middle slope; (3) most productive Geranium gymnocaulon/Hedysarum caucasicum meadow (GHM) of the lower slope and (4) low productive snow bed community (SBC) of the slope bottom. Nitrogen transformation in the alpine soils produces distinct N pools with different 15N enrichment: DON/microbial biomass N > total N > N-NH4+ > N-NO3-. Grassland and meadow soils of the middle part of the toposequence are characterized by higher nitrogen transformation activities and higher δ15 values of total N and N-NH4+. Field incubation of alpine soils increased δ15N of N-NH4+ from -2.6 - +2.0‰ to +6.1 - +15.7‰. The N-NO3-produced in the incubation experiment had extremely low (negative) δ15N values (up to -14‰). We found a positive correlation between δ15N of different soil N pools (total N, N-NH4+ and N-NO3-) and net N mineralization and nitrification. Nitrification controls the formation of 15N enriched N-NH4+ pool while N mineralization probably had an important role in regulation of 15N enrichment of DON pool in alpine soils. Overall, our results support the hypothesis that 15N is more enriched in N-rich and more depleted in N-poor ecosystems. We conclude that δ15N values of different soil N pools could be a good indicator of microbial N transformation in alpine soils of the Northern Caucasus. Acknowledgement: This study was supported by Russian Science Foundation (16-14-10208).

  18. Characterising hydrological behaviour of springs draining different alpine formations

    Science.gov (United States)

    Volze, N.; Smoorenburg, M.; Kienzler, P.; Naef, F.; Rabenstein, L.; Kinzelbach, W.

    2012-04-01

    The project SACflood (Susceptibility of alpine catchment flood runoff to changes in meteorological boundary conditions) concentrates on alpine areas and wants to identify catchments that show a damped reaction to runoff but may react unexpectedly strong to increased precipitation as observed in 2005 in the Schächen. The catchment showed a delayed and damped behaviour for smaller precipitation events but reacted with strongly increased discharge when a threshold amount of rainfall was reached, causing a flood with high damages. This is attributed to the complex interaction of storage and drainage mechanisms that are not yet well enough understood. Typical alpine geomorphic formations are identified that are likely to be associated with large storages which could considerably delay runoff reaction but still contribute to flow within a timescale relevant for flood formation. From these geomorphic formations deep drainage is measured as outflow from several springs. In addition natural tracers are measured in the springs. On a steep hill slope, associated to one of the observed springs, ground water levels are observed. Geoelectric profiles were recorded to depict the structure of the underground. Discharge measurements from the springs show remarkable differences between the sites. After long dry periods certain springs do not react to rainfall immediately but need considerable amounts of rain to increase discharge. Even steep slopes as well as large talus areas can substantially delay runoff. Observations of the groundwater levels reveal an unexpected picture of the underground. The water table is not as often assumed above the bedrock but at a depth of several meters within the highly fractured bedrock material. This can result in a much higher storage capacity of such slopes despite the steepness of the surface. On the basis of the results from field work conceptual ideas are developed. The influence of parameters such as the depth of the unsaturated zone and the

  19. Enzymology under global change: organic nitrogen turnover in alpine and sub-Arctic soils

    NARCIS (Netherlands)

    Weedon, J.T.; Aerts, R.; Kowalchuk, G.A.; van Bodegom, P.M.

    2011-01-01

    Understanding global change impacts on the globally important carbon storage in alpine, Arctic and sub-Arctic soils requires knowledge of the mechanisms underlying the balance between plant primary productivity and decomposition. Given that nitrogen availability limits both processes, understanding

  20. Enzymology under global change: organic nitrogen turnover in alpine and sub-Arctic soils.

    NARCIS (Netherlands)

    Weedon, J.T.; Aerts, R.; Kowalchuk, G.A.; van Bodegom, P.M.

    2011-01-01

    Understanding global change impacts on the globally important carbon storage in alpine, Arctic and sub-Arctic soils requires knowledge of the mechanisms underlying the balance between plant primary productivity and decomposition. Given that nitrogen availability limits both processes, understanding

  1. Time-lapse ERT and DTS for seasonal and short-term monitoring of an alpine river hyporheic zone

    Science.gov (United States)

    Boaga, Jacopo; Laura, Busato; Mariateresa, Perri; Giorgio, Cassiani

    2016-04-01

    The hyporheic zone (HZ) is the area located beneath and adjacent to rivers and streams, where the interactions between surface water and groundwater take place. This complex physical domain allows the transport of several substances from a stream to the unconfined aquifer below, and vice versa, thus playing a fundamental role in the river ecosystem. The importance of the hyporheic zone makes its characterization a goal shared by several disciplines, which range from applied geophysics to biogeochemistry, from hydraulics to ecology. The frontier field of HZ characterization stays in applied non-invasive methodologies as Electrical Resistivity Tomography - ERT - and Distributed Temperature Sensing - DTS. ERT is commonly applied in cross-well configuration or with a superficial electrodes deployment while DTS is used in hydro-geophysics in the last decade, revealing a wide applicability to the typical issues of this field of study. DTS for hydro-geophysics studies is based on Raman scattering and employs heat as tracer and uses a fiber-optic cable to acquire temperature values. We applied both techniques for an alpine river case studies located in Val di Sole, TN, Italy. The collected measurements allow high-resolution characterization of the hyporheic zone, overcoming the critical problem of invasive measurements under riverbeds. In this work, we present the preliminary results regarding the characterization of the hyporheic zone of the alpine river obtained combining ERT and DTS time-lapse measurements. The data collection benefits from an innovative instrumentation deployment, which consists of both an ERT multicore cable and a DTS fiber-optic located in two separated boreholes drilled 5m under the watercourse and perpendicular to it. In particular we present the first year monitoring results and a short time-lapse monitoring experiment conducted during summer 2015. The site and the results here described are part of the EU FP7 CLIMB (Climate Induced Changes on the

  2. Close-Range Sensing Techniques in Alpine Terrain

    Science.gov (United States)

    Rutzinger, M.; Höfle, B.; Lindenbergh, R.; Oude Elberink, S.; Pirotti, F.; Sailer, R.; Scaioni, M.; Stötter, J.; Wujanz, D.

    2016-06-01

    Early career researchers such as PhD students are a main driving force of scientific research and are for a large part responsible for research innovation. They work on specialized topics within focused research groups that have a limited number of members, but might also have limited capacity in terms of lab equipment. This poses a serious challenge for educating such students as it is difficult to group a sufficient number of them to enable efficient knowledge transfer. To overcome this problem, the Innsbruck Summer School of Alpine Research 2015 on close-range sensing techniques in Alpine terrain was organized in Obergurgl, Austria, by an international team from several universities and research centres. Of the applicants a group of 40 early career researchers were selected with interest in about ten types of specialized surveying tools, i.e. laser scanners, a remotely piloted aircraft system, a thermal camera, a backpack mobile mapping system and different grade photogrammetric equipment. During the one-week summer school, students were grouped according to their personal preference to work with one such type of equipment under guidance of an expert lecturer. All students were required to capture and process field data on a mountain-related theme like landslides or rock glaciers. The work on the assignments lasted the whole week but was interspersed with lectures on selected topics by invited experts. The final task of the summer school participants was to present and defend their results to their peers, lecturers and other colleagues in a symposium-like setting. Here we present the framework and content of this summer school which brought together scientists from close-range sensing and environmental and geosciences.

  3. Forgotten Edible alpine plants in the canton of Valais

    OpenAIRE

    Abbet, Christian Paul

    2014-01-01

    Tradition possesses plenty of forgotten wild edible plants and may help researchers in the quest for new food varieties. Swiss alpine cantons, especially the canton of Valais, have still had a viable tradition. However, societal changes and extensive urbanization have caused this knowledge to be confined to lateral valleys. This contribution aimed to document wild edible plants which were collected in the canton of Valais. 38 informants originating from four different valleys of the canton (V...

  4. What are the most crucial soil factors for predicting the distribution of alpine plant species?

    Science.gov (United States)

    Buri, A.; Pinto-Figueroa, E.; Yashiro, E.; Guisan, A.

    2017-12-01

    Nowadays the use of species distribution models (SDM) is common to predict in space and time the distribution of organisms living in the critical zone. The realized environmental niche concept behind the development of SDM imply that many environmental factors must be accounted for simultaneously to predict species distributions. Climatic and topographic factors are often primary included, whereas soil factors are frequently neglected, mainly due to the paucity of soil information available spatially and temporally. Furthermore, among existing studies, most included soil pH only, or few other soil parameters. In this study we aimed at identifying what are the most crucial soil factors for explaining alpine plant distributions and, among those identified, which ones further improve the predictive power of plant SDMs. To test the relative importance of the soil factors, we performed plant SDMs using as predictors 52 measured soil properties of various types such as organic/inorganic compounds, chemical/physical properties, water related variables, mineral composition or grain size distribution. We added them separately to a standard set of topo-climatic predictors (temperature, slope, solar radiation and topographic position). We used ensemble forecasting techniques combining together several predictive algorithms to model the distribution of 116 plant species over 250 sites in the Swiss Alps. We recorded the variable importance for each model and compared the quality of the models including different soil proprieties (one at a time) as predictors to models having only topo-climatic variables as predictors. Results show that 46% of the soil proprieties tested become the second most important variable, after air temperature, to explain spatial distribution of alpine plants species. Moreover, we also assessed that addition of certain soil factors, such as bulk soil water density, could improve over 80% the quality of some plant species models. We confirm that soil p

  5. The Relationship among Leg Strength, Leg Power and Alpine Skiing Success.

    Science.gov (United States)

    Gettman, Larry R.; Huckel, Jack R.

    The purpose of this study was to relate leg strength and power to alpine skiing success as measured by FIS points. Isometric leg strength was represented by the knee extension test described by Clarke. Leg power was measured by the vertical jump test and the Margaria-Kalamen stair run. Results in the strength and power tests were correlated with…

  6. A probabilistic method for streamflow projection and associated uncertainty analysis in a data sparse alpine region

    Science.gov (United States)

    Ren, Weiwei; Yang, Tao; Shi, Pengfei; Xu, Chong-yu; Zhang, Ke; Zhou, Xudong; Shao, Quanxi; Ciais, Philippe

    2018-06-01

    Climate change imposes profound influence on regional hydrological cycle and water security in many alpine regions worldwide. Investigating regional climate impacts using watershed scale hydrological models requires a large number of input data such as topography, meteorological and hydrological data. However, data scarcity in alpine regions seriously restricts evaluation of climate change impacts on water cycle using conventional approaches based on global or regional climate models, statistical downscaling methods and hydrological models. Therefore, this study is dedicated to development of a probabilistic model to replace the conventional approaches for streamflow projection. The probabilistic model was built upon an advanced Bayesian Neural Network (BNN) approach directly fed by the large-scale climate predictor variables and tested in a typical data sparse alpine region, the Kaidu River basin in Central Asia. Results show that BNN model performs better than the general methods across a number of statistical measures. The BNN method with flexible model structures by active indicator functions, which reduce the dependence on the initial specification for the input variables and the number of hidden units, can work well in a data limited region. Moreover, it can provide more reliable streamflow projections with a robust generalization ability. Forced by the latest bias-corrected GCM scenarios, streamflow projections for the 21st century under three RCP emission pathways were constructed and analyzed. Briefly, the proposed probabilistic projection approach could improve runoff predictive ability over conventional methods and provide better support to water resources planning and management under data limited conditions as well as enable a facilitated climate change impact analysis on runoff and water resources in alpine regions worldwide.

  7. Feed selection and radiocaesium intake by reindeer, sheep and goats grazing alpine summer habitats in southern Norway

    International Nuclear Information System (INIS)

    Staaland, H.; Garmo, T.H.; Hove, K.; Pedersen, O.

    1995-01-01

    Radiocaesium concentrations ( 137 Cs) were measured in extrusa from oesophageally fistulated sheep, goats and reindeer grazing alpine summer vegetation in Griningsdalen, Southern Norway in the period 1987-1989. The experiments with sheep and goats were conducted in different sub-alpine areas. The reindeer were, in addition, grazed in three areas in the low alpine zone. Grazing bouts lasted for 10-20 min and bite selections were recorded every 15 s through the grazing bout. Reindeer and goats had the most diverse food selection whereas sheep fed mainly on grasses, forbs and to some extent, on leaves of willow. The reindeer extrusa had the highest radiocaesium activity, apparently to a large extent caused by intake of lichens in areas where this type of plants were present. Depending on the type of vegetation in the grazed areas the transfer of radiocaesium from soil to grazed vegetation (Bq kg -1 dry extrusa/Bq m -2 soil) was estimated to 0.02-0.04 in sheep, 0.02-0.05 in goats and 0.02-0.43 in reindeer for 1987. (author)

  8. [The seroconversion of Chlamydia abortus in sheep from the region of Vorarlberg before and after Alpine pasturing].

    Science.gov (United States)

    Blumer, S; Moestl, K; Krametter-Froetscher, R; Hässig, M; Pospischil, A; Borel, N

    2012-01-01

    In total, 796 serum samples of sheep on commune alpine pastures in the region of Vorarlberg were investigated by a commercial ELISA kit for antibodies against Chlamydia abortus, the agent of ovine enzootic abortion. The aim of the study was to determine the seroprevalence within this region and to compare these results with the seroprevalence in the neighboring canton Graubünden as well as to obtain data on the seroconversion after alpine pasturing. Therefore, 421 samples were collected before and 375 samples after alpine pasturing, whereas corresponding serum samples were available from 359 sheep. Within the region of Vorarlberg, a mean seroprevalence of 9.2 % was calculated with a threshold of 60 %. Seroconversion for C. abortus occurred in 5.0 % of animals with corresponding serum samples. Seroprevalence values were comparable to Swiss regions with similar management systems, although the neighboring canton Graubünden is known to have a much more higher seroprevalence of 43 %. In conclusion, the traditional animal exchange between these two regions is not significantly favoring the spread of C. abortus.

  9. Water and Sediment Output Evaluation Using Cellular Automata on Alpine Catchment: Soana, Italy - Test Case

    Science.gov (United States)

    Pasculli, Antonio; Audisio, Chiara; Sciarra, Nicola

    2017-12-01

    In the alpine contest, the estimation of the rainfall (inflow) and the discharge (outflow) data are very important in order to, at least, analyse historical time series at catchment scale; determine the hydrological maximum and minimum estimate flood and drought frequency. Hydrological researches become a precious source of information for various human activities, in particular for land use management and planning. Many rainfall- runoff models have been proposed to reflect steady, gradually-varied flow condition inside a catchment. In these last years, the application of Reduced Complexity Models (RCM) has been representing an excellent alternative resource for evaluating the hydrological response of catchments, within a period of time up to decades. Hence, this paper is aimed at the discussion of the application of the research code CAESAR, based on cellular automaton (CA) approach, in order to evaluate the water and the sediment outputs from an alpine catchment (Soana, Italy), selected as test case. The comparison between the predicted numerical results, developed through parametric analysis, and the available measured data are discussed. Finally, the analysis of a numerical estimate of the sediment budget over ten years is presented. The necessity of a fast, but reliable numerical support when the measured data are not so easily accessible, as in Alpine catchments, is highlighted.

  10. The Balearic Islands in the Alpine Orogeny

    Energy Technology Data Exchange (ETDEWEB)

    Bourrouilh, R.

    2016-10-01

    The place of the Balearic Islands in the Alpine orogeny is examined using detailed sedimentology studies, stratigraphical studies from the Lower Devonian (Lochkovian) to modern times and a careful tectonic review of sedimentary formations from the Western Mediterranean. Despite being considered as the ultimate end of the north-eastern termination of the Betic Cordillera, the history of the Balearic archipelago seems to be closer to the tectonic opening of the Gulf of Valencia and to the Corsica-Sardinia rotation, and thus to the tectonic history of the Western Mediterranean Sea, than to the tectonics of the Betic Cordillera which appear as its symmetrical image with respect to this opening. (Author)

  11. Prevalence and Molecular Identification of Nematode and Dipteran Parasites in an Australian Alpine Grasshopper (Kosciuscola tristis)

    Science.gov (United States)

    Umbers, Kate D. L.; Byatt, Lachlan J.; Hill, Nichola J.; Bartolini, Remo J.; Hose, Grant C.; Herberstein, Marie E.; Power, Michelle L

    2015-01-01

    In alpine Australia, Orthoptera are abundant, dominant herbivores, important prey species, and hosts for parasites and parasitoids. Despite the central role of orthopterans in alpine ecosystems, the impact of parasites on orthopteran populations is under-explored. In this study we describe the relationship between parasite prevalence and host sex, body size and year of collection. We accessed an existing, preserved collection of 640 Kosciuscola tristis collected from across its range between 2007 and 2011. Upon dissection we collected juvenile parasites and used molecular tools to identify them to three families (Nematoda; Mermithidae, and Arthropoda: Diptera: Tachinidae and Sarcophagidae). The prevalence of nematodes ranged from 3.5% to 25.0% and dipterans from 2.4% to 20.0%. Contrary to predictions, we found no associations between parasite prevalence and grasshopper sex or size. Although there was an association between prevalence of both nematodes and dipterans with year of collection, this is likely driven by a small sample size in the first year. Our results provide a foundation for future studies into parasite prevalence within the alpine environment and the abiotic factors that might influence these associations. PMID:25919745

  12. Effects of permafrost degradation on alpine grassland in a semi-arid basin on the Qinghai–Tibetan Plateau

    International Nuclear Information System (INIS)

    Yi Shuhua; Zhou Zhaoye; Ren Shilong; Xu Ming; Qin Yu; Chen Shengyun; Ye Baisheng

    2011-01-01

    Permafrost on the Qinghai–Tibetan Plateau (QTP) has degraded over the last few decades. Its ecological effects have attracted great concern. Previous studies focused mostly at plot scale, and hypothesized that degradation of permafrost would cause lowering of the water table and drying of shallow soil and then degradation of alpine grassland. However, none has been done to test the hypothesis at basin scale. In this study, for the first time, we investigated the relationships between land surface temperature (LST) and fractional vegetation cover (FVC) in different types of permafrost zone to infer the limiting condition (water or energy) of grassland growth on the source region of Shule River Basin, which is located in the north-eastern edge of the QTP. LST was obtained from MODIS Aqua products at 1 km resolution, while FVC was upscaled from quadrat (50 cm) to the same resolution as LST, using 30 m resolution NDVI data of the Chinese HJ satellite. FVC at quadrat scale was estimated by analyzing pictures taken with a multi-spectral camera. Results showed that (1) retrieval of FVC at quadrat scale using a multi-spectral camera was both more accurate and more efficient than conventional methods and (2) the limiting factor of vegetation growth transitioned from energy in the extreme stable permafrost zone to water in the seasonal frost zone. Our study suggested that alpine grassland would respond differently to permafrost degradation in different types of permafrost zone. Future studies should consider overall effects of permafrost degradation, and avoid the shortcomings of existing studies, which focus too much on the adverse effects.

  13. Community-specific hydraulic conductance potential of soil water decomposed for two Alpine grasslands by small-scale lysimetry

    Science.gov (United States)

    Frenck, Georg; Leitinger, Georg; Obojes, Nikolaus; Hofmann, Magdalena; Newesely, Christian; Deutschmann, Mario; Tappeiner, Ulrike; Tasser, Erich

    2018-02-01

    For central Europe in addition to rising temperatures an increasing variability in precipitation is predicted. This will increase the probability of drought periods in the Alps, where water supply has been sufficient in most areas so far. For Alpine grasslands, community-specific imprints on drought responses are poorly analyzed so far due to the sufficient natural water supply. In a replicated mesocosm experiment we compared evapotranspiration (ET) and biomass productivity of two differently drought-adapted Alpine grassland communities during two artificial drought periods divided by extreme precipitation events using high-precision small lysimeters. The drought-adapted vegetation type showed a high potential to utilize even scarce water resources. This is combined with a low potential to translate atmospheric deficits into higher water conductance and a lower biomass production as those measured for the non-drought-adapted type. The non-drought-adapted type, in contrast, showed high water conductance potential and a strong increase in ET rates when environmental conditions became less constraining. With high rates even at dry conditions, this community appears not to be optimized to save water and might experience drought effects earlier and probably more strongly. As a result, the water use efficiency of the drought-adapted plant community is with 2.6 gDW kg-1 of water much higher than that of the non-drought-adapted plant community (0.16 gDW kg-1). In summary, the vegetation's reaction to two covarying gradients of potential evapotranspiration and soil water content revealed a clear difference in vegetation development and between water-saving and water-spending strategies regarding evapotranspiration.

  14. Combined Heat Transfer in High-Porosity High-Temperature Fibrous Insulations: Theory and Experimental Validation

    Science.gov (United States)

    Daryabeigi, Kamran; Cunnington, George R.; Miller, Steve D.; Knutson, Jeffry R.

    2010-01-01

    Combined radiation and conduction heat transfer through various high-temperature, high-porosity, unbonded (loose) fibrous insulations was modeled based on first principles. The diffusion approximation was used for modeling the radiation component of heat transfer in the optically thick insulations. The relevant parameters needed for the heat transfer model were derived from experimental data. Semi-empirical formulations were used to model the solid conduction contribution of heat transfer in fibrous insulations with the relevant parameters inferred from thermal conductivity measurements at cryogenic temperatures in a vacuum. The specific extinction coefficient for radiation heat transfer was obtained from high-temperature steady-state thermal measurements with large temperature gradients maintained across the sample thickness in a vacuum. Standard gas conduction modeling was used in the heat transfer formulation. This heat transfer modeling methodology was applied to silica, two types of alumina, and a zirconia-based fibrous insulation, and to a variation of opacified fibrous insulation (OFI). OFI is a class of insulations manufactured by embedding efficient ceramic opacifiers in various unbonded fibrous insulations to significantly attenuate the radiation component of heat transfer. The heat transfer modeling methodology was validated by comparison with more rigorous analytical solutions and with standard thermal conductivity measurements. The validated heat transfer model is applicable to various densities of these high-porosity insulations as long as the fiber properties are the same (index of refraction, size distribution, orientation, and length). Furthermore, the heat transfer data for these insulations can be obtained at any static pressure in any working gas environment without the need to perform tests in various gases at various pressures.

  15. Population Spatial Dynamics of Larix potaninii in Alpine Treeline Ecotone in the Eastern Margin of the Tibetan Plateau, China

    OpenAIRE

    Jia’nan Cui; Jihong Qin; Hui Sun

    2017-01-01

    The high-altitude treeline is known to be sensitive to climate variability, and is thus considered as a bio-monitoring indicator of climate change. However, our understanding of the population dynamics and the cumulative climate-change effects on the alpine treeline ecotone in recent decades is limited. Here, we investigated the population dynamics of Larix potainii on the south- and north-facing slopes in the alpine treeline ecotone in the eastern margin of the Tibetan Plateau, China, includ...

  16. An inverse radiation model for optical determination of temperature and species concentration: Development and validation

    DEFF Research Database (Denmark)

    Ren, Tao; Modest, Michael F.; Fateev, Alexander

    2015-01-01

    2010 (Rothman et al. (2010) [1]), which contains line-by-line (LBL) information for several combustion gas species, such as CO2 and H2O, was used to predict gas spectral transmissivities. The model was validated by retrieving temperatures and species concentrations from experimental CO2 and H2O...

  17. Pattern-process interactions at alpine treeline in southwest Yukon, Canada

    Science.gov (United States)

    Danby, R.

    2011-12-01

    Results from an ensemble of studies conduced in southwest Yukon have uncovered a distinct "top-down/bottom-up" interaction at alpine treeline whereby terrain-induced gradients of solar radiation result in fundamental differences in plant-scale biological processes which, in turn, structure vegetation pattern at the landscape scale. Varied insolation creates differences in snow depth and timing of melt, soil temperature, and permafrost on opposing slopes that result in distinct physiological differences in white spruce (Picea glauca), the dominant treeline conifer. Measurement of young individuals indicated that secondary growth and lateral growth was significantly greater on south-facing slopes. Photosynthetic efficiency was reduced in individuals on south-facing slopes, while over-winter damage and mortality was significantly greater. Population-level processes also differed. Dendroecology and repeat photography indicated that treeline advanced on south-facing slopes during the 20th century, but that range expansion was limited on north-facing slopes. These process-related differences appear to be the mechanism for differences in treeline pattern at the landscape scale, including a higher treeline elevation and greater clustering of individuals on south-facing slopes. These results can be used to inform theory on the functional causation of treeline, rationalize differential treeline dynamics observed worldwide, and better inform predictions of future treeline dynamics.

  18. Soil nematodes in alpine meadows of the Tatra National Park (Slovak Republic)

    Czech Academy of Sciences Publication Activity Database

    Háněl, Ladislav

    2017-01-01

    Roč. 54, č. 1 (2017), s. 48-67 ISSN 0440-6605 R&D Projects: GA ČR(CZ) GA14-09231S Institutional support: RVO:60077344 Keywords : soil nematodes * diversity * maturity * soil food web * alpine meadow Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 0.472, year: 2016

  19. Short-term Effect of Nitrogen Addition on Microbial and Root Respiration in an Alpine Spruce Ecosystem

    Directory of Open Access Journals (Sweden)

    Jian Wang1

    2017-03-01

    Full Text Available Soil respiration plays an important role in the carbon (C flux of the global C cycle and is greatly affected by nitrogen (N additions in the form of deposition or fertilization. The aim of this study was to investigate the response of total soil respiration (Rs, microbial respiration (Rm, and root respiration (Rr to short-term N addition and the potential mechanisms of short-term N deposition influencing soil respiration in an alpine spruce ecosystem. Four N treatment levels (0, 50, 100, 150 kg N ha-1 year-1 were applied monthly in a Picea balfouriana (commonly known as "alpine spruce" plantation beginning in November 2013 and Rs, Rm, and Rr were measured from May to November 2014. The results show that simulated N depositions stimulate Rs, Rm, and Rr and the beneficial effects decreased along N gradients from hourly to seasonal scales. The seasonal temperature coefficients (Q10 of Rs, Rm, and Rr ranged from 2.50 to 3.8, 2.99 to 4.63, and 1.86 to 2.96, while the diurnal Q10 ranged from 1.71 to 2.04, 1.89 to 2.32, 1.42 to 1.75, and there was a similar trend with soil respiration along N gradients. In addition, Rr showed significant positive correlation with fine root biomass, and Rm was likely driven by soil enzyme related to the microbial C cycle in the growing season. Our results indicate that short-term N addition stimulated fine root biomass and soil enzymatic activity to bring about a potential increase in soil respiration rates under low-N addition, while the opposite occurred under high-N addition.

  20. Development of strong-sense validation benchmarks for the fluoride salt-cooled high-temperature reactor

    International Nuclear Information System (INIS)

    Blandford, E. D.

    2012-01-01

    The Fluoride salt-cooled High-temperature Reactor (FHR) is a class of reactor concepts currently under development for the U. S. Dept. of Energy. The FHR is defined as a Generation IV reactor that features low-pressure liquid fluoride salt cooling, coated-particle fuel, a high-temperature power cycle, and fully passive decay heat rejection. Recent experimental work using simulant fluids have been performed to demonstrate key 'proof of principle' FHR concepts and have helped inform the reactor design process. An important element of developing FHR technology is to sufficiently validate the predictive accuracy of the computer codes used to model system response. This paper presents a set of thermal-hydraulics experiments, defined as Strong-Sense Benchmarks (SSB's), which will help establish the FHR validation domain for simulant fluid suitability. These SSB's are more specifically designed to investigate single-phase natural circulation which is the dominant mode of FHR decay heat removal during off-normal conditions. SSB s should be viewed as engineering reference standards and differ from traditional confirmatory experiments in the sense that they are more focused on fundamental physics as opposed to reproducing high levels of physical similarity with the prototypical design. (authors)

  1. EXPLORING THE POTENTIAL OF AERIAL PHOTOGRAMMETRY FOR 3D MODELLING OF HIGH-ALPINE ENVIRONMENTS

    Directory of Open Access Journals (Sweden)

    K. Legat

    2016-03-01

    Based on the very promising results, some general recommendations for aerial photogrammetry processing in high-alpine areas are made to achieve best possible accuracy of the final 3D-, 2.5D- and 2D products.

  2. Seed dormancy and germination changes of snowbed species under climate warming: the role of pre- and post-dispersal temperatures

    Science.gov (United States)

    Bernareggi, Giulietta; Carbognani, Michele; Mondoni, Andrea; Petraglia, Alessandro

    2016-01-01

    Background and Aims Climate warming has major impacts on seed germination of several alpine species, hence on their regeneration capacity. Most studies have investigated the effects of warming after seed dispersal, and little is known about the effects a warmer parental environment may have on germination and dormancy of the seed progeny. Nevertheless, temperatures during seed development and maturation could alter the state of dormancy, affecting the timing of emergence and seedling survival. Here, the interplay between pre- and post-dispersal temperatures driving seed dormancy release and germination requirements of alpine plants were investigated. Methods Three plant species inhabiting alpine snowbeds were exposed to an artificial warming treatment (i.e. +1·5 K) and to natural conditions in the field. Seeds produced were exposed to six different periods of cold stratification (0, 2, 4, 8, 12 and 20 weeks at 0 °C), followed by four incubation temperatures (5, 10, 15 and 20 °C) for germination testing. Key Results A warmer parental environment produced either no or a significant increase in germination, depending on the duration of cold stratification, incubation temperatures and their interaction. In contrast, the speed of germination was less sensitive to changes in the parental environment. Moreover, the effects of warming appeared to be linked to the level of (physiological) seed dormancy, with deeper dormant species showing major changes in response to incubation temperatures and less dormant species in response to cold stratification periods. Conclusions Plants developed under warmer climates will produce seeds with changed germination responses to temperature and/or cold stratification, but the extent of these changes across species could be driven by seed dormancy traits. Transgenerational plastic adjustments of seed germination and dormancy shown here may result from increased seed viability, reduced primary and secondary dormancy state, or both, and

  3. Insights into microbial communities mediating the bioremediation of hydrocarbon-contaminated soil from an Alpine former military site.

    Science.gov (United States)

    Siles, José A; Margesin, Rosa

    2018-05-01

    The study of microbial communities involved in soil bioremediation is important to identify the specific microbial characteristics that determine improved decontamination rates. Here, we characterized bacterial, archaeal, and fungal communities in terms of (i) abundance (using quantitative PCR) and (ii) taxonomic diversity and structure (using Illumina amplicon sequencing) during the bioremediation of long-term hydrocarbon-contaminated soil from an Alpine former military site during 15 weeks comparing biostimulation (inorganic NPK fertilization) vs. natural attenuation and considering the effect of temperature (10 vs. 20 °C). Although a considerable amount of total petroleum hydrocarbon (TPH) loss could be attributed to natural attenuation, significantly higher TPH removal rates were obtained with NPK fertilization and at increased temperature, which were related to the stimulation of the activities of indigenous soil microorganisms. Changing structures of bacterial and fungal communities significantly explained shifts in TPH contents in both natural attenuation and biostimulation treatments at 10 and 20 °C. However, archaeal communities, in general, and changing abundances and diversities in bacterial and fungal communities did not play a decisive role on the effectiveness of soil bioremediation. Gammaproteobacteria and Bacteroidia classes, within bacterial community, and undescribed/novel groups, within fungal community, proved to be actively involved in TPH removal in natural attenuation and biostimulation at both temperatures.

  4. Diversity and community structure of ectomycorrhizal fungi associated with Larix chinensis across the alpine treeline ecotone of Taibai Mountain.

    Science.gov (United States)

    Han, Qisheng; Huang, Jian; Long, Dongfeng; Wang, Xiaobing; Liu, Jianjun

    2017-07-01

    Alpine treeline ecotones represent ecosystems that are vulnerable to climate change. We investigated the ectomycorrhizal (ECM) community, which has potential to stabilize alpine ecosystems. ECM communities associated with Larix chinensis were studied in four zones along a natural ecotone from a mixed forest stand over pure forest stands, the timberline, and eventually, the treeline (3050-3450 m) in Tabai Mountain, China. Sixty operational taxonomic units (OTUs) of ECM fungi were identified by sequencing the rDNA internal transcribed spacer of ECM tips. The richness of ECM species increased with elevation. The soil C/N ratio was the most important factor explaining ECM species richness. The treeline zone harbored some unique ECM fungi whereas no unique genera were observed in the timberline and pure forest zone. Elevation and topography were equally important factors influencing ECM communities in the alpine region. We suggest that a higher diversity of the ECM fungal community associated with L. chinensis in the treeline zone could result from niche differentiation.

  5. Seasonal Dynamics of Water Use Strategy of Two Salix Shrubs in Alpine Sandy Land, Tibetan Plateau.

    Science.gov (United States)

    Zhu, Yajuan; Wang, Guojie; Li, Renqiang

    2016-01-01

    Water is a limiting factor for plant growth and vegetation dynamics in alpine sandy land of the Tibetan Plateau, especially with the increasing frequency of extreme precipitation events and drought caused by climate change. Therefore, a relatively stable water source from either deeper soil profiles or ground water is necessary for plant growth. Understanding the water use strategy of dominant species in the alpine sandy land ecosystem is important for vegetative rehabilitation and ecological restoration. The stable isotope methodology of δD, δ18O, and δ13C was used to determine main water source and long-term water use efficiency of Salix psammophila and S. cheilophila, two dominant shrubs on interdune of alpine sandy land in northeastern Tibetan Plateau. The root systems of two Salix shrubs were investigated to determine their distribution pattern. The results showed that S. psammophila and S. cheilophila absorbed soil water at different soil depths or ground water in different seasons, depending on water availability and water use strategy. Salix psammophila used ground water during the growing season and relied on shallow soil water recharged by rain in summer. Salix cheilophila used ground water in spring and summer, but relied on shallow soil water recharged by rain in spring and deep soil water recharged by ground water in fall. The two shrubs had dimorphic root systems, which is coincident with their water use strategy. Higher biomass of fine roots in S. psammophila and longer fine roots in S. cheilophila facilitated to absorb water in deeper soil layers. The long-term water use efficiency of two Salix shrubs increased during the dry season in spring. The long-term water use efficiency was higher in S. psammophila than in S. cheilophila, as the former species is better adapted to semiarid climate of alpine sandy land.

  6. Validation of a Climate-Data Record of the "Clear-Kky" Surface Temperature of the Greenland Ice Sheet

    Science.gov (United States)

    Hall, Dorothy K.; Box, Jason E.; Koenig, Lora S.; DiGirolamo, Nicolo E.; Comiso, Josefino C.; Shuman, Christopher A.

    2011-01-01

    Surface temperatures on the Greenland Ice Sheet have been studied on the ground, using automatic weather station (AWS) data from the Greenland-Climate Network (GC-Net), and from analysis of satellite sensor data. Using Advanced Very High Frequency Radiometer (AVHRR) weekly surface temperature maps, warming of the surface of the Greenland Ice Sheet has been documented since 1981. We extended and refined this record using higher-resolution Moderate-Resolution Imaging Spectroradiometer (MODIS) data from March 2000 to the present. We developed a daily and monthly climate-data record (CDR) of the "clear-sky" surface temperature of the Greenland Ice Sheet using an ice-surface temperature (1ST) algorithm developed for use with MODIS data. Validation of this CDR is ongoing. MODIS Terra swath data are projected onto a polar stereographic grid at 6.25-km resolution to develop binary, gridded daily and mean-monthly 1ST maps. Each monthly map also has a color-coded image map that is available to download. Also included with the monthly maps is an accompanying map showing number of days in the month that were used to calculate the mean-monthly 1ST. This is important because no 1ST decision is made by the algorithm for cells that are considered cloudy by the internal cloud mask, so a sufficient number of days must be available to produce a mean 1ST for each grid cell. Validation of the CDR consists of several facets: 1) comparisons between ISTs and in-situ measurements; 2) comparisons between ISTs and AWS data; and 3) comparisons of ISTs with surface temperatures derived from other satellite instruments such as the Thermal Emission and Reflection Radiometer (ASTER) and Enhanced Thematic Mapper Plus (ETM+). Previous work shows that Terra MODIS ISTs are about 3 C lower than in-situ temperatures measured at Summit Camp, during the winter of 2008-09 under clear skies. In this work we begin to compare surface temperatures derived from AWS data with ISTs from the MODIS CDR. The

  7. Climate and land-use changes affecting river sediment and brown trout in alpine countries--a review.

    Science.gov (United States)

    Scheurer, Karin; Alewell, Christine; Bänninger, Dominik; Burkhardt-Holm, Patricia

    2009-03-01

    Catch decline of freshwater fish has been recorded in several countries. Among the possible causes, habitat change is discussed. This article focuses on potentially increased levels of fine sediments going to rivers and their effects on gravel-spawning brown trout. Indications of increased erosion rates are evident from land-use change in agriculture, changes in forest management practices, and from climate change. The latter induces an increase in air and river water temperatures, reduction in permafrost, changes in snow dynamics and an increase in heavy rain events. As a result, an increase in river sediment is likely. Suspended sediment may affect fish health and behaviour directly. Furthermore, sediment loads may clog gravel beds impeding fish such as brown trout from spawning and reducing recruitment rates. To assess the potential impact on fine sediments, knowledge of brown trout reproductive needs and the effects of sediment on brown trout health were evaluated. We critically reviewed the literature and included results from ongoing studies to answer the following questions, focusing on recent decades and rivers in alpine countries. Have climate change and land-use change increased erosion and sediment loads in rivers? Do we have indications of an increase in riverbed clogging? Are there indications of direct or indirect effects on brown trout from increased suspended sediment concentrations in rivers or from an increase in riverbed clogging? Rising air temperatures have led to more intensive precipitation in winter months, earlier snow melt in spring, and rising snow lines and hence to increased erosion. Intensification of land use has supported erosion in lowland and pre-alpine areas in the second half of the twentieth century. In the Alps, however, reforestation of abandoned land at high altitudes might reduce the erosion risk while intensification on the lower, more easily accessible slopes increases erosion risk. Data from laboratory experiments show

  8. Alpine deformations in Donbass: Periodicity, character of stresses, and their probable sources

    Science.gov (United States)

    Kopp, M. L.; Korchemagin, V. A.; Kolesnichenko, A. A.

    2010-09-01

    The periodicity, dynamics, and kinematics of the insufficiently studied Cenozoic (Alpine) movements in the Donets Fold Edifice and its framework are considered. The synthesis of the available data on the Donets Basin (Donbass) and the adjacent territories of the Russian and Scythian plates shows that the Early Alpine, or Laramian epoch of deformation in the Paleocene and the Late Alpine, or recent epoch of deformation in the early Miocene-Quaternary were divided by a tectonic pause in the Eocene and Oligocene. Judging from macrostructural pattern and results of mesotectonic observations, both epochs were characterized by meridional compression and latitudinal extension but substantially differed in the scope of deformation and the style of structure. The former developed to the west of the Donbass and resulted in compression of diapirs in the Dnieper-Donets Aulacogen, whereas the latter created the recent Donets-Azov Swell and brought about right-lateral strike-slip faulting along the North Donets and Persianovsky faults bounding the Donbass. The recent movements and related deformation in the eastern area, including the substantial role of right-lateral strike-slip faulting, more intense deformation in comparison with Laramian movements, and the mobilization of the basement not only in the Dnieper-Donets Aulacogen but also far beyond its limits allow us to connect these phenomena with coeval orogeny in the Greater Caucasus. The nature of the moderate Laramian movements confined to the axial zone of the aulacogen is more questionable; however, it can be explained in terms of within-plate reactivation of western and part of eastern Europe as a response to plate collision in the Alps, Dinarides, and Pontides in combination with coeval onset of spreading in the North Atlantic and Arctic, which created counter-pressure from the north. The eventual result of both processes was inversion and compression of some European aulacogens, including the Dnieper-Donets Aulacogen.

  9. Validation of gyrokinetic simulations with measurements of electron temperature fluctuations and density-temperature phase angles on ASDEX Upgrade

    Science.gov (United States)

    Freethy, S. J.; Görler, T.; Creely, A. J.; Conway, G. D.; Denk, S. S.; Happel, T.; Koenen, C.; Hennequin, P.; White, A. E.; ASDEX Upgrade Team

    2018-05-01

    Measurements of turbulent electron temperature fluctuation amplitudes, δTe ⊥/Te , frequency spectra, and radial correlation lengths, Lr(Te ⊥) , have been performed at ASDEX Upgrade using a newly upgraded Correlation ECE diagnostic in the range of scales k⊥scale non-linear gyrokinetic turbulence simulations of the outer core (ρtor = 0.75) of a low density, electron heated L-mode plasma, performed using the gyrokinetic simulation code, GENE. The ion and electron temperature gradients were scanned within uncertainties. It is found that gyrokinetic simulations are able to match simultaneously the electron and ion heat flux at this radius within the experimental uncertainties. The simulations were performed based on a reference discharge for which δTe ⊥/Te measurements were available, and Lr(Te ⊥) and αnT were then predicted using synthetic diagnostics prior to measurements in a repeat discharge. While temperature fluctuation amplitudes are overestimated by >50% for all simulations within the sensitivity scans performed, good quantitative agreement is found for Lr(Te ⊥) and αnT. A validation metric is used to quantify the level of agreement of individual simulations with experimental measurements, and the best agreement is found close to the experimental gradient values.

  10. Low-Frequency Earthquakes Associated with the Late-Interseismic Central Alpine Fault, Southern Alps, New Zealand

    Science.gov (United States)

    Baratin, L. M.; Chamberlain, C. J.; Townend, J.; Savage, M. K.

    2016-12-01

    Characterising the seismicity associated with slow deformation in the vicinity of the Alpine Fault may provide constraints on the state of stress of this major transpressive margin prior to a large (≥M8) earthquake. Here, we use recently detected tremor and low-frequency earthquakes (LFEs) to examine how slow tectonic deformation is loading the Alpine Fault toward an anticipated large rupture. We initially work with a continous seismic dataset collected between 2009 and 2012 from an array of short-period seismometers, the Southern Alps Microearthquake Borehole Array. Fourteen primary LFE templates are used in an iterative matched-filter and stacking routine. This method allows the detection of similar signals and establishes LFE families with common locations. We thus generate a 36 month catalogue of 10718 LFEs. The detections are then combined for each LFE family using phase-weighted stacking to yield a signal with the highest possible signal to noise ratio. We found phase-weighted stacking to be successful in increasing the number of LFE detections by roughly 20%. Phase-weighted stacking also provides cleaner phase arrivals of apparently impulsive nature allowing more precise phase and polarity picks. We then compute improved non-linear earthquake locations using a 3D velocity model. We find LFEs to occur below the seismogenic zone at depths of 18-34 km, locating on or near the proposed deep extent of the Alpine Fault. Our next step is to estimate seismic source parameters by implementing a moment tensor inversion technique. Our focus is currently on generating a more extensive catalogue (spanning the years 2009 to 2016) using synthetic waveforms as primary templates, with which to detect LFEs. Initial testing shows that this technique paired up with phase-weighted stacking increases the number of LFE families and overall detected events roughly sevenfold. This catalogue should provide new insight into the geometry of the Alpine Fault and the prevailing stress

  11. Geochip-based analysis of microbial communities in alpine meadow soils in the Qinghai-Tibetan plateau.

    Science.gov (United States)

    Zhang, Yuguang; Lu, Zhenmei; Liu, Shanshan; Yang, Yunfeng; He, Zhili; Ren, Zuohua; Zhou, Jizhong; Li, Diqiang

    2013-03-29

    GeoChip 3.0, a microbial functional gene array, containing ~28,000 oligonucleotide probes and targeting ~57,000 sequences from 292 functional gene families, provided a powerful tool for researching microbial community structure in natural environments. The alpine meadow is a dominant plant community in the Qinghai-Tibetan plateau, hence it is important to profile the unique geographical flora and assess the response of the microbial communities to environmental variables. In this study, Geochip 3.0 was employed to understand the microbial functional gene diversity and structure, and metabolic potential and the major environmental factors in shaping microbial communities structure of alpine meadow soil in Qinghai-Tibetan Plateau. A total of 6143 microbial functional genes involved in carbon degradation, carbon fixation, methane oxidation and production, nitrogen cycling, phosphorus utilization, sulphur cycling, organic remediation, metal resistance, energy process and other category were detected in six soil samples and high diversity was observed. Interestingly, most of the detected genes associated with carbon degradation were derived from cultivated organisms. To identify major environmental factors in shaping microbial communities, Mantel test and CCA Statistical analyses were performed. The results indicated that altitude, C/N, pH and soil organic carbon were significantly (P the microbial functional structure and a total of 80.97% of the variation was significantly explained by altitude, C/N and pH. The C/N contributed 38.2% to microbial functional gene variation, which is in accordance with the hierarchical clustering of overall microbial functional genes. High overall functional genes and phylogenetic diversity of the alpine meadow soil microbial communities existed in the Qinghai-Tibetan Plateau. Most of the genes involved in carbon degradation were derived from characterized microbial groups. Microbial composition and structures variation were

  12. Organic Farming and Social-Ecological Resilience: the Alpine Valleys of Sölktäler, Austria

    Directory of Open Access Journals (Sweden)

    Rebecka Milestad

    2003-12-01

    Full Text Available Farming in the Austrian Alps is small in scale and involves a high degree of manual labor. In the face of structural changes in agriculture, alpine farms are finding it increasingly difficult to remain economically viable. Organic farming presents a promising alternative for alpine farmers because it receives considerable financial support under the Common Agricultural Policy of the European Union. Recent years have seen an increase in the number of organic farms in Austria in general, and in alpine areas in particular. Using data from an empirical study carried out in the alpine area of Sölktäler, Austria, this paper examines the issues of how closely the regulations and principles of organic farming match farmers' perspectives on sustainable agriculture and whether or not organic farming is capable of building social-ecological resilience for local farms. Qualitative interviews and a series of workshops were used to learn about farmers' "desired system state" with regard to their region, disturbances to this system, and their perspectives on organic farming. The desired system in Sölktäler as formulated by the farmers depicts a vivid farming community that manages a diverse traditional agricultural landscape and performs a number of ecological services. The desired system and the principles of organic farming have several aspects in common, and many management practices and features of the social system support social-ecological resilience. The vulnerability of farms increases, however, when farmers must deal with structural changes in agriculture, the erosion of traditional ecological knowledge, and societal transformation. In conclusion, organic farming is a tool that can be used to build social-ecological resilience for Sölktäler farms, because it secures economic funding for the area and makes it possible to sustain environmentally benign practices. What remains is the question of whether the farming community is capable of

  13. Validation of the Suomi NPP VIIRS Ice Surface Temperature Environmental Data Record

    Directory of Open Access Journals (Sweden)

    Yinghui Liu

    2015-12-01

    Full Text Available Continuous monitoring of the surface temperature is critical to understanding and forecasting Arctic climate change; as surface temperature integrates changes in the surface energy budget. The sea-ice surface temperature (IST has been measured with optical and thermal infrared sensors for many years. With the IST Environmental Data Record (EDR available from the Visible Infrared Imaging Radiometer Suite (VIIRS onboard the Suomi National Polar-orbiting Partnership (NPP and future Joint Polar Satellite System (JPSS satellites; we can continue to monitor and investigate Arctic climate change. This work examines the quality of the VIIRS IST EDR. Validation is performed through comparisons with multiple datasets; including NASA IceBridge measurements; air temperature from Arctic drifting ice buoys; Moderate Resolution Imaging Spectroradiometer (MODIS IST; MODIS IST simultaneous nadir overpass (SNO; and surface air temperature from the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR reanalysis. Results show biases of −0.34; −0.12; 0.16; −3.20; and −3.41 K compared to an aircraft-mounted downward-looking pyrometer; MODIS; MODIS SNO; drifting buoy; and NCEP/NCAR reanalysis; respectively; root-mean-square errors of 0.98; 1.02; 0.95; 4.89; and 6.94 K; and root-mean-square errors with the bias removed of 0.92; 1.01; 0.94; 3.70; and 6.04 K. Based on the IceBridge and MODIS results; the VIIRS IST uncertainty (RMSE meets or exceeds the JPSS system requirement of 1.0 K. The product can therefore be considered useful for meteorological and climatological applications.

  14. Alpine Windharvest: development of information base regarding potentials and the necessary technical, legal and socio-economic conditions for expanding wind energy in the Alpine Space - GIS analysis methodology - Workbook and results

    Energy Technology Data Exchange (ETDEWEB)

    Daellenbach, F.; Schaffner, B. [Meteotest, Berne (Switzerland)

    2005-07-01

    This report presents the development work carried out by the Swiss meteorology specialists of the company METEOTEST as part of a project carried out together with the Swiss wind-energy organisation 'Suisse Eole'. The framework for the project is the EU Interreg IIIB Alpine Space Programme, a European Community Initiative Programme funded by the European Regional Development Fund. The project investigated the use of digital relief-analysis. The report describes the development of basic information system to aid the investigation of the technical, legal and socio-economical conditions for the use of wind energy in the alpine area. The report deals with the use of Geographic Information Systems (GIS) methodology, which includes three steps: the identification of limiting factors for wind power production, the compilation of a GIS layer for each of these factors and, thirdly, their aggregation into a result layer. The methodology was implemented for four case studies in Austria, Italy, Slovenia and Switzerland.

  15. Geophysical validation of temperature retrieved by the ESA processor from MIPAS/ENVISAT atmospheric limb-emission measurements

    Directory of Open Access Journals (Sweden)

    M. Ridolfi

    2007-08-01

    Full Text Available The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS has been operating since March 2002 onboard of the ENVIronmental SATellite of the European Space Agency (ESA. The high resolution (0.035 cm−1 full width half maximum, unapodized limb-emission measurements acquired by MIPAS in the first two years of operation have very good geographical and temporal coverage and have been re-processed by ESA with the most recent versions (4.61 and 4.62 of the inversion algorithms. The products of this processing chain are pressures at the tangent points and geolocated profiles of temperature and of the volume mixing ratios of six key atmospheric constituents: H2O, O3, HNO3, CH4, N2O and NO2. As for all the measurements made with innovative instruments and techniques, this data set requires a thorough validation. In this paper we present a geophysical validation of the temperature profiles derived from MIPAS measurements by the ESA retrieval algorithm. The validation is carried-out by comparing MIPAS temperature with correlative measurements made by radiosondes, lidars, in-situ and remote sensors operated either from the ground or stratospheric balloons.

    The results of the intercomparison indicate that the bias of the MIPAS profiles is generally smaller than 1 or 2 K depending on altitude. Furthermore we find that, especially at the edges of the altitude range covered by the MIPAS scan, the random error estimated from the intercomparison is larger (typically by a factor of two to three than the corresponding estimate derived on the basis of error propagation.

    In this work we also characterize the discrepancies between MIPAS temperature and the temperature fields resulting from the analyses of the European Centre for Medium-range Weather Forecasts (ECMWF. The bias and the standard deviation of these discrepancies are consistent with those obtained when

  16. INTERACT Management planning for arctic and northern alpine stations - Examples of good practices

    DEFF Research Database (Denmark)

    of visitors, outreach, science plans, data management and education. The target audience for the book is mainly managers of research stations in arctic and alpine areas, but it is our hope that it will also be a useful tool for others being involved in science coordination and logistics....

  17. Recent climate warming forces contrasting growth responses of white spruce at treeline in Alaska through temperature thresholds

    Science.gov (United States)

    Martin Wilmking; Glenn P. Juday; Valerie A. Barber; Harold S.J. Zald

    2004-01-01

    Northern and high-latitude alpine treelines are generally thought to be limited by available warmth. Most studies of tree-growth-climate interaction at treeline as well as climate reconstructions using dendrochronology report positive growth response of treeline trees to warmer temperatures. However, population-wide responses of treeline trees to climate remain largely...

  18. In-situ carbon and nitrogen turnover dynamics and the role of soil functional biodiversity therein; a climate warming simulation study in Alpine ecosystems

    Science.gov (United States)

    Djukic, Ika

    2010-05-01

    the original site. The bacterial to fungal ratio of the translocated soil cores showed a rapid acclimatization to the new (host) soil conditions. Our study demonstrates that rising temperatures in Alpine ecosystems will accelerate decomposition of fresh C pools but also lead to rapid adaptation of the microbial community to the new conditions.

  19. Analysis of streamflow variability in Alpine catchments at multiple spatial and temporal scales

    Science.gov (United States)

    Pérez Ciria, T.; Chiogna, G.

    2017-12-01

    Alpine watersheds play a pivotal role in Europe for water provisioning and for hydropower production. In these catchments, temporal fluctuations of river discharge occur at multiple temporal scales due to natural as well as anthropogenic driving forces. In the last decades, modifications of the flow regime have been observed and their origin lies in the complex interplay between construction of dams for hydro power production, changes in water management policies and climatic changes. The alteration of the natural flow has negative impacts on the freshwater biodiversity and threatens the ecosystem integrity of the Alpine region. Therefore, understanding the temporal and spatial variability of river discharge has recently become a particular concern for environmental protection and represents a crucial contribution to achieve sustainable water resources management in the Alps. In this work, time series analysis is conducted for selected gauging stations in the Inn and the Adige catchments, which cover a large part of the central and eastern region of the Alps. We analyze the available time series using the continuous wavelet transform and change-point analyses for determining how and where changes have taken place. Although both catchments belong to different climatic zones of the Greater Alpine Region, streamflow properties share some similar characteristics. The comparison of the collected streamflow time series in the two catchments permits detecting gradients in the hydrological system dynamics that depend on station elevation, longitudinal location in the Alps and catchment area. This work evidences that human activities (e.g., water management practices and flood protection measures, changes in legislation and market regulation) have major impacts on streamflow and should be rigorously considered in hydrological models.

  20. Identifying genetic signatures of selection in a non-model species, alpine gentian (Gentiana nivalis L.), using a landscape genetic approach

    DEFF Research Database (Denmark)

    Bothwell, H.; Bisbing, S.; Therkildsen, Nina Overgaard

    2013-01-01

    It is generally accepted that most plant populations are locally adapted. Yet, understanding how environmental forces give rise to adaptive genetic variation is a challenge in conservation genetics and crucial to the preservation of species under rapidly changing climatic conditions. Environmental...... loci, we compared outlier locus detection methods with a recently-developed landscape genetic approach. We analyzed 157 loci from samples of the alpine herb Gentiana nivalis collected across the European Alps. Principle coordinates of neighbor matrices (PCNM), eigenvectors that quantify multi...... variables identified eight more potentially adaptive loci than models run without spatial variables. 3) When compared to outlier detection methods, the landscape genetic approach detected four of the same loci plus 11 additional loci. 4) Temperature, precipitation, and solar radiation were the three major...

  1. Electron Temperature Fluctuation Measurements and Transport Model Validation at Alcator C-Mod

    Energy Technology Data Exchange (ETDEWEB)

    White, Anne [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2017-06-22

    The tokamak is a type of toroidal device used to confine a fusion plasma using large magnetic fields. Tokamaks and stellarators the leading devices for confining plasmas for fusion, and the capability to predict performance in these magnetically confined plasmas is essential for developing a sustainable fusion energy source. The magnetic configuration of tokamaks and stellarators does not exist in Nature, yet, the fundamental processes governing transport in fusion plasmas are universal – turbulence and instabilities, driven by inhomogeneity and asymmetry in the plasma, conspire to transport heat and particles across magnetic field lines and can play critical roles in impurity confinement and generation of intrinsic rotation. Turbulence exists in all plasmas, and in neutral fluids as well. The study of turbulence is essential to developing a fundamental understanding of the nature of the fourth state of matter, plasmas. Experimental studies of turbulence in tokamaks date back to early scattering observations from the late 1970s. Since that time, great advances in turbulence diagnostics have been made, all of which have significantly enhanced our knowledge and understanding of turbulence in tokamaks. Through comparisons with advanced gyrokinetic theory and turbulent-transport models a great deal of evidence exists to implicate turbulent-driven transport as an important mechanism determining transport in all channels: heat, particle and momentum However, prediction and control of turbulent-driven transport remains elusive. Key to development of predictive transport models for magnetically confined fusion plasmas is validation of the nonlinear gyrokinetic transport model, which describes transport due to turbulence. Validation of gyrokinetic codes must include detailed and quantitative comparisons with measured turbulence characteristics, in addition to comparisons with inferred transport levels and equilibrium profiles. For this reason, advanced plasma diagnostics

  2. Lack of sex-biased dispersal promotes fine-scale genetic structure in alpine ungulates

    Science.gov (United States)

    Gretchen H. Roffler; Sandra L. Talbot; Gordon Luikart; George K. Sage; Kristy L. Pilgrim; Layne G. Adams; Michael K. Schwartz

    2014-01-01

    Identifying patterns of fine-scale genetic structure in natural populations can advance understanding of critical ecological processes such as dispersal and gene flow across heterogeneous landscapes. Alpine ungulates generally exhibit high levels of genetic structure due to female philopatry and patchy configuration of mountain habitats. We assessed the spatial scale...

  3. Integration of 3D geological modeling and gravity surveys for geothermal prospection in an Alpine region

    Science.gov (United States)

    Guglielmetti, L.; Comina, C.; Abdelfettah, Y.; Schill, E.; Mandrone, G.

    2013-11-01

    Thermal sources are common manifestations of geothermal energy resources in Alpine regions. The up-flow of the fluid is well-known to be often linked to cross-cutting fault zones providing a significant volume of fractures. Since conventional exploration methods are challenging in such areas of high topography and complicated logistics, 3D geological modeling based on structural investigation becomes a useful tool for assessing the overall geology of the investigated sites. Geological modeling alone is, however, less effective if not integrated with deep subsurface investigations that could provide a first order information on geological boundaries and an imaging of geological structures. With this aim, in the present paper the combined use of 3D geological modeling and gravity surveys for geothermal prospection of a hydrothermal area in the western Alps was carried out on two sites located in the Argentera Massif (NW Italy). The geothermal activity of the area is revealed by thermal anomalies with surface evidences, such as hot springs, at temperatures up to 70 °C. Integration of gravity measurements and 3D modeling investigates the potential of this approach in the context of geothermal exploration in Alpine regions where a very complex geological and structural setting is expected. The approach used in the present work is based on the comparison between the observed gravity and the gravity effect of the 3D geological models, in order to enhance local effects related to the geothermal system. It is shown that a correct integration of 3D modeling and detailed geophysical survey could allow a better characterization of geological structures involved in geothermal fluids circulation. Particularly, gravity inversions have successfully delineated the continuity in depth of low density structures, such as faults and fractured bands observed at the surface, and have been of great help in improving the overall geological model.

  4. Alpine cloud climatology using long-term NOAA-AVHRR satellite data

    Energy Technology Data Exchange (ETDEWEB)

    Kaestner, M.; Kriebel, K.T.

    2000-07-01

    Three different climates have been identified by our evaluation of AVHRR (advanced very high resolution radiometer) data using APOLLO (AVHRR processing scheme over land, clouds and ocean) for a five-years cloud climatology of the Alpine region. The cloud cover data from four layers were spatially averaged in boxes of 15 km by 14 km. The study area only comprises 540 km by 560 km, but contains regions with moderate, Alpine and Mediterranean climate. Data from the period July 1989 until December 1996 have been considered. The temporal resolution is one scene per day, the early afternoon pass, yielding monthly means of satellite derived cloud coverages 5% to 10% above the daily mean compared to conventional surface observation. At nonvegetated sites the cloudiness is sometimes significantly overestimated. Averaging high resolution cloud data seems to be superior to low resolution measurements of cloud properties and averaging is favourable in topographical homogeneous regions only. The annual course of cloud cover reveals typical regional features as foehn or temporal singularities as the so-called Christmas thaw. The cloud cover maps in spatially high resolution show local luff/lee features which outline the orography. Less cloud cover is found over the Alps than over the forelands in winter, an accumulation of thick cirrus is found over the High Alps and an accumulation of thin cirrus north of the Alps. (orig.)

  5. The Impact of Tourist Traffic on the Condition and Cell Structures of Alpine Swards

    Directory of Open Access Journals (Sweden)

    Marlena Kycko

    2018-02-01

    Full Text Available This research focuses on the effect of trampling on vegetation in high-mountain ecosystems through the electromagnetic spectrum’s interaction with plant pigments, cell structure, water content and other substances that have a direct impact on leaf properties. The aim of the study was to confirm with the use of fluorescence methods of variability in the state of high-mountain vegetation previously measured spectrometrically. The most heavily visited part of the High Tatras in Poland was divided into polygons and, after selecting the dominant species within alpine swards, a detailed analysis of trampled and reference patterns was performed. The Analytical Spectral Devices (ASD FieldSpec 3/4 were used to acquire high-resolution spectral properties of plants, their fluorescence and the leaf chlorophyll content with the difference between the plant surface temperature (ts, and the air temperature (ta as well as fraction of Absorbed Photosynthetically Active Radiation (fAPAR used as reference data. The results show that, along tourist trails, vegetation adapts to trampling with the impact depending on the species. A lower chlorophyll value was confirmed by a decrease in fluorescence, and the cellular structures were degraded in trampled compared to reference species, with a lower leaf reflectance. In addition, at the extreme, trampling can eliminate certain species such as Luzula alpino-pilosa, for which significant changes were noted due to trampling.

  6. A more holistic understanding of soil organic matter pools of alpine and pre-alpine grassland soils in a changing climate

    Science.gov (United States)

    Garcia Franco, Noelia; Wiesmeier, Martin; Kiese, Ralf; Dannenmann, Michael; Wolf, Benjamin; Brandhuber, Robert; Beck, Robert; Kögel-Knabner, Ingrid

    2016-04-01

    In southern Germany, the alpine and pre-alpine grassland systems (> 1 Mio ha) provide an important economic value via fodder used for milk and meat production and grassland soils support environmental key functions (C and N storage, water retention, erosion control and biodiversity hot spot). In addition, these grassland soils constitute important regions for tourism and recreation. However, the different land use and management practices in this area introduce changes which are likely to accelerate due to climate change. The newly launched SUPSALPS project within the BonaRes Initiative of the German Ministry for Education and Research is focused on the development and evaluation of innovative grassland management strategies under climate change with an emphasis on soil functions, which are on the one hand environmental sustainable and on the other hand economically viable. Several field experiments of the project will be initialized in order to evaluate grassland soil functioning for a range of current and climate adapted management practices. A multi-factorial design combines ongoing and new plant-soil meso-/macrocosm and field studies at a multitude of existing long-term research sites along an elevation gradient in Bavaria. One of the specific objectives of the project is to improve our knowledge on the sensitivity of specific soil organic matter (SOM) fractions to climate change. Moreover, the project aims to determine the processes and mechanisms involved in the build-up and stabilization of C and N pools under different management practices. In order to derive sensitive SOM pools, a promising physical fractionation method was developed that enables the separation of five different SOM fractions by density, ultrasonication and sieving separation: fine particulate organic matter (fPOM), occluded particulate organic matter (oPOM>20μm and oPOM 20 μm; medium + fine silt and clay, management changes.

  7. Active and fossil mantle flows in the western Alpine region unravelled by seismic anisotropy analysis and high-resolution P wave tomography

    Science.gov (United States)

    Salimbeni, Simone; Malusà, Marco G.; Zhao, Liang; Guillot, Stéphane; Pondrelli, Silvia; Margheriti, Lucia; Paul, Anne; Solarino, Stefano; Aubert, Coralie; Dumont, Thierry; Schwartz, Stéphane; Wang, Qingchen; Xu, Xiaobing; Zheng, Tianyu; Zhu, Rixiang

    2018-04-01

    The anisotropy of seismic velocities in the mantle, when integrated with high-resolution tomographic models and geologic information, can be used to detect active mantle flows in complex plate boundary areas, providing new insights on the impact of mantle processes on the topography of mountain belts. Here we use a densely spaced array of temporary broadband seismic stations to analyze the seismic anisotropy pattern of the western Alpine region, at the boundary between the Alpine and Apenninic slabs. Our results are supportive of a polyphase development of anisotropic mantle fabrics, possibly starting from the Jurassic to present. Geophysical data presented in this work, and geologic evidence taken from the literature, indicate that: (i) fossil fabrics formed during Tethyan rifting may be still preserved within the Alpine and Apenninic slabs; (ii) mantle deformation during Apenninic slab rollback is not compensated by a complete toroidal flow around the northern tip of the retreating slab; (iii) the previously observed continuous trend of anisotropy fast axes near-parallel to the western Alpine arc is confirmed. We observe that this arc-parallel trend of fast axes is located in correspondence to a low velocity anomaly in the European upper mantle, beneath regions of the Western and Ligurian Alps showing the highest uplift rates. We propose that the progressive rollback of the Apenninic slab, in the absence of a counterclockwise toroidal flow at its northern tip, induced a suction effect at the scale of the supraslab mantle. The resulting mantle flow pattern was characterized by an asthenospheric counterflow at the rear of the unbroken Western Alps slab and around its southern tip, and by an asthenospheric upwelling, mirrored by low P wave velocities, that would have favored the topographic uplift of the Alpine belt from the Mont Blanc to the Mediterranean sea.

  8. Glaciation of alpine valleys: The glacier - debris-covered glacier - rock glacier continuum

    Science.gov (United States)

    Anderson, Robert S.; Anderson, Leif S.; Armstrong, William H.; Rossi, Matthew W.; Crump, Sarah E.

    2018-06-01

    Alpine ice varies from pure ice glaciers to partially debris-covered glaciers to rock glaciers, as defined by the degree of debris cover. In many low- to mid-latitude mountain ranges, the few bare ice glaciers that do exist in the present climate are small and are found where snow is focused by avalanches and where direct exposure to radiation is minimized. Instead, valley heads are more likely to be populated by rock glaciers, which can number in the hundreds. These rock-cloaked glaciers represent some of the most identifiable components of the cryosphere today in low- to mid-latitude settings, and the over-steepened snouts pose an often overlooked hazard to travel in alpine terrain. Geomorphically, rock glaciers serve as conveyor belts atop which rock is pulled away from the base of cliffs. In this work, we show how rock glaciers can be treated as an end-member case that is captured in numerical models of glaciers that include ice dynamics, debris dynamics, and the feedbacks between them. Specifically, we focus on the transition from debris-covered glaciers, where the modern equilibrium line altitude (ELA) intersects the topography, to rock glaciers, where the modern ELA lies above the topography. On debris-covered glaciers (i.e., glaciers with a partial rock mantle), rock delivered to the glacier from its headwall, or from sidewall debris swept into the glacier at tributary junctions, travels englacially to emerge below the ELA. There it accumulates on the surface and damps the rate of melt of underlying ice. This allows the termini of debris-covered glaciers to extend beyond debris-free counterparts, thereby decreasing the ratio of accumulation area to total area of the glacier (AAR). In contrast, rock glaciers (i.e., glaciers with a full rock mantle) occur where and when the environmental ELA rises above the topography. They require avalanches and rockfall from steep headwalls. The occurrence of rock glaciers reflects this dependence on avalanche sources

  9. Beta-alanine supplementation improves jumping power and affects severe-intensity performance in professional alpine skiers.

    Science.gov (United States)

    Gross, Micah; Bieri, Kathrin; Hoppeler, Hans; Norman, Barbara; Vogt, Michael

    2014-12-01

    Supplementation with beta-alanine may have positive effects on severe-intensity, intermittent, and isometric strength-endurance performance. These could be advantageous for competitive alpine skiers, whose races last 45 to 150 s, require metabolic power above the aerobic maximum, and involve isometric muscle work. Further, beta-alanine supplementation affects the muscle force-frequency relationship, which could influence explosiveness. We explored the effects of beta-alanine on explosive jump performance, severe exercise energy metabolism, and severe-intensity ski-like performance. Nine male elite alpine skiers consumed 4.8 g/d beta-alanine or placebo for 5 weeks in a double-blind fashion. Before and after, they performed countermovement jumps (CMJ), a 90-s cycling bout at 110% VO2max (CLT), and a maximal 90-s box jump test (BJ90). Beta-alanine improved maximal (+7 ± 3%, d = 0.9) and mean CMJ power (+7 ± 2%, d = 0.7), tended to reduce oxygen deficit (-3 ± 8%, p = .06) and lactate accumulation (-12 ± 31%) and enhance aerobic energy contribution (+1.3 ± 2.9%, p = .07) in the CLT, and improved performance in the last third of BJ90 (+7 ± 4%, p = .02). These effects were not observed with placebo. Beta-alanine supplementation improved explosive and repeated jump performance in elite alpine skiers. Enhanced muscle contractility could possibly explain improved explosive and repeated jump performance. Increased aerobic energy production could possibly help explain repeated jump performance as well.

  10. The superposed orogenesis of the alpine-mediterranean edifice; Las orogenesis superpuestas del edificio alpino-mediterraneo

    Energy Technology Data Exchange (ETDEWEB)

    Argyriadis, I.

    2016-10-01

    The circum-Mediterranean chains must be considered as the result of two distinct orogenies. The apparent unity of the present structure is of formal order, due to the latest deformations. Since the Hercynian time there have been two periods of paroxysmal deformation; the younger fits the definition of the alpine orogeny; the older occured during the Cretaceous and may correspond to the first great convergent relative drift of the Eurasiatic and African blocks. The Cretaceous or Mesogean orogeny is independent from the Alpine orogeny stricto sensu (Oligo-Miocene) and cannot be considered as its prefiguration. Being independent in time, it is independent in space as well. Even if this Mesogean orogeny can appear locally restricted to the internal parts of the Alpine chains (Central Mediterranean area, Carpathes, Dinarides) this cannot be taken as a rule: towards the west, the Cretaceous deformations cross the axis of the western Alps and extend (new investigations) over Provence to the Betic chains and the Pyrenean area. Towards the east, the deformations of this period cross the Hellenides (new observations) and spread over the external area in a spectacular way, interesting areas which have never been tectonised again (Cyprus, south-eastern Anatolia, northern Syria, Oman). As a whole, this large Cretaceous orogenic zone is part of a wider domain which extends over central Iran towards the Himalayas and eastern Asia, and has its equivalent on the western side of the Atlantic Ocean, in the Caribbean islands, Mexico and the Americas. (Author)

  11. Exhumation of the North Alpine Foreland Basin- Quantitative insights from structural analysis, thermochronology and a new thermal history model

    Science.gov (United States)

    Luijendijk, Elco; von Hagke, Christoph; Hindle, David

    2016-04-01

    Due to a wealth of geological and thermochronology data the northern foreland basin of the European Alps is an ideal natural laboratory for understanding the dynamics of foreland basins and their interaction with surface and geodynamic processes. We present an unprecedented compilation of thermochronological data from the basin and quantify cooling and exhumation rates in the basin by combining published and new vitrinite reflectance, apatite fission track and U-Th/He data with a new inverse burial and thermal history model. No correlation is obvious between inferred cooling and exhumation rates and elevation, relief or tectonics. We compare derived temperature histories to exhumation estimates based on the retro-deformation of Molasse basin and the Jura mountains, and to exhumation caused by drainage reorganization and incision. Drainage reorganization can explain at most 25% of the observed cooling rates in the basin. Tectonic transport of the basin's sediments over the inclined basement of the alpine foreland as the Jura mountains shortened can explain part of the cooling signal in the western part of the basin. However, overall a substantial amount of cooling and exhumation remains unexplained by known tectonic and surface processes. Our results document basin wide exhumation that may be related to slab roll-back or other lithospheric processes. Uncertainty analysis shows that thermochronometers can be explained by cooling and exhumation starting as early as the Miocene or as late as the Pleistocene. New (U-Th)/He data from key areas close to the Alpine front may provide better constraints on the timing of exhumation.

  12. Effect of altitude and season on microbial activity, abundance and community structure in Alpine forest soils

    Czech Academy of Sciences Publication Activity Database

    Siles, J. A.; Cajthaml, Tomáš; Minerbi, S.; Margesin, R.

    2016-01-01

    Roč. 92, č. 3 (2016), fiw008 ISSN 0168-6496 Institutional support: RVO:61388971 Keywords : Alpine soil s * forest * altitude Subject RIV: EE - Microbiology, Virology Impact factor: 3.720, year: 2016

  13. Water erosion and climate change in a small alpine catchment

    Science.gov (United States)

    Berteni, Francesca; Grossi, Giovanna

    2017-04-01

    WATER EROSION AND CLIMATE CHANGE IN A SMALL ALPINE CATCHMENT Francesca Berteni, Giovanna Grossi A change in the mean and variability of some variables of the climate system is expected to affect the sediment yield of mountainous areas in several ways: for example through soil temperature and precipitation peak intensity change, permafrost thawing, snow- and ice-melt time shifting. Water erosion, sediment transport and yield and the effects of climate change on these physical phenomena are the focus of this work. The study area is a small mountainous basin, the Guerna creek watershed, located in the Central Southern Alps. The sensitivity of sediment yield estimates to a change of condition of the climate system may be investigated through the application of different models, each characterized by its own features and limits. In this preliminary analysis two different empirical mathematical models are considered: RUSLE (Revised Universal Soil Loss Equation; Renard et al., 1991) and EPM (Erosion Potential Method; Gavrilovic, 1988). These models are implemented in a Geographical Information System (GIS) supporting the management of the territorial database used to estimate relevant geomorphological parameters and to create different thematic maps. From one side the geographical and geomorphological information is required (land use, slope and hydrogeological instability, resistance to erosion, lithological characterization and granulometric composition). On the other side the knowledge of the weather-climate parameters (precipitation and temperature data) is fundamental as well to evaluate the intensity and variability of the erosive processes and estimate the sediment yield at the basin outlet. Therefore different climate change scenarios were considered in order to tentatively assess the impact on the water erosion and sediment yield at the small basin scale. Keywords: water erosion, sediment yield, climate change, empirical mathematical models, EPM, RUSLE, GIS

  14. Seasonal shift in climatic limiting factors on tree transpiration: evidence from sap flow observations at alpine treelines in southeast Tibet

    Directory of Open Access Journals (Sweden)

    Liu Xinsheng

    2016-07-01

    Full Text Available Alpine and northern treelines are primarily controlled by low temperatures. However, little is known about the impact of low soil temperature on tree transpiration at treelines. We aim to test the hypothesis that in cold-limited forests, the main limiting factors for tree transpiration switch from low soil temperature before summer solstice to atmospheric evaporative demand after summer solstice, which generally results in low transpiration in the early growing season. Sap flow, meteorological factors and predawn needle water potential were continuously monitored throughout one growing season across Smith fir (Abies georgei var. smithii and juniper (Juniperus saltuaria treelines in southeast Tibet. Sap flow started in early May and corresponded to a threshold mean air-temperature of 0 oC. Across tree species, transpiration was mainly limited by low soil temperature prior to the summer solstice but by vapor pressure deficit and solar radiation post-summer solstice, which was further confirmed on a daily scale. As a result, tree transpiration for both tree species was significantly reduced in the pre-summer solstice period as compared to post-summer solstice, resulting in a lower predawn needle water potential for Smith fir trees in the early growing season. Our data supported the hypothesis, suggesting that tree transpiration mainly responds to soil temperature variations in the early growing season. The results are important for understanding the hydrological response of cold-limited forest ecosystems to climate change.

  15. Physiological response to etho-ecological stressors in male Alpine chamois: timescale matters!

    Science.gov (United States)

    Corlatti, Luca; Palme, Rupert; Lovari, Sandro

    2014-07-01

    From a life history perspective, glucocorticoids secreted by the neuroendocrine system, integrating different sources of stress through an adaptive feedback mechanism, may have important consequences on individual fitness. Although stress responses have been the object of several investigations, few studies have explored the role of proximate mechanisms responsible for the potential trade-offs between physiological stress and life history traits integrating social and environmental stressors. In 2011 and 2012, we collected data on faecal cortisol metabolites (FCM) in a marked male population of Alpine chamois, within the Gran Paradiso National Park (Italy). Using a model selection approach we analysed the effect of potential etho-ecological stressors such as age, social status (territorial vs. non-territorial males), minimum temperature, snow depth and precipitation on FCM variation. To correctly interpret environmentally and socially induced stress responses, we conducted model selections over multiple temporal scales defined a priori: year, cold months, spring, warm months, mating season. Over the year, FCM levels showed a negative relationship with minimum temperature, but altogether, climatic stressors had negligible effects on glucocorticoid secretion, possibly owing to good adaptations of chamois to severe weather conditions. Age was negatively related to FCM during the rut, possibly due to greater experience of older males in agonistic contests. Social status was an important determinant of FCM excretion: while both the `stress of subordination' and the `stress of domination' hypotheses received some support in spring and during the mating season, respectively, previous data suggest that only the latter may have detrimental fitness consequences on male chamois.

  16. Drivers of spatial heterogeneity in nitrogen processing among three alpine plant communities in the Rocky Mountains

    Science.gov (United States)

    Churchill, A. C.; Beers, A.; Grinath, J.; Bowman, W. D.

    2017-12-01

    Nitrogen cycling across the globe has been fundamentally altered due to regional elevated N deposition and there is a cascade of ecosystem consequences including shifts in species composition, eutrophication, and soil acidification. Making predictions that encompass the factors that drive these ecosystem changes has frequently been limited to single ecosystem types, or areas with fairly homogenous abiotic conditions. The alpine is an ecosystem type that exhibits changes under relatively low levels of N depositions due to short growing seasons and shallow soils limiting N storage. While recent work provided estimates for the magnitude of N associated with ecosystem changes, less is known about the within-site factors that may interact to stabilize or amplify the differential response of N pools under future conditions of resource deposition. To examine numerous potential within-site and regional factors (both biotic and abiotic) affecting ecosystem N pools we examined the relationship between those factors and a suite of ecosystem pools of N followed by model selection procedures and structural equation modelling. Measurements were conducted at Niwot Ridge Long Term Ecological Research site and in Rocky Mountain National Park in three distinct alpine meadow ecosystems (dry, moist, and wet meadows). These meadows span a moisture gradient as well as plant community composition, thereby providing high variability of potential biotic and abiotic drivers across small spatial scales in the alpine. In general, regional scale abiotic factors such as site levels of annual average N deposition or precipitation were poor predictors of seasonal pools of N, while spring soil water pools of N were negatively correlated with elevation. Models containing multiple abiotic and biotic drivers, however, were best at predicting soil and plant pools of N across the two sites. Future analysis will include highlight interactions among with-site factors affecting N pools in the alpine using

  17. Evaluation of the anaerobic ability of alpine skiing skiers through the slalom simulator

    Directory of Open Access Journals (Sweden)

    Vasilios Giovanis

    2017-10-01

    Full Text Available Purpose: The purpose of the research was the evaluation of efficiency of anaerobic ability (power, anaerobic endurance, anaerobic fatigue and the restitution of the pulse rate of alpine skiing students through the slalom simulator. In addition, the aim of the research was the correlation of the special tests of alpine skiing on dry ground (octagon test and in snow (triangle test and slalom test with the target of determining ability levels. Methods: The 20 people sample was composed by two teams of male and female who took the course for advanced (n = 7 aged 23±1.40 years and for beginners course (n = 13 aged 20±1.49 years. For the evaluation process two special tests were used, on the ground and in snow. The ground test was completed in the slalom simulator for 40 seconds. The second ground test was the octagon bouncing (40cm each side x 3. The snow test was the Haczkiewicz test (triangle test and the slalom (7 gates, where the time of a try was measured. Results: The best efficiency in anaerobic power was made by the advanced males and females, while in the anaerobic endurance by the beginners males and females. The best performance in the dexterity tests in snow on the triangle and slalom test was made by the advanced males and beginners females respectively. Conclusions: The significant correlation between the results of anaerobic performance in the slalom simulator and the triangle test in snow confirms the means of diagnosing skill and fitness on dry ground and snow respectively. There is a significant correlation between snow test results and there is no correlation with the octagon test. The aforementioned results can be used in the talent selection process of alpine skiing.

  18. Vertical distribution of organochlorine pesticides in humus along Alpine altitudinal profiles in relation to ambiental parameters

    Energy Technology Data Exchange (ETDEWEB)

    Kirchner, M., E-mail: kirchner@helmholtz-muenchen.d [Helmholtz Zentrum Muenchen, GmbH, Institutes of Ecological Chemistry, Developmental Genetics and Soil Ecology, Ingolstaedter Landstrasse 1, D-85764 Neuherberg (Germany); Faus-Kessler, T.; Jakobi, G.; Levy, W.; Henkelmann, B.; Bernhoeft, S.; Kotalik, J.; Zsolnay, A. [Helmholtz Zentrum Muenchen, GmbH, Institutes of Ecological Chemistry, Developmental Genetics and Soil Ecology, Ingolstaedter Landstrasse 1, D-85764 Neuherberg (Germany); Bassan, R. [Regional Agency for Environmental Prevention and Protection of Veneto (Italy); Belis, C. [Regional Agency for Environmental Protection of Lombardy (Italy); Kraeuchi, N. [Swiss Federal Institute for Forest, Snow and Landscape Research (Switzerland); Moche, W. [Federal Environment Agency Ltd. (Austria); Simoncic, P. [Slovenian Forestry Institute (Slovenia); Uhl, M.; Weiss, P. [Federal Environment Agency Ltd. (Austria); Schramm, K.-W. [Helmholtz Zentrum Muenchen, GmbH, Institutes of Ecological Chemistry, Developmental Genetics and Soil Ecology, Ingolstaedter Landstrasse 1, D-85764 Neuherberg (Germany)

    2009-12-15

    In forest soils along vertical profiles located in different parts of the Alps, concentrations of persistent organic pollutants (POPs), namely organochlorine pesticides (OCPs) like dichlorodiphenyltrichloroethanes (DDTs), hexachlorobenzene (HCB), hexachlorocyclohexanes (HCH), heptachlor, aldrin, dieldrin and mirex, were measured. Though local characteristics of the sites are influenced by numerous factors like orographic and meteorological parameters, forest stand characteristics and humus parameters, we ascertained a marked vertical increase of concentrations of some organochlorine compounds in the soil. On the basis of climatological values of each site, we found that the contamination increase with altitude can be ascribed to a certain 'cold condensation effect'. In addition, the perennial atmospheric deposition of POPs is controlled by precipitation. Other key parameters explaining the accumulation of POPs are the soil organic carbon stocks, the turnover times, the re-volatilisation and degradation processes, which vary with altitude. - Caused by temperature-dependent processes regarding deposition, re-volatilization and decomposition of POPs, the concentration of organochlorine pesticides varies in the Alpine region with altitude.

  19. Snowboarding injuries, a four-year study with comparison with alpine ski injuries.

    Science.gov (United States)

    Davidson, T M; Laliotis, A T

    1996-03-01

    Snowboarding is a rapidly growing winter sport. Its unorthodox maneuvers and young participants raise many safety concerns. We examined injury patterns in recreational snowboarders, comparing these patterns with those found in alpine skiers. Snowboarding and skiing injury patterns differed significantly (P knee (17% versus 39%) or thumb (2% versus 4%) injuries than skiers. For snowboarders, wrist injuries were most common in beginners (30%), knee injuries in low intermediates (28%), ankle injuries in intermediates (17%), and shoulder or clavicle injuries in advanced snowboarders (14%). Most snowboarders (90%) wore soft-shelled boots, 73% of lower extremity injuries occurred to the lead-foot side, and 73% of wrist injuries occurred during backward falls; 67% of knee injuries occurred during forward falls. Of all injuries, 8% occurred while loading onto or unloading from a ski lift. The sport of snowboarding brings with it a different set of injuries from those seen in alpine skiing. The data focus attention on improvements such as wrist guards or splints, releasable front-foot bindings, and better instruction for beginner snowboarders to improve the safety of this sport. Finally, the data confirm that snowboarders and skiers may be safely combined on the same slopes.

  20. Ontogenetic niche shifts in three Vaccinium species on a sub-alpine mountain side

    DEFF Research Database (Denmark)

    Auffret, Alistair G.; Meineri, Eric; Bruun, Hans Henrik

    2010-01-01

    Background: Climate warming in arctic and alpine regions is expected to result in the altitudinal migration of plant species, but current predictions neglect differences between species' regeneration niche and established niche. Aims: To examine potential recruitment of Vaccinium myrtillus, V. ul...

  1. How to make a tree ring: Coupling stem water flow and cambial activity in mature Alpine conifers

    Science.gov (United States)

    Peters, Richard L.; Frank, David C.; Treydte, Kerstin; Steppe, Kathy; Kahmen, Ansgar; Fonti, Patrick

    2017-04-01

    Inter-annual tree-ring measurements are used to understand tree-growth responses to climatic variability and reconstruct past climate conditions. In parallel, mechanistic models use experimentally defined plant-atmosphere interactions to explain past growth responses and predict future environmental impact on forest productivity. Yet, substantial inconsistencies within mechanistic model ensembles and mismatches with empirical data indicate that significant progress is still needed to understand the processes occurring at an intra-annual resolution that drive annual growth. However, challenges arise due to i) few datasets describing climatic responses of high-resolution physiological processes over longer time-scales, ii) uncertainties on the main mechanistic process limiting radial stem growth and iii) complex interactions between multiple environmental factors which obscure detection of the main stem growth driver, generating a gap between our understanding of intra- and inter-annual growth mechanisms. We attempt to bridge the gap between inter-annual tree-ring width and sub-daily radial stem-growth and provide a mechanistic perspective on how environmental conditions affect physiological processes that shape tree rings in conifers. We combine sub-hourly sap flow and point dendrometer measurements performed on mature Alpine conifers (Larix decidua) into an individual-based mechanistic tree-growth model to simulate sub-hourly cambial activity. The monitored trees are located along a high elevational transect in the Swiss Alps (Lötschental) to analyse the effect of increasing temperature. The model quantifies internal tree hydraulic pathways that regulate the turgidity within the cambial zone and induce cell enlargement for radial growth. The simulations are validated against intra-annual growth patterns derived from xylogenesis data and anatomical analyses. Our efforts advance the process-based understanding of how climate shapes the annual tree-ring structures

  2. Experimental Validation of Various Temperature Modells for Semi-Physical Tyre Model Approaches

    Science.gov (United States)

    Hackl, Andreas; Scherndl, Christoph; Hirschberg, Wolfgang; Lex, Cornelia

    2017-10-01

    With increasing level of complexity and automation in the area of automotive engineering, the simulation of safety relevant Advanced Driver Assistance Systems (ADAS) leads to increasing accuracy demands in the description of tyre contact forces. In recent years, with improvement in tyre simulation, the needs for coping with tyre temperatures and the resulting changes in tyre characteristics are rising significantly. Therefore, experimental validation of three different temperature model approaches is carried out, discussed and compared in the scope of this article. To investigate or rather evaluate the range of application of the presented approaches in combination with respect of further implementation in semi-physical tyre models, the main focus lies on the a physical parameterisation. Aside from good modelling accuracy, focus is held on computational time and complexity of the parameterisation process. To evaluate this process and discuss the results, measurements from a Hoosier racing tyre 6.0 / 18.0 10 LCO C2000 from an industrial flat test bench are used. Finally the simulation results are compared with the measurement data.

  3. Functional traits and root morphology of alpine plants.

    Science.gov (United States)

    Pohl, Mandy; Stroude, Raphaël; Buttler, Alexandre; Rixen, Christian

    2011-09-01

    Vegetation has long been recognized to protect the soil from erosion. Understanding species differences in root morphology and functional traits is an important step to assess which species and species mixtures may provide erosion control. Furthermore, extending classification of plant functional types towards root traits may be a useful procedure in understanding important root functions. In this study, pioneer data on traits of alpine plant species, i.e. plant height and shoot biomass, root depth, horizontal root spreading, root length, diameter, tensile strength, plant age and root biomass, from a disturbed site in the Swiss Alps are presented. The applicability of three classifications of plant functional types (PFTs), i.e. life form, growth form and root type, was examined for above- and below-ground plant traits. Plant traits differed considerably among species even of the same life form, e.g. in the case of total root length by more than two orders of magnitude. Within the same root diameter, species differed significantly in tensile strength: some species (Geum reptans and Luzula spicata) had roots more than twice as strong as those of other species. Species of different life forms provided different root functions (e.g. root depth and horizontal root spreading) that may be important for soil physical processes. All classifications of PFTs were helpful to categorize plant traits; however, the PFTs according to root type explained total root length far better than the other PFTs. The results of the study illustrate the remarkable differences between root traits of alpine plants, some of which cannot be assessed from simple morphological inspection, e.g. tensile strength. PFT classification based on root traits seems useful to categorize plant traits, even though some patterns are better explained at the individual species level.

  4. Explaining plant-soil diversity in Alpine ecosystems: more than just time since ecosystem succession started

    Science.gov (United States)

    Lane, Stuart; Baetz, Nico; Borgeaud, Laure; Verrecchia, Eric; Vittoz, Pascal

    2014-05-01

    Ecosystem succession in Alpine environments has been a focus of research for many decades. Following from the classic ideas of Jenny (1941, 1961), following perturbation, an ecosystem (flora, fauna and soil) should evolve as a function of time at a rate conditioned by external variables (relief, climate, geology). More recently, biogeomorphologists have focused upon the notion of co-evolution of geomorphic processes with ecosystems over very short through to very long (evolutionary) time-scales. Alpine environments have been a particular focus of models of co-evolution, as a means of understanding the rate of plant colonization of previously glaciated terrain. However, work in this field has tended to adopt an over simplified view of the relationship between perturbation and succession, including: how the landform and ecosystem itself conditions the impact of a perturbation to create a complex spatial impact; and how perturbations are not simply ecosystem destroyers but can be a significant source of ecosystem resources. What this means is that at the within landform scale, there may well be a complex and dynamic topographic and sedimentological template that co-evolves with the development of soil, flora and fauna. In this paper, we present and test conceptual models for such co-evolution for an Alpine alluvial fan and an Alpine piedmont braided river. We combine detailed floristic inventory with soil inventory, survey of edaphic variables above and below ground (e.g. vertical and lateral sedimentological structure, using electrical resistance tomography) and the analysis of historical aerial imagery. The floristic inventory shows the existence of a suite of distinct plant communities within each landform. Time since last perturbation is not a useful explanatory variable of the spatial distribution of these communities because: (1) perturbation impacts are spatially variable, as conditioned by the extent distribution of topographic, edaphic and ecological

  5. Linking sheep density and grazing frequency to persistence of herb species in an alpine environment

    Czech Academy of Sciences Publication Activity Database

    Lanta, V.; Austrheim, G.; Evju, M.; Klimešová, Jitka; Mysterud, A.

    2014-01-01

    Roč. 29, č. 3 (2014), s. 411-420 ISSN 0912-3814 R&D Projects: GA ČR GA526/09/0963 Institutional support: RVO:67985939 Keywords : sheep grazing * alpine pastures * Norway Subject RIV: EH - Ecology, Behaviour Impact factor: 1.296, year: 2014

  6. Experimental soil warming and cooling alters the partitioning of recent assimilates: evidence from a (14)C-labelling study at the alpine treeline.

    Science.gov (United States)

    Ferrari, A; Hagedorn, F; Niklaus, P A

    2016-05-01

    Despite concerns about climate change effects on ecosystems functioning, little is known on how plant assimilate partitioning changes with temperature. Particularly, large temperature effects might occur in cold ecosystems where critical processes are at their temperature limit. In this study, we tested temperature effects on carbon (C) assimilate partitioning in a field experiment at the alpine treeline. We warmed and cooled soils of microcosms planted with Pinus mugo or Leucanthemopsis alpina, achieving daily mean soil temperatures (3-10 cm depth) around 5.8, 12.7 and 19.2 °C in cooled, control and warmed soils. We pulse-labelled these systems with (14)CO2 for one photoperiod and traced (14)C over the successive 4 days. Plant net (14)C uptake increased steadily with soil temperature. However, (14)C amounts in fungal hyphae, soil microbial biomass, soil organic matter, and soil respiration showed a non-linear response to temperature. This non-linear pattern was particularly pronounced in P. mugo, with five times higher (14)C activities in cooled compared to control soils, but no difference between warmed and control soil. Autoradiographic analysis of the spatial distribution of (14)C in soils indicated that temperature effects on the vertical label distribution within soils depended on plant species. Our results show that plant growth, in particular root metabolism, is limited by low soil temperature. As a consequence, positive temperature effects on net C uptake may not be paralleled by similar changes in rhizodeposition. This has important implications for predictions of soil C storage, because rhizodeposits and plant biomass vary strongly in their residence times.

  7. Reconstruction of Holocene changes in alpine vegetation and climate in the Maligne Range, Jasper National Park, Alberta

    Science.gov (United States)

    Luckman, B. H.; Kearney, M. S.

    1986-09-01

    Pollen, macrofossil (logs and needles), and oxygen-isotope data from tree rings are presented for three alpine bog sites in the Maligne Range of the Canadian Rockies. Organic sedimentation at the Watchtower site began prior to ca. 9500 14C yr B.P. and by 8770 yr B.P. timberlines were at least 100 m above present levels. The two pollen records are dominated by Pinus and subsequent changes in timberlines are inferred from pollen-ratio data ( Abies/Pinus) and from macrofossils. The recovered records indicate two periods of high Hypsithermal timberlines ca. 8800-7500 and 7200-5200 yr B.P. separated by a short interval ca. 7300-7400 yr B.P. when timberline approached modern levels. After ca. 4500 yr B.P. timberlines have been similar to or lower than present, reaching minimum values in the last 500 yr. δ 18O determinations from the α-cellulose of samples of 5 or 10 annual rings cut from contemporary Picea englemannii at timberline show strong correlations with mean annual temperatures at Jasper. Isotopic determinations from Hypsithermal-age logs recovered from sites above present timberline indicate mean annual temperatures were at least 0.5°C warmer ca. 8060 and 8770 yr B.P. than at present at the Watchtower site. Data from logs at the Maligne Pass site suggest that temperatures were about 1.2° and 1.6°C warmer ca. 6000 and 5300 yr B.P. Estimates of temperature from the pollen-ratio data are more conservative and suggest maximum differences of ca. 1.0°C in July temperatures over the last 8000 yr.

  8. Alpine grassland soil organic carbon stock and its uncertainty in the three rivers source region of the Tibetan Plateau.

    Directory of Open Access Journals (Sweden)

    Xiaofeng Chang

    Full Text Available Alpine grassland of the Tibetan Plateau is an important component of global soil organic carbon (SOC stocks, but insufficient field observations and large spatial heterogeneity leads to great uncertainty in their estimation. In the Three Rivers Source Region (TRSR, alpine grasslands account for more than 75% of the total area. However, the regional carbon (C stock estimate and their uncertainty have seldom been tested. Here we quantified the regional SOC stock and its uncertainty using 298 soil profiles surveyed from 35 sites across the TRSR during 2006-2008. We showed that the upper soil (0-30 cm depth in alpine grasslands of the TRSR stores 2.03 Pg C, with a 95% confidence interval ranging from 1.25 to 2.81 Pg C. Alpine meadow soils comprised 73% (i.e. 1.48 Pg C of the regional SOC estimate, but had the greatest uncertainty at 51%. The statistical power to detect a deviation of 10% uncertainty in grassland C stock was less than 0.50. The required sample size to detect this deviation at a power of 90% was about 6-7 times more than the number of sample sites surveyed. Comparison of our observed SOC density with the corresponding values from the dataset of Yang et al. indicates that these two datasets are comparable. The combined dataset did not reduce the uncertainty in the estimate of the regional grassland soil C stock. This result could be mainly explained by the underrepresentation of sampling sites in large areas with poor accessibility. Further research to improve the regional SOC stock estimate should optimize sampling strategy by considering the number of samples and their spatial distribution.

  9. Effect on milk production of F1 crossbreds resulted from Alpine breed (♂ x Albanian local goat breed (♀

    Directory of Open Access Journals (Sweden)

    Kristaq Kume

    2012-07-01

    Full Text Available About 950,000 goats, farmed mostly in hilly and mountainous areas of Albania, contribute about 8% of the country’s total milk production. In order to increase milk production, farmers are currently using crosses of the local goat breed with exotic breeds, mainly the Alpine breed from France. This study examines milk production data of first lactation from 45 goats of the local breed, 82 goats of the Alpine breed and 58 F1 crosses (♂Alpine breed x ♀local breed. The goats were kept on small-scale farms according to the traditional Albanian system. Milking was carried out in the morning and evening. Kids were weaned at 65 days of age after which milking started. Milk yield was recorded twice with a 15-day interval between the two readings. Total milk yield was calculated using the Fleischmann method. The F1 goats produced 37.8 kg more milk than local breed goats although the lactation length (P<0.05 of F1 goats was six days shorter compared to that of local breed goats (P<0.05. Analysis of variance showed a highly significant effect (P<0.01 of the genotype factor on milk production. The average Cappio-Borlino curves of three genotypes indicated that the lactation curves of local breed and F1 crosses were similar. Although the F1 cross goats had 50% of their genomes from a genetically improved breed they were still able to deal with the difficult conditions that characterize the traditional extensive farming systems in Albania. Breeding pure Alpine breed or its crosses with the local goat breed improved milk production in an extensive traditional system.

  10. Validation of a Climate-Data Record of the "Clear-Sky" Surface Temperature of the Greenland Ice Sheet

    Science.gov (United States)

    Hall, Dorothy K.; Box, Jason E.; Koenig, Lora S.; DiGirolamo, Nicolo E.; Comiso, Josefino C.; Shuman, Christopher A.

    2011-01-01

    Surface temperatures on the Greenland Ice Sheet have been studied on the ground, using automatic weather station (AWS) data from the Greenland-Climate Network (GC-Net), and from analysis of satellite sensor data. Using Advanced Very High Frequency Radiometer (AVHRR) weekly surface temperature maps, warming of the surface of the Greenland Ice Sheet has been documented since 1981. We extended and refined this record using higher-resolution Moderate-Resolution Imaging Spectroradiometer (MODIS) data from March 2000 to the present. We developed a daily and monthly climate-data record (CDR) of the "clear-sky" surface temperature of the Greenland Ice Sheet using an ice-surface temperature (1ST) algorithm developed for use with MODIS data. Validation of this CDR is ongoing. MODIS Terra swath data are projected onto a polar stereographic grid at 6.25-km resolution to develop binary, gridded daily and mean-monthly 1ST maps. Each monthly map also has a color-coded image map that is available to download. Also included with the monthly maps is an accompanying map showing number of days in the month that were used to calculate the mean-monthly 1ST. This is important because no 1ST decision is made by the algorithm for cells that are considered cloudy by the internal cloud mask, so a sufficient number of days must be available to produce a mean 1ST for each grid cell. Validation of the CDR consists of several facets: 1) comparisons between ISTs and in-situ measurements; 2) comparisons between ISTs and AWS data; and 3) comparisons of ISTs with surface temperatures derived from other satellite instruments such as the Thermal Emission and Reflection Radiometer (ASTER) and Enhanced Thematic Mapper Plus (ETM+). Previous work shows that Terra MODIS ISTs are about 3 C lower than in-situ temperatures measured at Summit Camp, during the winter of 2008-09 under clear skies. In this work we begin to compare surface temperatures derived from AWS data with ISTs from the MODIS CDR.

  11. [Effects of simulated warming on the growth, leaf phenology, and leaf traits of Salix eriostachya in sub-alpine timberline ecotone of western Sichuan, China].

    Science.gov (United States)

    Xu, Zhen-feng; Hu, Ting-xing; Zhang, Li; Zhang, Yuan-bin; Xian, Jun-ren; Wang, Kai-yun

    2009-01-01

    By using open-top chamber (OTC), the effects of simulated warming on the growth, leaf phenology, and leaf traits of Salix eriostachya in sub-alpine timberline ecotone of Western Sichuan were studied. The results showed that comparing with the control, the mean air temperature at 1.2 m above the ground throughout S. eriostachya growth season in OTC increased by 2.9 degrees C, while the soil temperature at the depth of 5 cm only increased by 0.4 degrees C. The temperature increase in OTC made S. eriostachya budding advanced and defoliation postponed obviously, and the leaf life-span longer. The leaf and branch growth rates as well as the specific leaf area in OTC increased obviously, whereas the leaf nitrogen concentration decreased significantly. In OTC, the stomata conductance, net photosynthetic rate, photorespiration, and dark respiration rate of S. eriostachya all exhibited an increasing trend. It was suggested that S. eriostachya had stronger capability to adapt to warming, and, under the background of future global climate change, the elevation of S. eriostachya distribution in the timberline ecotone would be likely to ascend.

  12. Temperature studies of the TileCal ROD G-Links for the validation of the air-cooling system

    CERN Document Server

    Valero, A; Abdallah, J; Castillo, V; Cuenca, C; Ferrer, A; Fullana, E; González, V; Higón, E; Munar, A; Poveda, J; Salvachúa, B; Sanchis, E; Solans, C; Torres, J; Valls, J A

    2007-01-01

    In this paper we show the results of the temperature studies performed on the TileCal ROD G-Links in order to validate the air-cooling system. In the first part of the note we present results on the characterization tests of the temperature monitor system for the G-Link chips of the TileCal ROD motherboard, performed at IFIC-Valencia. We report on the performance of the temperature behavior system and some cooling studies of a single ROD motherboard. We conclude that the present system can be successfully used to online monitor the temperature of the ROD G-Links. In the second part we show the results of the studies performed with multiple RODs in a standard 9U VME crate in the laboratory at IFIC, and in their final location in the ATLAS cavern. We conclude that the air-cooling provided by the standard VME crate fans is enough to keep the temperature of the G-Links well within specifications.

  13. Climate change and tourism in the alpine regions of Switzerland

    OpenAIRE

    Bürki, R; Abegg, B; Elsasser, H

    2007-01-01

    For many alpine areas in Switzerland, winter tourism is the most important source of income, and snow-reliability is one of the key elements of the offers made by tourism in the Alps. 85% of Switzerland’s current ski resorts can be designated as snow-reliable. If climate change occurs, the level of snow-reliability will rise from 1200 m up to 1800 m over the next few decades. Only 44% of the ski resorts wouldthen still be snow-reliable. While some regions may be able to maintain their winter ...

  14. Seasonal Changes in the Character and Nitrogen Content of Dissolved Organic Matter in an Alpine/Subalpine Headwater Catchment

    Directory of Open Access Journals (Sweden)

    Eran W. Hood

    2001-01-01

    Full Text Available We are studying the chemical quality of dissolved organic nitrogen (DON in a high-elevation watershed in the Colorado Front Range. Samples were collected over the 2000 snowmelt runoff season at two sites across an alpine/subalpine ecotone to understand how the transition between the lightly vegetated alpine and forested reaches of the catchment influences the chemical character of DON. Samples were analyzed approximately weekly for dissolved organic material (DOM content and chemical character. A subset of samples was analyzed for the elemental content of fulvic and hydrophilic acids. Concentrations of DON at both sites were highest in the spring at the initiation of snowmelt, decreased during snowmelt, and increased again during the late summer and fall. In contrast, concentrations of dissolved organic carbon (DOC peaked on the ascending limb of the hydrograph and declined to seasonal minima on the descending limb of the hydrograph. The ratio of DOC:DON showed a seasonal shift at both sites with high values (40 to 55 during peak runoff in early summer and lower values (15 to 25 during low flows late in the runoff season. These results indicate that there was a seasonal change in the relative N content of DOM at both sites. Chemical fractionation of DOC showed that there were temporal and longitudinal changes in the chemical character of DOC. At the alpine site, the fulvic acid content of DOC decreased from 57% in June to 35% in September. The change in fulvic acid was less pronounced at the forested site, from 66% in June to 54% in September. Elemental analysis of fulvic and hydrophilic acids indicated that hydrophilic acids were N rich compared to fulvic acids. Additionally, fulvic and hydrophilic acids isolated at the alpine site had a lower C:N ratio than those isolated at the forested site. Similarly, the C:N ratio of organic acids at both sites was lower in September than in June during peak runoff. These differences appear to be a result

  15. A tale of two single mountain alpine endemics: Packera franciscana and Erigeron mancus

    Science.gov (United States)

    James F. Fowler; Carolyn H. Sieg; Brian M. Casavant; Addie E. Hite

    2012-01-01

    Both the San Francisco Peaks ragwort, Packera franciscana and the La Sal daisy, Erigeron mancus are endemic to treeline/alpine habitats of the single mountain they inhabit. There is little habitat available for these plant species to migrate upward in a warming climate scenario. For P. franciscana, 2008 estimates indicate over 18,000 ramets in a 4 m band along a...

  16. Controls on fault zone structure and brittle fracturing in the foliated hanging wall of the Alpine Fault

    Science.gov (United States)

    Williams, Jack N.; Toy, Virginia G.; Massiot, Cécile; McNamara, David D.; Smith, Steven A. F.; Mills, Steven

    2018-04-01

    Three datasets are used to quantify fracture density, orientation, and fill in the foliated hanging wall of the Alpine Fault: (1) X-ray computed tomography (CT) images of drill core collected within 25 m of its principal slip zones (PSZs) during the first phase of the Deep Fault Drilling Project that were reoriented with respect to borehole televiewer images, (2) field measurements from creek sections up to 500 m from the PSZs, and (3) CT images of oriented drill core collected during the Amethyst Hydro Project at distances of ˜ 0.7-2 km from the PSZs. Results show that within 160 m of the PSZs in foliated cataclasites and ultramylonites, gouge-filled fractures exhibit a wide range of orientations. At these distances, fractures are interpreted to have formed at relatively high confining pressures and/or in rocks that had a weak mechanical anisotropy. Conversely, at distances greater than 160 m from the PSZs, fractures are typically open and subparallel to the mylonitic or schistose foliation, implying that fracturing occurred at low confining pressures and/or in rocks that were mechanically anisotropic. Fracture density is similar across the ˜ 500 m width of the field transects. By combining our datasets with measurements of permeability and seismic velocity around the Alpine Fault, we further develop the hierarchical model for hanging-wall damage structure that was proposed by Townend et al. (2017). The wider zone of foliation-parallel fractures represents an outer damage zone that forms at shallow depths. The distinct inner damage zone. This zone is interpreted to extend towards the base of the seismogenic crust given that its width is comparable to (1) the Alpine Fault low-velocity zone detected by fault zone guided waves and (2) damage zones reported from other exhumed large-displacement faults. In summary, a narrow zone of fracturing at the base of the Alpine Fault's hanging-wall seismogenic crust is anticipated to widen at shallow depths, which is

  17. Alpine ski and snowboarding traumatic injuries: incidence, injury patterns, and risk factors for 10 years.

    Science.gov (United States)

    McBeth, Paul B; Ball, Chad G; Mulloy, Robert H; Kirkpatrick, Andrew W

    2009-05-01

    Alpine skiing and snowboarding are popular winter sports in Canada. Every year participation in these activities results in traumatic injury. The purpose of this study was to identify the incidence and injury patterns, as well as risk factors associated with ski and snowboarding injuries. A comprehensive 10-year retrospective review of Alpine ski and snowboarding injuries from 1996 to 2006 was conducted. The Alberta Trauma Registry was used as the primary source of data. A total of 196 patients (56.6% skiers, 43.4% snowboarders) were identified as having major traumatic injuries (Injury Severity Score, >or=12). Forty-three patients required intensive care unit support. The majority of injuries were related to falls and collisions with natural objects. Head injuries were most common, followed by chest, spinal, and extremity trauma. Seventy-nine patients required emergency surgery. Skiing and snowboarding represent activities with high potential for traumatic injury. Safety initiatives should be developed to target this population.

  18. Alpine plant distribution and thermic vegetation indicator on Gloria summits in the central Greater Caucasus

    International Nuclear Information System (INIS)

    Gigauri, K.; Abdaladze, O.; Nakhutsrishvili, G

    2016-01-01

    The distribution of plant species within alpine areas is often directly related to climate or climate-influenced ecological factors. Responding to observed changes in plant species, cover and composition on the GLORIA summits in the Central Caucasus, an extensive setup of 1m * 1m permanent plots was established at the treeline-alpine zones and nival ecotone (between 2240 and 3024 m a.s.l.) on the main watershed range of the Central Greater Caucasus nearby the Cross Pass, Kazbegi region, Georgia. Recording was repeated in a representative selection of 64 quadrates in 2008. The local climatic factors - average soil T degree C and growing degree days (GDD) did not show significant increasing trends. For detection of climate warming we used two indices: thermic vegetation indicator S and thermophilization indicator D. They were varying along altitudinal and exposition gradients. The thermic vegetation indicator decrease in all monitoring summits. The abundance rank of the dominant and endemic species did not change during monitoring period. (author)

  19. Hemiparasite abundance in an alpine treeline ecotone increases in response to atmospheric CO(2) enrichment.

    Science.gov (United States)

    Hättenschwiler, Stephan; Zumbrunn, Thomas

    2006-02-01

    Populations of the annual hemiparasites Melampyrum pratense L. and Melampyrum sylvaticum L. were studied at the treeline in the Swiss Alps after 3 years of in situ CO(2) enrichment. The total density of Melampyrum doubled to an average of 44 individuals per square meter at elevated CO(2) compared to ambient CO(2). In response to elevated CO(2), the height of the more abundant and more evenly distributed M. pratense increased by 20%, the number of seeds per fruit by 21%, and the total seed dry mass per fruit by 27%, but the individual seed size did not change. These results suggest that rising atmospheric CO(2) may stimulate the reproductive output and increase the abundance of Melampyrum in the alpine treeline ecotone. Because hemiparasites can have important effects on community dynamics and ecosystem processes, notably the N cycle, changing Melampyrum abundance may potentially influence the functioning of alpine ecosystems in a future CO(2)-rich atmosphere.

  20. Moisture rivals temperature in limiting photosynthesis by trees establishing beyond their cold-edge range limit under ambient and warmed conditions

    Science.gov (United States)

    Moyes, Andrew B.; Germino, Matthew J.; Kueppers, Lara M.

    2015-01-01

    Climate change is altering plant species distributions globally, and warming is expected to promote uphill shifts in mountain trees. However, at many cold-edge range limits, such as alpine treelines in the western United States, tree establishment may be colimited by low temperature and low moisture, making recruitment patterns with warming difficult to predict.

  1. Application of dGNSS in Alpine Ski Racing: Basis for Evaluating Physical Demands and Safety

    Science.gov (United States)

    Gilgien, Matthias; Kröll, Josef; Spörri, Jörg; Crivelli, Philip; Müller, Erich

    2018-01-01

    External forces, such as ground reaction force or air drag acting on athletes' bodies in sports, determine the sport-specific demands on athletes' physical fitness. In order to establish appropriate physical conditioning regimes, which adequately prepare athletes for the loads and physical demands occurring in their sports and help reduce the risk of injury, sport-and/or discipline-specific knowledge of the external forces is needed. However, due to methodological shortcomings in biomechanical research, data comprehensively describing the external forces that occur in alpine super-G (SG) and downhill (DH) are so far lacking. Therefore, this study applied new and accurate wearable sensor-based technology to determine the external forces acting on skiers during World Cup (WC) alpine skiing competitions in the disciplines of SG and DH and to compare these with those occurring in giant slalom (GS), for which previous research knowledge exists. External forces were determined using WC forerunners carrying a differential global navigation satellite system (dGNSS). Combining the dGNSS data with a digital terrain model of the snow surface and an air drag model, the magnitudes of ground reaction forces were computed. It was found that the applied methodology may not only be used to track physical demands and loads on athletes, but also to simultaneously investigate safety aspects, such as the effectiveness of speed control through increased air drag and ski–snow friction forces in the respective disciplines. Therefore, the component of the ground reaction force in the direction of travel (ski–snow friction) and air drag force were computed. This study showed that (1) the validity of high-end dGNSS systems allows meaningful investigations such as characterization of physical demands and effectiveness of safety measures in highly dynamic sports; (2) physical demands were substantially different between GS, SG, and DH; and (3) safety-related reduction of skiing speed might

  2. Application of dGNSS in Alpine Ski Racing: Basis for Evaluating Physical Demands and Safety

    Directory of Open Access Journals (Sweden)

    Matthias Gilgien

    2018-03-01

    Full Text Available External forces, such as ground reaction force or air drag acting on athletes' bodies in sports, determine the sport-specific demands on athletes' physical fitness. In order to establish appropriate physical conditioning regimes, which adequately prepare athletes for the loads and physical demands occurring in their sports and help reduce the risk of injury, sport-and/or discipline-specific knowledge of the external forces is needed. However, due to methodological shortcomings in biomechanical research, data comprehensively describing the external forces that occur in alpine super-G (SG and downhill (DH are so far lacking. Therefore, this study applied new and accurate wearable sensor-based technology to determine the external forces acting on skiers during World Cup (WC alpine skiing competitions in the disciplines of SG and DH and to compare these with those occurring in giant slalom (GS, for which previous research knowledge exists. External forces were determined using WC forerunners carrying a differential global navigation satellite system (dGNSS. Combining the dGNSS data with a digital terrain model of the snow surface and an air drag model, the magnitudes of ground reaction forces were computed. It was found that the applied methodology may not only be used to track physical demands and loads on athletes, but also to simultaneously investigate safety aspects, such as the effectiveness of speed control through increased air drag and ski–snow friction forces in the respective disciplines. Therefore, the component of the ground reaction force in the direction of travel (ski–snow friction and air drag force were computed. This study showed that (1 the validity of high-end dGNSS systems allows meaningful investigations such as characterization of physical demands and effectiveness of safety measures in highly dynamic sports; (2 physical demands were substantially different between GS, SG, and DH; and (3 safety-related reduction of skiing

  3. Application of dGNSS in Alpine Ski Racing: Basis for Evaluating Physical Demands and Safety.

    Science.gov (United States)

    Gilgien, Matthias; Kröll, Josef; Spörri, Jörg; Crivelli, Philip; Müller, Erich

    2018-01-01

    External forces, such as ground reaction force or air drag acting on athletes' bodies in sports, determine the sport-specific demands on athletes' physical fitness. In order to establish appropriate physical conditioning regimes, which adequately prepare athletes for the loads and physical demands occurring in their sports and help reduce the risk of injury, sport-and/or discipline-specific knowledge of the external forces is needed. However, due to methodological shortcomings in biomechanical research, data comprehensively describing the external forces that occur in alpine super-G (SG) and downhill (DH) are so far lacking. Therefore, this study applied new and accurate wearable sensor-based technology to determine the external forces acting on skiers during World Cup (WC) alpine skiing competitions in the disciplines of SG and DH and to compare these with those occurring in giant slalom (GS), for which previous research knowledge exists. External forces were determined using WC forerunners carrying a differential global navigation satellite system (dGNSS). Combining the dGNSS data with a digital terrain model of the snow surface and an air drag model, the magnitudes of ground reaction forces were computed. It was found that the applied methodology may not only be used to track physical demands and loads on athletes, but also to simultaneously investigate safety aspects, such as the effectiveness of speed control through increased air drag and ski-snow friction forces in the respective disciplines. Therefore, the component of the ground reaction force in the direction of travel (ski-snow friction) and air drag force were computed. This study showed that (1) the validity of high-end dGNSS systems allows meaningful investigations such as characterization of physical demands and effectiveness of safety measures in highly dynamic sports; (2) physical demands were substantially different between GS, SG, and DH; and (3) safety-related reduction of skiing speed might be

  4. Annual ecosystem respiration variability of alpine peatland on the eastern Qinghai-Tibet Plateau and its controlling factors.

    Science.gov (United States)

    Peng, Haijun; Hong, Bing; Hong, Yetang; Zhu, Yongxuan; Cai, Chen; Yuan, Lingui; Wang, Yu

    2015-09-01

    Peatlands are widely developed in the eastern Qinghai-Tibet Plateau, but little is known about carbon budgets for these alpine peatland ecosystems. In this study, we used an automatic chamber system to measure ecosystem respiration in the Hongyuan peatland, which is located in the eastern Qinghai-Tibet Plateau. Annual ecosystem respiration measurements showed a typical seasonal pattern, with the peak appearing in June. The highest respiration was 10.43 μmol CO2/m(2)/s, and the lowest was 0.20 μmol CO2/m(2)/s. The annual average ecosystem respiration was 2.06 μmol CO2/m(2)/s. The total annual respiration was 599.98 g C/m(2), and respiration during the growing season (from May to September) accounted for 78 % of the annual sum. Nonlinear regression revealed that ecosystem respiration has a significant exponential correlation with soil temperature at 10-cm depth (R (2) = 0.98). The Q 10 value was 3.90, which is far higher than the average Q 10 value of terrestrial ecosystems. Ecosystem respiration had an apparent diurnal variation pattern in growing season, with peaks and valleys appearing at approximately 14:00 and 10:00, respectively, which could be explained by soil temperature and soil water content variation at 10-cm depth.

  5. Focal mechanisms and inter-event times of low-frequency earthquakes reveal quasi-continuous deformation and triggered slow slip on the deep Alpine Fault

    Science.gov (United States)

    Baratin, Laura-May; Chamberlain, Calum J.; Townend, John; Savage, Martha K.

    2018-02-01

    Characterising the seismicity associated with slow deformation in the vicinity of the Alpine Fault may provide constraints on the stresses acting on a major transpressive margin prior to an anticipated great (≥M8) earthquake. Here, we use recently detected tremor and low-frequency earthquakes (LFEs) to examine how slow tectonic deformation is loading the Alpine Fault late in its typical ∼300-yr seismic cycle. We analyse a continuous seismic dataset recorded between 2009 and 2016 using a network of 10-13 short-period seismometers, the Southern Alps Microearthquake Borehole Array. Fourteen primary LFE templates are used in an iterative matched-filter and stacking routine, allowing the detection of similar signals corresponding to LFE families sharing common locations. This yields an 8-yr catalogue containing 10,000 LFEs that are combined for each of the 14 LFE families using phase-weighted stacking to produce signals with the highest possible signal-to-noise ratios. We show that LFEs occur almost continuously during the 8-yr study period and highlight two types of LFE distributions: (1) discrete behaviour with an inter-event time exceeding 2 min; (2) burst-like behaviour with an inter-event time below 2 min. We interpret the discrete events as small-scale frequent deformation on the deep extent of the Alpine Fault and LFE bursts (corresponding in most cases to known episodes of tremor or large regional earthquakes) as brief periods of increased slip activity indicative of slow slip. We compute improved non-linear earthquake locations using a 3-D velocity model. LFEs occur below the seismogenic zone at depths of 17-42 km, on or near the hypothesised deep extent of the Alpine Fault. The first estimates of LFE focal mechanisms associated with continental faulting, in conjunction with recurrence intervals, are consistent with quasi-continuous shear faulting on the deep extent of the Alpine Fault.

  6. Root reinforcement and its implications in shallow landsliding susceptibility on a small alpine catchment

    Science.gov (United States)

    Morandi, M. C.; Farabegoli, E.; Onorevoli, G.

    2012-04-01

    Roots shear resistance offers a considerable contribution to hill-slope stability on vegetated terrains. Through the pseudo-cohesion of shrubs, trees and turf's roots, the geomechanical properties of soils can be drastically increased, exerting a positive influence on the hillslope stability. We analysed the shallow landsliding susceptibility of a small alpine catchment (Duron valley, Central Dolomites, Italy) that we consider representative of a wide altitude belt of the Dolomites (1800 - 2400 m a.s.l). The catchment is mostly mantled by grass (Nardetum strictae s.l.), with clustered shrubs (Rhododendron hirsutum and Juniperus nana), and trees (Pinus cembra, Larix decidua and Picea abies). The soil depth, investigated with direct and indirect methods, ranges from 0 to 180 cm, with its peak at the hollow axes. Locally, the bedrock, made of Triassic volcanic rocks, is deeply incised by the Holocene drainage network. Intensive grazing of cows and horses pervades the catchment area and cattle-trails occupy ca 20% of the grass cover. We used laboratory and field tests to characterize the geotechnical properties of these alpine soils; moreover we designed and tested an experimental device that measures, in situ, the shear strengths of the grass mantle. In the study area we mapped 18 shallow landslides, mostly related to road cuts and periodically reactivated as retrogressive landslides. The triggering mechanisms of these shallow landslides were qualitatively analysed at large scale and modelled at smaller scale. We used SHALSTAB to model the shallow landsliding susceptibility of the catchment at the basin scale and SLIDE (RocScience) to compute the Safety Factor at the versant scale. Qualitative management solutions are provided, in order to reduce the shallow landsliding susceptibility risk in this alpine context.

  7. Treatment for moderate to severe atopic dermatitis in alpine and moderate maritime climates differentially affects helper T cells and memory B cells in children.

    Science.gov (United States)

    Heeringa, J J; Fieten, K B; Bruins, F M; van Hoffen, E; Knol, E F; Pasmans, S G M A; van Zelm, M C

    2018-06-01

    Treatment of atopic dermatitis (AD) is focused on topical anti-inflammatory therapy, epidermal barrier repair and trigger avoidance. Multidisciplinary treatment in both moderate maritime and alpine climates can successfully reduce disease activity in children with AD. However, it remains unclear whether abnormalities in B cell and T cell memory normalize and whether this differs between treatment strategies. To determine whether successful treatment in maritime and alpine climates normalizes B- and T lymphocytes in children with moderate to severe AD. The study was performed in the context of a trial (DAVOS trial, registered at Current Controlled Trials ISCRTN88136485) in which eighty-eight children with moderate to severe AD were randomized to 6 weeks of treatment in moderate maritime climate (outpatient setting) or in the alpine climate (inpatient setting). Before and directly after treatment, disease activity was determined with SA-EASI and serum TARC, and T cell and B cell subsets were quantified in blood. Both treatment protocols achieved a significant decrease in disease activity, which was accompanied by a reduction in circulating memory Treg, transitional B cell and plasmablast numbers. Alpine climate treatment had a significantly greater effect on disease activity and was accompanied by a reduction in blood eosinophils and increases in memory B cells, CD8+ TemRO, CD4+ Tcm and CCR7+ Th2 subsets. Clinically successful treatment of AD induces changes in blood B- and T cell subsets reflecting reduced chronic inflammation. In addition, multidisciplinary inpatient treatment in the alpine climate specifically affects memory B cells, CD8+ T cells and Th2 cells. These cell types could represent good markers for treatment efficacy. © 2018 John Wiley & Sons Ltd.

  8. Vertical distribution of the alpine lepidoptera in the Carpathians and in the Balkan peninsula in relation to the zonation of the vegetation

    Directory of Open Access Journals (Sweden)

    Varga, Z. S.

    2001-12-01

    Full Text Available The vertical distribution of arctic-alpine, alpine and Balkanic oreal species is discussed in connection with the vertical zonation of the vegetation, climatic conditions, substrate, type of alpine vegetation and co-occurrences of related species. Arctic-alpine species have mostly a Eurasian distribution and occur in the Arctic and in the alpine and subnival zones of the Central and Southern European high mountains with expressed glacial morphology and alpine vegetation. Alpine species are mostly European species and they are connected to the alpine and subnival zones of Central and South European high mountains. Balkanic oreal species are mostly southeast European species which in some cases occur locally in the southern parts of the Alps and Carpathians. Balkanic oreal species are most numerous at the timberline, preferred habitats being grasslands in the upper subalpine belts. The more diverse habitats of limestone mountains are usually home to a higher number of alpine (s. l. species than that of the mountains consisting of acidic rocks. The apparent petrophily of several alpine and tundro-alpine species correlates with their sheltering behaviour. The vertical distribution of butterflies is probably influenced also by the competition of closely related species. Closely related species often show some types of habitat partitioning. Data on species numbers and vertical distribution of species are presented in the tables 1-4.

    [de]
    Die vertikale Verbreitung der arktisch-alpinen, alpinen und balkanischen Orealarten wird hier im Zusammenhang mit den vertikalen Stufenfolgen der Vegetation, den klimatischen Verhdltnissen, den geologischen und geomorphologischen Bedingungen, den Vegetationstypen und dem Vorkommen der verwandt