نتایج جستجو برای: alpine
تعداد نتایج: 9936 فیلتر نتایج به سال:
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...
Alpine soils undergo dramatic temporal changes in their microclimatic properties, suggesting that the bacteria there encounter uncommon shifting selection gradients. Pseudomonads constitute important members of the alpine soil community. In order to characterize the alpine Pseudomonas community and to assess the impact of shifting selection on this community, we examined the ability of cold-tol...
This study examines the role of surface geomorphic features in tree establishment at the alpine treeline in Glacier National Park, Montana, through the presentation of a multiscale, conceptual model of biogeomorphic relationships at alpine treeline. Empirical observations gathered through a multiscale field methodology over three summers serve as a base for the model. The model highlights the i...
Over the past 50 years, the rising tree line along Jumpingpound Ridge in the Rocky Mountains of Alberta, Canada, has reduced the area of alpine meadows and isolated populations that reside within them. By analyzing an 11-year data set of butterfly population sizes for 17 subpopulations along the ridge, we show that forest habitat separating alpine meadows decouples the dynamics of populations o...
Alpine landscapes have evolved rapidly over the last two centuries. River embankments and urbanization have aff ected most of the large alluvial plains, agriculture has radically changed and its relative landscapes also. Forests are gaining space in most of the Alpine countries and tourism has modifi ed landscapes in several areas, both in alpine forelands and high valleys. In Switzerland, the ...
Remote lakes are usually unaffected by direct human influence, yet they receive inputs of atmospheric pollutants, dust, and other aerosols, both inorganic and organic. In remote, alpine lakes, these atmospheric inputs may influence the pool of dissolved organic matter, a critical constituent for the biogeochemical functioning of aquatic ecosystems. Here, to assess this influence, we evaluate fa...
Tall alpine herb field is largely absent from the Tasmanian alpine zone. This absence has been attributed to marsupial grazing. Small islands in the upper Ouse River valley are partly dominated by Craspedia paludicola, a showy tall alpine herb. The herbs dominate on the upstream ends of the islands. The surrounding vegetation on the banks is mainly grassland. The tall herbs are a very minor ele...
We report the first case of directly observed infanticide in the Alpine marmot (Marmota marmota). Moreover, previous and present observations suggest that 12 young could have been killed by infanticide in the population under study. The bodies of five of them were found with similar neck injuries. In all cases, infanticidal animals were adult males entering a territory in the absence of the res...
Genetic variability of the ovine parasite Haemonchus contortus from the Alpine area was investigated using mitochondrial DNA (nd4 gene), internal transcribed spacers 1 and 2 and microsatellites, in order to assess whether cross-transmission between domestic and wild ruminants occurs. The dataset was composed of 78 individual adult male H. contortus collected from chamois (Rupicapra r. rupicapra...
To explore grazing effects on carbon fluxes in alpine meadow ecosystems, we used a paired eddy-covariance (EC) system to measure carbon fluxes in adjacent fenced (FM) and grazed (GM) meadows on the Tibetan plateau. Gross primary productivity (GPP) and ecosystem respiration (Re) were greater at GM than FM for the first two years of fencing. In the third year, the productivity at FM increased to ...
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