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Résultats de la recherche (206 résultats)

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  • Radiation and energy budgets of alpine tundra environments of North America
  • Albedo ; Bioclimatology ; Ecosystem ; Energy balance ; Microclimate ; Mountain ; Radiation ; Spatial variation ; Topoclimate ; Tundra
  • Recent physical climatology research (radiation and energy budget) from North American alpine tundra environments is summarized and directions for further research suggested: analyses of the spatial variations of albedo, the role of sloping surfaces
  • The physical climatology of alpine tundra, Scout mountain, British Columbia, Canada
  • Albedo ; British Columbia ; Canada ; Climatology ; Evapotranspiration ; High mountain ; Orographic effect ; Radiation balance ; Snow ; Snow cover ; Synoptic climatology ; Tundra
  • Two field seasons at an alpine tundra site in southern British Columbia indicate synoptic-scale weather provided more controls on surface radiation transfers than did local controls. Other results were the negligible energy storage in the snowpack
  • , use of available energy by the snowmelt process, and rapid dessication of tundra. - (DWG)
  • Tree-tundra competitive hierarchies, soil fertility gradients, and treeline elevation in Glacier National Park, Montana
  • Biomass ; Ecosystem ; Ecotone ; Forest ; Geochemistry ; Montana ; Soil properties ; Tree line ; Tundra ; United States of America
  • . The tundra-line may be lower where more nutrients are available because tundra species may more readily alter their competitive ability than do the tree species in this area.
  • Late Quaternary history of tundra vegetation in northwestern Alaska
  • Alaska ; Climatic variation ; Palaeo-ecology ; Palynology ; Pollen diagram ; Quaternary ; Taxonomy ; Tundra ; Vegetation
  • Pollen analysis of a new core from Joe Lake indicates that the late Quaternary vegetation of northwestern Alaska was characterized by four tundra and two forest-tundra types. These vegetation types were differentiated by combining quantitative
  • Contexts for change in alpine tundra
  • Biodiversity ; Biogeography ; Climatic change ; Colorado ; Comparative study ; Ecological niche ; Montana ; Mountain ; National park ; Tundra ; United States of America ; Vegetation
  • Biodiversidad ; Biogeografía ; Cambio climático ; Colorado ; Estados Unidos ; Estudio comparativo ; Montaña ; Nicho ecológico ; Parque nacional ; Tundra ; Vegetación
  • The AA. test the relevance of niche and neutral theories of biogeography to alpine tundra change and assess the continuum and classification approaches to biogeographic description as tools to describe similarity. Two extensive studies of alpine
  • tundra, from the Indian Peaks area, Colorado and Glacier National Park, Montana, are combined. Using the Mantel test, the correlation between difference and distance is discussed. In monitoring programs such as GLORIA, the assesment of observed changes
  • in alpine tundra over the coming decades will require more advanced analyses.
  • Surface energy budgets over alpine tundra in summer, Niwot Ridge, Colorado Front Range
  • Climatology ; Colorado ; Energy balance ; Evapotranspiration ; Meadow;Grassland ; Mountain ; Precipitation ; Radiation ; Soil moisture ; Summer ; Temperature ; Tundra ; United States
  • High variation in heat energy balance values was found to occur on five different kinds of tundra surfaces largely as a result of yearly changes in precipitation.―(DWG)
  • Hydrological connectivity and seasonal storage change of tundra ponds in a polar oasis environment, Canadian High Arctic
  • Canada ; Climatic warming ; Cold area ; Ellesmere ; Evaporation ; Humid environment ; Hydrology ; Northwest Territories ; Pond ; Runoff ; Tundra
  • This paper examines the hydrological connectivity and the storage status of a cluster of tundra ponds in a High Arctic polar oasis, relating seasonal hydrological changes to lateral drainage, pond water balance and active layer thaw conditions.
  • Decomposition of plant litter and cellulose in the tundras of the Taymyr peninsula
  • Modern tundra landscapes of the Kolyma Lowland and their evolution in the Holocene
  • Asian part of Russia ; Climatic change ; Eastern Siberia ; Geomorphogenesis ; Holocene ; Lake ; Landscape ; Magadan ; Periglacial features ; Permafrost ; Thermokarst ; Tundra
  • Cambio climático ; Geomorfogénesis ; Holoceno ; Lago ; Paisaje ; Pergelisol ; Periglaciar ; Termokarst ; Tundra
  • The different tundra landscapes of the Kolyma Lowland, northern Siberia are described, focusing on landscape typology, digital mapping and the calculation of areas occupied by different landscape complexes. The genesis, age and evolution of yedoma
  • Structural evolution of tundra permafrost nongley soils (tundra cryozems)
  • Asian part of Russia ; Cryopedology ; Cryoturbation ; Cryozem ; Frozen ground ; Ground freezing ; Ground ice ; Sakha ; Soil ; Soil moisture ; Tundra
  • Microbial controls on methane fluxes from a polygonal tundra of the Lena Delta, Siberia
  • Asian part of Russia ; Delta ; Geochemistry ; Humid environment ; Micro-organism ; Periglacial features ; Permafrost ; Siberia ; Soil wedge polygon ; Tundra
  • The aim of this study was to verify the role of the microbial processes for the seasonal fluctuation of methane fluxes from tundra environments. The analysis included measurements of seasonal methane fluxes and environmental parameters as well
  • as the quantification of methane production and oxidation under in situ conditions within the active layer of permafrost soils, in a typical polygonal tundra in the Lena Delta, Siberia.
  • Climatic variability and tree response within the forest-alpine tundra ecotone
  • -alpine tundra ecotone.
  • Spatial analysis of soils, vegetation, productivity, and carbon stored in mountain tundra ecosystems, Khibiny Mountains, Russia
  • Biogeography ; Biomass ; Carbon ; Ecosystem ; European part of Russia ; Mountain ; Murmansk ; Soil ; Spatial analysis ; Tundra ; Vegetation
  • Pedogenic carbonate cutans as a record of the Holocene history of relic tundra-steppes of the Upper Kolyma Valley (North-Eastern Asia)
  • Asian part of Russia ; C 14 dating ; Carbonate ; Cold area ; Ecosystem ; Holocene ; Microstructure ; Palaeo-environment ; Soil ; Soil properties ; Steppe ; Tundra
  • insufficient to provide the desired reliability for paleo-landscape reconstructions. Nevertheless, the combination of absolute dating, cutan morphology and composition has shed light on the Holocene evolution of tundra-steppes in North-Eastern Asia.
  • Tundra v usloviâh menâûŝegosâ klimata
  • Arctic Region ; Atmospheric circulation ; Climatic warming ; Ecosystem ; Forecast ; Impact study ; Palaeogeography ; Tundra ; Vegetation
  • Circulación atmosférica ; Ecosistema ; Estudio de impacto ; Paleogeografía ; Previsión ; Recalentamiento climático ; Tundra ; Vegetación ; Ártica
  • Arctic Region ; Carbon ; Ecosystem ; European part of Russia ; Geographical information system ; Organic materials ; Plant cover ; Soil ; Soil classification ; Taiga ; Tundra
  • and 2 separate upscaling tools. Results are compared with previous estimates for taiga and tundra ecosystems. This research is part of the TUNDRA (TUNdra Degradation in the Russian Arctic) project that examines the role of Arctic feedback processes
  • Belowground tundra research: a commentary
  • Soil moisture and temperature variation under different types of tundra vegetation during the growing season : A case study from the Fuglebekken catchment, SW Spitsbergen
  • Active layer ; Arctic Region ; Climatic change ; Cold area ; Cryosol ; Permafrost ; Soil moisture ; Soil properties ; Soil temperature ; Spitsbergen ; Svalbard ; Tundra ; Watershed
  • Cambio climático ; Cuenca hidrográfica ; Humedad del suelo ; Molisol ; Pergelisol ; Propiedades del suelo ; Spitzberg ; Temperatura del suelo ; Tundra ; Zona fría ; Ártica
  • carried out between June 24 and September 9 of 2008. The studied sites represented : 1) Turbic Cryosol, poorly covered by vegetation and exhibiting evidences of strong cryogenic processes; 2) Hyperskeletic Cryosol covered by a community of wet moss tundra
  • vegetation with variable moisture which evolves under the influence of water flowing from the adjacent mountain slopes occupied by Little Auk colonies; and 3) Haplic Cryosol covered by lichen–herb–heath tundra vegetation, located on a raised marine terrace
  • . It is shown that : 1) Temperature of Arctic soils is connected with influence of cold thawing water; 2) Cryosols covered by wet moss tundra vegetation are the wettest and coldest; and 3) Cryosols covered by lichen-herb-heath tundra vegetation are the driest
  • Arid area ; Atmospheric circulation ; Bibliography ; Climatology ; Energy balance ; Forest ; Mesoclimate ; Microclimate ; Periglacial features ; Semi-arid area ; Tundra ; Urban climate
  • , and mostly high-latitude ice, snow, permafrost and tundra landscapes).
  • Arctic Region ; Bibliography ; Biogeography ; Biomass ; Cold area ; LANDSAT ; MSS ; Remote sensing ; SPOT ; Spectral reflectance ; Thematic Mapper ; Tundra ; Vegetation ; Vegetation index
  • The goal of this paper is to review remote sensing studies applied in arctic environments to estimate vegetation community structure and biophysical properties. Tundra spectral characteristics and biomass estimation using vegetation indices