Sökning: "NATURAL SCIENCES Earth sciences Exogenous earth sciences Physical geography"

Visar resultat 1 - 5 av 41 avhandlingar innehållade orden NATURAL SCIENCES Earth sciences Exogenous earth sciences Physical geography.

  1. 1. Palaeoglaciology of the northeastern Tibetan Plateau

    Detta är en avhandling från Stockholm : Department of Physical Geography and Quaternary Geology, Stockholm University

    Författare :Jakob Heyman; Stockholms universitet.; [2010]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Tibetan Plateau; palaeoglaciology; NATURAL SCIENCES Earth sciences Exogenous earth sciences Physical geography; NATURVETENSKAP Geovetenskap Exogen geovetenskap Naturgeografi; NATURAL SCIENCES Earth sciences Exogenous earth sciences Quaternary geology; NATURVETENSKAP Geovetenskap Exogen geovetenskap Kvartärgeologi; Physical Geography; naturgeografi;

    Sammanfattning : This study concerns the palaeoglaciation of the northeastern Tibetan Plateau, with emphasis on the Bayan Har Shan (Shan = Mountain) in the headwaters of Huang He (Yellow River). To reconstruct past glacier development multiple techniques, including remote sensing, field investigations, cosmogenic exposure dating, and numerical modelling have been employed. LÄS MER

  2. 2. Carbon metabolism in clear-water and brown-water lakes

    Detta är en avhandling från Umeå : Institutionen för ekologi, miljö och geovetenskap, Department of Ecology and Environmental Sciences

    Författare :Jenny Ask; Umeå universitet.; [2010]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; clear-water lakes; brown-water lakes; primary production; bacterial production; benthic; pelagic; net ecosystem production; allochthonous organic carbon; CO2; DOC; NATURAL SCIENCES Earth sciences Exogenous earth sciences Physical geography; NATURVETENSKAP Geovetenskap Exogen geovetenskap Naturgeografi; NATURAL SCIENCES Biology Terrestrial; freshwater and marine ecology Freshwater ecology; NATURVETENSKAP Biologi Terrestrisk; limnisk och marin ekologi Limnisk ekologi; limnologi; Limnology; naturgeografi; Physical Geography;

    Sammanfattning : The trophic state of lakes is commonly defined by the concentration of nutrients in the water column. High nutrient concentrations generate high phytoplankton production, and lakes with low nutrient concentrations are considered low-productive. LÄS MER

  3. 3. Production and emission of CO2 in two unproductive lakes in northern Sweden

    Detta är en avhandling från Umeå : Institutionen för Ekologi, miljö och geovetenskap, Umeå universitet

    Författare :Jan Åberg; Umeå universitet.; [2009]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; lake; carbon dioxide; organic carbon; inorganic carbon; boreal; arctic; DOC; DIC; CO2; emission; thermal stratification; allochthonous organic carbon; NATURAL SCIENCES Biology Terrestrial; freshwater and marine ecology Freshwater ecology; NATURVETENSKAP Biologi Terrestrisk; limnisk och marin ekologi Limnisk ekologi; NATURAL SCIENCES Earth sciences Exogenous earth sciences Physical geography; NATURVETENSKAP Geovetenskap Exogen geovetenskap Naturgeografi; naturgeografi; Physical Geography;

    Sammanfattning : Unproductive lakes are one of few natural landscape compartments with net release of carbon to the atmosphere. Lakes also generally decrease the net terrestrial carbon uptake, since most of the CO2 production in unproductive lakes are derived from organic carbon produced on land (e.g. in forests). LÄS MER

  4. 4. Late Quaternary climate and environmental change in the summer rainfall region of South Africa : A study using trees and wetland peat cores as natural archives

    Detta är en avhandling från Stockholm : Institutionen för naturgeografi och kvartärgeologi

    Författare :Elin Norström; Stockholms universitet.; [2008]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; paleoclimate; Late Quaternary; pollen; stable isotopes; diatoms; phytoliths; dendroclimatology; South Africa; NATURAL SCIENCES Earth sciences Exogenous earth sciences Physical geography; NATURVETENSKAP Geovetenskap Exogen geovetenskap Naturgeografi; Physical Geography; naturgeografi;

    Sammanfattning : This thesis contributes with information on past climate and environmental changes in South Africa’s summer rainfall region. The study is based on multi-proxy analyses on wetland peat cores and analyses of stable isotope composition (δ13C, δ18O) and wood anatomy in cross sections from subtropical trees (Breonadia salicina). LÄS MER

  5. 5. Cross-scale perspectives on heterogeneity in Swedish boreal forests

    Detta är en avhandling från Stockholm : Department of Physical Geography and Quaternary Geology, Stockholm University

    Författare :Sofia Eriksson; Stockholms universitet.; Södertörns högskola.; [2011]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURAL SCIENCES Earth sciences Exogenous earth sciences Physical geography; NATURVETENSKAP Geovetenskap Exogen geovetenskap Naturgeografi; geografi med naturgeografisk inriktning; Geography; Physical Geography; sustainable forest management; biodiversity conservation; landscape analysis; historical maps; ownership;

    Sammanfattning : Maintaining species diversity, ecosystem functioning, and socioeconomic values requires continued ecosystem heterogeneity across scales. This thesis aims to bridge gaps between ecological theory, environmental goals, and practical application of sustainable forest management needed to maintain such heterogeneity. LÄS MER