Sökning: "biome"

Visar resultat 1 - 5 av 24 avhandlingar innehållade ordet biome.

  1. 1. Geophysical Applications of Vegetation Modeling

    Författare :Jed O Kaplan; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Environmental chemistry; Växtbiokemi; Plant biochemistry; CH4; CO2; stable isotopes; carbon cycle; wetland; ice core; methane; Holocene; mammoths; tundra; ice age; LGM; biogeography; biome; biogeochemistry; Vegetation model; Miljökemi; Physical geography; geomorphology; pedology; cartography; climatology; Fysisk geografi; geomorfologi; marklära; kartografi; klimatologi;

    Sammanfattning : This thesis describes the development and selected applications of a global vegetation model, BIOME4. The model is applied to problems in high-latitude vegetation distribution and climate, trace gas production, and isotope biogeochemistry. LÄS MER

  3. 2. Multispectral Remote Sensing and Deep Learning for Wildfire Detection

    Författare :Xikun Hu; Yifang Ban; Ioannis Gitas; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; active fire detection; biome; multi-criteria; Sentinel-2; Landsat-8; burned area mapping; deep learning; semantic segmentation; machine learning.; aktiv branddetektering; biom; multikriterietillvägagångssätt; Sentinel-2; Landsat-8; kartläggning av bränt område; djupinlärning; semantisk segmentering; maskininlärningsmetoderna; Geoinformatik; Geoinformatics;

    Sammanfattning : Remote sensing data has great potential for wildfire detection and monitoring with enhanced spatial resolution and temporal coverage. Earth Observation satellites have been employed to systematically monitor fire activity over large regions in two ways: (i) to detect the location of actively burning spots (during the fire event), and (ii) to map the spatial extent of the burned scars (during or after the event). LÄS MER

  4. 3. Natural and social dimensions of forest carbon accounting

    Författare :Wilhelm Dubber; Institutionen för naturgeografi och ekosystemvetenskap; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Forest carbon fluxes; REDD ; boreal forest; LPJ-GUESS; BIOME-BGC; remote sensing;

    Sammanfattning : Global forests store large amounts of carbon both in living biomass and in the soil. The ability of forests to counteract climate change by acting as carbon sinks have been recognized in global climate politics, such as the 2015 Paris agreement which calls for national commitments to reduce greenhouse gas emissions. LÄS MER

  5. 4. Northern Permafrost Region Soil Carbon Dynamics since the Last Glacial Maximum : a terrestrial component in the glacial to interglacial carbon cycle

    Författare :Amelie Lindgren; Gustaf Hugelius; Peter Kuhry; Fortunat Joos; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Soil organic carbon; Permafrost; Peat; Loess; Vegetation; Biome reconstruction; Last Glacial Maximum; Deglaciation; Glacial-interglacial cycle; Carbon cycle; Physical Geography; naturgeografi;

    Sammanfattning : At the Last Glacial Maximum (LGM), after ~100,000 years of relatively cold temperatures and progressively lower atmospheric carbon dioxide (CO2) concentrations, CO2 levels reached ~180 ppm, which is less than half of what we see today in a much warmer world (~400 ppm). Although much of this increase since the LGM is due to human-induced emissions, about 100 ppm of this increase can be attributed to natural variations seen over glacial to interglacial cycles. LÄS MER

  7. 5. Circumpolar impacts of herbivores on Arctic tundra vegetation

    Författare :Elin Lindén; Johan Olofsson; Maja K. Sundqvist; Mariska te Beest; Elisabeth S. Bakker; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; herbivores; grazing; Arctic; circumpolar; tundra; vegetation; plant defence; secondary metabolites; shrub birch; exclosures; vegetation; species diversity; biology; biologi;

    Sammanfattning : Arctic tundra vegetation provides many ecological services that have implications for the global climate. However, the tundra biome is currently changing in response to increasing temperatures. Herbivores may mitigate some of these responses to warming through their impact on Arctic vegetation. LÄS MER