Sökning: "vegetation."

Visar resultat 21 - 25 av 525 avhandlingar innehållade ordet vegetation..

  1. 21. Hydrodynamics of very shallow lakes - A study in Lake Krankesjön, Sweden

    Författare :Charlotta Borell Lövstedt; Avdelningen för Teknisk vattenresurslära; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; alternative stable states; field measurements; reed; resuspension; wave damping; waves; differential heating; vegetation; convective currents;

    Sammanfattning : Shallow lakes have great ecological and recreational values. They are also largely affected by humans, mainly through eutrophication, and great efforts are therefore being put into the understanding of these ecosystems. The knowledge is however not complete, and more research is needed to manage these lakes in a sustainable way. LÄS MER

  2. 22. European ecosystems on a changing planet : Integrating climate change and land-use intensity data

    Författare :Jan Hendrik Blanke; Institutionen för naturgeografi och ekosystemvetenskap; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; LPJ-GUESS; land-use intensity; climate change; carbon; nitrogen; ecosystem functions; trade-offs; vegetation;

    Sammanfattning : Dynamic global vegetation models are mathematical models that provide a bottom-up description of plant communities. They explicitly model physiological and population-level processes such as growth, photosynthesis, carbon allocation, regeneration and mortality. LÄS MER

  3. 23. Spatio-Temporal Estimation for Mixture Models and Gaussian Markov Random Fields - Applications to Video Analysis and Environmental Modelling

    Författare :Johan Lindström; Matematisk statistik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; vegetation; time series analysis; video segmentation; spatio-temporal modelling; precipitation; Markov chain Monte Carlo; Gaussian Markov random fields; expectation maximisation; change point detection; Bayesian recursive estimation; African Sahel; adaptive Gaussian mixtures;

    Sammanfattning : In this thesis computationally intensive methods are used to estimate models and to make inference for large, spatio-temporal data sets. The thesis is divided into two parts: the first two papers are concerned with video analysis, while the last three papers model and investigate environmental data from the Sahel area in northern Africa. LÄS MER

  4. 24. 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

  5. 25. SAR Remote Sensing of Forests, from Microwaves to VHF

    Författare :Hans Israelsson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; microwave; backscattering models; SAR; VHF; vegetation;

    Sammanfattning : The number of SAR systems available for civilian remote sensing purposes has grown in the nineties. A Synthetic Aperture Radar produces high resolution images of the earth independent on daylight and atmospheric conditions. This thesis mainly examines the applications of SAR remote sensing to monitoring forested areas. LÄS MER