Sökning: "naturvetenskap geovetenskap och miljövetenskap miljövetenskap"

Visar resultat 16 - 20 av 2610 avhandlingar innehållade orden naturvetenskap geovetenskap och miljövetenskap miljövetenskap.

  1. 16. Measured and modelled long-term effects of whole-tree harvest : impact on soil and surface water acid-base status in boreal forests

    Författare :Therese Zetterberg; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : This thesis examines the impact of whole-tree harvest (WTH) on soils and surface waters acid-base status in coniferous forests compared with conventional harvesting (CH). A combination of field observations (up to four decades) and dynamic modelling was used to describe the impact on soil calcium (Ca²⁺) pools and surface water acid neutralizing capacity (ANC). LÄS MER

  3. 17. Quantification of population exposure and health impacts associated with air pollution

    Författare :David Segersson; Christer Johansson; Lars Gidhagen; Ranjeet S. Sokhi; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; air pollution; health impact assessment; dispersion modelling; population exposure; Applied Environmental Science; tillämpad miljövetenskap;

    Sammanfattning : There is substantial evidence that air pollution, in particular particulate matter (PM), affects our health. The overall objective of this thesis is to understand and quantify population exposure to ambient air pollution and related health impacts. LÄS MER

  4. 18. Greenhouse gas emission from tropical reservoirs : Spatial and temporal dynamics

    Författare :Annika Linkhorst; Sebastian Sobek; Frédéric Guérin; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; methane; carbon dioxide; climate; carbon cycle; lake; limnology; inland water;

    Sammanfattning : The emission of methane (CH4) and carbon dioxide (CO2) from reservoirs has been estimated to make up for about 1.3% of the global anthropogenic greenhouse gas emission. The impoundment of a river leads to the accumulation of sediment that is brought in from inflowing rivers, and the sediment organic matter is degraded to CH4 and CO2. LÄS MER

  5. 19. Intramolecular isotope analysis reveals plant ecophysiological signals covering multiple timescales

    Författare :Thomas Wieloch; Jürgen Schleucher; Mats Nilsson; Gerd Gleixner; Lisa Wingate; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NMR spectroscopy; tree ring; isotope ratio; isotope effect; intramolecular 13C 12C signal; carbon allocation; acclimation; plant performance; climate reconstruction; plant ecophysiology;

    Sammanfattning : Our societies' wellbeing relies on stable and healthy environments. However, our current lifestyles, growth-oriented economic policies and the population explosion are leading to potentially catastrophic degradation of ecosystems and progressive disruption of food chains. LÄS MER

  7. 20. Distribution and Biogeochemical Cycling of Arsenic In Grey and Brown Sand Aquifers in the Bengal Delta Plains (India)

    Författare :Devanita Ghosh; Joyanto Routh; Teresia Svensson; Punyasloke Bhadury; M. E. Donselaar; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Arsenic; aquifer; arsenite oxidation; aioA gene; Bengal delta plains; biogeochemical cycling biomarkers; DOC; SOC; Arsenik; akvifärer; arsenitoxiderande; aioA gene; Bengal delta plains; biogeokemiska omsättning; biomarkörer; DOC; SOC;

    Sammanfattning : An elevated level of Arsenic (As) in aquifers from India and Bangladesh affecting the human health has been widely reported since the late 1980s. The thesis aim is to investigate the present status of As contamination and biogeochemical cycling with direct role of diverse indigenous bacterial communities in As cycling in the Bengal Delta Plain (BDP) aquifers in Nadia district, West Bengal (India). LÄS MER