Sökning: "phosphorus nitrogen"

Visar resultat 16 - 20 av 167 avhandlingar innehållade orden phosphorus nitrogen.

  1. 16. The role of nutrients for stream ecosystem function in Arctic landscapes : drivers of productivity under environmental change

    Författare :Maria Myrstener; Ryan A. Sponseller; Reiner Giesler; Ann-Kristin Bergström; Tenna Riis; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Nutrients; Stream; Arctic; Boreal; Primary productivity; Algae; Biofilm; Nutrient limitation; Nitrogen; Phosphorus;

    Sammanfattning : Arctic and sub-Arctic freshwaters are currently experiencing substantial ecosystem changes due to the effects of global warming. Global warming effects on these freshwaters include increasing water temperatures, altered hydrological patterns, shifts in riparian vegetation and changes in the export of nutrients and carbon from soils. LÄS MER

  3. 17. Remote sensing of grassland communities : integrated effects of soil nutrients and habitat age

    Författare :Oskar Löfgren; Biodiversitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Remote sensing; Plant ecology; semi-natural grassland; Nitrogen; Phosphorus; Semi-natural grassland; Plant ecology; Remote sensing; Nitrogen; Phosphorus; Spectral reflectance; grassland specialists; Succession;

    Sammanfattning : Semi-natural grasslands are characterized by high fine-scale plant species richness. The richest grassland communities, with many habitat-specialist species, are found in ancient grassland sites that have a long continuity of grazing management and low levels of soil nutrients. Grazed grasslands were widespread in the historical landscape. LÄS MER

  4. 18. Environmental impact of peat mining : Development of storm water treatment methods

    Författare :Bjørn Kløve; Avdelningen för Teknisk vattenresurslära; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; geographical and geological engineering; Hydrogeology; drainage artificial floodplaines; phosphorus; suspended solids; nitrogen; erosion; peat mining; peak runoff controll; sedimentation; water treatment; water resources; hydrology; hydraulics; Hydrogeologi; teknisk geologi; teknisk geografi; Geophysics; physical oceanography; meteorology; Geofysik; fysisk oceanografi; meteorologi;

    Sammanfattning : Drainage of peatlands increases the transport of suspended solids (SS) and the leaching of nutrients to downstream receiving waters. Increased settling of peat and eutrophication of lakes has been noted in many studies downstream from peat mines. LÄS MER

  5. 19. Peatlands at a Threshold: Greenhouse Gas Dynamics in a Changing Climate

    Författare :Magnus Lund; Institutionen för naturgeografi och ekosystemvetenskap; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; chamber; greenhouse gas; nitrous oxide; methane; carbon dioxide; carbon; bog; Peatland; mire; eddy covariance; nitrogen; phosphorus; fertilization;

    Sammanfattning : To be able to predict the strength of climate change and its consequences for mankind, it is of major importance to understand the contemporary greenhouse gas exchange of the terrestrial biosphere, as well as its response to changes in climate. To achieve such understanding both descriptive studies and manipulation experiments are required. LÄS MER

  7. 20. Free-Vehicle Benthic Lander Technology for the Study of Biogeochemical Processes in Marine Sediments

    Författare :Anders Tengberg; Göteborgs universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; marine sediments; benthic fluxes; incubations; chambers; in-situ; benthic landers; autonomous vehicles; lander technology; hydrodynamics; calibration; experimental design; Partial Least Squares PLS ; sensors; fugacity; oxygen; carbon; nitrogen; phosphorus; silica; dissolved organic carbon DOC ; total carbonate; recycling; burial; lander technology;

    Sammanfattning : Various sediment sampling and incubation techniques were used to characterize benthic biogeochemical processes important for an improved understanding of the oceanic carbon cycle. Recent flux data from the Arctic Siberian shelf are revealing differences (often by a factor of ten) between areas affected by the big Russian river outlets (high fluxes) and areas with low influence from land (low fluxes). LÄS MER