Search for dissertations about: "soil stress"

Showing result 1 - 5 of 95 swedish dissertations containing the words soil stress.

  2. 1. Genetic adaptation to soil acidification in four grasses

    Author : Pernilla Göransson; Biologiska institutionen; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Växtekologi; Plant ecology; Deschampsia flexuosa; Deschampsia cespitosa; Elymus caninus; Poa nemoralis; arbuscular mycorrhiza; stress; tolerance; genetic variation; local adaptation; Al; Soil acidification; pH;

    Abstract : Soil acidification has become a source of serious concern in many parts of the world. In southern Sweden, the deposition of acidifying substances, such as nitrogen and sulphur compounds, has decreased the mean pH of forest soils by almost one unit since the 1950s. READ MORE

  4. 2. Spring water stress in Scots pine: interaction of snow and soil temperature

    Author : Per-Erik Mellander; Mittuniversitetet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Low temperature; soil warming; transpiration; root water uptake; carbon dioxide assimilation; soil frost; silvicultural practice; Pinus Sylvestris; Biology; Biologi;

    Abstract : Water use and net carbon assimilation during spring was examined on Scots pine trees exposed to different soil warming dynamics in the field. Sap flow, needle water potential and net carbon assimilation were measured on trees that were exposed to a wide range of soil temperature regimes caused by manipulating the snow cover on tree-scale soil plots. READ MORE

  5. 3. Effects of deep excavations in soft clay on the immediate sourroundings-Analysis of the possibility to predict deformations and reactions against the retaining system

    Author : Anders Kullingsjö; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; MIT-S1; Sheet pile wall; Soil-structure interaction; Strain; Stress; Ground surface settlement; Finite element method; Case history; Shear test; Shear strength; Pore pressure; Analysis; Constitutive models; Plane strain; Elastoplasticity; Laboratory tests; Factor of safety; Stiffness; e-ADP; Earth pressure; Anisotropy; Soft Clay; Deep excavation; Retaining wall; Shear stress; Deformation;

    Abstract : When excavating in an urban environment, the evaluation of the magnitude and distribution of ground movements is an important part of the design process, since excessive movements can damage adjacent buildings and utilities. In order to minimize movement of the surrounding soil, a retaining wall support system is used for deep excavations to provide lateral support. READ MORE

  6. 4. Effects of heavy metal contamination on carbon and nitrogen cycling : An ecological approach to assess risks to soil functions

    Author : Ingrid Rijk; Alf Ekblad; Dan Berggren Kleja; Erik Karltun; Örebro universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; heavy metals; soil contamination; stable isotopes; N cycling microbial guilds; 13C; 15N; nitrification; denitrification; biochar; soil respiration; microbial activity; bioavailability;

    Abstract : Soil contamination with heavy metals may disrupt soil microorganisms with important roles in carbon (C) and nitrogen (N) cycling. However, there is a lack of understanding on how microorganisms are affected in soil, which may lead to a mismatch when assessing risks of contaminants to field soils. READ MORE

  7. 5. Impact of root and mycorrhizal exudation on soil carbon fluxes : influence of elevated CO2 and metals

    Author : Emma M. Johansson; Patrick van Hees; Bert Allard; Phil Ineson; Örebro universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; amino acids; 13C; carbon cycle; ectomycorrhiza; elevated CO2; exudation; DOC; LMWOA; metal stress; monosaccharides; oxalate; Pinus sylvestris; saprotrophic fungi; soil respiration; NATURAL SCIENCES; NATURVETENSKAP; Environmental chemistry; Miljökemi; Enviromental Science; Miljövetenskap;

    Abstract : The thesis concerns the behavior of root and ectomycorrhizal (ECM) exudates. In particular, the dynamics of soluble low molecular weight (LMW) organic compounds such as organic acids (LMWOAs), amino acids, monosaccharides, and dissolved organic carbon (DOC) have been studied. READ MORE