Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
1998
Authors
Sondre Skatter Olav Albert HøibøAbstract
Scots pine (Pinus silvestris) logs and 106 Norway spruce (Picea abies) logs. Two of the models were the classical 3-parametric circle model and the 5-parametric ellipse model. These models were compared to the third model, the Fourier coefficient model, which had a variable number of parameters. By increasing the number of parameters in the Fourier coefficient model, this model fits the true shape perfectly. With the same number of parameters the Fourier model performed approximately as good as the two other models. To get a substantial improvement over the ellipse model the number of parameters had to be raised dramatically.
Authors
Sondre SkatterAbstract
No abstract has been registered
Authors
Tore SkrøppaAbstract
No abstract has been registered
Authors
Karl Hilding Thunes Fred MidtgaardAbstract
No abstract has been registered
Authors
J.F.G. Lancho J.A.E. Rodriguez M.I.G. Hernandez C.Q. Gonzalo A.V. Esteban F.I. SanchezAbstract
No abstract has been registered
Abstract
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Authors
Dag FjeldAbstract
No abstract has been registered
Abstract
Changes in the ectomycorrhizal fungus flora were studied in connection with nitrogen addition and removal experiments in a Norway spruce forest at Gårdsjön, W Sweden during a 5-year period. The above-ground ectomycorrhizal fruit body production was recorded from permanent transect plots, and the below-ground mycorrhizal fine-roots density and morphotype differentiation were studied from soil core samples from the surface root layer. The experiments were performed by adding N-enriched and N-free water, respectively, by means of sprinkling systems. Ammonium nitrate (about 35 kg N ha−1 yr−1) was added to catchment G2 NITREX, whereas at adjacent catchment G1 ROOF ambient N deposition was removed by means of a roof. The addition of N led to a rapid and substantial decrease in species diversity and fruit body production of most species in the NITREX catchment, representing one of very few biological responses to the treatments at Gårdsjön. Stress-intolerant groups such as the initially-dominant genus Cortinarius were almost absent after 5 yr of N addition. Only one dominant species (Cantharellus tubaeformis) increased fruit body production after treatment. In the nitrogen removal (G1 ROOF) experiment, the fruit body production increased strongly the first years, but then declined. No response in the below-ground mycorrhiza and fine-root density and diversity was found. All fine roots had developed ectomycorrhiza. The difference in response above ground and below ground indicates that: (1) the fruit-body producing macrofungi play a minor role below ground, and that (2) there is probably a considerable time-lag in the mycorrhizal fine-root versus fruit body production response to enhanced N levels.
Authors
Bernt Olav Hoel Knut Asbjørn SolhaugAbstract
No abstract has been registered
Abstract
No abstract has been registered