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.
1988
Authors
Tonje ØklandAbstract
The vegetation in a beech forest, Fritzøehusparken, is analysed using one hundred sample plots, each 25 m2, distributed by a restricted random procedure. Percentage cover and frequency in subplots are used for quantification of species amounts, and their relative performance are evaluated. Advantages of choosing frequency in subplots are discussed.Thirteen environmental variables are measured from each of the sample plots. The vegetation is divided into four topographical/ecological types. This classification served as a reference in the further treatment. Ecological gradients corresponding to the most important vegetational gradients in the beech forest are identified by means of DCA ordination followed by statistical interpretation. Two main complex gradients were recognized; (1) the gradient in nutrient conditions, and (2), the gradient inlitter-wind conditions. The advantages of using DCA and statistical interpretation with integration of ecological measurements are emphasized.
Authors
Simen GjølsjøAbstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Tore SkrøppaAbstract
No abstract has been registered
Authors
Torild Wickstrøm W. Lund R. ByeAbstract
Iron(III) can minimize the serious interference from copper(II) and nickel(II) on the determination of tellurium by hydride generation/atomic absorption spectrometry. The optimal concentrations were found to be 1 g/l and 2 g/l Fe(III) in 4.0 mol/l HCl in presence of nickel(II) and copper(II), repectively. The signals were only 25% lower in a solution og 1.6 g/l Ni(II) than for a nickel-free solution. For copper(II), reasonable sensitivity was retained in the presence of 100 mg/l Cu(II).
Authors
Richard HorntvedtAbstract
Fifty pole stage trees were inoculated with O. polonicum at monthly intervals between May and September. Most infection, measured as the area of sapwood blue-stained, occurred in July and least in May and September. The difference between July, August and September might be explained by the effect of temperature on fungal growth, but in May and June the trees had a higher resistance than expected. Tree resistance was correlated with resinosis. Tree variables not correlated with resistance were DBH, annual ring width, periodic growth, vigor index, or phloem carbohydrate concentration.
Authors
Oddvar SkreAbstract
Frost damages may take place by rapid intracellular freezing or by extracellular ice formation and cell dehydration. The damages are measured visually or by electroconductivity measurements.The first hardeing stage is induced by short days and light, and is related to dormancy induction. The second stage is induced by low temperatures (-2-5 C). During this and the third stage, water binding forms of proteins and sugars are formed, and the membranes are re-structured in order to better withstand dehydration.Potassium prevents frost damages by increasing the resistance against dehydration while nitrogen and phosphorus in high concentrations are extending the growth period and exhaust carbohydrate reserves, making the plants more exposed to frost damages.
Authors
Kåre Hobbelstad Ole HofstadAbstract
No abstract has been registered
Authors
Ann Merete Furuberg GjedtjernetAbstract
No abstract has been registered
Authors
Magne Støen Bjørn Langerud Bonsak HammeraasAbstract
No abstract has been registered