Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
1988
Forfattere
Tonje ØklandSammendrag
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.
Forfattere
Kåre Hobbelstad Ole HofstadSammendrag
Det er ikke registrert sammendrag
Forfattere
Bjørn Langerud Martin Sandvik Anders SjøvoldSammendrag
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Forfattere
Tore SkrøppaSammendrag
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Forfattere
Jarle Bergan Trygve EideSammendrag
During 1979-82 seven field tests were carried out at 69°N in Norway (Table 1). Four tests included seeding of Pinus sylvestris under plastic cones (K) and funnels (T) compared to seeding without cover (S) and plug planting (P) (see Fig. 1). Three field tests included seeding of Picea abies in funnels located in virgin vegetation in birch forests on the hillsides. Here the seeding in funnels was compared to plug planting. The plant percentage means the percentage of seeds forming plants up to the first autumn. The germination percentage of the seed used has been 92.5% to 95.0%. The number of pine seeds per spot was four seeds in cones and funnels, and 15 seeds in open sowings on scarified patches. Six spruce seeds were used in each funnel in the tests on the hillside. The survival percentage means the percentage of cones, funnels or patches with one or more living plants. The vegetation type of the areas of pine plots is Vaccinio-Pinetum boreale, and on spruce areas Eu-Piceetum abietis-subass. dryopteridetosum. The seeding in cones (Method K) has turned out to be a reliable method with high survival percentage and relatively good height development, especially the first years with seedlings inside the cones. The consumption of seed is very low in relation to open sowings (Method S). The plant percentage in cones has in average been about 80% compared to 53% in open sowings (Table 2). However, there is a risk of cones being removed by persons, birds, and strong wind. Method S has shown more varying results as regards plant percentage and survival percentage. However, by using 25 seeds per patch instead of 15 seeds, the possibility of increasing the survival percentage in years with unfavourable climatic conditions, would have been quite good. Bergan (1957 and 1981) found high positive correlation between the number of plants per patch and the survival percentage. Also plug planting is a highly acceptable regeneration method. On the other hand, sowing in funnels (Method T) has been less successful in all tests both regarding survival percentage and height development. The choice of regeneration method between the methods K, S and P at pine areas at these northern latitudes depends on the supply of seed, economic calculations, and administration conditions.
Forfattere
Oddvar SkreSammendrag
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Forfattere
Oddvar SkreSammendrag
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Forfattere
Magne Støen Bjørn Langerud Bonsak HammeraasSammendrag
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Forfattere
Simen GjølsjøSammendrag
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Forfattere
Torild Wickstrøm W. Lund R. ByeSammendrag
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