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.
1989
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Knut SolbraaSammendrag
There is a wide range of interpretations concerning the practical implications of multiple-use within nature management in Norway. The author suggests that managers who really are evaluating the needs of two or more groups of forest users or inhabitants and who pay attention to these needs are practicing multiple-use. Differing opinions about the importance of each group\"s needs, and thereby of the content and extent of multiple-use, must be expected.All species of plants and animals (human beings included) which live in, sometimes move within, or otherwise find forests useful are to be taken into consideration in multiple-use. Multiple-use starts by evaluating of the interests involved in each case and must cover a wide range of interests, including lumber production. Choosing alternatives may be difficult because of lack of knowledge and conflicting interests between groups. Furthermore, there are both biological and economic limitations in this choice.The aim of multiple-use in forestry is to solve or reduce conflicts between different users and to result in maximum public utility of the forests. Our present state of knowledge is at a sufficient level to take an important step towards this goal. The framework set by laws, rules, and state investment contributions, as well as the influence exercised by state and private service organizations and voluntary organizations, considerably influence the choice of alternatives. This effect may partly even out the differences between public and private use.In most cases, economic output will be an important factor in forest management. Commercial products other than lumber are supposed to have an increasing importance in the future. Among others, these products are fishing, hunting, cottages or cottage sites, guiding in undisturbed and/or picturesque forest landscapes, and mammal or bird watching.Initially, all forestry was devoted to multiple-use principles. Management has, however, followed the same course of development as within other parts of society towards a common goal: the highest possible production and/or net profit. Still in keeping with society in general, foresters now also show their willingness to pay respect both to the environment and to other users of the forests.The technical parts of this report give a short introduction both to the variability of forest treatment under different natural circumstances as well as to multiple-use adjustments. Reports, which give a more thorough coverage of each item are listed in Litteratur, while Vegetasjonstyper gives a short survey of the vegetation types used in the text. Usually, we can choose between several methods of forest regeneration in areas below approximately 500 m.a.s.l. in southeastern Norway.Decreasing seed production and increasing frequency of damages (e.g., frost, fungi) reduce the number of alternatives at higher altitudes. In areas close to the forest border line, the choice is very restricted or limited to only one alternative: Local conditions may result in similar restrictions even at low altitudes (e.g., frost, moose browsing).Production of high-quality lumber demands an initial density of at least 2000 plants per hectare. This number should be reduced successively as the trees grow taller. Under good growth conditions, a sufficient number may be killed in competition with the tallest ones. A thinning may then have insignificant influence on the composition of the stand at harvest.Thinning may, however, be a useful means of regulating tree species, removing poor-quality trees, and utilizing surplus trees. The choice of time for the thinning operations, of resulting tree densities, and of resulting tree species composition is rather open.There is a considerable lack of knowledge about which species of plants and animals are threatened by silviculture, their specific claims to living areas, and the possibilities of maintaining these species within multiple-use forests. Based on present knowledge, this report briefly mentions both general and specific multiple-use adjustments. General adjustments should be carried out on the whole forest area. Specific adjustments should be taken into consideration only in areas which are important for the groups in question.
Forfattere
Per Holm NygaardSammendrag
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Forfattere
Bjørn LangerudSammendrag
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Forfattere
Øystein JohnsenSammendrag
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Sammendrag
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Sammendrag
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Forfattere
Halvor SolheimSammendrag
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Forfattere
Erik Christiansen Alf BakkeSammendrag
De store barkbilleangrepene i 1970-årene ga støtet til en omfattende utforskning av granbarkbillens biologi og økologi. Denne artikkelen er en oppsummering av de viktigste resultatene av denne forskningen, og inkluderer også eldre viten om arten. Artikkelen beskriver granbarkbillens livssyklus, kjemisk kommuniksjon, angrepet på trærne - herunder den rollen sopper spiller, trærnes forsvar - og hva som påvirker deres motstandskraft. Videre omtales en modell som beskriver hvordan masseangrep kan oppstå, og hvorledes slike angrep kan forebygges og bekjempes.
Forfattere
Tor J. JohansenSammendrag
Det er ikke registrert sammendrag