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.
2005
Authors
J. Brian Hardaker Gudbrand LienAbstract
Because the analysis of risky choice in agriculture and rural resource management is important but difficult, we argue that there is a need for some agreed principles on how to proceed. This paper is intended as a first step to this end. We start with the proposition that the importance of risk aversion has generally been exaggerated relative to the task of finding better ways to deduce relevant and reliable probabilities. Getting better probabilities demands careful thought, drawing on what is know about the pitfalls and on evolving insights into better ways of proceeding. Our aim is to stimulate a debate leading to a clearer consensus about better practice in these matters.
Authors
Nina Jøhnk Ari M. Hietala Carl Gunnar Fossdal Mari-Anne Newman David B. Collinge Harald KvaalenAbstract
Stilbene synthases make the backbone of stilbenes in a single enzymatic step. Many stilbenes are stressinduced antimicrobial phenolics, believed to work in disease resistance. In conifers, stilbenes are found in pine (Pinus), spruce (Picea) and a few other genera.Stilbene synthase isoforms in pine use cinnamyl-CoA to form pinosylvin, these are termed pinosylvin synthases, whereas stilbene synthases in spruce use pcoumaryl- CoA to form resveratrol and are sometimes termed resveratrol synthases.Pinosylvin has been found to be more effective than resveratrol in inhibiting fungal growth and wood decay (Seppnen et al. 2004), and pathogens of non-pinosylvin producing species have been found to be less tolerant of pinosylvin than pine pathogens (Seppnen et al. 2004). In the present study, Norway spruce (Transformation of Norway spruce with the pinosylvin synthase gene, PSS1) was transformed using the biolistic technique with a gene encoding pinosylvin synthase, PSS1, from Scots pine and the E. coli nptII antibiotic resistance gene.Vector constructs carrying PSS1 in sense and antisense, as well as control vectors without PSS1 were transferred into two embryogenic cell lines of Norway spruce, 11703-B63 and 186-3C. Selection condition for transgenic tissue was conferred by nptII in combination with the antibiotic geneticin. Geneticin resistant lines were recovered from all transformation events, a total of 55 lines.NptII was detected by PCR analysis in many of these lines, the majority derived from the cell line 11703 B63. However, nptII protein was detected in just five lines, and several lines of evidence indicate that the transgenic lines obtained in this study might be chimaeras.Fifty-six seedlings were successfully regenerated from antibiotic resistant lines, 50 of these were derived from cell line 11703 B63. All seedlings died during cold storage before further testing could be carried out.
Abstract
The uptake of chitosan based impregnation solutions were tested on Scots pine (Pinus sylvestris L), Beech (Fagus sylvatica L.), Downy birch (Betula pubescens Ehrh.) and Norway spruce (Picea abies L. Karst.) in longitudinal, radial and tangential directions separately. The four chitosans tested had a fraction of acetylated residues (FA) of 0.198 and average molecular weights ranging from 18 to 129kDalton. The kinetic viscosity of the 2.4% (weight/volume) solutions at pH 5.0 was in the range of 2.95 to 28.8mm2s-1. The general trend showed that there was an increase in uptake of chitosan based impregnation solutions with decreasing viscosity, and the chitosan solution with the lowest viscosity had almost comparable uptake with water for Pine and Beech in the longitudinal direction. In general, the lower the ability for uptake of impregnation solution, the more the viscosity influences the uptake.
Authors
Vegard Gundersen Lars Helge Frivold Irja Löfström Bruno Bilde Jørgensen Jan Falck Bernt-Håvard ØyenAbstract
No abstract has been registered
Authors
Vegard GundersenAbstract
Det overordna målet med avhandlingen er å frembringe relevant kunnskap om urbane skoger i Norge. Artikkel I og II undersøker tilstand og forvaltningspraksis i urbane skoger. Jeg undersøker to faktorer som har vært viktig for forvaltningen av urbane skoger, folks preferanser for skog (Artikkel III) og naturskogens kontinuitet (Artikkel IV, V). Til slutt diskuterer jeg disse resultatene i forhold til Aldo Leopold ideer om hvordan estetikk og økologi kan integreres i forvaltningen (Artikkel VI, VII). Skog dekker dominerende arealer rundt de vel 900 byer og tettsteder i Norge, og urban skog dekker anslagsvis 2 % av det totale skogarealet. Selv om nesten 80 % av befolkningen har de urbane skogene som nærområde, angir avhandlingen at tilstand og forvaltning er ganske lik det øvrige skogarealet, og det fremkommer heller ingen vesentlig forskjell mellom byer og tettsteder. Tradisjonell forvaltningspraksis utviklet for landlige forhold dominerer også de urbane skogene. Avhandlingen diskuterer hvordan forvaltningen kan videreutvikles i urbane skoger, inkludert fokus på langsiktige visjoner for utvikling av urbane skoger ved bruk av en aktiv og dynamisk forvaltningstilnærming. Kunnskap fra preferanseundersøkelser kan brukes til å innarbeide generelle hensyn i skogskjøtselen. Folks preferanser for tilstander i naturskog er lite studert, men de studiene som finnes indikerer lav preferanseverdi. Avhandlingen diskuterer noen utfordringer i skogskjøtselen knyttet til konflikter mellom økologi og estetikk, der også forhold mellom skogens dynamikk og forvaltningen inngår. En konklusjon fra avhandlingen er at forvaltningen av urbane skoger bør videreutvikles på to nivåer: 1) generell soningsmodell for tilpasninger i forvaltningen til spekteret av verdier og funksjoner i urbane skoger, 2) stedstilpasset forvaltning, der skogeiere, forvaltere og lokalbefolkningen motiveres til en aktiv forvaltningspraksis som avtegner en signatur som klart viser at de bryr seg om stedet.
Authors
Vegard Gundersen Lars Helge Frivold B.B. Jørgensen J. Falck Bernt-Håvard ØyenAbstract
A postal questionnaire survey about the forest situation and management in urban woodland was carried out around the three largest urban agglomerations in each of the five Nordic countries, Denmark, Finland, Iceland, Norway and Sweden. Twenty estate managements responded, giving a respondent rate of 54%. Our material from 13 cities includes 108,888ha productive forests, representing approximately 13% of all urban woodland areas in the Nordic region. The tree species composition in the urban woodland areas largely reflected the typical tree species distribution in the respective vegetation zones. It is expected that the percentage of Fagus sylvatica and Quercus spp. in the nemoral zone, and boreal hardwoods will increase in the future. The proportion of young and middle-aged forests is high in all urban woodlands, despite the focus on old forests in urban woodland management policy and research since the 1970s. Current silvicultural systems belonging to even-aged forestry prevail in most cities. However, the use of clear-cutting has decreased over the last 30 years. A conservative felling policy makes it likely that the proportion of old stands will increase. Various restrictions on forest management are briefly discussed. Reasons for changes in silvicultural practices differ from city to city, but recreation and conservation are most commonly reported.
Authors
Toril Drabløs Eldhuset Holger Lange Nicholas Clarke Per Otto Flæte Erlend Ystrøm Haartveit Gro Wollebæk O. Janne KjønaasAbstract
Root and needle litter are the most important sources of organic carbon in forest soils. Their decomposition is thus important for the long-term storage of C in, and release of CO2 from, the soil. Different components in the organic matter will decompose with different speeds. NIRS (Near InfraRed Spectroscopy) is a relatively simple and promising way of analysing the composition of organic matter, but its use in forest soil and litter studies has been limited up to now. We will present preliminary results from litter decomposition studies in two forest ecosystems: Picea abies stands (30 and 120 years old) from Nordmoen, Norway, and uneven-aged P. abies stands with a mean age of 90 years and under different N treatments at Gårdsjön, Sweden. ags with litter collected from the stands have been buried in the soil for different time periods and have been analysed using a CHN-analyzer and NIRS. Two aspects will be discussed: a) model calibration and validation for C and N concentrations, and b) assessment of decomposability using NIRS.
Authors
Rosario Mosello Monica Amoriello Tiziana Amoriello Silvia Arisci Andrea Carcano Nicholas Clarke John Derome Kirsti Derome Nils Konig Gabriele Tartari Erwin UlrichAbstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Magne SætersdalAbstract
No abstract has been registered