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.
2004
Abstract
No abstract has been registered
Authors
Ken Olaf StoraunetAbstract
Number of years since death was estimated by dendrochronological cross-dating of 107 standing dead trees (snags) of Norway spruce [Picea abies (L.) Karst.] in a submountainous old-growth forest in south-central Norway. Snag characteristics (size, bark cover, branch order present and variables derived from tree-ring analyses) were used in stepwise linear regression procedures to identify variables that explained time since death.Number of branch orders present (where branches growing directly on the stem were branch order 1, branches growing on order 1 branches were order 2, and so on) explained two-thirds of the variation in time since death. Adding other significant variables, such as diameter, relative height of snags, percentage bark cover and average tree-ring width in the final years before death, increased model precision only moderately.The models were validated by the PRESS statistic, which showed that new observations were predicted fairly well with 65-69% of the variation explained.
Authors
Axel Schmidt K. Witzel Gazmend Zeneli D. Martin J. Bohlmann Paal Krokene Trygve Krekling Ari M. Hietala Carl Gunnar Fossdal Erik Christiansen Jonathan GershenzonAbstract
The study of conifer chemical defense has been dominated by investigations of oleoresin and its components. However, the actual function of resin components in plant defense and their mode of action is still uncertain, and the role of other defense compounds is relatively unexplored.We are studying the biochemical and molecular bases of chemical defenses, including terpenes, phenolics and chitinases, in Norway spruce (Picea abies) to learn more about how the accumulation of defense compounds is regulated, with the long-term goal of manipulating defense levels to test their function.Manipulation can be crudely accomplished by treatment with methyl jasmonate, which often mimics the general increases in defenses seen following herbivore or pathogen attack. Such treatment was shown to increase resistance to a fungal associate of bark beetles.To more conclusively test function, isolated genes of defense biosynthetic pathways are being transformed into Norway spruce to produce plants whose defense profiles are altered more precisely.
Authors
Sjur Spildo PrestegardAbstract
Norway, Switzerland, the European Union, Korea, Japan and some other countries place substantial emphasis on the so-called non-trade concerns in the ongoing WTO negotiations on further agricultural trade liberalisation. In addition to the production of food and fibre, agriculture also may provide national food security, environmental benefits, and viable rural areas. The term «multifunctional agriculture» has been increasingly applied to describe these additional functions. This working paper focuses on how to achieve the multifunctional goals that nations may have with minimal tradedistortion. In this study, the economic concepts of externalities and public goods are used to analyse non-trade concerns and multifunctional agriculture. It is argued that just as a tax is widely accepted as the optimum policy for a negative externality, so should the use of a production-tied subsidy or payment be accepted as optimum policy for a positive externality or public good that is produced jointly with or complementary to agricultural production. The study concludes with suggestions for international trade rules to prevent such policies from becoming a form of protectionism.
Authors
Sjur Spildo PrestegardAbstract
One of the questions debated in the ongoing WTO agricultural negotiations is whether ‘trade-distorting’ subsidies, or subsidies outside the ‘green box’, are needed in order to pursue non-trade concerns. The term ‘multifunctional agriculture’ is increasingly applied to describe non-trade concerns. This article focuses on how to achieve the multifunctional goals that nations may have with minimal trade-distortion. In the first part of the article, this is done by a literature review and a theoretical analysis. The findings are then converted into an analysis of possible policy formulations in a Norwegian context using a partial equilibrium model. The article argues that multifunctionality hardly can justify the use of market support, while it may justify production-related budget support if the positive externalities or public goods are produced jointly with or complementary to agricultural production. The article concludes with suggestions for WTO trade rules to prevent such policies from becoming a form of protectionism.
Authors
Per Otto Flæte Erlend Ystrøm HaartveitAbstract
In Scandinavia Scots pine (Pinus sylvestris L.) is an important commercial tree species. Its heartwood has traditionally been used in constructions exposed to risk of decay. In a laboratory experiment Scots pine wood specimens sampled from inner heartwood, outer heartwood and sapwood were exposed to the brown rot fungus Poria placenta.In general outer heartwood was more resistant than inner heartwood, but there were variations even within the same wood zone. NIR spectra obtained on solid wood prior to decay testing were used in multivariate calibrations to predict decay resistance of heartwood.Results from segmented cross validated partial least squares (PLS1) regression modelling showed that resistance to decay in Scots pine heartwood could be predicted with satisfying precision using NIR spectroscopy. As NIR spectra were collected on solid wood, development of the method for industrial use is potentially possible.
Authors
Live Semb Vestgarden Petter Nilsen Gunnar AbrahamsenAbstract
No abstract has been registered
Authors
Per Otto Flæte Erlend Ystrøm HaartveitAbstract
No abstract has been registered
Authors
Ole K. Hansen Ulrik Bräuner Nielsen Øyvind Meland Edvardsen Brynjar Skulason Jan-Ole SkageAbstract
In three Nordic field trials, 26 provenances of Abies lasiocarpa (Hook.) Nutt. and Abies lasiocarpa var. arizonica (Merriam) Lemmon were evaluated 3 yrs after establishment. The focus was on 16 traits important for adaptation, establishment and production of Christmas trees.For all three sites in Denmark, Norway and Iceland, survival ranged from 89 to 96%. Provenances showed statistically significant differences for all but two traits. For all traits there was significant interaction between provenance and site. Analysis of ecovalens showed that for most traits, only a limited number of provenances contributed substantially to the interaction. Therefore, a large proportion of the provenances showed a fairly consistent ranking across sites.The frequency of potential Christmas trees in the provenances ranged from 10 to 49%. Southern provenances from New Mexico and Arizona seemed to have the best potential for producing high-quality Christmas trees. The southern provenances added substantially to the interaction between provenance and site for budset, lammas growth and colour. When using multivariate statistical methods on all measured traits, the provenance clusters fitted neatly into six distinct geographical regions.
Abstract
No abstract has been registered