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.
2002
Authors
Halvor TorgersenAbstract
No abstract has been registered
Authors
Kjell Esser Tor Gunnar Vågen Yibabe Tilahun Mitiku HaileAbstract
No abstract has been registered
Authors
Peder Gjerdrum H. Säll H.M. StorøAbstract
Any evident grain deviation will reduce strength and increase warp in sawn timber. To describe the magnitude and variance of grain angle in Norway spruce, specimens from 1046 Norwegian sawlogs and 380 logs from Sweden and Finland were examined. For individual specimens, grain angle outside the innermost zone closest to the pith might be expressed by a simple linear function of radial distance from the pith. The intercept and inclination of this function are close to bivariate normally distributed with mean values (SD) of 2.7 deg. (1.9) and -0.039 deg/mm(0.037), respectively. Inclination is less negative for wider annual rings (r = 0.3), and intercept and inclination are negatively correlated (r = -0.4). The constant rate of change indicates inherited property rather than influence of any dynamic, external stimulus. No predictor for grain angle pattern was found. The linear model leads to simplifications both when observing the grain angle in the forestry, and in calculations of strength properties and distortion in the timber industry.
Authors
Lars Sandved Dalen Carl Gunnar Fossdal R. Bhalerao John Beck Jensen Teemu H. TeeriAbstract
Trees cover over one-third of the world\"s land area and carry out about two-thirds of global photosynthesis. Coniferous forests cover 1.2 billion hectares of Alaska, Canada, Scandinavia, and Russia, and comprise one-fourth of the world\"s boreal and temperate forests. More than 50% of Scandinavia\"s land area consists of forests, mostly coniferous. Information about the molecular responses in trees to biotic and abiotic factors is therefore of great importance - both scientifically and practically. Generation of expressed sequence tags (ESTs) is an important part of genome research. Randomly selected cDNA clones are partially sequenced, and the ESTs reflect the level and complexity of gene expression in the sampled tissue. In order to find interesting gene products and to study gene expression in the most common and economically important conifer in the Nordic countries, we have started an EST-project on Norway spruce. So far we have sequenced ~3500 cDNA clones based on mRNA isolated from needles and cell cultures. Here, we present the frequency of the different ESTs, their putative function and their functional classification. We aim at sequencing another 20,000-30,000 cDNA-clones from wood-forming tissues and from seedlings treated with drought, low temperatures, pathogen infection, etc. The long-term goal is to develop a non-redundant and annotated collection of Norway spruce clones to be used in combination with microarray analysis
Abstract
In 2001, a zone site C, was established as a circular areas with 50 km radius and centred in Greåker close to Sarpsborg in South-eastern Norway. Zone site C is complementary to the similar zone sites A and B established in 2000. From June 2001 to December 2002, 601 wood samples were collected from 66 forest blocks, all situated within the 3 existing zone sites A, B and C. The sampling was carried out in the provinces Akershus, Buskerud, Vestfold and Østfold, but was concentrated to the South-eastern region, where 399 samples were taken from 45 forest blocks in the province of Østfold. Samples from Scots pine (Pinus sylvestris) formed 96% of the collected material, while Norway spruce (Picea abies) was a minor fraction. Lying trees and various kinds of detached wood formed the main part of the objects sampled. The frequency of objects showing signs of attack by wood boring insects was 44%. Some samples were also taken in Porsgrunn in the province of Telemark from a consignment of spruce imported from Russia. Nematodes were often more common in samples from objects with signs of insect activity. In four samples, all from lying pine trees, nematodes belonging to the genus Bursaphelenchus were detected. Bursaphelenchus mucronatus was recorded for the second time in Norway, and occurred in a lying pine tree attacked by Monochamus at Ombudstvedt in the municipality of Våler in the province of Østfold. The pine wood nematode Bursaphelenchus xylophilus was not detected, nor in forests or in 5 samples from spruce imported from Russia
Abstract
This report looks at the special measures for agriculture within the field of taxation and social security. Chapter 1 and 2 deal with general overview of taxes and taxation principles. Chapter 3 give more detailed information of the tax system in the selected countries, US, Canada, Australia, Germany, UK, France, Ireland, Italy and Switzerland. Chapter four deals with notifications to the Committee on Agriculture in the World Trade Organisation (WTO) concerning tax measures. In chapter 5 we have tried to systematize the different tax schemes in the selected countries.
Abstract
The Norwegian intensive monitoring programme of forest condition has recorded rainfall, throughfall and soil water data from 1986 at 16 forest plots. Using covariance analysis, this study has examined short term and episodic influences on soil water ionic concentration at three of the plots, and identified both seasonal and long-term temporal trends. Acidity has decreased in bulk precipitation and throughfall, and the concentrations of base cations in the organic soil horizon have increased. Nevertheless, there is evidence of continued acidification in the organic and mineral soil horizons, though of a small scale. The influence of sea salt and drought effects on soil water chemistry are examined, but found to be unimportant in causing acidification effects such as increased soil aluminium concentration.
Authors
Steen Koekebakker Gudbrand LienAbstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Christian Anton Smedshaug Svein-Erik Lund Audun Brekke Geir Sonerud Trond RafossAbstract
Størrelse på hjemmeområde og habitatvalg for 26 hekkende kråker (Corvus corone cornix) ble registrert ved bruk av radiotelemetri i et fragmentert jord- og skogbrukslandskap i sørøst-Norge i april-juni i 1993, 1995 og 1996. Hjemmeområdet (95% minimum konveks polygon) basert på en lokalisering per dag var i gjennomsnitt 0.15 km2. Habitatsammensetningen i kråkenes hjemmeområde avvek fra habitat-sammensetningen i studieområdet, og kråkenes habitatbruk avvek fra habitat-sammensetningen i deres hjemmeområder. I begge tilfeller av habitatseleksjon rangerte kantsonen (skog < 30 m fra åpne habitat) og beitemark høyest, etterfulgt av åker, skog (>30 m fra åpne habitat) og hogstflater og plantefelt. Kråkene brukte mer tid på å sitte stille enn på å furasjere, og brukte for det meste kantsonen når den satt stille, og nesten bare beitemark og åker til å furasjere. Kråkenes bruk av kantsonen økte med økende tilgang av kantsone i hjemmeområdet, og kråkene benyttet kantsonen mer enn tilfeldig forventet så lenge kantsonen utgjorde < 40% av habitattilgangen i hjemmeområdet. Kråkenes hjemmeområde minket, når andelen av kantsone i hjemmeområdet økte. Dette antyder at en økning av andelen av kantsone mellom jordbruksmark og skog øker tettheten av hekkende kråker, og således øker predasjonsrisiko fra sittende kråker på fuglereir plassert i denne kantsonen.