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.
2004
Forfattere
K.M.J. Taulavuori E.B. Taulavuori Oddvar Skre Jan-Erik Ørnelund Nilsen B. Igeland Kari M. LaineSammendrag
The aim was to elucidate the effects of elevated winter temperatures on the dehardening process of mountain birch (Betula pubescens ssp. czerepanovii) ecotypes and to evaluate their susceptibility to frost damage under warming climate conditions. Ecotypes from 60 to 71N latitudes and 20750 m altitudes were grown in northern Norway (70N) and subjected to simulation of the photoperiod in southern Norway (60N) by artificial illumination from September onwards. In November, the seedlings were transported to the south (60N) to overwinter at ambient or 4C above ambient temperatures. Frost hardiness and lipid peroxidation were determined during JanuaryApril. The higher winter temperature accelerated dehardening, and there were significant differences between the ecotypes. Among tree individuals of southern origin, the alpine ecotype exhibited the most rapid rate of dehardening, whereas the oceanic type showed the slowest rate. Lipid peroxidation supported the above findings. Since temperature elevation was unequal for the ecotypes with respect to climatic change, the frost hardiness results were normalized to obtain an equal 4C temperature rise. The risk of frost injury seemed to be lowest in the northernmost ecotypes under a temperature elevation of 4C, obviously due to their adaptation to a wider temperature range.
Sammendrag
I år med tidlig setting, mye nedbør/vanning etter plastavtak og stor avling (sein høsting) får en størst utslag for delgjødsling. Bladgjødsling (med Stopit, Wuxal, Allgrow) kan gi betydelige avlingsutslag, og vi ubetinget være positivt. Dersom en skal ut i åkeren med tørråtesprøyting bør det drfor alltid tas med et bladgjødslingsmiddel, men det kan også tilrådes separate bladgjødsling-sprøytinger. Sortene reagerer forskjellig på delgjødsling og bladgjødsling, der Rutt gir bedre respons på dette enn t.d. Ostara. Det ser også ut itl at sortene reagerer forskjellig på delgjødsling/bladgjødsling med hensyn til tørrstoffinnhold. Rutt "tåler" dette bedre enn Ostara. Det blir atså viktig å kjenne de enkelte sortene sine behov/reaksjoner på de ulike innsatsfaktorene.
Forfattere
Bernt Olav Hoel Hans Jostein TandsætherSammendrag
Ulike strategier for delgjødsling til bygg og havre prøves med 2003 som første forsøksår. I artikkelen vektlegges bakgrunn og forsøksplan.
Sammendrag
A method for determination of the climate gases CH4, CO2 and N2O in air samples and soil atmosphere was developed using GC-MS. The method uses straightforward gas chromatography (separation of the gases) with a mass spectrometric detector in single ion mode (specific determination).The gases were determined with high sensitivity and high sample throughput (18 samples h1). The LOD (3) for the gases were 0.10 L L1 for CH4, 20 L L1 for CO2 and 0.02 L L1 for N2O. The linear range (R2 = 0.999) was up to 500 L L1 for CH4, 4000 L L1 for CO2 and 80 L L1 for N2O. The samples were collected in 10 mL vials and a 5 L aliquot was injected on column.The method was tested against certified gas references, the analytical data gave an accuracy within 5% and a precision of 3%. The presence of 10% by volume of C2H2 (often used experimentally to prevent N2 formation from N2O) did not interfere with detection for the targeted trace gases.
Sammendrag
A home designed diffusion chamber was used during the isolation of fluoride from plant material. The chamber contained two beakers, one for the sample (milled plant material) and the other for the trapping solution (0.1M NaOH). Hexamethyldisiloxane (HMDS) in 3.5M perchloric acid was added into the sample beaker through a septum, after the chamber was closed.Fluoride in the sample reacts with HMDS and forms the volatile trimethylfluorosilane (TMFS), which is trapped and hydrolyzed to fluoride. The diffusion time was 2h and 20 samples were handled at the same time. The fluoride concentration was determined by a flow injection analysis (FIA) system using an ion selective electrode (about 50 samples/hour).The results by acid extraction were compared to the results obtained after an ashing/alkaline fusion. Both a certified sample of timothy grass (NIST 2695, high level) and more typical vegetation from forest were analyzed. For the timothy grass, the recovery increased from 48 to 84% when ashing/alkali fusion was used before the diffusion. However, higher recovery was not obtained by using ashing/alkaline fusion for the determination of fluoride in natural vegetation from forest. Acid extraction in combination with addition of HMDS was sufficient as pretreatment in these types of plant materials.The method was routinely used for the determination of fluoride both in research and forest monitoring.
Sammendrag
Konfidensiell.
Sammendrag
Sweet cherry trees sometimes suffer from dieback symptoms under Scandinavian growing conditions. Some combinations of cultivars and rootstocks are more susceptible to this than others. The graft union between a rootstock and a scion is a junction between two different tissues. Differences in tissue development in the union may provide a mechanistic explanation of inhibiting transport of water and nutritional substances and likely inhibit growth of the scion. In order to investigate the relationship between growth and the amount of functional xylem tissue of potted sweet cherry trees, an experiment was conducted during 2002-2003. One year old field budded and bench grafted (from green house) sweet cherry trees of the cultivars Van, Ulster and Lapins in all combinations of the three rootstocks Prunus avium seedling, Colt and Gisela 5 were grown in pots for two growing seasons. After shoot extension had terminated when trees were in full leaf the second year, the total growth of the different parts of the trees and the quantification of functional area using safranin staining were conducted. The total mass production (tree dry weight, the length of two year old wood and number of leaves) was significant larger in the budded trees. Similarly the trunk cross sectional area was significant larger 10 cm above and in the middle of the graft union, but not 10 cm below. The Colt trees were the most vigorous followed by the seedling and Gisela 5. Small differences between the different cultivars were registered. Xylem staining with aqueous safranin combined with quantitative image analysis showed that the rootstock stem had a higher proportion of stained tissue than the scion stem. Sections taken in the middle of the graft tissue and above showed that the proportion of stained tissue declined proportionally with the distance from the roots. The total area of stained stem xylem was larger for the two vigorous rootstocks compared to Gisela 5. Small differences were observed between cultivars and propagation methods.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
The anatomical defense responses in stems of Norway spruce (Picea abies) clones of different resistance to pathogenic fungi were characterized over time and distance from small mechanical wounds or wounds inoculated with the root rot fungus Heterobasidion annosum. Common responses for both treatments included division of ray parenchyma and other cells in the cambial zone, accumulation of phenolic inclusions in ray parenchyma cells, activation of phloem parenchyma (PP) cells, and formation of traumatic resin ducts (TDs) in the xylem. TD formation occurred synchronously from a tangential layer of cells, or symplasmic domain, within the zone of xylem mother cells. TD induction is triggered by a signal, which propagates a developmental wave in the axial direction at about 2.5cm per day. TDs are formed at least 30cm above single inoculations within 16–36days after inoculation. The size and number of TDs is attenuated further away from the inoculation site, indicating a dose-dependent activity leading to TD development. Compared to sterile wounding, fungal inoculation gave rise to more and larger TDs in all clones, and multiple rows of TDs in weak clones. Fungal inoculation also induced the formation of more new PP cells, increasing the number of PP cells in the phloem in the year of inoculation up to 100%. TD and PP cell formation was greater in susceptible compared to resistant clones and after fungal versus sterile inoculation. Potential mechanisms responsible for this variable response are discussed.
Forfattere
Jørn Kristian Lileng Erlend Ystrøm HaartveitSammendrag
Forest roads ensure access to standing timber and their standards may restrict the opportunity set for efficient logistical solutions. Traditionally, the objective of road investments has been maximisation of returns for the landowner.Investments in forest roads in Norway are subsidised by the Norwegian government. These subsidies should preferably be allocated to projects creating the best premises for efficient log supply. The total cost approach evaluates costs using a holistic perspective. In this paper we use this approach to evaluate the profitability of investments in forest roads so that the total costs for log supply to the industry are minimised.The distribution of standing timber in the catchment area of the forest road is also taken into account. The results show that the sum of costs for road construction, harvesting and forwarding account for more than 99% of the total costs, compared to less than 1% for the sum of log hauling costs. Differentiation of forest road standards is more appropriate in situations where the volume of standing timber decreases in remote areas of the forest road network.