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
Peder Gjerdrum G. Arrighetti Mauro BernabeiSammendrag
Resin pocket is a natural property considered one of the main drawbacks of spruce timber, particularly important for appearance and joinery applications. The resins, viscous by nature, might only be solidified at temperatures superior to conventional kiln drying.Induced in the active cambium by traumas of unknown origin, size as well as location of resin pockets are random. Surrounding annual rings appear unaffected, while on the microscopic scale discrepancies in cell structure are easily recognised. Ca. 200 resin pockets per m3 timber have been reported in Scandinavian timber. More resin pockets were experienced in boards sawn from the ca. 16% of logs demonstrating resin pocket in the crosscuts.
Forfattere
Svein SolbergSammendrag
Summer drought, i.e. unusually dry and warm weather, has been a significant stress factor for Norway spruce in southeast Norway during the 14 years of forest monitoring. Dry and warm summers were followed by increases in defoliation, discolouration of foliage, cone formation and mortality. The causal mechanisms are discussed. Most likely, the defoliation resulted from increased needle-fall in the autumn after dry summers.During the monitoring period 19882001, southeast Norway was repeatedly affected by summer drought, in particular, in the early 1990s. The dataset comprised 455 Forest officers plots with annual data on crown condition and mortality. Linear mixed models were used for estimation and hypothesis testing, including a variancecovariance structure for the handling of random effects and temporal autocorrelation.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
The quantitative expression and the regulation of chitinase-encoding genes ech30, ech42 and nag1 in Trichoderma atroviride P1 under varying growth conditions were investigated using real-time RTPCR, principle component and multivariate analyses. Twelve media combinations including 0.1% and 3% glucose as carbon source and no (0 mmol/L), low (10 mmol/L) and high (100 mmol/L)ammonium acetate as nitrogen source combined with or without colloidal chitin at 3 time intervals and 2 replications were applied to current study. The real-time RT-PCR analysis showed that the expression of ech30, ech42 and nag1 was regulated by the interaction of nitrogen, glucose and chitin under different growth conditions. The highest and earliest expressions of ech30 were induced by glucose and nitrogen starvation i.e. 0.1% glucose and 10 mmol/L ammonium acetate in the growth media. This was also the case for ech42 and nag1 but at a relatively low level. In contrast, high (3 %) glucose and high (100 mmol/L) ammonium acetate concentrations repressed the expression of all the genes studied. These results were confirmed by principle component and multivariate analyses.The effect of chitin on ech30, ech42 and nag1 expression varied depending on the concentrations of glucose and ammonium acetate.
Forfattere
Vegard GundersenSammendrag
Det er ikke registrert sammendrag
Forfattere
Petter Nilsen Bernt-Håvard ØyenSammendrag
Det er ikke registrert sammendrag
Forfattere
Erik Jautris Joner D. Hirmann O.J.H. Szolar D. Todorovic C. Leyval A.P. LoibnerSammendrag
An experiment was conducted to distinguish priming effects from the effects of phytoremediation of a creosote-polluted soil. The concentration of 13 polycyclic aromatic hydrocarbons (PAHs), and their combined soil toxicity (using four bioassays), was determined on recently excavated, homogenized soil and on such soil subjected to a time-course phytoremediation experiment with lucerne.The results showed a high priming effect, with minor positive and synergistic effects of planting and fertilization on PAH degradation rates. At the end of the experiment, PAH degradation reached 86% of the initial 519 mg PAHs kg-1. Two of the four toxicity tests (bioluminescence inhibition and ostracod growth inhibition) corroborated the chemical data for residual PAHs, and indicated a significant reduction in soil toxicity.We conclude that priming effects can easily surpass treatment effects, and that an unintentional pre-incubation that ignores these effects can jeopardize the full quantitative assessment of in situ bioremediation of contaminated soil.
Sammendrag
Chitosan, a derivate of the natural amino polysaccharide chitin, has proven effective as a potential environmentally benign antimicrobial component. Few studies have focused on chitosan applied to wood against wood inhabiting and decaying fungi.In these screening studies several mycological experiments were performed to screen chitosan as a potential wood protecting agent. Growth studies on chitosan-amended media showed total inhibition of Poria placenta, Coriolus versicolor and Aspergillus niger using 1% w/v concentration.Chitosan with high average molecular weight (MW) was more efficient against mould and staining fungi than chitosan with low MW. Agar plate leaching tests showed only a small leaching effect using a 5% concentration on A. niger and P. placenta. Decay testing with P. placenta demonstrated efficacy using 5% and 2.5% concentrations in unleached samples. Leaching decreased the efficacy of chitosan and further investigations are needed to improve the fixation in wood.
Tidsskriftspublikasjon – Etablering av kvalitetsskog
Per Holm Nygaard, Kjersti Holt Hanssen, J. Moss
Forfattere
Per Holm Nygaard Kjersti Holt Hanssen J. MossSammendrag
Det er ikke registrert sammendrag
Forfattere
Geir ØstrengSammendrag
Artikkelen er basert på resultater fra et nordisk kurs i kalibrering av apparater for måling av CO2-frigivelse fra jord. Geir Østreng deltok på kurset med det apparatet som er brukt bl.a. i SIP Karbondynamikk i skogsjord 2000-2005, og han er medforfatter.