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.
2010
Sammendrag
Le gel printanier peut etre dommageable pour les semis de Picea abies (L.) Karst. nouvellement plantes si leur rythme de croissance n'est pas suffisamment adapte aux conditions climatiques de la station forestiere. Les objectifs de cette etude consistaient a determiner de quelle facon le debourrement et la resistance au gel printanier sont influences par un traitement de jours courts (JC) appliques a differents moments et avec differents regimes de temperature durant la periode de formation des bourgeons. A la suite d'un entreposage hivernal, la resistance au gel a ete evaluee apres une, trois et cinq semaines dans des conditions de forcage. Le traitement JC a avance le debourrement comparativement aux semis temoins. Par comparaison, le moment du traitement et les differentes temperatures ont eu peu d'effet sur le debourrement. Le traitement JC a augmente la resistance au gel des aiguilles d'un an pendant la periode de desendurcissement. Applique tot, le traitement JC a augmente la resistance au gel des aiguilles d'un an et le diametre au collet comparativement a une application plus tardive. Il est important que la periode de noirceur atteigne une duree critique lorsque le traitement JC prend fin pour eviter une deuxieme eclosion des bourgeons. Des temperatures basses a la suite du traitement JC ont augmente la resistance au gel des aiguilles et diminue celle de la tige. Les effets contraires de la temperature sur differents tissus vegetaux demontrent l'importance d'examiner differents tissus apres des essais de gel-degel. Spring frost may result in detrimental damage in newly planted Picea abies (L.) Karst. seedlings if their growth rhythm is not sufficiently adapted to the climatic conditions on the forest site. The aims of this study were to evaluate how bud break and spring frost hardiness were influenced by short-day (SD) treatments with different timing and different temperature regimes during bud formation. Following winter storage, frost hardiness was tested after 1, 3 and 5 weeks in forcing conditions. The SD treatment advanced bud break compared with the control seedlings. In comparison, the effects of timing and the different temperatures on bud break were small. The SD treatment improved frost hardiness in first-year needles during dehardening. The early SD treatment resulted in improved frost hardiness in first-year needles and greater root collar diameter compared with later SD treatment. To avoid a second bud flush, it is important that a critical night length is attained when the SD treatment terminates. Low temperatures following the SD treatment resulted in increased hardiness of the needles and decreased hardiness of the stems. The contrasting effect of temperature in different plant tissues demonstrates the importance of examining different tissues following freezing tests.
Sammendrag
The suitability of interferometric X-band radar for forest monitoring was investigated. Working in a spruce-dominated forest in southeast Norway, top height, mean height, stand density, stem volume, and biomass were related to space shuttle interferometric height above ground. A ground truth dataset was produced for each radar data pixel in the study area by combining a field inventory and automatic tree detection with airborne laser scanning data. Pixels were aggregated to forest stands. Interferometric height was strongly related to all of the five forest variables, and most strongly to top height with R-2 = 0.71 and RMSE = 13% at the pixel level and R-2 = 0.82 and RMSE = 5.6% at the stand level. Interferometric height was linearly related to stem volume and biomass up to 400 m(3)/ha and 200 t/ha, respectively, and RMSE was approximately 19% for both variables. These errors contain error components caused by the 3.5-year time lag between the radar acquisition and the laser scanning. It is concluded that interferometric X-band radar has potential for use in forest monitoring.
Sammendrag
Development in surface mould growth on painted/unpainted wooden claddings and acting climatic factors were investigated over a period of 3 years. Eight wood substrates, including modified, preservative-treated and untreated wood, were tested in combination with three types of paint: (1) water-borne alkyd modified acrylic paint without fungicide; (2) solvent-borne alkyd paint without fungicide; and (3) ICP (internal comparison product). One set of samples was exposed unpainted. The samples were tested according to a modified version of EN 927-3. A logistic regression model was fitted to the data. The degree of mould growth varied with exposure time, coating typology, wood substrate, temperature and relative humidity. Exposure time and coating typology contributed most to the model. After 3 years of outdoor exposure unpainted panels and panels coated with solvent-borne paint without fungicide had more mould growth than panels coated with ICP and water-borne paint without fungicide. Unpainted oil/copper–organic preservative-treated claddings had higher resistance to mould growth than other unpainted wood substrates. Coated untreated pine and coated acetylated pine were more susceptible to mould growth than other coated wooden substrates.
Sammendrag
During the first few weeks of life, chicks of the capercaillie (Tetra urogallus) and black grouse (T. tetrix) subsist mainly on insects, of which lepidopteran and hymenopteran larvae are the main components. We studied the breeding phenology of these two species and examined how the timing of breeding was related to the temporal distribution of their larval food source. During a five-year survey, capercaillie mated and hatched consistently four to six days before black grouse. Depending on the vegetation type, the number of larvae (>= 2 mm in length) increased between five and ten times within 10 days, and hatching coincided roughly with the peaks in larval numbers. Due to body growth, however, larval abundance in terms of volume was reached later and occurred 8-9 and 13-14 days after the mean hatching dates in the two species, respectively. Slightly later development of Hymenoptera as compared with that of Lepidoptera contributed in extending the period of high larval abundances for more than one week. The timing of breeding of the two species appears, therefore, to match the temporal distribution of insect food for the fast-growing chicks as they hatch several days before the peak in larval volumes. In one year, when mating was advanced, presumably due to exceptionally warm weather before mating (yet the temporal abundance of larvae was unchanged), breeding success was higher than in years when mating occurred later.
Forfattere
Mari Mette TollefsrudSammendrag
Det er ikke registrert sammendrag
Forfattere
Mari Mette TollefsrudSammendrag
Det er ikke registrert sammendrag
Forfattere
Mari Mette TollefsrudSammendrag
Det er ikke registrert sammendrag
Forfattere
Mari Mette TollefsrudSammendrag
Det er ikke registrert sammendrag
Forfattere
Rasmus AstrupSammendrag
Skog som hugges til sagtømmer, massevirke eller bioenergi vil gjenoppstå og er – i motsetning til fossilt brennstoff – fornybar. Spørsmålet er bare i hvilket tidsperspektiv. Skogen bør hugges for å gi størst mulig produksjon av trevirke over tid. Rapporten ”Klimakur 2020” har skapt debatt om skogens rolle i klimapolitikken, og rundt bruken av skog som klimatiltak. Skog er sentral for klimagassregnskapet – både nasjonalt og globalt. Men skal skogen brukes til å maksimere CO2–opptaket på kort sikt, eller er hovedmålet mer langsiktig; leveranse av energi og trematerialer på vei mot et karbonnøytralt samfunn?
2009
Forfattere
Holger Lange Nicholas Clarke O. Janne Kjønaas Wenche Aas Kjell Andreassen Isabella Børja Harald Bratli Susanne Eich-Greatorex Toril Drabløs Eldhuset Kjersti Holt Hanssen Tonje Økland Ingvald Røsberg Trine Aulstad Sogn Tomasgaard Volkmar TimmermannSammendrag
Det er ikke registrert sammendrag