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.
2006
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Peder GjerdrumSammendrag
En kortfattet beskrivelse av tre brukt i musikkinstrumenter.
Forfattere
Terje Birkeland Knut FinstadSammendrag
Vi fant liten effekt på sagtømmervolumet av å tillate kortere minstelengde på massevirke i våre simuleringer. Treforedlingsindustrien ønsker ikke kortere minstelengde av hensyn til sikkerhet, utnyttelse av kapasitet lastebærer/tømmerbil og areal industritomt. Erfaringer fra tidligere da kortere minstelengde blei brukt i visse distrikter i landet tyder på langt høgere økning i sagtømmerandelen enn det vi fant. Ulike sammenhenger gjør at den reelle effekten på sagtømmervolumet sannsynligviser høgere enn det vi fant i simuleringhene, men lågere enn tidligere erfaringer.
Sammendrag
This study is based on data from the Level I and from forest Officers plots. We combined three sets of data on growth, deposition and soil chemistry, totally 204 plots in south-eastern and mid-Norway. As response variable we used observed growth in % of estimated growth calculated from standard Norwegian growth models. In this way we filtered out the influence of site and stand properties as this were included in the model.The dependent deposition variable used was the N deposition from the national air and precipitation monitoring program. The dependent soil chemistry variables were N, C/N ratio, base saturation, pH, Al, and Ca/Al ratio. Soil chemistry variables should reflect the properties that most likely are influenced by S and N deposition, and that could influence the trees in the hypothesised ways.We used analyses of covariance as statistical method. Growth was positively correlated to nitrogen deposition and to soil nitrogen, and negatively correlated to the C/N ratio in the soil. Also, nitrogen deposition was positively correlated to soil nitrogen and negatively to soil C/N.It was concluded that N deposition probably has increased N availability and thereby growth in southernmost Norway with an order of magnitude around 25%. There were no relationships between growth and the soil acidification variables pH, base saturation, Al concentration or Ca/Al-ratio, and we concluded that no evidence for negative effects of soil acidification on forest growth was found.
Forfattere
Jan-Ole Skage Tormod Stavrum Torben HenriksenSammendrag
Deler av Nord-Korea er mer eller mindre avskoget som følge av folks behov for arealer til matproduksjon og brensel til matlaging og oppvarming. Det bor omlag 22 millioner mennesker i Nord-Korea, på et areal som er omkring 1/3 del av Norges. Nord-Korea er et meget ressursfattig land og befolkningen er i hovedsak tvunget til å være selvforsynt med mat og energi. Det dyrkes i all hovedsak ris og mais, men også grønnsaker, frukt og bær. Når skogene i åssider og opp mot fjellet er hogget, blir jorda utsatt for sterk erosjon. Faren for flom i lavlandet øker også betydelig når skogen er borte. Produksjonen av mat blir dermed ytterlig redusert på grunn av oversvømmelse. Norges Røde Kors har på den bakgrunn etablert et samarbeid med Nord-Koreas Røde Kors om treplanting i tre provinser på vestkysten av landet for å redusere skadevirkningene.
Sammendrag
In this study, we present a new method for single tree segmentation and characterization from a canopy surface model (CSM), and its corresponding point cloud, based on airborne laser scanning. The method comprises new algorithms for controlling the shape of crown segments, and for residual adjustment of the canopy surface model (CSM). We present a new criterion that measures the success of locating trees, and demonstrate how this criterion can be used for optimizing the degree of CSM smoothing. From the adjusted CSM segments, we derived tree height and crown diameter, and based on all first laser pulse measurements within the segments we derived crown-base height. The method was applied and validated in a Norway spruce dominated forest reserve having a heterogeneous structure. The number of trees automatically detected varied with social status of the trees, from 93 percent of the dominant trees to 19 percent of the suppressed trees. The RMSE values for tree height, crown diameter, and crown-base height were around 1.2 m, 1.1 m, and 3.5 m, respectively. The method overestimated crown diameter (0.8 m) and crown base height (3.0 m).
Forfattere
Jenny Fäldt Halvor Solheim Bo Långström Anna-Karin Borg-KarlsonSammendrag
To identify chemical resistant markers induced by fungal or mechanical injury, young trees of Scots pine (Pinus sylvestris) were subjected to inoculations of blue stain fungi associated with the pine shoot beetles Tomicus piniperda and T. minor. Among the 20 trees selected for chemical analyses, 16 were divided into four groups: one as control and three were pretreated by wounding only, or by inoculation with either the blue stain fungus Leptographium wingfieldii or Ophiostoma canum.Four wk after pretreatment, all 16 pretreated trees were mass-inoculated with L. wingfieldii. The absolute and relative amounts, as well as the enantiomeric compositions of monoterpene hydrocarbons in the phloem, were determined via a small sample of the phloem before and after the pretreatment and mass inoculation, by using two-dimensional gas chromatography (2D GC) and GC-mass spectrometry (MS).After mass inoculation, the absolute amounts of most of the monoterpenes decreased in the phloem sampled 20 cm from the fungal infection, and were higher in the phloem sampled within the infected reaction zone.The relative amounts of both ()--pinene and ()-limonene increased in phloem samples taken 20 cm above the fungal inoculation in the preinoculated trees compared with phloem sampled from the remaining four control trees. The enantiomeric compositions of -pinene and limonene changed, after fungal growth, at defined distances from the inoculation site: the proportion of the ()-enantiomers was highest in the phloem sampled 20 cm from the fungal inoculation.Four wk after pretreatment, monoterpene production in the phloem at the site of inoculation was more enhanced by L. wingfieldii than by O. canum. However, the different virulence levels of the fungi did not affect the enantiomeric composition of the monoterpenes. The biosynthesis of monoterpene enantiomers is discussed in relation to induced pathogen resistance.
Forfattere
Per Otto FlæteSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Harald Bratli Erik Framstad Jogeir N. Stokland Odd Egil StabbetorpSammendrag
Det er ikke registrert sammendrag