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.
2007
Forfattere
Peder GjerdrumSammendrag
Predicting the yield and quality of sawn timber continues to be a challenging task, influenced by several stochastic processes: Log dimension and shape under bark varies, accuracy of sawing is not perfect, etc. This work presents an annotated model based on an approach successfully applied in the industry through a couple of decades. A number of important timber yield predictors are identified, and the following models give unbiased yield estimates. Being in need of adjustment before transferring to new locations, the approach might be considered a powerful tool to analyse and improve the operation, rather than a complete model in itself. Nevertheless, the notional, purely geometric, models might be superior for analysing unfamiliar sawing patterns, even if they tend to overestimate the yield. Thus, the two methods should preferably be used in combination, rather than one replacing the other. Finally, the everyday use of such models is illustrated and a procedure for associating sawn timber with suitable logs is outlined.
Forfattere
Ketil Kohmann Finn SønstebySammendrag
Denne undersøkelsen at planter som ble knoppsatt med langnattbehandling i juni/juli har god overlevelse og utvikling ved planting i juli måned. Diametertilveksten hos plantene fortsetter etter utplantingen, i motsetning til ved langnattbehandling i månedsskiftet juli/august. Også rotveksten er betydelig etter utplantingen midtsommers; aktiv rotvekst etter utplanting som ga et godt feste i bakken. Ingen av de tre tidspunktene for behandlingene eller de ulike lengder som langnattbehandlingen varte i planteskolen, resulterte i høstskuddskyting etter utplanting. Ved siden av avgang, skader og høydeutvikling, ble også diameterveksten registrert i de tre år undersøkelsen varte. Allerede i utplantingsåret var rothalsdiameteren i middel godt over 4 mm, og ved slutten av det andre år var rothalsdiameteren i middel godt over 6 mm. Plantene har da nådd en størrelse som gjør dem sterke mot snutebilleangrep. Angrep av snutebiller i forsøket var imidlertid helt sporadisk - også første år. Det skyldes god behandling med insekticider og effekt av manuell avflekking av vegetasjonen rundt plantene. Når heller ikke plantene ble påført skader av snutebillegnag det andre året, må dette ha sin årsak i plantenes særdeles sterke tekniske og fysiologiske status. I dette forsøket hadde kontrollplantene, som bare ble plantet den 10. juli av praktiske årsaker, også en god utvikling. Når vi likevel anbefaler tidlig langnattbehandling ved planting i juli, skyldes dette mulighetene for tidlig høstfrost (august/september), men som vi ikke hadde i dette forsøket. Det er heller ikke gjennomførbart i praktisk målestokk å pakke, transportere og plante planter som ikke er knoppsatt uten en betydelig frekvens av toppbrekk. Produksjonsmetoden har praktisk relevans med begrensning i forhold relatert til breddegrad og proveniens; på grunn av faren for ny skuddskyting (høstskudd), bør metoden begrenses til planteskoler omkring 60 °N med stedegne eller nordligere provenienser (Kohmann & Johnsen, 2007). For å oppnå en tilsvarende diameterutvikling som i forsøket bør produksjonen planlegges slik at plantene har høvelig størrelse (minst 25 cm) når langnattbehandlingen settes inn. Analyser av frostresistens sent på høsten (Kohmann & Johnsen, 2007) viser at det er ingen grunn til at slike langnattbehandlete planter, i tillegg til å plantes hele sommeren og høsten, ikke også kan vinterlagres og plantes neste år.
Forfattere
Clemens Reimann Arnold Arnoldussen Rognvald Boyd Tor Erik Finne Friedrich Koller Øystein Nordgulen Peter EnglmaierSammendrag
Forty samples each of leaves of birch (Betula pubescens Ehrh.), European mountain ash (Sorbus aucuparia (L.)) and bracken fern (Pteridium aquilinum (L.) Kuhn) as well as spruce needles (Picea abies (L.) Karsten) were collected along a 120 km south–north transect running through Norway\"s largest city, Oslo. Concentrations of 25 chemical elements (Ag, Au, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, La, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sb, Sr, Ti, and Zn) as well as loss on ignition for the 4 sample materials are reported. The decline of input of sea spray with distance from the coast, geology, pH and anthropogenic contamination all played a role for the observed element concentrations in the leaves. Although growing under exactly the same natural conditions each plant species displayed quite unique uptake characteristics. Plant-species dependency and individual differences in the reaction of the plant leaves to different element sources make the investigated species of very limited value as bioindicators of anthropogenic activities. Anthropogenic contamination influences plant-leaf element content within a limited distance ( 20 km) from the source.
Forfattere
Peder Gjerdrum Mauro BernabeiSammendrag
Resin pockets, being an important natural characteristic for wood quality and tree physiology, were observed on the surfaces of boards sawn from four large Norway spruce (Picea abies (L.) Karst.) trees and analysed for size and distribution. Axial length varied between trees and increased from pith to surface and from butt to top; however, three quarters of the variation were random and normally distributed. Also resin pocket frequency varied between trees. Within the stem, the resin pockets remained independent and randomly distributed following the exponential distribution in all three directions: radial, angular and axial, corresponding to a constant probability during the lifespan of the tree. No association between size and frequency was identified. The initiation and the expansion of a resin pocket appear to be controlled by two different physiological processes. The findings should add to the understanding of resin pocket formation in spruce and should be applicable to wood quality
Forfattere
Anna Arneberg Per Holm Nygaard Odd Egil Stabbetorp Bjarni D. Sigurdsson Edda Sigurdis OddsdóttirSammendrag
The aim of this study was to investigate variation in decomposition and vegetation due to afforestation. The ICEWOODS sites containing stands of different tree species and age in the western (Skorradalur) and eastern (Hallormsstaður) parts of Iceland were investigated during the summer of 2004. These stands were compared with treeless pastures. The planted stands represent chronosequences, i.e., different age classes within each tree species were studied. Decomposition was studied by a cotton strip assay. Cotton strip decomposition increased with incubation time and decreased with soil depth. The tree species can be ranked according to increasing decomposition in the following series: lodgepole pine < Sitka spruce< Siberian larch < mountain birch. In general, decomposition decreased with increasing age of the stands...
Forfattere
Clemens Reimann Arnold Arnoldussen Peter Englmaier Peter Filzmoser Tor Erik Finne Robert G. Garrett Friedrich Koller Øystein NordgulenSammendrag
Rock samples and the C-, B- and O-horizons of soils developed on these rocks were collected in forested areas along a 120-km south–north transect in southern Norway, passing through the city of Oslo. Forty samples (1 site/3 km) were analysed for 37 chemical elements (Ag, Al, As, Au, B, Ba, Bi, Ca, Cd, Co, Cr, Cu, Fe, Ga, Hg, K, La, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sb, Sc, Se, Sr, Te, Th, Ti, Tl, U, V, W and Zn) following an aqua regia digestion; pH (water extract) and loss on ignition were also determined. The O-horizon soils were additionally analysed for Pt. Gold is the only element that shows a clear anthropogenic peak in the O-horizon soils collected from the city of Oslo. Silver, Au, Bi, Cd, Hg, Pb, S, Sb, Se and Sr all show a strong enrichment in the O-horizon when compared to the underlying C-horizon or the bedrock along the full length of the transect. Neither geology nor anthropogenic input of elements dominate the observed patterns. The most important factors for the observed element concentrations in the O-horizon are weathering, uptake (or rejection) of elements by plants and the kinetics of decay of the organic material in the O-horizon. Climate, especially temperature and precipitation, has an important influence on the formation and decay rates of the organic soil layer. Acid precipitation will delay the decomposition of the organic layer and lead to a natural enrichment of several metals in the O-horizon. Land use change, deforestation and liming can all increase the decay kinetics of organic matter and thus result in a release of the stored element pool.
Forfattere
Bernt-Håvard ØyenSammendrag
Det er ikke registrert sammendrag
Forfattere
Inge BjørdalSammendrag
Markslagsinstruksen er hovuddokumetasjonen på arealklassifikasjonssystemet som er nytta i Økonomisk kartverk. Den inneheld ein komplett oversikt over alle markslagsklasser, definisjonar, prinsippa for klassifikasjonen og reglar for praktisk kartlegging i felt. Instruksen har vore nytta heilt sidan oppstarten av markslagskartlegging, men har gjennomgått mange større og mindre revisjonar. Denne utgåva vert den siste sidan ein frå 2007 går over til å nytte AR5 i staden for DMK. Men markslagsinstruksen vil også vere det viktigaste kjeldematerialet til dette nye klassifikasjonssystemet.
Sammendrag
The aim of this study was to use Energy-Dispersive X-ray Spectroscopy (EDS) to localize chitosan in the cell wall of chitosan impregnated Scots pine. It is of both general and specific interest to investigate the concentration of chitosan in the wood matrix to gain further knowledge and understanding of chitosan as a wood protective system.After deacetylation, chitosan was re-acetylated with chloroacetic anhydride to achieve a covalent bonding of chloride to the chitosan polymer. Chloride labeled chitosan was measured by EDS using a Scanning Electron Microscope (SEM) and described in apparent concentration of chloride. Analysis for free chloride anions was tested by dialysis and ion chromatography.There was a significant correlation between the molecular weight of chitosan and the apparent concentration of covalent bonded chloride to the chitosan polymer. High molecular weight chitosan showed a better interaction with the cell wall structure than low molecular chitosan.
Forfattere
Anders Often Harald BratliSammendrag
Det er ikke registrert sammendrag