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.
2011
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Helge Bonesmo Odd Magne Harstad Arne Oddvar Skjelvåg Arnold Arnoldussen Ole Einar Tveito Ove Klakegg Harald Volden Egil Prestløkken Tonje Storlien Kjell Staven Otto SjelmoSammendrag
Det er ikke registrert sammendrag
Forfattere
Helge Bonesmo Odd Magne Harstad Arne Oddvar Skjelvåg Arnold Arnoldussen Ole Einar Tveito Ove Klakegg Harald Volden Egil Prestløkken Tonje Storlien Kjell Staven Otto SjelmoSammendrag
Det er ikke registrert sammendrag
Forfattere
Rolf Jens Brunstad Ivar Gaasland Klaus Mittenzwei Erling VårdalSammendrag
Det er ikke registrert sammendrag
Sammendrag
Rapporten omhandler vannområdet øst for Randsfjorden fra utløpet av Vigga og sørover til Jevnaker. Innsjøens nedbørfelt er på 354 km2. Arealet er dekket av skog (~70%) og jordbruk (28%. Husdyrtettheten er ikke høy og industrivirksomheten er begrenset. Berggrunnsgeologi i områder har kalkrike bergarter noe som gir en rekke sjeldne kransalgesjøer. Nedbørfeltet er dekket av tynt morenedekke i høyden, og tykkere i dalen langs Vigga. I område med skifrige bergartene er det forvitringsjord. Inndeling av delnedbørfelt er gjort med digital høydemodell. Til hvert nedbørfelt er det beregnet næringsstoffbelastning med hovedvekt på fosfor. Det er beregnet fosforbidrag i naturtilstand (2744 kg), dagens utmarksavrenning (1364 kg / 12,4%), atmosfærisk deposisjon (103 kg / 0,9%), avrenning fra tette flater og samferdsel (919kg / 8,3%), spredt avløp (4084 kg / 37%), kommunale renseanlegg (50 kg / 0,5%), arealavrenning fra landbruk(4040 kg / 36,6%), husdyr (480 kg / 4,3%). Tilførselsberegninger er gjort med modellene AgriCat-P, JOVA-Nest, WEBGIS avløp og koeffisienter for arealavrenning fra andre kilder. I prosjektet er det testet en del tiltaksscenarioer som det er gjort effektberegninger for. Disse inkluderer, oppgradering av spredt avløp, påkobling til kommunalkloakk i 28 områder, bygging av 5 fangdammer, omlegging til 80% stubb, 5m 8m og 10m vegetasjonssone langs vassdrag, reduksjon av fosfornivået i jorda ved redusert fosforgjødsling. Det er også gjort beregninger av samlet samspillseffekt av å gjøre alle tiltakene i landbruket. Siste del av rapporten er 51 kransalgesjøer oppsummert pr nedbørfelt. Der det foreligger datagrunnlag er det gjort egne fosforresponsmodelleringer.
Forfattere
Ram Prasad Sharma Andreas Brunner Tron Haakon Eid Bernt-Håvard ØyenSammendrag
We developed dominant height growth models for Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestris L.) in Norway using national forest inventory (NFI) data. The data were collected for a different purpose which potentially causes problems for dominant height growth modelling due to short time series and large age errors. We used the generalized algebraic difference approach and fitted 15 different models using nested regression techniques. Despite the potential problems of NFI data the models fitted to these data were unbiased for most of the age and site index range covered by the NFI data when tested against independent data from long-term experiments (LTE). Biased predictions for young stands and better site indices that are better represented in the LTE data, led us to fit models to a combined data set for unbiased predictions across the total data range. The models fitted to the combined data that were unbiased with little residual variation when tested against an independent data set based on stem analysis of 73 sample trees from southeastern Norway. No indications of regional differences in dominant height growth across Norway were detected. We tested whether the better growing conditions during the short time series (22 years) of the NFI data had affected our dominant height growth models relative to long-term growing conditions, but found only minor bias. The combination with LTE data that have been collected during a longer period (91 years) reduced this potential bias. The dominant height growth models presented here can be used as potential height growth models in individual tree-based forest growth models or as site index models.
Forfattere
Tore Filbakk Olav Albert Høibø Janka Dibdiakova Juha NurmiSammendrag
To achieve optimal utilisation of logging residues for energy, it is important to know how different handling and storage methods affect fuel properties. The aim of this study was to model how the moisture content and dry matter losses of logging residues develop during storage. Logging residues were collected from five different stands of spruce and pine during different seasons of the year and stored in the same location. The logging residues were stored in covered piles of bundled residues and loose residues. Only minor differences were found in the moisture content profiles between piles of bundles and loose residues. Logging residues located in the centre of both types of piles had considerably lower moisture content than the outer parts. The moisture content significantly affected dry matter loss, with the highest dry matter losses being found in the samples with the least favourable drying conditions. The dry matter losses varied between 1 and 3% per month. Significantly higher dry matter losses were found in the spruce bundles than in the pine bundles. Seasoned logging residues had the lowest dry matter loss, while the logging residues harvested and piled in the autumn had the highest loss.
Forfattere
John Marshall Bryden Tom Johnson Kenneth J. Thomson Tibor FerencziSammendrag
Det er ikke registrert sammendrag
Forfattere
Tore Filbakk Olav Albert Høibø Juha NurmiSammendrag
Small dimensions regenerated forests are considered a useful fuel resource for small local heat plants in Norway, since it is not relevant for the timber industry. Most small heat plants built so far are constructed for moisture contents of about 35% on wet basis. Therefore, the material must be dried. Because artificial drying induces additional costs, storing the material in piles roadside as whole trees until desired moisture content is obtained is considered beneficial. Traditionally, leaf seasoning has been considered an efficient method. To increase the understanding of these processes, a study on drying whole trees in piles has been accomplished at three different locations with different climatic conditions. The study focuses on the following explanatory variables: harvesting season, location, climatic conditions, position in the pile, tree species, and relative crown length. The effect of covering the piles in order to reduce the moisture uptake during winter was also studied. Models, estimating the moisture content with time profiles, were developed. During spring and summer the moisture content was reduced to approximately 35% also when the material was harvested in the autumn the year before. The climatic conditions were important for the drying result, but drying was effective also in the moist climate in western Norway. Covering the dry piles before the winter was important in order to maintain the requested moisture content. The effect of covering the material harvested in autumn was limited.
Forfattere
Aksel DøvingSammendrag
Det er ikke registrert sammendrag