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 GjerdrumSammendrag
With wood, the moisture content is an intrinsic volatile property - constantly changing in accordance to the environment. For the efficient use of timber, knowledge about the MC is increasingly being requested, and the sawmill being required to reveal such information. This paper presents an algorithm for estimating, on a weekly basis, the running MC and MC variation of a timber lot. Input variables are the MC of the lot when leaving the kiln, storage condition and running weather observations. The model, described in mathematical terms, is valid for timber stored on stickers, i.e. under homogeneous air circulation, and meant for implementation in the sawmill’s MPS.
Forfattere
Erlend Ystrøm Haartveit R.A. Kozak T.C. ManessSammendrag
In this paper, we review the development of supply chain management (SCM) and identify a number of considerations for applying these techniques to the forest products industry. A review of the literature found that SCM initiatives were primarily customer focused, where a significant amount of market pull exists. However, the forest products industry is characterized by sales of commodity products with push marketing. Successful implementation of SCM in these types of supply chains were found to focus on efficiencies through: 1) increasing throughput and 2) reducing inventories. Potential for efficiency improvements are larger when a holistic perspective is applied, integrating processes across companies in the supply chain. Two supply chain mapping methods were identified from the literature as key techniques for use in the forest products industry, and these were applied to three case companies in the western Canadian province of British Columbia. In general, it was found to be especially challenging to apply these techniques (and SCM in general) to commodity-based supply chains because of uncertainty in raw material supply, the relatively long lead times in production, and production processes that generate a relatively high percentage of consequence products. However, the mapping processes yielded some promising results with respect to creating an overview of supply chain structures, time consumption, and inventories. One major benefit derived from applying these methods would be improved communications between actors, customers, and suppliers along the supply chain. The authors suggest that SCM mapping tools be modified to improve their performance in analyzing supply chains for the forest products industry.
Forfattere
Peder GjerdrumSammendrag
EMC is traditionally analysed using small, clear wood specimens. However, some discrepancy was observed in full-size boards in a sawmill. In this experiment specimens of varying length from 10 to 120 mm clear wood and from 120 to 900 mm natural quality were tested. Commercial spruce boards were used. After kiln drying and proper conditionning, the samples were kept in a constant climate (40 °C, 65% RH) for half a year, until apparent equilibrium was reached. The EMC was observed by the dry weight method separately for adsorption and desorption. The EMC (average for ad- and desorption) was found to increase proportionally to the natural logarithm of the specimen length. Further, clear wood showed sifgnificantly higher EMC than natural quality. While for desorption the EMC was hardly influenced by length, desorption was highly length dependent. The difference in EMC (desorption) between a full-length board and a 10-mm clear specimen was estimated to 0.013 (fraction of dry wood). Accordingly, the hysteresis A:D ratio decreased from 0.96 for the shortest specimens to 0.88 for the longest. The results verify and extend earlier findings and are important for understanding and estimating the wood-moisture interaction of kiln dried timber, particulary for high drying quality specifications. However, the difficulty of deciding the EMC for large specimens should not be underestimated.
Sammendrag
Pathogen colonization and transcript levels of three host chitinases,putatively representing classes I, II, and IV, were monitored with real-time PCR after wounding and bark infection by Heterobasidion annosum in 32-year-old trees of Norway spruce (Picea abies) with low (clone 409) or high (clone 589) resistance to this pathogen. Three days after inoculation, comparable colonization levels were observed in both clones in the area immediately adjacent to inoculation. At 14 days after infection, pathogen colonization was restricted to the area immediately adjacent to the site of inoculation for clone 589 but had progressed further into the host tissue in clone 409. Transcript levels of the class II and IV chitinases increased after wounding or inoculation, but the transcript level of the class I chitinase declined after these treatments. Transcript levels of the class II and class IV chitinases were higher in areas immediately adjacent to the inoculation site in clone 589 than in similar sites in clone 409 3 days after inoculation. This difference was even more pronounced 2 to 6 mm away from the inoculation point, where no infection was yet established, and suggests that the clones differ in the rate of chitinase-related signal perception or transduction. At 14 days after inoculation, these transcript levels were higher in clone 409 than in clone 589, suggesting that the massive upregulation of class II and IV chitinases after the establishment of infection comes too late to reduce or prevent pathogen colonization.
Sammendrag
We have monitored the H. annosum colonization rate and expression of host chitinases in Norway spruce material with differing resistances. Transcript levels of three chitinases, representing classes I, II and IV, were monitored with real-time PCR. Ramets of two 32 -year-old clones differing in resistance were employed as host material and inoculation and wounding was performed. Quantification of fungal colonization: Multiplex real-time PCR detection of host and pathogen DNA was performed. Chitinase transcript levels were also monitored with real-time PCR. Three days after inoculation, comparable colonization levels were observed in both clones in the area immediately adjacent to inoculation. Fourteen days after infection, pathogen colonization was restricted to the area immediately adjacent to the site of inoculation for the strong clone (589), but had progressed further into the host tissue in the weak clone (409). Transcript levels of the class II and IV chitinases increased following wounding or inoculation, while the transcript level of the class I chitinase declined following these treatments. Transcript levels of the class II and class IV chitinases were higher in areas immediately adjacent to the inoculation site in 589 than in similar sites in 409 three days after inoculation, suggesting that the clones differ in the rate of chitinase-related signal perception. The spatiotemporal accumulation patterns obtained for the two clones used are consistent with their resistance classifications, these warranting further and more detailed studies on these chitinases.
Forfattere
Geir Isak Vestøl Olav Albert Høibø Sander Lilleslett Harald MyhreSammendrag
Bruk av rundtømmer og firkant av furu fra høyereliggende skog til bindingsverk og lafting har lange tradisjoner. Til lafting brukes det fortsatt mye rundtømmer, men i bindingsverk har det blitt mindre vanlig. I Nord-Gudbrandsdalen ønsker man å ta opp igjen tradisjonen med å bruke rundtømmer og firkant i bindingsverk, men det mangler dokumentasjon på egenskapene til slike materialer. Hensikten med dette arbeidet er å dokumentere de konstruktive egenskapene til rundtømmer og firkant av furu fra høyereliggende skog i regionen. Statisk bøyefasthet, elastisitetsmodul ved statisk bøying (E-modul) og basisdensitet ble testet på 94 prøver av rundtømmer med nominell dimensjon (toppdiameter) fra 100 mm til 225 mm. De samme egenskapene ble testet på 57 prøver av firkant skåret med tilnærmet 2/3 kant. Dimensjonene til firkant var fra 75 x 75 mm2 til 200 x 200 mm2. Rundtømmer ble tatt ut av 60 trær fra fire felt med høyereliggende furuskog i Lesja og Dovre, mens firkant ble tatt ut av 18 trær fra to av de samme feltene. Feltene ble valgt slik at de representerer variasjon i bonitet innenfor ulike høydelag. Gjennomsnittlig bøyefasthet til rundtømmer er 58,9 MPa og nedre 5 % fraktil er 40,0 MPa. Gjennomsnittlig E-modul er 12,1 GPa. Gjennomsnittlig basisdensitet er 382 kg/m3 og nedre 5 % fraktil er 333 kg/m3. Bøyefastheten øker med økende basisdensitet og E-modul, mens den avtar med økende årringbredde og dimensjon. Basisdensitet og E-modul er lavere for andrestokker enn for rotstokker, mens det ikke er funnet noen effekt av dimensjon på disse egenskapene. Gjennomsnittlig bøyefasthet til firkant skåret med 2/3 kant er 44,3 MPa, og nedre 5 % fraktil er 32,8 MPa. Gjennomsnittlig E-modul er 9,0 GPa. Gjennomsnittlig basisdensitet er 381 kg/m3 og nedre 5 % fraktil er 327 kg/m3. Bøyefasthet til firkant av rotstokkene er høyere enn firkant fra de øvrige stokkene. Verdiene for bøyefasthet og E-modul til rundtømmer av furu fra høyereliggende skog i Lesja og Dovre er høye. Særlig de laveste verdiene for bøyefasthet er høye sammenlignet med trelast. Dette medfører at dimensjonerende verdi for bøyefasthet til rundtømmer blir høy og at materialene derfor vil være godt egnet som konstruksjonsmaterialer. Rundtømmer kan styrkesorteres visuelt, men europeiske reglement som finnes er utviklet for tynningsvirke og undervurderer bøyefastheten til dette materialet. Styrkesortering basert på dimensjon, E-modul og basisdensitet vil gi mulighet for bedre nøyaktighet enn visuell sortering. Firkant med 2/3 kant har betydelig lavere bøyefasthet og E-modul enn rundtømmer, men verdiene for bøyefasthet er likevel relativt høye sammenlignet med skarpkantet trelast. Til formål hvor det er viktig med plane flater og hvor kravet til bøyefasthet og E-modul er mindre kan firkant være et godt alternativ.
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.
Forfattere
John Y. LarssonSammendrag
De siste prognosene fra klimaforskerne antyder at årsmiddeltemperaturen i ulike deler av Norge de neste 50 årene vil øke med 1,0 – 2,5 grader. En forflytning av klimasonene nordover og oppover for de nordlige og tempererte skogene vil føre til endringer i skogens sammensetning. Det boreale barskogbeltet vil flytte seg nordover og oppover. Edellauvskog vil ta over for barskog i sør, og gran og furu vil ta over for bjørk mot fjellet nordover. Bjørk vil okkupere store areal som nå er snaufjell. Dette vil i Norge føre til en betydelig økning av skogarealet. De fleste forskerne er enige om at et godt sted å se etter bevis på endringer er blant populasjoner på kanten av artens geografiske (klimatiske) utbredelse. Landsskogtakseringes prøveflatenett kan være egna for overvåking av skogrensa gjennom et systematisk utlagt prøveflatenett, kobla til det eksisterende nettet.
Forfattere
Gunnar EnganSammendrag
Denne rapporten er første trykte utgave av 3Q Instruks for flybildetolking. Den har foreligget som internt dokument siden 1998. Instruksen gir detaljerte regler for avgrensing og figurering av areal, linjeelement og punktobjekt som tolkes fra flybilder i målestokk 1:12.500 på 1 km² store 3Q-flater i jordbrukets kulturlandskap. Arealklassifikasjonen er bygd opp hierarkisk, med 3 nivå. I alt er 94 ulike arealtyper definert på nivå 3.