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
Sammendrag
Studies of defense mechanisms in Norway spruce Picea abies against the spruce bark beetle Ips typographus show that inducible defenses are triggered by unsuccessful beetle attacks. Moreover, spruce trees can be vaccinated against bark beetle attacks through stem bark inoculation with Ceratocystis polonica, an aggressive fungal associate of Ips typographus. Artificial inoculation with certain other fungi has a similar effect, making treated trees a tougher mach for attacking beetles. A similar enhancement of resistance can be achieved by stem surface treatment with methyl jasmonate. Enhanced resistance is associated with the formation of traumatic resin ducts, and mobilization of phenolic substances in living parenchyma cells. The phenolics appear to mix with the traumatic resin. Similar mechanisms are operating in other conifers. We hypothesize that unsuccessful beetle attacks produce a vaccination effect in the trees, enhancing their resistance to later attack. Adding the effect of induced resistance as a model factor shows an immediate effect on the population dynamics of Ips typographus.
Forfattere
Ievina Sturite Trond Maukon Henriksen Tor Arvid BrelandSammendrag
We have studied to what degree Italian ryegrass (Lolium multiflorum Lam.), white clover (Trifolium repens L.) and meadow fescue (Festuca pratensis L.) are able to preserve nitrogen (N) and phosphorous (P) in shoots and roots from one growing season to the next in a northern temperate climate. Field experiments were performed during four consecutive winters in central southeast Norway (60 degrees 42'N, 10 degrees 51'E), and N and P in plant biomass were measured in the autumn and in the spring. We also measured the contents of total N, total P and organic carbon (C) in seepage water that percolated through the aboveground plant material. Uptake of N and P in Italian ryegrass and white clover was substantially larger than in meadow fescue. The winter losses varied greatly from year to year, depending on the winter climate. On the average for all three of the plant species, the winter losses of N from aboveground biomass were 6, 35, 68 and 10% in the four experimental years, respectively. The corresponding P losses were 11, 36, 60 and 22%. On the average for all plant species and experimental years, 43 (+/- 12)% (S.E., n = 12) of the N, 34 (+/- 9)% of the P and 4 (+/- 1)% of the C that was lost from the aboveground plant biomass during the winter, was recovered in seepage water, basically as a nutrient pulse in melt water in early spring. The very low C recovery rate in seepage water suggested a considerable microbial growth on lost plant C. Assuming that all un-recovered plant C was consumed by microorganisms not included in measurements of the seepage water, modelling showed that microbial immobilisation theoretically might explain the unexpectedly low recovery rates of N and P. The study was not designed to investigate the possible effects of psychrophilic microbes on N and P cycling. Therefore, it is inconclusive and underlines the need for more knowledge on this matter. (c) 2006 Elsevier B.V. All rights reserved.
Sammendrag
Furfurylated wood (wood modified by furfuryl alcohol) has over the last years gained marked shares from both tropical wood and conventional preservative treated wood and this has, in turn, generated several research projects concerning process development. The impregnation of spruce is well known from literature to be a difficult task. Furthermore, the sapwood of Scandinavian grown Scots pine is also known to be difficult to fully impregnate from time to time. The primary objective of the study was to evaluate whether the Oscillating Pressure Method (OPM) could be used to impregnate green and dry Norway spruce wood (Picea abies) with a Furfuryl alcohol (FA) - mixture. The secondary objective of the study was to evaluate if OPM could improve the penetration of FA in Scots pine (Pinus sylvestris) as compared to conventional full cell (Bethell) treatment. Impregnation tests were carried out on boards and planks as well as 300 mm and 500 mm clear wood samples. Samples were removed for MC measurement and the initial weight of the test samples was determined. Four different impregnation schemes were tested. The results indicate that Norway spruce can be impregnated by the OPM method to produce a protective shell of treated wood around a core of untreated wood. The penetration in Spruce showed great variation between different boards and between different parts of the individual boards. This is in part expected, but can also be caused by uncontrolled pre drying of the test material which was stacked uncovered after sawing. For Scots pine, the OPM improved the penetration of both sapwood and, to some extent, the outer heartwood.
Sammendrag
The objective was to evaluate whether Lowry-impregnation of Scots pine with FA100-mix, instead of the FA40-mix, would lead to similar or slightly higher WPGs and to investigate any potential changes in penetration pattern. The results indicate that the penetration was better, also penetrating the outer zone of the heartwood. Furthermore, it was possible to reduce the WPG-levels for pine down to 50-70% (corresponding to PFA retentions of 260- 315 kg/m³) from 120% (approx. 550 kg/m³) with full-cell impregnation using FA100-mix. Using the Lowry process with FA100-mix would probably be a possible treating schedule for products aimed for use in ground contact. The reduced content of hygroscopic salts in the furfurylated wood product would also further reduce hygroscopisity compared with FA-40 mix. However, more trials are needed in order to optimize penetration while still keeping the final WPG low.
Sammendrag
Vannkvalitet og -kvantitet i elver over hele verden er samlet inn og vurdert mht potensiale for saltkraft. Arbeidet er utført på oppdrag for Statkraft Development, alle henvendelser om prosjektet bes rettes til oppdragsgiver (www.statkraft.no).
Forfattere
Guro HenselSammendrag
Egen informasjonsside for mindre avløpsanlegg på internett. Informasjonen retter seg først og fremst mot to interessegrupper; saksbehandlere for mindre avløpsanlegg i kommunene, og privatpesoner som skal etablere avløpsanlegg. Nettsiden er inndelt i følgende tre hovedtemaer: "Kommuneveildning" er info som er tilpasset saksbehandlere i kommunene. "Hvordan velge avløpsløsning" er info spesielt for utbyggere av anlegg, mens " Renseløsninger" er generell informasjon om ulike typer mindre avløpsanlegg på markedet Informasjonen som i hovedsak er utformet av Bioforsk Jord og miljø (tidligere Jordforsk) og UMB i tidligere prosjekter, er tilrettelagt og bearbeidet for internett med delfinansiering av Statens forurensningstilsyn, SFT. Bioforsk er faglig ansvarlig for innholdet å på nettstedet. Ansvarlig redaktør for sidene er Anders W. Yri ( Bioforsk).
Sammendrag
Good soil structure is recognised to be of key importance in organic farming, and soil compaction poses a major threat with respect to this. The relative importance of tractor weight (2-4 vs. 5-7 Mg), ploughing depth (ca. 15 vs. 25 cm) and wheel placement during ploughing (in-furrow vs. on-land) have been studied for four years on two soil types (well-drained loam and imperfectly drained silty clay loam) in southern and central Norway. On the site with imperfectly drained silty clay loam supposed to be most suceptible to soil compaction, the soil aeration and penetration resistance, but not the yield of barley, was affected by the treatments imposed. On the site with the well-drained loam, shallow ploughing with the heavier tractor and wheel in-furrow caused lower yields of wheat, but not of barley than did the other treatment combinations. This may partly be related to reduced air permeability and volume of air filled pores at 18-22 cm and partly to a higher incidence of perennial weeds after shallow than after deep ploughing.
Forfattere
Inger HansenSammendrag
Oppsummering over resultater fra tapsundersøkelser på sau og lam de siste 15 år. Tapsomfang og tapsårsaker på landsbasis.
Forfattere
Inger HansenSammendrag
Om tap, tapsårsaker og forebyggende tiltak mot tap av sau på beite
Forfattere
Britt I.F. HenriksenSammendrag
Både normal og unormal åtferd blir registrert ved gardsbesøka i Økologisk Ku-komfort. Dette er også registreringar ein som gardbrukar sjølv kan gjere.