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.
2008
Forfattere
Jim Treasurer Oddvar Ottesen Richard Fitzgerald Julie Maguire Nonna Zhuravleva Celine ReboursSammendrag
Det er ikke registrert sammendrag
Forfattere
Celine Rebours Jim Treasurer Richard Fitzgerald Julie Maguire Nina Zhuravleva Oddvar OttesenSammendrag
Biological control of sea lice with wrasse is considered an alternative to medicines and can form part of an integrated sea lice management plan (Mordue and Pike, 2002). While wrasse have been used previously in sea lice control there have been reservations about fishing the wrasse from wild stocks with possible erosion of local stocks and changes in population structure (Sayer, Gibson and Atkinson, 1996; Varian, Deady and Fives, 1996). An EU Northern Periphery Project entitled "Ecofish" has been established to examine the rearing of ballan wrasse Labrus bergylta and the application of this species in sea lice control. This species has been shown to be a successful cleaner of sea lice in preliminary trials and may be more suitable than smaller wrasse with larger second production year salmon.
Sammendrag
Arthropods were collected by fogging the canopy of Scots pine Pinus sylvestris selected from a 2 km2 boreal forest area in Sigdal, Norway with the overall purpose to examine whether there were faunal differences in the representation of arthropods among mature and old trees, and specifically for this paper, the biting midges (Ceratopogonidae). Target trees were chosen as pairs, one mature (70-110 years) and one old (250 years or older) tree from six different stands. All knock-down treatments were performed in June and July 1999, before dawn and after a dry and windless night. Knocked-down arthropods were collected in plastic funnels placed systematically on the ground. Funnels remained in place for circa one hour after treatment. Among the 61 species records new to Norway, the most frequently encountered taxon of invertebrates was Diptera, and the family of biting midges, Ceratopogonidae, comprised 30 of 61 (49%) of all new records, compared with the overall species numbers showing 40 biting midges of 193 recorded species (21%). Among the Ceratopogonidae new to Norway, two species new to science and two first records from Europe were found. Coleman rarefaction curves were constructed by running 500 iterations without replacements using EstimateS and showed that there were significantly more new records of Diptera in old trees in comparison with mature trees. A similar pattern of significance (by comparing standard deviations estimated by EstimateS) was found for Diptera when Ceratopogonidae was excluded. New species records of Ceratopogonidae were more common in old trees than in mature trees, although not significantly so. No predominance of new records in old trees was found for arthropods other than Diptera. Old trees are rare and may provide a variety of resources (e.g. resting sites, places to over-winter, hiding places, sites for oviposition, larval habitat, etc.) that are rarely found in younger trees. Thus, the high number of new species records probably result from studying a whole arthropod taxon (Diptera) in a part of a forest ecosystem (canopies) with a suite of microhabitats (old pine trees) that in combination has been poorly investigated earlier.
Forfattere
Espen GovasmarkSammendrag
Det er ikke registrert sammendrag
Forfattere
Espen Govasmark Trine Aulstad SognSammendrag
Innhold av selen (Se) i grovfôr og matkorn i Norge er lavt vurdert i forhold til gjeldende normer for daglig behov til henholdsvis melkeku og sau, og til mennesker. Det finnes i dag ingen kjente akseptable gjødselkilder for Se i økologisk landbruk som øker innholdet av Se i grovfôr og/eller matkorn.
Forfattere
Espen GovasmarkSammendrag
Det er ikke registrert sammendrag
Forfattere
Espen Govasmark Bal Ram Singh John A. MacLeod Mark G GrimmettSammendrag
Selenium (Se) deficiency in Scandinavian soils is a common problem, and crops generally contain inadequate amounts to meet human need. This study shows a relationship of the Se concentration in spring wheat (Triticum aestivum L., c.v. 'Helena') and leaching water with timing of nitrogen (N) [as ammonium nitrate (NH4NO3)] and Se [as sodium selenate (Na2SeO4)] application. Ammonium-nitrate was applied by two methods (i) whole amount at sowing and (ii) in split application as 75% at sowing and 25% at stem elongation. Selenate was applied at cereal growth stages after sowing, e.g., tillering, stem elongation, head emergence, and milking. Split N application in comparison to one N application increased the grain protein content from 12.1 to 13.7 mg g(-1), and grain Se was increased from 0.8 to 1.1 mg kg(-1) when Se was applied at stem elongation and from 0.6 to 0.9 mg kg(-1) when applied at heading. The highest Se concentration in plant was achieved with the split N application and Se application at stem elongation or heading. Selenium leaching losses increased with increasing selenium concentration in the wheat grains. No differences in Se leaching losses were obtained with split N application. Applying selenate and ammonium-nitrate together after tillering increased the grain Se concentration, but did not affect the potential leaching of Se, and thus could be considered as an appropriate time of application of these elements.
Forfattere
Espen GovasmarkSammendrag
Det er ikke registrert sammendrag
Forfattere
Espen GovasmarkSammendrag
Det er ikke registrert sammendrag
Forfattere
Peder GjerdrumSammendrag
Pine (Pinus sylvestris) heartwood and pine sapwood can, in several respects, be considered two different timber products. Sapwood demonstrates open structures that easily adsorb moisture and is vulnerable to bio-chemical disintegration, but also more easily painted, glued or impregnated. Heartwood, on the other hand, is less disposed to moisture fluctuations, hence, more dimensionally stable, and durable. Heartwood content is closely related to cambial age and to the progress of annual ring width. It is also the nature of pine is to grow timber of quite varying quality along the stem. Resins are more abundant near the base, and the knottiness is shifting, following certain patterns from the base upwards. Several of those traits can be identified prior to breakdown, applying specific wood technology knowledge, recent research and standard log scanner equipment. Even with this potential for producing more homogeneous board quality by including heartwood in the breakdown decision basis, one should not forget the practical implications for the sawmill. The cost of keeping separate heartwood quality classes and the risk of mistakes might easily exceed the price gain.