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.
1998
Sammendrag
The seasonal variations in volume of the milk in Norwegian goat dairyfarming, complicate production of brand goat cheeses. In the specialised goat dairy farming system most kids are culled shortly after birth without utilising the meat. In this paper the farm economics of an alternative system with altered period of kidding (currently in theperiod from January to March) combined with production of meat and cashmere fibre, is examined. May kidding combined with raising the kids for 8 or 20 months yielded the m ost promising economical return. Raising the kids one year is also profitable when kidding takes place in February while December kidding seems to perform best with thepresent system of culling the kids right after birth. Cashmere fibre production seems to be profitable on Norwegian dairy goat farms and fibre and meat could become an optio n in countries seeking to improve incomes on dairy goat farms. Compared to the present system the changes also would be favourable from an animal welfare point of view.
Forfattere
Mekjell MelandSammendrag
Det er ikke registrert sammendrag
Forfattere
Oleif Elen Birgitte HenriksenSammendrag
Sprøyting med soppmidler førte til en økning av Fusarium-infiserte korn.
Forfattere
H.J. Rosenfeld Ragnar T. Samuelsen P. LeaSammendrag
Det er ikke registrert sammendrag
Forfattere
Albert Tietema Bridget A. Emmett Per Gundersen O. Janne Kjønaas Chris J. KoopmansSammendrag
As part of four European ecosystem manipulation experiments in coniferous forests, field-scale 15N tracer experiments have been carried out. The experiments involved a year-long addition of 15NH4 and/or 15NO3- to throughfall at experimental plots with different N inputs. The fate of this applied 15N in the important ecosystems pools (trees, ground vegetation, forest floor and mineral soil), as well as in drainage was measured. About 10-30% of added 15N was taken up by the trees and 10-15% was retained in the mineral soil. Both retention efficiencies were found to be constant with N input. The part of 15N retained in the organic layer was relatively high (20-45% of applied) at low N inputs (0-30 kg N ha-1 yr-1) but low (10-20%) at high N inputs (30-80 kg N ha-1 yr-1). An inverse relationship between N input and the loss of 15N in drainage was found: drainage losses increased as a function of N input. These results suggest that increased N inputs exceed the capacity of the microbial population to retain throughfall-N in the organic layer, with the result that N leaching increases.
Sammendrag
The genus Bryomyia comprises altogether eight species in the Palearctic region, including one new species Bryomyia amurensis Mamaev et Økland described in the present article. A revised key to the species of Bryomyia in the Holarctic region is presented.
Forfattere
T. Edland G.O. EvansSammendrag
Det er ikke registrert sammendrag
Forfattere
Bjørn Arne Rukke Fred MidtgaardSammendrag
Effects of isolation, habitat size and several microhabitat variables on presence/absence of the monophagous Bolitophagus reticulatus (L.) (Coleoptera, Tenebrionidae) were investigated in 58 forest fragments in an agricultural landscape (15 km2) in south-eastern Norway. All potential habitats of the beetle, dead Fomes fomentarius (L.) Kickx basidiocarps (n=587), were collected from trees (n=185) within the study area. The basidiocarps were dissected and the number of B. reticulatus specimens (larvae, pupae and adults) counted. The material was analysed at four distinguishable spatial scales: basidiocarp-, tree-, tree-group- and forest island level. Different patterns of beetle presence emerged at the different scales. Increasing habitat size and decreasing degree of isolation increased the probability of B. reticulatus presence at three (basidiocarp-, tree- and forest island level) and one (tree level) scales, respectively, whilst no such trends were found at the fourth level (tree-group level). Increasing insolation and thereby higher ambient temperatures, indicated by several microhabitat variables, improved the probability of beetle presence amongst the trees. The number of beetle specimens correlated positively with an increase in the habitat size at the tree level.
Forfattere
Bjørn Arne Rukke Fred MidtgaardSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag