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.
2002
Authors
Galina N. Koptsik S. Teveldal Sergey V. Koptsik Lars StrandAbstract
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Authors
Bjørn ØklandAbstract
Several studies conclude that sun-exposed habitats with sufficient supply of dead wood are essential for many saproxylic and mycetophagous beetle species in forests. This has induced Scandinavian foresters to leave artificial tall stumps on clear-cuts in spruce forests.In the present study of Norway spruce forest, habitat preferences during flight were studied for saproxylic and mycetophagous beetles recorded as sporocarp-visitors of Fomitopsis pinicola and Fomes fomentarius, using 690 randomly placed window traps in 69 sites covering three forest types: clear-cuts, young and oldgrowth stands.Many of the sporocarp-visitors showed a strong preference for oldgrowth forest, avoiding clear-cuts and young replantations. By stepwise linear multiple regression, presence of canopy cover appeared as a major factor while variables associated with sporocarps and dead wood were most often secondary in importance. The results indicate that sufficient canopy cover is important for many sporocarp-visiting beetles in Norway spruce forests
Abstract
Det er ikke registrert sammendrag
Abstract
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Abstract
In this article, we present an empirical account of how the Codex Alimentarius Commission (CAC), as an intergovernmental body, has changed after being referred to in the SPS Agreement of the WTO as the reference point for the elaboration of international food standards. We explore key issues that have recently been discussed in the Codex and which may have a significant impact on international food trade. Further, we develop a theoretical framework based on two alternative versions of institutional theory. We then analyze the observed changes of the role and functioning of Codex from these frameworks. Our conclusion is that a logic of consequences prevails over a logic of appropriateness in explaining nation-state behavior in an international context. Finally, our study of the Codex recognizes the importance of identifying the core interests of states, their strategic use of arguments based on these interests, as well as the institutional framework that affects them.
Authors
Ricardo Holgado S. Andersson J. RoweAbstract
Cereal cyst nematodes (CCN), Heterodera spp., are common pests of cereal crops in Norway. Fifteen populations were investigated morphologically, through biotests, and through electrophoretic studies, using isoelectric focusing and silver staining of proteins. In the biotest the populations were grouped by their virulence on barley differentials (resistance genes) Varde (Rha), Emir (Rha"E"), Ortolan (Rha1), KVL 191 (Rha2), Siri (Rha2) and Morocco C.I. 3902 (Rha3). Eleven populations expressed themselves as H. avenae pathotype Ha11. These were all fairly similar morphologically and electrophoretically. The biotest further suggested two populations belonging to pathotype Ha12. One of them was morphologically and electrophoretically similar to H. avenae; the other different in both respects, indicating a possible undescribed species. Two other populations appeared to be H. filipjevi, pathotype `West". One population under study was different in all aspects, morphologically, in the biotest and biochemically. Earlier studies in Norway have also indicated the occurrence of CCN pathotype Ha51. Thus, the situation in Norway regarding the CCN is very complicated.
Abstract
Phytopththora infestans is an important pathogen on potato and tomato in Vietnam during the winter season. There are no earlier reports on studies of P. infestans populations in this country. During January 2002 leaf samples were collected from potato and tomato in three provinces in north of Vietnam; Lao Cai, Hanoi and Hai Phong. About 120 pure isolates were obtained. Results from testing of these isolates for mating type, metalaxyl resistance and mitochondrial DNA haplotype will be presented.
Abstract
A checklist of naturally occurring microbes and nematodes that are pathogenic to insects and mites in Norway is presented. All records are listed by pathogen group (fungi, bacteria, viruses, and nematodes). Each record is listed with reference to the original author, and subsequent references have been included. The checklist should be updated periodically to assist researchers and policy makers within the field of entomology and crop protection.
Authors
T. Hoshino M. Tojo H. Kanda Maria Herrero Anne-Marte Tronsmo M. Kiriaki Y. Yokota I. YumotoAbstract
Det er ikke registrert sammendrag
Abstract
Concentrations and fluxes of dissolved organic carbon (DOC) and dissolved organic nitrogen (DON), together with pools of carbon and nitrogen in the soil and biomass, were determined along north-south and east-west transects across Norway, Sweden and Finland. The data were analysed statistically and modelled using the mechanistic model DyDOC.Concentrations of DOC and DON were greatest in the O horizon and decreased downwards in the soil. The highest production of dissolved organic matter appears to take place in the O horizon and any contribution from thoroughfall is probably small. A pronounced seasonal effect with peak DOC concentrations in late summer/early autumn may be due to a seasonal (largely temperature) effect on DOC production.The effect of acidic precipitation upon DOC concentrations and fluxes was unclear. DOC in the O horizon was mostly of recent origin, while DOC in the B horizon appeared to include some older material, possibly desorbed from the soil. A positive correlation was found with electrical conductivity and a negative correlation with pH in DOC concentrations from the O horizon.A lack of correlation between DOC concentrations and temperature is probably due to a time lag between peak temperatures and peak DOC concentrations. Modelling of DOC concentrations and fluxes using DyDOC gave rasonable results, suggesting that it might be possible to use DyDOC as a general tool for modelling and forecasting DOC concentrations and fluxes in Nordic forest ecosytems.Scenario analysis using DyDOC suggested that increased temperature without increased litter input might result in increased production of CO2 rather than DOC. An increase in both temperature and litter input would lead to increased DOC concentrations, with possible implications for drinking water quality. Increased precipitation will lead to increased fluxes of DOC.