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.
2017
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Liv Røhnebæk Bjergene Gry Alfredsen Vincentius Gerardus Henricus Eijsink Aniko Varnai Olav Aaseth HegnarSammendrag
Energi fra trær og planter skal på sikt erstatte oljen. Men å hente ut godsakene fra ei gran eller furu, er en omstendelig prosess.
Forfattere
Aniko Varnai Olav Aaseth Hegnar Dejan Petrovic Barry Goodell Gry Alfredsen Vincentius Gerardus Henricus EijsinkSammendrag
Det er ikke registrert sammendrag
Forfattere
Linda Meyer-Veltrup Christian Brischke Gry Alfredsen Miha Humar Per Otto Flæte Tord Isaksson Pia Larsson Brelid Mats Westin Jöran JermerSammendrag
Comprehensive approaches to predict performance of wood products are requested by international standards, and the first attempts have been made in the frame of European research projects. However, there is still an imminent need for a methodology to implement the durability and moisture performance of wood in an engineering design method and performance classification system. The aim of this study was therefore to establish an approach to predict service life of wood above ground taking into account the combined effect of wetting ability and durability data. A comprehensive data set was obtained from laboratory durability tests and still ongoing field trials in Norway, Germany and Sweden. In addition, four different wetting ability tests were performed with the same material. Based on a dose– response concept, decay rates for specimens exposed above ground were predicted implementing various indicating factors. A model was developed and optimised taking into account the resistance of wood against soft, white and brown rot as well as relevant types of water uptake and release. Decay rates from above-ground field tests at different test sites in Norway were predicted with the model. In a second step, the model was validated using data from laboratory and field tests performed in Germany and Sweden. The model was found to be fairly reliable, and it has the advantage to get implemented into existing engineering design guidelines. The approach at hand might furthermore be used for implementing wetting ability data into performance classification as requested by European standardisation bodies.
Sammendrag
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Sammendrag
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Sammendrag
Global warming is predicted to adversely affect the reproduction of birds, especially in northern latitudes. A recent study in Finland inferred that declining populations of black grouse, Tetrao tetrix, could be attributed to advancement of the time of mating and chicks hatching too early—supporting the mismatch hypothesis. Here, we examine the breeding success of sympatric capercaillie, T. urogallus, and black grouse over a 38-year period in southeast Norway. Breeding season temperatures increased, being most pronounced in April. Although the onset of spring advanced nearly three weeks, the peak of mating advanced only 4–5 days. In contrast to the result of the Finnish study, breeding success increased markedly in both species (capercaillie: 62%, black grouse: 38%). Both brood frequency and brood size increased during the study period, but significantly so only for brood frequency in capercaillie. Whereas the frequency of capercaillie broods was positively affected by rising temperatures, especially during the pre-hatching period, this was not the case in black grouse. Brood size, on the other hand, increased with increasing post-hatching temperatures in both species. Contrary to the prediction that global warming will adversely affect reproduction in boreal forest grouse, our study shows that breeding success was enhanced in warmer springs.
Sammendrag
Hønsehauken er oppført som "nær truet" (NT) i Norsk Rødliste for Arter 2015. Det antas at arten påvirkes negativt av skogbruk fordi skogsdrift forringer jakthabitat, tilgang på byttedyr, og tilgjengelige reirplasser. Den ble i 2010 nedgradert fra kategorien sårbar (VU) til nær truet (NT) basert på at bestanden trolig ikke lenger avtar men har stabilisert seg på et lavt nivå. Det har vært indikasjoner på at bestanden kan ha økt i kulturlandskap. Prosjektet er en videreføring av prosjektet "Varaldskogen: Hønsehauk, skogsdrift og skogshøns" i 2013-2014. I denne oppfølgingen har målsetningen vært å: (1) Kartlegge og sammenligne hekkebestand, ungeproduksjon, og habitatbruk under jakt ved hjelp av GPS-telemetri i et intensivt drevet skoglandskap (Varaldskogen) og et intensivt drevet kulturlandskap (Follo). (2) Vurdere hvordan reirlokaliteter for hønsehauk bedre kan kartlegges og gjøres tilgjengelig for skogeiere og driftsselskaper i skogbruket. I 2013-2016 er 6 lokaliteter overvåket på Varaldskogen, med en gjennomsnittlig beboelsesrate på 50%, 58% vellykket hekking, og 2,6 utflydde unger pr. vellykket hekking. Tilsvarende tall for 7 lokaliteter i Follo i samme periode var 96% bebodd, 92% vellykket hekking, og 2,4 utflydde unger pr. vellykket hekking. Bestandstetthet basert på bebodde lokaliteter var over dobbelt så høy i Follo (3,4 par pr. 100 km2) som på Varaldskogen (1,5 par pr. 100 km2).
Sammendrag
Tick-borne fever (TBF) is stated as one of the main disease challenges in Norwegian sheep farming during the grazing season. TBF is caused by the bacterium Anaplasma phagocytophilum that is transmitted by the tick Ixodes ricinus. A sustainable strategy to control tick-infestation is to breed for genetically robust animals. In order to use selection to genetically improve traits we need reliable estimates of genetic parameters. The standard procedures for estimating variance components assume a Gaussian distribution of the data. However, tick-count data is a discrete variable and, thus, standard procedures using linear models may not be appropriate. Thus, the objectives of this study were twofold: 1) to compare four alternative non-linear models: Poisson, negative binomial, zero-inflated Poisson and zero-inflated negative binomial based on their goodness of fit for quantifying genetic variation, as well as heritability for tick-count and 2) to investigate potential response to selection against tick-count based on truncation selection given the estimated genetic parameters from the best fit model. Our results showed that zero-inflated Poisson was the most parsimonious model for the analysis of tick count data. The resulting estimates of variance components and high heritability (0.32) led us to conclude that genetic determinism is relevant on tick count. A reduction of the breeding values for tick-count by one sire-dam genetic standard deviation on the liability scale will reduce the number of tick counts below an average of 1. An appropriate breeding scheme could control tick-count and, as a consequence, probably reduce TBF in sheep.
Sammendrag
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