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.
2018
Forfattere
Anne Falk Øgaard Ola Stedje Hanserud Marianne Bechmann Annbjørg Kristoffersen Åge MolversmyrSammendrag
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Sammendrag
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Forfattere
Pieternella C. Luttikhuizen Freek H. M. van den Heuvel Celine Rebours Harry J. Witte Judith D. L. van Bleijswijk Klaas TimmermansSammendrag
Kelp aquaculture is globally developing steadily as human food source, along with other applications. One of the newer crop species is Saccharina latissima, a northern hemisphere kelp inhabiting temperate to arctic rocky shores. To protect and docu-ment its natural genetic variation at the onset of this novel aquaculture, as well as increase knowledge on its taxonomy and phylogeography, we collected new geneticdata, both nuclear and mitochondrial, and combined it with previous knowledge to estimate genetic connectivity and infer colonization history. Isolation-with- migration coalescent analyses demonstrate that gene flow among the sampled locations is vir -tually nonexistent. An updated scenario for the origin and colonization history of S. latissima is developed as follows: We propose that the species (or species complex) originated in the northwest Pacific, crossed to the northeast Pacific in the Miocene, and then crossed the Bering Strait after its opening ~5.5 Ma into the Arctic and northeast Atlantic. It subsequently crossed the Atlantic from east to west. During the Pleistocene, it was compressed in the south with evidence for northern refugia in Europe. Postglacial recolonization led to secondary contact in the Canadian Arctic. Saccharina cichorioides is shown to probably belong to the S. latissima species com -plex and to derive from ancestral populations in the Asian North Pacific. Our novel approach of comparing inferred gene flow based on coalescent analysis versus Wright’s island model suggests that equilibrium levels of differentiation have not yet been reached in Europe and, hence, that genetic differentiation is expected to in -crease further if populations are left undisturbed.
Foredrag – Størrelsessortering av kornpartier med høyt innhold av Fusarium/mykotoksiner.
Guro Brodal
Forfattere
Guro BrodalSammendrag
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The prevalence of livestock grazing in wildlife area s is increasing. This transformation of ecosys- tems into agroecosystems is concerning because the intr oduction of new species may cause niche displacement of the functionally related native species. We used a la rge-scale fence scheme and f ecal analyses to study the in fl uence of free-ranging livestock on moose diet on thr ee boreal forest ranges. We found low interspeci fi cdiet overlap between moose and livestock (mean Pianka ’ s O across ranges = 0.21, SD = 0.104), and the diet overlap with livestock did not differ between moose in areas with livestock and in adjacent control areas without live- stock. Still, moose sympatric with livestock had less fe cal nitrogen (a proxy for diet quality) than moose in the control areas. Our fi ndings suggest that interspeci fi c interactions other than direct food competition contributed to reduce the moose ’ foraging opportunities, such as altered forag e abundance and composition, or behavioral avoidance of livestock. We caution that displacement in the foodscape (i.e., spati otemporal use of food) can occur through pathways not evident in niche indices based on composition of plant species in the diet.
Sammendrag
A number of factors such as low soil temperature, desiccation and thatch can be serious limiting factors for the successful reestablishment of golf greens following winter damages. The rate of germination and seedling root growth have important implications for competition between species on a golf green. This research project has shown that P. annua is a very competitive species, due to quicker germination at lower temperatures, especially compared to A. stolonifera and F. rubra ssp communtata. Root growth of P.annua was also significantly quicker than of the Agrostis species tested. Seedlings of Agrostis species and F.rubra ssp commutata that germinate in close proximity to P. annua seedlings stand a large chance of being choked out. In order to reduce competition with P.annua, early seeding should be avoided. In this study, no difference in turfgrass establishment wasobserved when seedlings were grown using soil water extracts or soil from an ice-encased green,compared to a control. However, further investigations regarding reestablishment following iceencasement are warrant, and should be investigated on older greens with a higher organic mattercontent. The results from the demonstration trials emphasize the importance of using a sowingtechnique that ensures proper seed – soil contact. This is of particular importance for theestablishment of turfgrass species on golf greens, due to the high risk of desiccation.
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1 The European spruce bark beetle Ips typographus is a damaging pest on spruce in Europe. Beetle interactions with tree species originating outside the natural range of the beetle are largely unknown and may be unpredictable because trees without a co-evolutionary history with the beetle may lack effective defences. 2 The terpenoid composition and breeding suitability for I. typographus of the historic host Norway spruce Picea abies were compared with two evolutionary naïve spruces of North American origin that are extensively planted in North-West Europe: Sitka spruce Picea sitchensis and Lutz spruce Picea glauca x lutzii. 3 The bark of all three species had a similar chemical composition and similar levels of total constitutive terpenoids, although Norway spruce had higher total induced terpenoid levels. 4 Beetles tunnelling in the three spruce species produced similar amounts of aggregation pheromone. Controlled breeding experiments showed that I. typographus could produce offspring in all three species, with a similar offspring length and weight across species. However, total offspring production was much lower in Sitka and Lutz spruce. 5 Overall, the results of the present study suggest that I. typographus will be able to colonize Sitka and Lutz spruce in European plantations and in native spruce forests in North America if introduced there.
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