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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

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Sammendrag

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.

Sammendrag

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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The project “Sustainable food production through quality optimized raw-material production and processing technologies for premium quality vegetable products and generated by-products” [SUNNIVA] aimed at the development of a sustainable food system from production to consumption, addressing the entire food supply chain for the vegetables tomato and Brassicae. The goal was better utilisation of the vegetable raw materials, reduced energy and water consumption, higher profitability and healthier food. This was achieved by providing various valorisation strategies to reduce waste and limiting environmental impact. Preservation of the intrinsic health-beneficial phytochemicals present in the raw material in order to improve the nutritional properties of vegetable food products was central in the project. The project contained optimization of harvest time and pre-processing storage conditions, development of novel mild processing design based on modelling, and a two-track valorisation strategy. SUNNIVA has demonstrated how the various residual raw materials can be exploited to the full: Either directly for sustainable production of healthy food (as a refined product or an ingredient), or indirectly by bringing it back into the food chain (as organic fertilizers and soil amendment products) in order to generate renewed primary production with minimal environmental impact.

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Arbuscular mycorrhizal fungi (AMF) colonise roots of most plants; their extra-radical mycelium (ERM) extends into the soil and acquires nutrients for the plant. The ERM coexists with soil microbial communities and it is unresolved whether these communities stimulate or suppress the ERM activity. This work studied the prevalence of suppressed ERM activity and identified main components behind the suppression. ERM activity was determined by quantifying ERM-mediated P uptake from radioisotope-labelled unsterile soil into plants, and compared to soil physicochemical characteristics and soil microbiome composition. ERM activity varied considerably and was greatly suppressed in 4 of 21 soils. Suppression was mitigated by soil pasteurisation and had a dominating biotic component. AMF-suppressive soils had high abundances of Acidobacteria, and other bacterial taxa being putative fungal antagonists. Suppression was also associated with low soil pH, but this effect was likely indirect, as the relative abundance of, e.g., Acidobacteria decreased after liming. Suppression could not be transferred by adding small amounts of suppressive soil to conducive soil, and thus appeared to involve the common action of several taxa. The presence of AMF antagonists resembles the phenomenon of disease-suppressive soils and implies that ecosystem services of AMF will depend strongly on the specific soil microbiome.