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Publications

NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.

2012

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Abstract

Insect outbreaks in northern-boreal forests are expected to intensify owing to climate warming, but our understanding of direct and cascading impacts of insect outbreaks on forest ecosystem functioning is deficient. The duration and severity of outbreaks by geometrid moths in northern Fennoscandian mountain birch forests have been shown to be accentuated by a recent climatemediated range expansion, in particular of winter moth (Operophtera brumata). Here, we assess the effect of moth outbreak severity, quantified from satellite-based defoliation maps, on the state of understory vegetation and the abundance of key vertebrate herbivores in mountain birch forest in northern Norway. We show that the most recent moth outbreak caused a regional-scale state change to the understory vegetation, mainly due to a shift in dominance from the allelopathic and unpalatable dwarf-shrub Empetrum nigrum to the productive and palatable grass Avenella flexuosa. Both these central understory plant species responded significantly and nonlinearly to increasing outbreak severity. We further provide evidence that the effects of the outbreak on understory vegetation cascaded to cause strong but opposite impacts on the abundance of the two most common herbivore groups. Rodents increased with defoliation, largely mirroring the increase in A. flexuosa, whereas ungulate abundance instead showed a decreasing trend. Our analyses also suggest that the response of understory vegetation to defoliation may depend on the initial state of the forest, with poorer forest types potentially allowing stronger responses to defoliation

Abstract

Norway has the world’s largest facility for testing and improving CO2 capture. The aim of carbon capture technology is to minimize greenhouse gas emissions through a reaction between amines and effluents from gas power plants. During the overall process of CO2 capture, amines and their transformation products might escape to the environment through emissions, leakage, and as solid waste. The two main groups of transformation products with the most potential to cause environmental harm have been identified as nitrosamines and nitramines, both of which are considered to be carcinogenic. Recent theoretical modelling as well as laboratory experiments have found nitramine compounds, 2-nitroaminoethanol (CAS: 74386-82-6) and dimethylnitramine (CAS: 4164-28-7) to be present. However, despite the likelihood of these compounds increasing in the environment, no environmental toxicity data for these compounds currently exist. The aim of this project was to provide an environmental risk assessment for the selected nitramine compounds taking into account the key trophic groups within freshwater, marine and terrestrial environments. The toxicity assessment was made using a suite of standardised bioassays for the measure of acute and chronic toxicity. In the soil environment, the most potent compound was 2-nitroaminoethanol, which impaired the reproduction of earthworms and the seedling emergence of sunflower and ryegrass. The opposite was found in the aquatic environment, with freshwater and marine species consistently more affected by dimethylnitramine. All the tested freshwater species were more sensitive to nitramines than marine species. The selected amines were not acutely toxic to aquatic and soil species, with EC50 in the mg/L range. Both nitramines increased the nitrogen and carbon transformation activity of soil microorganisms.

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Abstract

There is increasing concern that the intensification of dairy production reduces the concentrations of nutritionally desirable compounds in milk. In this study we therefore compared important quality parameters (protein and fatty acid profiles, α-tocopherol and carotenoid concentrations) in milk from four dairy systems with contrasting production intensities (in terms of feeding regimes and milking systems). The concentrations of several nutritionally desirable compounds (β-lactoglobulin, omega-3 fatty acids, omega-3/omega-6 ratio, conjugated linoleic acid c9t11 and/or carotenoids) decreased with increasing feeding intensity (organic outdoor ≥ conventional outdoor ≥ conventional indoors). Milking system intensification (use of robotic milking parlours) had a more limited effect on milk composition, but increased mastitis incidence. Multivariate analyses indicated that differences in milk quality were mainly linked to contrasting feeding regimes, and that milking system and breed choice also contributed to differences in milk composition between production systems.

Abstract

In Norway, most lambs are slaughtered at the end of the grazing season in September. An increased demand for fresh meat during the off-season may change this pattern. Castration of male lambs is not permitted, and off-season slaughtering may affect the acceptability of the meat. The objective of this study was to determine the effect of gender on meat quality from Norwegian White Sheep lambs slaughtered in September at the age of five months. Twenty-nine male lambs and 46 female lambs were included in the experiment. Loin samples of M. Longissimus dorsi were analysed for sensory profile. Meat from male lambs had higher scores for the less pleasant sensory attributes of cloying (P < 0.05) and rancid (P = 0.08) flavour, and lower scores for the more pleasant attributes of sour and sweet taste (P < 0.05 for both attributes) compared to meat from female lambs. The differences were more apparent between lambs grazing ryegrass than between lambs fed a concentrate and roughage diet. It is concluded that even at the normal slaughtering time in September, significant differences between genders may occur.

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Abstract

The aim of this experiment was to investigate the effect of increasing the number of ewes per nipple drinker on water intake, feed intake and drinking behaviour of ewes. A group of 30 1¾ year old, pregnant ewes of the Norwegian Dala breed were exposed to three treatments, each treatment lasting one week: 7.5 ewes per nipple drinker (N7.5: four nipple drinkers), 15 ewes per nipple drinker (N15: two nipple drinkers) and 30 ewes peer nipple drinker (N30: one nipple drinker). The experiment was performed both in January (week 4–6, replicate 1) and replicated in April (week 13–15, replicate 2). The ewes were kept in insulated building and had free access to good quality hay. Water metres were connected to the pipeline for water supply and water wastage was collected and weighed. In addition, the daily intake of hay was recorded and the ewes were video recorded the three last days of each experimental period. Total drinking time per individual was calculated from observations of drinking behaviour from the video, as were also incidents of queuing and displacements. Both water and feed intake was higher in replicate 2 than in replicate 1. Increasing the number of individuals per nipple drinker had no effect on water intake in replicate 1, whereas in replicate 2 the water intake was (mean±SE) 3.5±0.3; 4.2±0.1 and 4.9±0.1 l/ewe and day in the treatments N7.5, N15 and N30, respectively (P<0.05). Regardless of replicate, the time spent drinking increased significantly when number of ewes per nipple drinker increased. Queuing was not affected by increasing the number of ewes per nipple drinker. In replicate 1 the number of displacements increased significantly when the number of individuals per nipple drinker increased (N7.5=7.6±1.7; N15=15.0±4.2 and N30=36.7±5.2; P<0.05) and the same trend could be seen in replicate 2, although not significant. In conclusion, one nipple drinker with an acceptable flow rate can serve up to 30 ewes without negatively affecting water and feed intake