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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.

2017

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Abstract

Dette kapittelet presenterer forslaget til fagsystem for vurdering av god økologisk tilstand og begrunner valgene som er tatt. Deltagere i undergruppe hav (Per Fauchald, Normann Whitaker Green, Eva Ramirez-Llodra, Sylvia Frantzen, Cecilie von Quillfeldt og Anne Kirstine Frie) har bidratt betydelig til å utvikle egenskapene som gir en normativ beskrivelse av god økologisk tilstand i kapittel 3.4 .

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Abstract

We reconstructed family relationships, parent-child and siblings, among the brown bear (Ursus arctos) sampled in Sør-Varanger, Norway. Basis of this study are observed family relationships by the wildlife management. We compared this strong indication of relatedness with testing particular family relationships using SNP- and STR-genotype data of 154 brown bears sampled mainly non-invasively in the area from 2004 to 2016. We calculated likelihood ratios (LRs) and reconstructed family groups with the program FAMILIAS, which was used to reconstruct family relationships in human forensics. When the LR of each relationship, parent-child or siblings, was tested, 40 (38.1%) relationships were confirmed based solely on genetic data. The allele sharing analysis visualized as dendrograms supported that a large proportion of the remaining observed cases that were not confirmed as parent-child or siblings did share a closer family relationship. More detailed analysis is necessary to deduce the nature of these relationships (cousins, uncle-nephew etc.). Based on the genetic data we found, that the minimum number of cubs per year was on average 4.08. The applied SNP-chip has been developed on the Swedish brown bear population, a population different to the bears living in Sør-Varanger. The performance of the SNP-chip in this study rises questions of its applicability for family analysis in other brown bear populations and shows the need for further evaluation of the individual loci on the chip. Nevertheless, the combined SNP-data from all loci seems to provide power enough to detect the previously reported subpopulation structure. The observational data, sampling effort and quality of the sample material of the brown bears in Sør-Varanger is remarkable and the material provides an excellent testing ground to validate and improve the SNP-chip to reconstruct family groups.

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Abstract

Soil application of organic residues from anaerobic digestion of municipal food waste and/or sewage sludge may introduce considerable amounts of heavy metals into the environment. In a column leaching experiment, mobility and release of Cu, Ni and Zn were investigated in three contrasting soils (sand, silt, loam) fertilized with biogas digestates of different origin. The effect of commercial digestates, based on food waste and sewage sludge, was compared to that of experimental digestates based on animal manure and whey permeate with or without fish ensilage, as well as untreated manure, mineral fertilizer and an untreated control. Manure and digestates were added to the columns as fresh material at equal amounts of available nitrogen. The experiment simulated high-intensity rainfall over a period of 7 days. In general, soil treated with the commercial digestates with higher original metal content showed less environmental impact in terms of Ni, Cu and Zn leaching than that treated with experimental digestates with lower original metal content and less than when animal manure or mineral fertilizer was applied. Although effects of digestate application on metal mobility in soils were seen in conditions of extreme precipitation, the leached concentrations of metals were below limitations published by the WHO but still significantly higher than that measured for control soils.

Abstract

The Christmas tree industry in Norway is increasing and Abies lasiocarpa is, together with Abies nordmanniana, the most common exotic species for Christmas tree production. A. lasiocarpa today constitutes ca. 50% of the fir sold in Norway, and there is high demand for sufficient supply of high-quality seed and knowledge of seed sources with a potential for high Christmas tree quality. Two experimental plots were established to identify seed sources with potentially high survival and satisfactory Christmas tree quality. The high variation in traits on the two sites indicates promising possibilities for further selection of A. lasiocarpa clones for growing Christmas trees in Norway. Selection for late bud break to avoid spring frost is important. Pathogens were not found in any of the studied trials, but are an important factor to consider when selecting seed sources for Christmas trees. Due to the early bud break of this species, it is also of high importance to choose planting sites with minimal risks for spring frost. Good localities are slopes where the frost drains away during cold nights. In eastern Norway, A. lasiocarpa should be used with care in districts and sites where spring frost is commonly occurring.

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Abstract

Fire blight, caused by Erwinia amylovora, was detected for the first time in Norway in 1986. It was a limited outbreak on the south-western coast, only on ornamentals, and particularly on Cotoneaster spp. An action group handling the eradication and containment of the disease was quickly established. Comprehensive statutory powers and resources were given by the government to do surveys and eradicate diseased or symptomless but highly susceptible plant species from contaminated areas. These activities have likely restricted fire blight to the western and southern coastal areas. Eastern and northern parts of Norway are considered free from fire blight. The disease has not been observed in important fruit-growing areas. Uncontrolled movement of beehives from areas with fire blight to areas free from the disease has contributed to its introduction to new areas. From 1969 to 2016 import of most host plants of E. amylovora from countries with fire blight was prohibited. A yearly program for annual surveys in parts of the country with commercial fruit-growing and nurseries, using digital maps on internet connected tablets with GPS and software for in situ registrations, proved to be an efficient method for discovering new outbreaks at an early stage, and to start eradication and thus limit further spread.

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Abstract

Knowing the historical variation in fire regimes is instrumental in managing forests today and in predicting what may happen in the future. By cross-dating 745 fire scars in 378 samples of remnant Scots pines, we delineated 254 individual forest fires during the past 700 years in a 74-km2 section of Trillemarka-Rollagsfjell Nature Reserve in south-central Norway. Fire sizes, numbers, burn rates, and frequencies were compared with historical climate proxies, vegetation maps, and written sources. The results revealed patterns consistent with a predominantly climate-driven fire regime up to 1625, followed by periods of strong anthropogenic influence that increased fire frequency during 1600–1700s and diminished fires during 1800–1900s. This was documented by an abrupt increase in number of small fires from the early 1600s that markedly shortened fire intervals from a median of 73 to 37 yr. This shift in fire frequency coincided with a sudden appearance of early-season fires from 1625 and onward. Whereas late-season burn rate increased with summer temperature, no such relationship was found for early-season fires. These results were corroborated by written sources that describe anthropogenic forest fires and slash-and-burn cultivation expanding with the increasing population from the late 1500s and subsequently diminishing due to increasing timber values during 1700–1800s. Whereas human activity strongly influenced the fire regime at multidecadal to centennial scales, it was the interannual variability in climate that triggered large fire events, especially during the pre-1625 period. Prior to 1625, the percentage of years with fire tripled from 7% during cold summers (10–12°C) to 21% during warm summers (14–16°C). Burn rate increased even more, from 0.01% to 1.3% for the same temperature intervals. Ecologically, the post-1625 period is remarkable in such a way that human activity, first by greatly increasing fire frequency and subsequently almost eradicating fires, possibly influenced the fire regime to such an extent that it may be unprecedented for millennia.