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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Long-term and varied land use has had a major influence on the vegetation in rural Norway, and the traditional open landscapes are now being replaced by forests. In the present investigation, we assess and quantify structural vegetation changes caused by changes in land use and climate. Up-to-date actual vegetation maps from three rural study areas were compared with interpreted historical vegetation maps and potential natural vegetation (PNV) models. Our findings indicate that the present vegetation structure is strongly influenced by land use. In the studied sites, 56–66% of the areas presently have another vegetation type than expected from a natural state (PNV). The mean turnover of vegetation types in the study areas during the past 35–40 years was 25%. Our study highlights that the influence of land-use needs to be accounted for when considering the effects of climate change.
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Eivind Vangdal Sigrid Flatland Iren Knutsen Hanne LarsenAbstract
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Editors
Udaya Sekhar Nagothu A.K. Gosain K. PalanisamiAbstract
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In order to detect the efficiency of the nitrogen (N2) fixation in clover-grass leys in northern climate conditions, we studied how soil compaction affects growth and N2 -fixation of white clover (Trifolium repens L.) under contrasting growth conditions. A pot experiment was carried out under controlled climatic conditions in the phytotron at Holt (Tromsø). Sandy soil was compacted to two levels, 60% and 85% of the standard degree of compactness (SDC). Four seedlings of white clover plants or timothy (Phleum pratense L.) were carefully planted in each pot. Timothy was used as reference plant. The plants were placed at 15 ºC for twelve weeks and subjected to 18 or 24 h daylight. The 15N isotope dilution method was used to assess N2 -fixation. Results suggest that 24 h daylight increased white clover biomass production as compared to 18 h daylight and favoured leaf and stolon production significantly more at 85% of SDC than at 60% of SDC. However, for white clover plants grown at 18 h day length higher compactness reduced the root development. On average, white clover derived 44-58% of its total N from N2 -fixation grown at 60% of SDC and 46-47% at 85% of SDC, regardless of light conditions. The N2 -fixation was somewhat higher at 24 h day length only under the low soil compaction level.
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Authors
Marie Davey Einar Heegaard Rune Halvorsen Mikael Ohlson Håvard KauserudAbstract
Bryophytes are a dominant vegetation component of the boreal forest, but little is known about their associated fungal communities, including seasonal variation within them.•Seasonal variation in the fungal biomass and composition of fungal communities associated with three widespread boreal bryophytes was investigated using HPLC assays of ergosterol and amplicon pyrosequencing of the internal transcribed spacer 2 (ITS2) region of rDNA.•The bryophyte phyllosphere community was dominated by Ascomycota. Fungal biomass did not decline appreciably in winter (P = 0.272). Significant host-specific patterns in seasonal variation of biomass were detected (P = 0.003). Although seasonal effects were not the primary factors structuring community composition, collection date significantly explained (P = 0.001) variation not attributed to locality, host, and tissue. Community homogenization and a reduction in turnover occurred with the onset of frost events and subzero air and soil temperatures. Fluctuations in the relative abundance of particular fungal groups seem to reflect the nature of their association with mosses, although conclusions are drawn with caution because of potential methodological bias.•The moss-associated fungal community is dynamic, exhibiting seasonal turnover in composition and relative abundance of different fungal groups, and significant fungal biomass is present year-round, suggesting a winter-active fungal community.