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.
2010
Sammendrag
Concentrations of dissolved organic carbon (DOC) in throughfall and soil solutions at 5, 15 and 40-cm depth were studied in 16 Norway spruce and two Scots pine plots throughout Norway between 1996 and 2006 (Wu et al. 2010a). Average DOC concentrations ranged from 2.3 to 23.1 mg/l and from 1.1 to 53.5 mg/l in throughfall water and soil solutions, respectively. Concentrations of DOC in throughfall and soil waters varied seasonally at most plots with peaks in the growing season. In contrast to reported positive long-term trends in DOC concentrations in surface waters between 1986 and 2003, soil water data from 1996 to 2006 showed largely negative trends in DOC concentrations and no significant trends in throughfall. However, regression analysis for individual sites, particularly at 5- and 15-cm soil depths, showed that DOC concentrations in soil water were significantly and negatively related to non-marine sulphate and chloride. Further studies were carried out on dissolved organic nitrogen (DON, Wu et al. 2010b). Dissolved organic nitrogen (DON) concentrations were significantly and positively correlated to DOC concentrations in throughfall (r2=0.72, p<0.0001) and soil water at 5, 15, and 40 cm (r2=0.86, 0.32, and 0.84 and p<0.0001, 0.04, and <0.0001, respectively). At most sites, the annual median DOC/DON ratio in throughfall ranged from 20.3 to 55.5, while values in soil water were higher, ranging from 24.5 to 81.3 but gradually decreasing with soil depth. DON concentrations varied seasonally in throughfall at many plots and in soil water at 5 cm depth at one plot only, with higher values in the growing season, but there was no noticeable seasonality at greater depth. The ratios of DOC/DON in soil water were significantly positively related to the C/N ratio in soil at the same depth. Above-ground litter input was the main factor having a significant, negative relationship to DOC/DON in soil water at all depths studied. This might reflect the effect of site conditions on both DOC/DON ratios and litter quantity. A comparison of DOC and DON concentrations and fluxes at two Norwegian sites (Birkenes and Hirkjølen) and five Finnish Level II plots (Tammela, Juupajoki, Uusikaarlepyy, Kivalo and Pallasjärvi) showed no obvious correlation between concentrations and site and stand properties such as growing season length, temperature, precipitation, stand age, or soil C or N. DOC concentrations in the O horizon could not be linked to N deposition. However, there were clear within-site seasonal trends, compatible with an effect of temperature on microbial activity.
Forfattere
Nadeem Yaqoob Jan Karlsson Benedicte Riber Albrectsen Halvor Solheim Carl Gunnar FossdalSammendrag
Plants are exposed to a variety of pathogens in their natural habitats. To understand the key processes of defense responses in aspen (Populus tremulae) at the transcript level two clones C72 and C23 with differential level of resistance from the SwAsp collection were inoculated with a foliar rust (Melampsora magnusiana Wagnar). Leaf samples were collected from adjacent areas of the inoculation site to examine the long distance (systemic) defense responses at day1, day3 and day14 post treatments. We performed microarray experiments on the biothrophic interaction, on comparison with the healthy controls we found that the two clones respond in a widely different fashion to the rust. Clone C23 showed almost no response to biotroph after 24 hours while clone 72 gave a clear defense response to the pathogen. Quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) showed a significant differential expression patterns in susceptible and resistant colnes. Chitinase, cinnamic acid reductase and the iaa genes showed signification up-regulation in resistant clone. The level of expression was 5.9 delta threshold cycles in chitinase gene at day14. Data analysis from extracted total phenolics and condensed tannins verify the results of cDNA arrays and qRT-PCR.
Forfattere
Trond MæhlumSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Espen Govasmark Jessica Stäb Børge Holen Mirja Salkinoja-Salonen Douve HoornstraSammendrag
The European Union Council directive 1999/31/EC states that no waste should be deposited on landfills without being treated in some way. Source separating of organic wastes at the household is one way of treating the waste to reduce the amount of waste entering the landfill. Anaerobic digestion on biogas plants (BGP) is a management strategy of organic wastes which combines recycling of plant nutrients in organic waste with production of renewable energy (Hartmann & Ahring 2006). The anaerobic digested residue (ADR) can be used as fertilizer, thereby recycling nutrients back to agriculture and horticulture. However, the ADR is not a harmless product since it may contain pollutants such as heavy metals, organic pollutants and pesticide but also pathogenic bacteria which are introduced to the soil ecosystem by its application (Kupper at al. 2008; Brändli et al 2007; Brändli et al., 2005; Sahlström 2003). Therefore, it is important to assess the safety of using digestate as fertilizer with respect to the chemical and bacteriological content. Anaerobically digested organic waste was analysed for the content of heavy metals, organic pollutants, pesticides and the bacteria E.coli and B.cereus each month in a year. The digestate was separated into a fiber and liquid fraction by centrifugation at the BGP. Heavy metal concentrations (mg/kg DM) in the fiber was (min-max); Zn (162-364), Cu (34-69), Cd (0.2-0.4), Ni (6-19), Cr (15-33), Pb (6-13) and Hg (0.03-0.17), and in the liquid; Zn (132-422), Cu (23-57), Cd (0.2-0.6), Ni (3-11), Pb (4-6) and Hg (0.05-0.15). Organic pollutant and pesticide concentrations (µg/kg DM) in the fiber was: ∑PAH 16 (585-1544), ∑PBDE (2.4-9.5), DEHP (13440-64874), Imazalil (380-4190) and Tiabendazol (140-670) and in the liquid: ∑PAH 16 (n.d-65), ∑PBDE (n.d-0.2), DEHP (233-2113), Imazalil (370-5770) and Tiabendazol (n.d-730). The digestate did not contain viable E.coli but contained 0.5 to 10 × 106 viable B.cereus per ml of which 1 % were heat stable spores. Culturable presumptive B.cereus was isolated in 9 out of 10 samples. The concentration of heavy metals was within class I according to the Norwegian standard. Only DEHP were found in concentrations higher than the threshold values for composts in Austria and Denmark, but lower than for sewage sludge used as fertilizer in EU. The concentration of Imazalil and Thiabendazol was higher than expected, but not threshold are available. Analysis of DNA showed that the digestate contained B. cereus and a portion of the B. cereus genomes possessed the cesB gene. Approximately 1 % of the heat stable spores represented B. cereus. The content of viable B. cereus in the digestate was acceptable for foods. The authors therefor conclude that the digestate is safe to use as fertilizers in agriculture with respect to heavy metals, organic pollutants, pesticides and the bacteria E.coli and B.cereus. REFERENCES Brändli, R.C., Bucheli, T.D., Kupper, T., Mayer, J., Stadelmann, F.X. & Tarradellas, J. 2007. Fate of PCBs, PAHs and their sorce characteristics ratios during composting and digestion of source-separated organic waste in full-scale plants. Environmental Pollution 148, pp. 520-528. Brändli, R.C., Bucheli, T.D., Kupper, T., Furrer, R., Stadelmann, F.X., & Tarradellas, J. 2005. Persistent Organic Pollutants in Source-Separated Compost and Its Feedstock Materials - a Review of Field Studies. Journal of Environmental. Quality 34(3), pp. 735-760. EC. 1999. Council directive of 1999/31/EC on 26 April 1999 on the landfill of waste. Official Journal of the European Communities, European commission, Brussels, Belgium, L182, pp 1-19. Hartmann, H. & Ahring B.K. 2006. Strategies for the anaerobic digestion of the organic fraction of municipal solid waste; an overview. Water Science. Technology 53 (8), pp. 7-22. Kupper, T., Bucheli, T.D., Brändli, R.C., Ortelli, D. & Edder,P. 2008. Dissipation of pesticides during composting and anaerobic digestion of source-separated organic waste at full-scale plants. Bioresource Technology 99, pp. 7988-7994. Sahlström, L. 2003. A review of survival of pathogenic bacteria in organic waste used in biogas plants. Bioresource Technology 87, pp. 161-166.
Forfattere
Espen Govasmark Jessica Stäb Børge Holen Douwe Hoornstra Mirja Salkinoja-SalonenSammendrag
Det er ikke registrert sammendrag
Forfattere
Aruppillai Suthaparan Arne Stensvand Sissel Torre Maria Herrero Rolf Inge Pettersen David Gadoury Hans Ragnar GislerødSammendrag
The effect of day length on production and germinability of conidia and severity of disease caused by Podosphaera pannosa, the causal agent of rose powdery mildew, was studied. Whole potted plants or detached leaves of Rosa interspecific hybrid 'Mistral' were inoculated with P. pannosa and exposed to 0, 12, 18, 20, 22, or 24 h of artificial light per day in growth chambers equipped with mercury lamps. Increasing duration of illumination from 18 to 20 to 24 h per day reduced production of conidia by 22 to 62%. Exposure to 24 h of illumination per day also strongly reduced disease severity compared with 18 h. Our results suggest that increasing day lengths from 18 h per day to 20 to 24 h may suppress the disease significantly and, thereby, reduce the need for fungicide applications against powdery mildew.
Forfattere
Morten Nitteberg Bruce Talbot Karl Stampfer Daniel KindernaySammendrag
Det er ikke registrert sammendrag
Forfattere
Anita SønstebySammendrag
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Sammendrag
Det er ikke registrert sammendrag