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
Sammendrag
Increasing abundance of Juncus effusus (soft rush) and Juncus conglomeratus (compact rush) in pastures and meadows in western Norway has caused reductions in forage yield and quality in recent decades. Understanding plant development and regrowth following cutting is essential in devising cost-effective means to control rushes. In a field experiment in western Norway, we investigated development of above- and below-ground fractions of rush from seedlings to three-year-old plants, including the impact on vigour of disturbing growth by different cutting frequencies during the period 2009–2012. Each year, the plants were exposed to one or two annual cuts or left untreated and five destructive samplings were performed from March to early December. Juncus effusus showed significantly more vigorous growth than Juncus conglomeratus in the last two years of the study period. The above-ground:below-ground biomass ratio of both species increased mainly in spring and early summer and was reduced in late summer and autumn. Removal of aerial shoots also reduced the below-ground fraction of both species. One annual cut in July effectively reduced biomass production in both species by 30–82%, which was only a slightly smaller reduction than with two annual cuts, in June and August. Mechanical control measures such as cutting can thus effectively reduce rush vigour when performed late in the growing season.
Sammendrag
I dette studiet har vi ved hjelp av livsløpsanalyse (LCA) analysert miljøeffektane av å produsere norsk svinekjøtt. Utgangspunktet for analysa har vore eit fiktivt gardsbruk, plassert i Stange kommune, med kombinert svineproduksjon (både smågris-og slaktegrisproduksjon) og med kornproduksjon (bygg, vårkveite og havre) der gjødsla frå svinebesetninga blir utnytta. Som utgangspunkt analyserte vi eit tradisjonelt opplegg der grisane fekk kraftfôrblandingar tilpassa behovet som einaste fôr. Soya utgjorde 8% kraftfôrblandinga på råvektbasis. Vi analyserte svineproduksjonen under to ulike alternativ: a) At dei norske kornråvarene i kraftfôret var produsert på garden eller på ein tilsvarande gard, b) At dei norske kornråvarene i kraftfôret kom frå husdyrfrie gardar med mineralgjødsel som einaste gjødselslag. I tillegg analyserte vi på tilsvarande måte svineproduksjonen på garden i ein situajson der arealgrunnlaget blei utvida til også å omfatte eng, og der engavlinga blei brukt i ein bioraffineringsprosess til å produsere grassaft som proteinfôr til slaktegrisane i besetninga. Pressresten (pulp) blei selt som grovfôr til lokale storfeprodusentar. I tillegg til grassaft fekk slaktegrisane kraftfôr med redusert innhald av soya (6%) samanlikna med standardblandinga. Samla ga denne fôrrasjonen dekning av slaktegrisane sitt næringsbehov, slik at tilvekst og produksjonsresultat var det same i begge produksjonsopplegga.....
Sammendrag
In recent years, rising competition for water coupled with new environmental regulations has exerted pressure on water allocations for turfgrass irrigation. In this article, we reviewed published scientific and industry evidence on the agronomic and environmental impacts of turfgrass irrigation using a robust systematic review methodology. Our focus was on the links between (i) irrigation management (amount and frequency), (ii) agronomic responses to irrigation (turf quality, growth rates and rooting) and (iii) environmental impacts (nitrogen leaching). Based on an initial screening of 653 studies and data extracted from 83 papers, our results show that in most cases, under moderate levels of deficit irrigation (50%–60% of actual evapotranspiration), turf quality can be maintained at an acceptable level but with lower water consumption compared to irrigating back to field capacity. Irrigation beyond field capacity was found to increase the risk of nutrient leaching. However, evidence also showed that the concentration and total loss of urn:x-wiley:09312250:media:jac12265:jac12265-math-0001 in leachate were influenced more by nitrogen (N) rates, soil characteristics, turfgrass species and turfgrass growth rates than by irrigation practices. Our analyses suggest that turfgrass irrigation should be scheduled to apply water at moderate levels of deficit irrigation, sufficient to maintain turfgrass quality but limited to promote a deep and extensive rooting system. The findings provide new insights and valuable evidence for both scientists and practitioners involved in turfgrass research and management.
Forfattere
Thomas Dirnböck Gisela Pröll Kari Austnes Jelena Beloica Burkhard Beudert Roberto Canullo Alessandra De Marco Maria Francesca Fornasier Martyn Futter Klaus Goergen Ulf Grandin Maria Holmberg Antti-Jussi Lindroos Michael Mirtl Johan Neirynck Tomasz Pecka Tiina Maileena Nieminen Jørn-Frode Nordbakken Maximilian Posch Gert-Jan Reinds Edwin C. Rowe Maija Salemaa Thomas Scheuschner Franz Starlinger Aldona Katarzyna Uzieblo Salar Valinia James Weldon Wieger G W Wamelink Martin ForsiusSammendrag
Atmospheric nitrogen (N) pollution is considered responsible for a substantial decline in plant species richness and for altered community structures in terrestrial habitats worldwide. Nitrogen affects habitats through direct toxicity, soil acidification, and in particular by favoring fast-growing species. Pressure from N pollution is decreasing in some areas. In Europe (EU28), overall emissions of NO x declined by more than 50% while NH3 declined by less than 30% between the years 1990 and 2015, and further decreases may be achieved. The timescale over which these improvements will affect ecosystems is uncertain. Here we use 23 European forest research sites with high quality long-term data on deposition, climate, soil recovery, and understory vegetation to assess benefits of currently legislated N deposition reductions in forest understory vegetation. A dynamic soil model coupled to a statistical plant species niche model was applied with site-based climate and deposition. We use indicators of N deposition and climate warming effects such as the change in the occurrence of oligophilic, acidophilic, and cold-tolerant plant species to compare the present with projections for 2030 and 2050. The decrease in N deposition under current legislation emission (CLE) reduction targets until 2030 is not expected to result in a release from eutrophication. Albeit the model predictions show considerable uncertainty when compared with observations, they indicate that oligophilic forest understory plant species will further decrease. This result is partially due to confounding processes related to climate effects and to major decreases in sulphur deposition and consequent recovery from soil acidification, but shows that decreases in N deposition under CLE will most likely be insufficient to allow recovery from eutrophication.
Forfattere
Heidi Udnes Aamot Katherine Ann Gredvig Nielsen Shiori Koga Anne Kjersti Uhlen Ulrike Böcker Erik Lysøe Guro Brodal Ruth Dill-Macky Ingerd Skow HofgaardSammendrag
The proportion of Norwegian wheat used for food has varied significantly during the recent decade, mainly because of the instability of factors that are essential to baking quality (i.e. protein content and gluten functionality). During the same period, serious contamination of Fusarium spp. and mycotoxins was observed in some grain lots [1, 2]. A project was established to generate greater knowledge of the interface between gluten functionality and effects of Fusarium species and other microorganisms on Norwegian wheat quality. Instances of severe degradation of gluten proteins that resulted in an almost complete loss of gluten functionality were observed in some lots of Norwegian wheat. The degradation of the gluten appeared to be caused by exogenous proteases. Metabarcoding of fungi and bacteria in these grain lots identified fungi within the Fusarium Head Blight complex, as well as one bacterial species, as candidate species for influencing gluten functionality. Some of these candidates were inoculated on wheat during flowering [3]. Analysis of baking quality of the flour from this experiment revealed a reduced proportion of un-extractable polymeric proteins (%UPP) and severe reductions in the gluten’s resistance to stretching (RMAX) in wheat flour from plants inoculated with Fusarium graminearum. Flour from wheat inoculated with Fusarium avenaceum was generally less infested, and showed minimal or no reduction in gluten functionality and %UPP compared to flour from the F. graminearum infested samples. Flour from wheat inoculated with Michrodochium majus is yet to be analysed. References 1. Koga, S., et al., Investigating environmental factors that cause extreme gluten quality deficiency in winter wheat (Triticum aestivum L.). Acta Agriculturae Scandinavica, Section B—Soil & Plant Science, 2016. 66(3): p. 237-246. 2. Hofgaard, I., et al., Associations between Fusarium species and mycotoxins in oats and spring wheat from farmers’ fields in Norway over a six-year period. World Mycotoxin Journal, 2016. 9(3): p. 365-378. 3. Nielsen, K.A.G., Effect of microorganisms on gluten quality in wheat., in Faculty of Biosciences. 2017, Norwegian University of Life Sciences: Ås.
Forfattere
Svetlana Pakhomova Evgeniy Yakushev Elizaveta Protsenko Sylvain Rigaud Daniel Cossa Joel Knoery Raoul-Marie Couture Olivier Radakovitch Shamil Yakubov Dominika Krzeminska Alice NewtonSammendrag
This study presents a specifically designed Mercury module in a coupled benthic-pelagic reactive-transport model - Bottom RedOx Model (BROM) that allows to study mercury (Hg) biogeochemistry under different conditions. This module considers the transformation of elemental mercury (Hg(0)), divalent mercury (Hg(II)) and methylmercury (MeHg). The behavior of mercury species in the model is interconnected with changes of oxygen, hydrogen sulfide, iron oxides, organic matter, and biota. We simulated the transformation and transport of Hg species in the water column and upper sediment layer under five different scenarios, combining various levels of oxygenation and trophic state in the Berre lagoon, a shallow eutrophic lagoon of the French Mediterranean coast subjected to seasonal anoxia. The first scenario represents the conditions in the lagoon that are compared with experimental data. The four other scenarios were produced by varying the biological productivity, using low and high nutrient (N and P) concentrations, and by varying the redox conditions using different intensity of vertical mixing in the water column. The results of the simulation show that both oxidized and reduced sediments can accumulate Hg, but any shifts in redox conditions in bottom water and upper sediment layer lead to the release of Hg species into the water column. Eutrophication and/or restricted vertical mixing lead to reducing conditions and intensify MeHg formation in the sediment with periodic release to the water column. Oxygenation of an anoxic water body can lead to the appearance of Hg species in the water column and uptake by organisms, whereby Hg may enter into the food web. The comparison of studied scenarios shows that a well-oxygenated eutrophic system favors the conditions for Hg species bioaccumulation with a potential adverse effect on the ecosystem. The research is relevant to the UN Minimata convention, EU policies on water, environmental quality standards and Mercury in particular.
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.
Forfattere
Alan C. Gange Einar Heegaard Lynne Boddy Carrie Joy Andrew Paul M. Kirk Rune Halvorsen Thomas W. Kuyper Claus Bässler Jefferey M. Diez Jacob Heilman-Clausen Klaus Høiland Ulf Büntgen Håvard KauserudSammendrag
Despite the dramatic phenological responses of fungal fruiting to recent climate warming, it is unknown whether spatial distributions of fungi have changed and to what extent such changes are influenced by fungal traits, such as ectomycorrhizal (ECM) or saprotrophic lifestyles, spore characteristics, or fruit body size. Our overall aim was to understand how climate and fungal traits determine whether and how species‐specific fungal fruit body abundances have shifted across latitudes over time, using the UK national database of fruiting records. The data employed were recorded over 45 yr (1970–2014), and include 853 278 records of Agaricales, Boletales and Russulales, though we focus only on the most common species (with more than 3000 records each). The georeferenced observations were analysed by a Bayesian inference as a Gaussian additive model with a specification following a joint species distribution model. We used an offset, random contributions and fixed effects to isolate different potential biases from the trait‐specific interactions with latitude/climate and time. Our main aim was assessed by examination of the three‐way‐interaction of trait, predictor (latitude or climate) and time. The results show a strong trait‐specific shift in latitudinal abundance through time, as ECM species have become more abundant relative to saprotrophic species in the north. Along precipitation gradients, phenology was important, in that species with shorter fruiting seasons have declined markedly in abundance in oceanic regions, whereas species with longer seasons have become relatively more common overall. These changes in fruit body distributions are correlated with temperature and rainfall, which act directly on both saprotrophic and ECM fungi, and also indirectly on ECM fungi, through altered photosynthate allocation from their hosts. If these distributional changes reflect fungal activity, there will be important consequences for the responses of forest ecosystems to changing climate, through effects on primary production and nutrient cycling.
Forfattere
Matthew Schwarzkopf Michael Burnard Viacheslav Tverezovskiy Andreas Treu Miha Humar Andreja KutnarSammendrag
Within the Slovenian region of Istria, the olive growing and oil production industry is strong. This industry has a long history and the olives grown here have high levels of biologically active compounds including a variety of phenolic compounds. Using residual materials generated by this industry in potential wood protection systems would not only valorise low-value materials and stimulate rural economies but would also provide an alternative to currently used oil-based protection systems. The objective of this study was to produce an oil treatment for wood protection and assess its efficacy in reducing leaching, weathering effects, and fungal decay. Two maleinisation techniques were used to chemically modify low-value lampante oil in an attempt to limit leaching when impregnated in wood. Pinus sylvestris (Scots pine) and Fagus sylvatica (European beech) were treated with the modified oils and underwent leaching, accelerated weathering, and decay tests. Leaching of the treatment oils was relatively low compared with other experiments and beech wood specimens treated with a direct maleinisation treatment showed improvement in performance compared to control specimens. In addition, it was found that the modified oils were not completely removed from the wood after solvent extraction indicating that they could potentially be used as an immobilisation agent in combination with other treatments thereby reducing the amount of active component of the protective agent.
Sammendrag
Freezing and thawing have large effects on water flow in soils since ice may block a large part of the pore space and thereby prevent infiltration and flow through the soil. This, in turn, may have consequences for contaminant transport. For example, transport of solutes contained at or close to the soil surface can be rapidly transported through frozen soils in large pores that were air filled at the time of freezing. Accounting for freezing and thawing could potentially improve model predictions used for risk assessment of contaminant leaching. A few numerical models of water flow through soil accounts for freezing by coupling Richards’ equation and the heat flow equation using of the generalized Clapeyron equation, which relates the capillary pressure to temperature during phase change. However, these models are not applicable to macroporous soils. The objective of this study was to develop and evaluate a dual-permeability approach for simulating water flow in soil under freezing and thawing conditions. To achieve this we extended the widely used MACRO-model for water flow and solute transport in macroporous soil. Richards’ equation and the heat flow equation were loosely coupled using the Clapeyron equation for the soil micropore domain. In accordance with the original MACRO model, capillary forces were neglected for the macropore domain and conductive heat flow in the macropores was not accounted for. Freezing and thawing of macropore water, hence, were solely governed by heat exchange between the pore domains. This exchange included a first-order heat conduction term depending on the temperature difference between domains and the diffusion pathlength (a proxy variable related to the distance between macropores) and convective heat flow. As far as we know, there are no analytical solutions available for water flow during freezing and thawing and laboratory data is limited for evaluation of water flow through macropores. In order to evaluate the new model approach we therefore first compared simulation results of water flows during freezing for the micropore domain to existing literature data. Our model was shown to give similar results as other available models. We then compared the first-order conductive heat exchange during freezing to a full numerical solution of heat conduction. Finally, simulations were run for water flow through frozen soil with initially air-filled macropores for different boundary conditions. Simulation results were sensitive to parameters governing the heat exchange between pore domains for both test cases.