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
Timothy (Phleum pratense L) is the most important forage grass in Scandinavia and it is therefore highly interesting to study how it will perform in a changing climate. In order to model winter survival, the dynamics of hardening and dehardening must be simulated with satisfactory precision. We investigated an early timothy frost tolerance model (LT50 model), and an LT50 model for winter wheat. Based on the assumption that timothy has no vernalization requirement, unlike winter wheat, but does have the ability to adapt to cold temperatures in a process linked to stage of development, two alternative versions of the winter wheat model were also constructed. In total, these four candidate models were calibrated by a Bayesian approach for the timothy cultivar Engmo. The candidate models were validated using independent observations on LT50 in timothy at different locations reflecting differences in climate. A sensitivity analysis, using the Morris method, to identify important model parameters suggested that there is a connection between frost tolerance and stage of plant development, even if there is no vernalization requirement. The simplified winter wheat model was selected as the best candidate model for LT50 in timothy based on model selection criteria and its ability to capture the hardening and dehardening processes. The results from the Bayesian calibration suggest that there are no major regional differences in Norway calling for regional calibration. However, cultivar-specific calibration is probably required, since there are hardy and less hardy cultivars within the same species. A functional LT50 model would allow risk assessments to be made of future winter survival using specifically tailored and downscaled climate scenarios. (C) 2010 Elsevier B.V. All rights reserved.
Sammendrag
Side effects related to liming have been studied in four dimictic lakes (553-642 ma.s.l.; 59 degrees 57'N) in Finnemarka, a forested area in Southern Norway with poor catchment buffer capacity. Data series from lake profiles have been sampled two decades apart; 10 years prior to liming and after 10 years of liming. Water samples were collected during spring after ice breakup and during summer after the development of thermal stratification. Before liming, there were very low concentrations of bicarbonate (HCO3-; or alkalinity) in the lakes. After 10 years of liming, up to 90% of the ions in hypolimnion originate from lime products. Hence, liming strengthened the chemical stratification and increased the vertical stability. Differences in chemocline developments between lakes were explained by differences in physical properties, i.e. their depth/surface area ratio. The chemocline developments lead to increased concentrations of organic matter in the hypolimnion with a subsequent reduction in oxygen concentrations. Lime additions during late spring, as an alternative to early autumn, lead to pronounced anoxic conditions in the hypolimnion.
Forfattere
Bringas Carlos M. Salas Tore Filbakk Geir Skjevrak Odd-Ivar Lekang Olav Høibø Reidar Barfod SchüllerSammendrag
The effects of drying temperature and storage time on the compressibility and strength of Scots pine pellets were analysed in this article. Compressibility was not affected, whereas the highest pellet strength was obtained from the wood with longest storing and highest drying temperature.
Forfattere
Christian Sonne Jan Ove Bustnes Dorte Herzke Veerle Jaspers Adrian Covaci Duncan Halley Truls Moum Igor Eulaers Marcel Eens Rolf A. Ims Sveinn Are Hanssen Kjell E Erikstad Trond Johnsen Lisbeth Schnug Frank F. Rigét Asger Lundorff JensenSammendrag
Organohalogen contaminants (OHCs) may affect various physiological parameters in birds including blood chemistry. We therefore examined blood plasma clinical-chemical parameters and OHCs in golden eagle, white-tailed eagle and goshawk chicks from Northern Norway. Correlation analyses on pooled data showed that alkaline phosphatase (ALKP), glucose and creatinine were significantly negatively correlated to various OHCs (all: p<0.05; r: -0.43 to -0.55; n=23), while alanine aminotransferase (ALAT), total protein, cholesterol, uric acid, total bilirubin, ratios protein:creatinine and uric acid:creatinine were significantly positively correlated to various OHCs (all: p<0.05; r: 0.43-0.96). Based on these relationships, we suggest that the OHC concentrations found in certain raptor chicks of Northern Scandinavia may impact blood plasma biochemistry in a way that indicates impacts on liver, kidney, bone, endocrinology and metabolism. In order to elaborate further on these relationships and mechanisms, we recommend that a larger study should take place in the near future.
Forfattere
Sebastian EiterSammendrag
This article uses an activity-based understanding of landscape to explore values related to perceived land cover diversity. Perceptions within two user groups, members of landowner families and hiking tourists in a mountain area in western Norway, were related to a simultaneous land cover survey, and compared to experts' evaluations of land cover and to the aims of landscape protection in the area. Users perceived the area as being significantly more diverse and valuable than experts did, which stresses the importance of taking user perception into account in landscape protection and management. Some central landscape values were dependent upon land use outside the boundaries of the protected area. This illustrates that measures within structurally defined land units are not necessarily sufficient for maintenance of landscape values experienced by users. Land use in both respects, as an upholder of values and as a way of experiencing or perceiving them, should receive an increased role in the determination of management units.
Forfattere
Jon Anders Stavang Rolf Inge Pettersen Micael Wendell Knut Asbjørn Solhaug Olavi Junttila Roar Moe Jorunn E. OlsenSammendrag
Active gibberellin (GA(1)) is an important mediator of thermoperiodic growth in pea. Plants grown under lower day than night temperature (negative DIF) elongate less and have reduced levels of GA(1) compared with plants grown at higher day than night temperature (positive DIF). By comparing the wild type (WT) and the elongated DELLA mutant la cry(s), this study has examined the effect of impaired GA signalling on thermoperiodic growth, photosynthesis, and respiration in pea. In the WT a negative DIF treatment reduced stem mass ratio and increased both root mass ratio and leaf mass ratio (dry weight of specific tissue related to total plant dry weight). Leaf, root and stem mass ratios of la cry(s) were not affected by DIF. Under negative DIF, specific leaf area (projected leaf area per unit leaf dry mass), biomass, and chlorophyll content of WT and la cry(s) plants were reduced. Young, expanding leaves of plants grown under negative DIF had reduced leaf area-based photosynthetic capacity. However, the highest photosynthetic electron transport rate was found in fully expanded leaves of WT plants grown under negative DIF. Negative DIF increased night respiration and was similar for both genotypes. It is concluded that GA signalling is not a major determinant of leaf area-based photosynthesis or respiration and that reduced dry weight of plants grown under negative DIF is caused by a GA-mediated reduction of photosynthetic stem and leaf tissue, reduced photosynthesis of young, expanding leaves, and reduced growth caused by low temperature in the photoperiod.
Forfattere
Monica Hauger Carlsen Bente Lise Halvorsen Kari Holte Siv Kjølsrud Bøhn Steinar Dragland Laura Sampson Carol Willey Haruki Senoo Yuko Umezono Chiho Sanada Ingrid Elisabet Barikmo Nega Berhe Walter C Willett KM Phillips David Jacobs Rune BlomhoffSammendrag
Open Access article distributed under the terms of Creative Commens Attribution License: http://creativecommons.org/licenses/by/3.0/
Sammendrag
In Scandinavia, high losses of soil and particulate-bound phosphorus (PP) have been shown to occur from tine-cultivated and mouldboard-ploughed soils in clay soil areas, especially in relatively warm, wet winters. Omitting primary tillage (not ploughing)in autumn and continuous crop cover are generally used to control soil erosion. In Norway, ploughing and shallow cultivation of sloping fields in spring instead of ploughing in autumn has been shown to reduce particle transport by up to 89% on soils with high erodibility. Particle erosion from clay soils can be reduced by 79% by direct drilling in spring compared with autumn ploughing. Hence, field experiments in Scandinavia on ploughless tillage of clay loams and clay soils compared with conventional ploughing in autumn usually show reductions in total P losses of 10-80%, via both surface runoff and subsurface runoff (lateral movements to drains). However, the effects of not ploughing during autumn on losses of dissolved reactive P (DRP) are frequently negative, since the proportion of DRP losses without ploughing compared conventional ploughing has increased up to fourfold in field experiment. In a comprehensive Norwegian field experiment at a site with high erosion risk the proportion of DRP compared to total P has increased twice in water after direct drilling compared to ploughing before winter wheat. Therefore erosion control measures should be further evaluated for fields with a low erosion risk since reduction in PP losses may be low and DRP losses still high. Ploughless tillage systems have potential side-effects, including an increased need for pesticides to control weeds (e.g. Elytrigia repens (L.) Desv. ex Nevski) and plant diseases (e.g. Fusarium spp.) harboured by crop residues on the soil surface. Overall, soil tillage systems should be appraised for their positive and negative environmental effects before they are widely used for all conditions of soil, management practices, climate and landscape.
Forfattere
Brita Toppe Arne Hückstädt María L. Herrero Jafar Razzaghian Andrew Dobson Hans Ragnar GislerødSammendrag
Moderat auka av frie koparion i næringsløysinga er kjent å kunna redusera spreiing av pseudosoppar som Pythium og Phytophthora. Effekten på Fusarium er meir usikker. Laboratorieforsøk gjennomført i prosjektet "Redusert åtak av rotsjukdomar i norske prydplanter" viser at konsentrasjon av frie koparion må aukast til relativt høge nivå for å hindra sporespiring hos Fusarium foetens.
Forfattere
Arild Andersen Solveig HaukelandSammendrag
De siste års forsøk med iberiaskogsnegl blir gjennomgått, blant annet testing av barrierer, effekten av naturlige fiender, og bruk av sneglemidler. Experiments on control of the invasive Iberian slug are described. Different barriers have been tested, along with the effect of natural enemies and pesticides.