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.
2009
Forfattere
Håkon BorchSammendrag
Det er ikke registrert sammendrag
Forfattere
Anne Kari BergjordSammendrag
I områder der vinterskader kan ha stor betydning for høstkveitens vekst og yteevne i den påfølgende vekstsesongen, vil modeller som gjør det mulig å estimere grad av overvintring og vekstpotensial om våren være et viktig tillegg til eksisterende plantevekstmodeller. Hovedformålet med studien har vært å generere kunnskap og funksjonelle sammenhenger som kan gjøre det mulig å utføre risikoanalyser for overvintring og vekst av høstkveite i nåværende og fremtidige dyrkingsområder og klima.To sorter av høstkveite ble dyrket i kasser satt ut i felt, og planter ble tatt inn regelmessig fra til sammen fire steder gjennom tre vintre. Plantenes frosttoleranse (LT50) og vekstpotensial ble testet, utviklingstrinnet til vekstpunktet ble undersøkt, og konsentrasjonen av vannløselige karbohydrater analysert. En modell, kalt FROSTOL, som simulerer daglig utvikling av frosttoleranse gjennom vinteren, ble utviklet. Modellen er basert på en kanadisk modell, og den ble kalibrert og optimert ved bruk av resultater fra testene av frosttoleranse, samt daglige målinger av jordtemperatur (2 cm) og snødybde fra tre av de fire stedene. Optimering av i alt fem koeffisienter, i fire av enkeltfunksjonene, ga et godt samsvar (R2 = 0.84) mellom registrert og simulert LT50. En kryssvalidering tydet på at koeffisientene var tilstrekkelig upåvirket av variasjon i vinterværet.En serie med finske sortsforsøk ble brukt for å evaluere modellens evne til å estimere grad av overvintring i felt gjennom vintre med ulike værforhold. Korrelasjonen mellom simulert, kumulativt stressnivå og prosent overlevende planter registrert i feltforsøkene var relativt svak (R2 = 0.34). FROSTOL beregner imidlertid kun skader forårsaket av lav temperatur, mens feltforsøkene uttrykker sortenes generelle evne til å tåle ulike former for påkjenning gjennom vinteren. Resultatene antydet at FROSTOL-simuleringene samsvarte rimelig godt med observasjoner fra felt i de tilfellene der lav temperatur var den dominerende påkjenningen.Flere forsøk har vist at det er nær sammenheng mellom induksjon av generativ utvikling og tidspunktet for når plantenes frosttoleranse begynner å avta. En fortsatt økende frosttoleranse etter fullført vernalisering ble observert under utviklingen av FROSTOL, og det antyder at den fenologiske modulen i modellen burde videreutvikles til også å omfatte daglengde som en drivvariabel, i tillegg til temperatur. Studiene av vekstpunkt hos planter som hadde vokst ved henholdsvis kort og lang dag etter inntak fra felt, bekreftet at vernalisering alene ikke var nok til å indusere plantene til generativ utvikling. Det var ingen synlig utvikling av vekstpunktet hos planter som ble dissekert ved inntaket fra felt, før våren kom. På et eller annet tidspunkt mottok plantene likevel signaler, og gjennomgikk fysiologiske endringer, som gjorde dem i stand til å gå over fra vegetativ til generativ fase også ved kort dag. Fordi kveiteplantenes vernaliserings- og daglengdekrav er av en kvantitativ karakter, som også påvirkes av plantenes alder, er det vanskelig å definere enkle kriterier for når plantene er indusert til generativ utvikling i tilstrekkelig grad til at frosttoleransen påvirkes. Tidspunktet for registrering av maksimal frosttoleranse tydet på at generativ induksjon under kortdagsforholdene i felt fant sted omtrent én måned etter fullført vernalisering.I løpet av herdingsperioden om høsten akkumulerer høstkveiteplantene reserver av fruktan og andre vannløselige karbohydrater (WSC) i bladslirer og kroner. Disse er avgjørende for plantenes mulighet til å overleve gjennom vinteren, når fotosyntesen er satt tilbake av lav temperatur og snødekke. Det var imidlertid ingen statistisk sikker sammenheng mellom konsentrasjon av WSC og plantenes tilvekstpotensial i denne studien. Resultatene tydet derimot på at kondisjonen til plantene ved vinterens slutt var sterkt påvirket av deres tilstand ved innvintring, og med varigheten av snødekket. Planter som hadde stått under et langvarig snødekke, hadde en lavere veksthastighet om våren enn de som var dekket av snø i en kortere periode. Varigheten av snødekket påvirket også hvor raskt konsentrasjonen av WSC sank i løpet av vinteren ved sin virkning på jordtemperatur og innstråling til plantene. Konsentrasjonen av WSC økte imidlertid raskt igjen etter snøsmelting, når en positiv karbonbalanse ble gjenopprettet.Vinterværets virkning på utviklingen av frosttoleranse og vekstpotensial har vært hovedemnet i dette arbeidet. De presenterte resultatene har gitt grunnlag for utvikling av en frosttoleranse-modell som ser ut til å kunne estimere grad av overvintring relativt godt under forhold der lav temperatur er hovedårsaken til utgang av planter. Studien har også vist at plantenes vekstpotensial om våren er sterkt påvirket av deres tilstand om høsten. For å utvikle modeller som kan predikere både vinteroverlevelse og vekstpotensial om våren, er det derfor nødvendig å studere nærmere sammenhengen mellom plantenes yteevne og vær- og dyrkingsforhold også om høsten.
Forfattere
Aksel DøvingSammendrag
Det er ikke registrert sammendrag
Forfattere
Ole Martin Bollandsås Ingvild Rekstad Erik Næsset Ingvald RøsbergSammendrag
The objectives of this study were (1) to develop models for estimation of total above-ground biomass, tree crown biomass and stem biomass of mountain birch (Betula pubescens spp. czerepanovii), and (2) to test the stability of the relationships between biomass and biophysical tree properties across geographical regions and tree size ranges. The models were developed using a mixed modelling approach accounting for the hierarchical structure of the data that originated from sample plots. Diameter at breast height, tree height, and the ratio between height and diameter were candidate explanatory variables, but only diameter was statistically significant (p0.05). The model fit values (pseudo-R 2) were 0.91, 0.60 and 0.85 for the three respective models. A substantial part of the model random errors could be attributed to between-plot variations. The conclusion related to objective (1) was that the models are well suited for biomass prediction of mountain birch in the mountain areas of southern Norway. Furthermore, models reported in previous research that had been calibrated on data from other regions were applied on the current data set. The results indicate that models calibrated for small trees produced predictions diverging from the observed values of the current data set. The differences between predicted and observed values also seem to vary along a site productivity gradient. Still, even though the differences between predicted and observed values using the different models varied quite a lot, the relationships were relatively stable within certain limits. The conclusion related to objective (2) was that biomass models can be applied outside the region for which they were developed, which in many cases is necessary because local models do not exist. However, the properties of the model development data related to tree size range and site productivity should be similar to those of the area for which predictions are being made.
Forfattere
Per Otto Flæte Olav HøibøSammendrag
Variation in heartwood diameter (HWD) along the stem was studied in 106 mature Scots pines (Pinus sylvestris L.) sampled from southern Norway. HWD decreased from the base towards the treetop, following a profile similar to that of the stem diameter (shape of the tree). A few trees deviated from this general pattern. In these trees HWD increased from the base of the stem to a maximum at 2-2.5 m and then decreased towards the top of the tree. Random coefficient mixed models based on a second-degree polynomial of vertical position in the tree and tree variables that can be measured in the forest were developed to predict HWD profiles of pine stems. Seven different models were developed in steps, based on how easily the input variables can be measured. Input variables consisted of information describing the size and shape of trees and information from increment cores. Performances of the models were validated with an independent sample (R-2 = 0.88-0.95, root mean square error = 12-19 mm). The high predictive abilities of the models indicate that they can be prospective tools for selecting trees and stem sections within trees to produce logs with HWD suitable for manufacturing of heartwood sawn-wood products.
Forfattere
alena gibalovaSammendrag
I dag regner vi potet, tomat, kålrot og agurk som tradisjonelle norske grønnsaker. Men i sin tid var de også fremmedelementer, som ikke uten videre ble godtatt i norsk matkultur. Nå prøver flere produsenter å dyrke asiatiske bladgrønnsaker. Framtida bestemmer forbrukerne.
Forfattere
Nadeem Yaqoob Carl Gunnar Fossdal Jan Karlsson Benedicte Riber Albrectsen Halvor SolheimSammendrag
Due to the great economic losses caused by the root and butt-rot pathogen Heterobasidion annosum, development of efficient control measures is warranted. H. annosum a necrotroph colonize the Norway spruce from inside and is responsible for 100s of millions of Euros losses annually. Considerable clonal variation has been recorded for Norway spruce in resistance towards H. annosum, but the defence mechanisms contributing to host resistance against both necrotrophic and biotrophic fungi remain poorly understood. The recent genome sequencing of Populus has made the genus a model to facilitate tree genetics. Genome-wide transcript profiling of Populus tremula upon pathogen attack will now be used, and homologues of Norway spruce genes to defence genes up-regulated in Populus will be identified. Two aspen clones (23 and 72) from the SwAsp collection (Luquez 2007) were used in the present study. Plants were propagated from tissue culture and kept in greenhouse under un-manipulated conditions. To study the host defence mechanisms, the rust (Melampsora magnusiana Wagner) and a bluestain fungus were used as a biotrophic and necrotrophic fungus respectively. Melampsora spores solution was applied to the underside of the leaf. To control for sectoriality six leaves were infected on each plant. To ensure high humidity and avoid cross contamination, plastic bags were wrapped around infected leaves. Leaves above infected leaves (10, 9, and 8) were harvested respectively 1, 3 and 14 days after inoculation. Initial results from microarray data indicate a clear separation between two Aspen clone (23 and 72) lines. For line 23 the response to biotroph and necrotroph seems to be similar. Whereas the response for line 72 is divergent for the treatments as they go in opposite direction. The controls show that there is an initial difference in the 2 lines (controls are separated). What are the genes that make biotrohic and necrotrophic treatment of 72 look so different will be worked out from microarray data. Differential expression of defense genes in biotrohic and necrotrophic treatment will be verified further with quantitative real time PCR. Chemical analysis of Aspen leaves gave less phenolic compounds as plants were kept in greenhouse. HPLC will be carried out after reaching some conclusion from microarray data analysis.
Sammendrag
Finska viken är en av Östersjöns mest eutrofierade bassänger. Vid sidan om betydelsen av fem-miljoners staden St Petersburg har lantbrukets andel varit oklar. Ett nytt svenskt-ryskt flerårigt samarbete har inletts i Leningrads län för att bland annat bygga ett nätverk av monitoringstationer. Dessa stationer ska ge underlag för bättre källfördelning men även för råd om motåtgärder mot övergödningen av Finska viken och Östersjön.
Forfattere
Arno Rein Ulrich Gosewinkel Karlson Carl Einar Amundsen Stefan TrappSammendrag
Arno Rein (1)(*), Ulrich Gosewinkel Karlson (2), Carl Einar Amundsen (3), Stefan Trapp (1)(1) Department of Environmental Engineering, Technical University of Denmark(2) Department of Environmental Chemistry and Microbiology, National Environmental Research Institute, University of Aarhus, Denmark(3) Bioforsk-Norwegian Institute for Agricultural and Environmental ResearchÅs, Norway(*) arnr@env.dtu.dkTree core sampling provides a new rapid, inexpensive and low-invasive alternative to investigate the extent and temporal development of subsurface contaminations (Trapp et al. 2008). Considering each tree as a combination of well, pump and passive sampler, the analysis of vegetation samples can deliver information on the occurrence of subsurface pollution. This method was repeatedly and successfully applied to delineate subsurface plumes of chlorinated solvents (Larsen et al. 2008). Two persons can sample up to 100 trees per day, and the only necessary equipment is an increment borer and vessels for the samples. At the former waste dumping site Møringa, located at the Oslofjord near Horten, Norway, tree core sampling was done in order to test the methodology for finding heavy metal subsurface pollution. Different tree species were sampled, and the results obtained by ICP analyses were compared to element concentrations (As, Cd, Cr, Cu, Ni, Pb, Zn) in soil obtained from detailed site investigations prior to the tree core sampling campaign (Amundsen et al. 2005). If all tree species were considered together, the correlation between concentrations in tree cores and soil samples was positive, but not significant for any metal. However, samples taken from willow trees (Salix caprea) showed high and significant correlation for arsenic, cadmium and chromium. Furthermore, there was a significant difference in the mean contents (t-test) in wood from the polluted site compared to wood from reference sites. Investigations will continue at the Møringa site and at Danish sites contaminated with heavy metals. The goal is to obtain a rapid but reliable method for screening and monitoring of contaminated sites for subsurface pollution. Amundsen CE, French H, Aasen R, Nordal O. 2005. Supplementary investigations at Møringa waste site, Horten. Risk assessment and remedial action plans (in Norwegian). Jordforsk-report. 19/05. Bioforsk, 1432 Aas, Norway. Larsen M, Burken J, Macháčková J, Karlson UG, Trapp S. 2008. Using tree core samples to monitor natural attenuation and plume distribution after a PCE spill. Environ. Sci. Technol. 42, 1711-1717.Trapp S, Larsen M, Legind CN, Burken J, Macháčková J, Gosewinkel Karlson U. 2008. A guide to vegetation sampling for screening of subsurface pollution. Available at http://homepage.env.dtu.dk/stt/GuidetoVegetationSampling.pdf
Sammendrag
Food quality labels linked to landscape, climate and geographical origin are favorable tools for rural development. Our project will link the benefits of farm animals grazing on mountain pasture to quality of local artisan food products. Then the French word "terroir" meaning the sense of place and defined as the impact of the soil, the climatic condition and the vegetation on the products could be used in marketing. Today"s consumers are looking for more than nutrition from their food; it should contribute to their health, they are looking for enjoyment, and they require a high ethical standard in the food production. Unsaturated fatty acids and antioxidants like carotenoids and polyphenols are considered important nutraceuticals according to many health benefits.These compounds are also used in traceability of animal feeding diet in the meat and milk products. Plant biomarkers are compounds that are not synthesized by animals, but occur in the food products due to the animals diet. Carotenoids and polyphenols are examples of such direct plant biomarkers, while fatty acids are metabolic markers deriving from animal metabolism and are called indirect markers. The objectives of the project are to document "terroir-effects" and high food quality that may give added values to the products and a better price in the market.The study is carried out in two representative summer-farming areas in Central Norway. Two summer-farms in Budalen (Forollhogna and Teijavollen) and one in Østerdalen (Gjermundshaug) participated in the study. Subalpine/alpine pastures are the main fodder source in the summer farming period, but all farmers use supplementary feeding consisting of concentrates in different quantities (3 kg - 7.5 kg per day). The analyzed local food was sour creams produced at the summer farms by the farmers. The reference product was an industrially produced (TINE) sour cream, based on different types of pastures, mostly high productive species, less species rich lowland pastures or silage and supplementary feeding by concentrates. In the last week before milk samples (for production of the test products) were taken in middle of August, herbs and grass samples from pastures belonging to the different summer farms were collected. The plants were frozen (dry ice) and transported together with samples of sour cream from each summer farm to the laboratory. Sour creams were analysed for composition and content of a range of fatty acids, carotenoids and content of total polyphenols. In addition a sensory preferencetest of the three summer-farm sour creams together with that from TINE was performed.Results showed that sour cream from mountain pastures in Teijavollen and Forollhogna has the same amount of a-linolenic acid (C18:3) in the pasture, 56.7 and 56.0 %, respectively. The sour cream from Forollhogna has significantly more of the healthy polyunsaturated fatty acid (C18:3) even if tless water content is taken into account. Probably these results could be explained by differences in metabolism in the two herds (low yielding Norwegian dairy breed versus the modern, moderate yielding dairy breed Norwegian Red (NRF), but also by differences in use of supplementary feeding of concentrates. Only small amounts of CLA are generally found in the pasture while sour cream from Forollhogna has nearly the double amount as the industrial produced sour cream from Tine. The amounts of polyphenols and carotenoids in sour cream and pastures from the mountains were also compared. The more polyphenols and carotenoids in the grazing areas the more were found in the sour creams. Two mountain sour creams and Tine factory sour cream were analysed in a sensory ranking test. No significant differences (P