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.
2013
Forfattere
Liv Østrem Birger Volden Arild LarsenSammendrag
The potential of ×Festulolium as a forage species for Nordic conditions was investigated by comparing Norwegian candivars (LpFp-T, LmFp-T, LpFp-D-N, LpFp-D-UK) differing in parental origin and ploidy level with commercial cultivars of ×Festulolium (Hykor, Felopa), the parental species perennial ryegrass (Lolium perenne L.) and meadow fescue (Festuca pratensis L.), and timothy (Phleum pratense L.). Plant development was observed as leaf:stem ratio and standardised development stage, and dry matter yield and digestibility were studied throughout two consecutive harvest seasons (2007 and 2008) as an effect of taking the first cut at four maturity stages, namely: 1) vegetative growth, 2) early heading), 3) heading and 4) anthesis, and then consecutive cuts throughout the season. Observations were made at two locations in Norway (61°N, 67°N). Leaf:stem ratio and standardised development stage were affected by maturity stage, and the loloid types of ×Festulolium (Felopa and the candivars) grouped between the parental species as to developmental pattern. The most extreme changes across maturity stages 1-4 in first cut were seen in the festucoid type Hykor (smallest) and in timothy (largest). Across maturity stages 2 and 3, for two years Hykor obtained higher dry matter yield than the other entries, but overall digestible dry matter yield was equal in Hykor and LpFp-T due to the better digestibility in LpFp-T. The lower dry matter yield obtained in ×Festulolium Felopa, the diploid candivars and LmFp-T was mainly due to winter damages. Consistency was found between the locations for the entries investigated. For Nordic growing conditions, in which winter hardiness is required for commercial cultivars, the amphitetraploid breeding approach of perennial ryegrass and meadow fescue should be pursued. It is the parental origin of the candivar LpFp-T, which was comparable to Hykor, the best of the commercial ×Festulolium cultivars, and performed better than the cultivars of the parental species.
Forfattere
Steffen Adler Annette Veberg Dahl Søren Krogh Jensen Erling Thuen Anne-Maj Gustavsson Håvard SteinshamnSammendrag
Previous research has shown that grazing pastures compared to feeding preserved forages has large impact on milk fatty acid (FA) composition, but differences between grazing red clover (Trifolium pratense L.) or white clover (Trifolium repens L.) are small, whereas the herbage proportions of dicotyledon botanical families is positively correlated with the milk-fat proportions of total polyunsaturated FA when grazing pastures in the Alps. The objective of the present study was to investigate the influence of botanically different pastures on bovine milk composition and milk susceptibility to oxidation. Two groups of 8 multiparous Norwegian Red dairy cows [mean (standard deviation); 599 (45.1)kg body weight, 73 (15.0)d in milk, 29.9 (2.90)kg milk/d at experiment start] grazed either a short-term pasture (SP) or a long-term pasture (LP). Both pastures were organically managed, meaning that no artificial fertilizers or herbicides were applied. The SP was representative for pastures, which are frequently, i.e. at least every third year, renewed by soil tillage and seeding, whereas LP was representative for pastures, which are less frequently renewed. The SP contained mainly meadow fescue (Festuca pratensis Huds.), timothy (Phleum pratense L.) and red clover and LP contained smooth meadow grass (Poa pratensis L.), white clover and a variety of unsown species. Sixteen cows were blocked according to milk yield, days in milk and sire, and randomly within block allocated to the 2 dietary treatments with a daily pasture allowance of 15–20kg dry matter per cow, supplemented with 3.0kg barley (Hordeum vulgare L.) concentrate. Milk was sampled during the last week of 3 experimental periods and analysed for FA composition by gas chromatography, concentrations of fat-soluble vitamins by high performance liquid chromatography, and oxidative stability in a light-exposure experiment by measuring the formation of hydroperoxides and by front-face fluorescence spectroscopy. Pasture type had no effect on milk yield, milk gross composition, and only minor effects on milk FA composition. Milk from SP had higher concentration of α-tocopherol than LP. The formation of hydroperoxides in milk was lower for SP than LP after 24h light exposure, but no differences were found after 48h. Front-face fluorescence spectroscopy revealed slightly higher formation of components in the area of 409–480nm wavelength for SP than LP, which may be related to milk-lipid oxidation. The experimental pastures differed mainly in herbage proportions of red clover and white clover and less in proportions of non-legume dicotyledons. This explains small differences in milk FA composition and milk susceptibility to oxidation.
Forfattere
Rajko Vidrih Branka Mozetic Vodopivec Janez Hribar Anja Mahne Opatic Eivind VangdalSammendrag
Plums varieties Jubileum, Excalibur and Reeves were harvested at commercial harvest date. After harvest fruits were dipped in hot water (56 °C) for 2 minutes then they were cooled down in cool water. Fruits were stored for 4 weeks in normal atmosphere (NA) and modified atmosphere (MAP) in xtend packaging film. In equilibrium state,modified atmosphere consisted of 10 % of O2 and 10 % of CO2. Excalibur contained the highest amount of total phenols, followed by Jubileum and Revees, while Jubileum had the highest antioxidative potential (AOP) followed by Excalibur and Revees. Significantly more total phenols was found at second week of storage followed by forth week and after harvest. On the other hand, Revees contained significantly more flavonoids, followed by Excalibur and Jubileum. The highest antioxidative potential was found immediately after harvest followed by that of 4 weeks storage and finally that of 2 weeks storage time. Significantly more flavonoids were found at the beginning of storage and least at the end of storage. Plums stored in modified atmosphere had the highest AOP, followed by NA, MAP hot water (HW) treated and NA hot water treated fruits. With regard to storage conditions, more flavonoids were found in NA stored plums, followed by MAP HW, MAP and NAHW. Revees had the highest polar AOP followed by Jubileum and Excalibur, but no statistically significant differences were found. Also the highest polar AOP was found in forth week of storage again no statistically significant differences were found. Storage atmosphere gave no statistically significant differences in polar AOP. Results showed that storage conditions influence the AOP, total phenols and flavonoids. Flavonoids are more abundant after harvest, total phenols in the middle of storage period. Hot water treatment is becoming popular because might be used for organically grown fruits and vegetables. In our experiment hot water treatment showed e tendency to decrease AOP, flavonoids and polar AOP but significantly decreases total phenols.
Sammendrag
There is a need for monitoring methods for forest volume, biomass and carbon based on satellite remote sensing. In the present study we tested interferometric X-band SAR (InSAR) from the Tandem-X mission. The aim of the study was to describe how accurate volume and biomass could be estimated from InSAR height and test whether the relationships were curvilinear or not. The study area was a spruce dominated forest in southeast Norway. We selected 28 stands in which we established 192 circular sample plots of 250 m2, accurately positioned by a Differential Global Positioning System (dGPS). Plot level data on stem volume and aboveground biomass were derived from field inventory. Stem volume ranged fromzero to 596 m3/ha, and aboveground biomass up to 338 t/ha.We generated 2 Digital Surface Models (DSMs) fromInSAR processing of two co-registered, HH-polarized TanDEM-X image pairs – one ascending and one descending pair.We used a Digital TerrainModel (DTM) from airborne laser scanning (ALS) as a reference and derived a 10 m × 10 m Canopy Height Model (CHM), or InSAR height model. We assigned each plot to the nearest 10 m × 10 m InSAR height pixel. We applied a nonlinear, mixed model for the volume and biomass modeling, and from a full model we removed effects with a backward stepwise approach. InSAR heightwas proportional to volume and aboveground biomass, where a 1 m increase in InSAR height corresponded to a volume increase of 23 m3/ha and a biomass increase of 14 t/ha. Root Mean Square Error (RMSE) values were 43–44% at the plot level and 19–20% at the stand level.
Sammendrag
De senere år har det blitt større oppmerksomhet rundt behovet for å redusere risikoen knyttet til tap av plantevernmidler fra punktkilder. Hovedmålet for prosjektet var å klarlegge behov og mulige metoder for å redusere forurensning fra punktkilder knyttet til bruk av plantevernmidler på norske gårdsbruk. Dette er søkt oppnådd ved en kartlegging av mulig forurensning fra punktkilder gjennom en spørreundersøkelse for å klarlegge bøndenes holdninger til problemstillingen, risikovurdering av forurensningen knyttet til aktuelle punktkilder samt en vurdering av mulige tiltak. Resultatene indikerer at over 50 % av bøndene i utvalget utførere utvendig vask av sprøyteutstyr på drenert areal uten kontroll på avløpsvannet, noe som i utgangspunktet bør oppfattes som en praksis som øker risikoen for punktkildeforurensning fra plantevernmidler. Modellsimuleringer med spredning av vaskevann på vegetasjonsdekt areal viser at denne anbefalte praksisen minker risikoen for forurensning. EUs direktiv for bærekraftig bruk av plantevernmidler setter fokus på behov for spesielle forurensningsreduserende tiltak i sårbare områder. Dette kan gi behov for økt fokus på punktkildeproblematikk bl.a. i nedslagsfelt til drikkevannskilder når disse bestemmelsene implementeres i ny norsk plantevernmiddelforskrift. I slike områder kan man dra nytte av eksisterende veiledningsmateriell for utforming av biobed og biofiltre for rensing av avløpsvann også i norsk landbruk. Vi vil anbefale at problemstillingen følges opp overfor norske bønder gjennom utarbeidelse av lettfattelige veiledninger og gjennomføring av informasjonskampanjer for å øke bøndenes oppmerksomhet for problemstillinger knyttet til plantevernmidler og punktkilder. Det bør videre vurderes om det er behov for spesielle tiltak i sårbare områder (drikkevannskilder).
Sammendrag
This study combines tree-ring and charcoal data to explore possible drivers of the charcoal record and its spatial variation in a boreal Norwegian forest landscape. Peat and mineral soil samples were collected in a multiple site sampling approach and the amount of charcoal in the peat is related to fire history, Holocene climate variation, major shifts in the vegetation composition, and fuel availability. Dendrochronologic dating was used to reveal the fire history over the last 600 years with spatial and temporal accuracy, and AMS radiocarbon dating of 20 peat columns and their charcoal records from four peatlands was used to elucidate the fire history over the Holocene. The average amount of charcoal was about 2.5 times higher in the mineral soil than in the peat (270 versus 100 g/m², respectively), and there were considerable between- and within-site variations. There was no relationship between the age of a given peatland and its content of charcoal, nor between the amount of charcoal in a given peatland and in the neighboring mineral soil. Although most of the charcoal mass in the peatlands was found in parts of the peat columns originating from relatively warm climatic periods and from the period before the local establishment of Norway spruce (Picea abies), charcoal accumulation rates (per 1000 yr) were higher during cold climatic periods and similar before and after spruce establishment. Recent fires showed up to a low degree in the peat columns. On fine spatial scales (1–10 m), fuel quality and distribution together with fire behaviour throughout millennia are likely to be responsible for variations in the charcoal record. On the landscape scale (100–1000 m), the charcoal records were site-specifically idiosyncratic, presumably due to topography, distribution of fire breaks and fuel types, and human land use, coupled with long-term variations inherent in these factors.
Sammendrag
Nano-sized zero valent iron (nZVI) has been studied for in situ remediation of contaminated soil and ground water. However, little is known about its effects on organisms in soil and aquatic ecosystems. In this study, the effect of nZVI on degradation of DDT and its ecotoxicological effects on collembola (Folsomia candida) and ostracods (Heterocypris incongruens) were investigated. Two soils were used in suspension incubation experiments lasting for 7 and 30 d; a spiked (20 mg DDT kg−1) sandy soil and an aged (>50 years) DDT-polluted soil (24 mg DDT kg−1). These were incubated with 1 or 10 g nZVI kg−1, and residual toxicity in soil and the aqueous phase tested using ecotoxicological tests with collembola or ostracods. Generally, addition of either concentration of nZVI to soil led to about 50% degradation of DDT in spiked soil at the end of 7 and 30 d incubation, while the degradation of DDT was less in aged DDT-polluted soil (24%). Severe negative effects of nZVI were observed on both test organisms after 7 d incubation, but prolonged incubation led to oxidation of nZVI which reduced its toxic effects on the tested organisms. On the other hand, DDT had significant negative effects on collembolan reproduction and ostracod development. We conclude that 1 g nZVI kg−1 was efficient for significant DDT degradation in spiked soil, while a higher concentration was necessary for treating aged pollutants in soil. The adverse effects of nZVI on tested organisms seem temporary and reduced after oxidation.
Sammendrag
Huldrestry (Usnea longissima) er en epifyttisk hengelav kategorisert som sterkt truet på Rødlista fordi det de siste 10-årene er registrert en betydelig bestandsreduksjon. I 2005-2006 gjennomførte vi undersøkelser av skogstruktur og skoghistorie i 24 huldrestrylokaliteter, i produktive granskogbestand (Picea abies) med relativt høy kubikkmasse i Saksumdalen, Lillehammer. I sju delområder ble det i 2004-2007 gjennomført hogstforsøk i form av gjennomhogst, småflatehogst eller stripehogst, der kubikkmassen ble redusert med 30 – 50 %. Ti av områdene fra 2005/06 ble undersøkt igjen i 2012, hvorav tre ikke var påvirket av forsøkshogstene. Her ble antall tråder med huldrestry på til sammen 401 trær telt på nytt for å se hvordan laven hadde utviklet seg. Rundt huldrestrytrærne ble grunnflatesum (m2/ha) målt med relaskop før og etter hogst, for å estimere tettheten av skogen og hogstuttaket. Totalt antall trær med huldrestry endret seg ikke vesentlig, mens totalt antall huldrestrytråder på trærne hadde økt med 34 % fra 2005/06 til 2012. Det var større økning i antall tråder med huldrestry på trærne som var påvirket av hogstinngrepene (ca 50 % økning) sammenlignet med de trærne som ikke var påvirket av hogst (ca 10 % økning). Det var en markert økning i mengde huldrestry der skogen var glissen (lav grunnflatesum enten naturlig eller på grunn av hogstinngrepene), mens det var uendret mengde eller litt mindre huldrestry der skogen var tett (høy grunnflatesum). Det var ikke størrelsen på hogstinngrepene i seg selv som påvirket mengden huldrestry, men derimot hvordan skogen ble seende ut etter hogsten. [...]
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Sigrun Hjalmarsdottir KværnøSammendrag
Det er ikke registrert sammendrag