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.
2008
Forfattere
Håvard Steinshamn Mats Høglind Øystein Havrevoll Kristin Saarem Inger Helene Lombnæs Asgeir SvendsenSammendrag
Målet med arbeidet var å granske effekten av fjellbeite på vekst og kjøttkvalitet hos ammekalvar. Ammekalvar med sine mødre gikk anten på innmarksbeite (I) ved garden eller på fjell-/skogsbeite (F) på fire (2006) og fem (2007) gardar. F-beita var ulike vegtasjonstypar frå opne, grasdominerte områder til skog med gras, urter og busker. Alle kalvane vart slakta rett etter beitesesongen då dei var i gjennomsnitt 203 (2006) og 193 (2007) dagar gamle. I gjennomsnitt var det ingen effekt av beitetype på produkskjon bortsett frå at slakta frå F vart klassifisert som feitare enn dei som kom frå I. I 2006 var den daglege tilveksten og slaktevekta signifikant høgare hos kalvane i frå I, medan det motsatte resultatet vart funne i 2007. Kjemiske analysar er ferdig berre for 2006. Totalt feittinnhald i ytrefileten var signifikant høgare hos kalvane på M (12 vs 14 g/kg, P < 0.05). Det var elles ingen skilnad mellom forsøksledda i kjøttkvalitet.
Sammendrag
Twenty-one species of green algae isolated from marine, freshwater and terrestrial environments were screened for the ability to produce H2 under anaerobic conditions. Seven strains found positive for H2 production under anaerobic conditions were also screened for the ability to produce H2 under sulfur (S) deprivation. In addition to the traditional model species Chlamydomonas reinhardtii, C. noctigama (freshwater) and C. euryale (brackish water) were able to produce significant amounts of H2 under S-deprivation. These species were also able to utilize acetate as a substrate for growth in light. The S-deprivation experiments were performed under photoheterotrophic conditions in a purpose-specific designed bioreactor, and it was shown that an automated pH adjustment feature was essential to maintain a stable pH in the cultures. Several materials commonly used in bioreactors, such as rubber materials, plastics and steel alloys, had a negative effect on the survival of S-deprived algae cultures. Unexpectedly, traces of H2 were produced under S-deprivation during O2 saturation in the cultures, possibly derived from local anaerobic environments formed in algal biofilms on the membranes covering the O2 electrodes.
Sammendrag
1. Results for Cornell University, New York: The optimal pH for velvet bentgrass was around 5.0, but velvet bentgrass was not sufficiently wear tolerant at an annual input of only 0.75 kg N/100m2/yr 2. Report from Rutgers University, New Jersey: The recuperative potential of velvet bentgrass is considered poor, but our findings have shown that the wear tolerance of velvet bentgrass is just as high as for creeping bentgrass and that the high density of velvet bentgrass will restrict Poa annua encroachment under trafficked conditions 3. Bosch & Mitowski 2006 Master thesis, University of Rhode Island : - Greenwich provides better turf quality than Avalon - More than 2.0 kg N/100 m2/ yr necessary to produce acceptable quality of on USGA greens - Around 3.0 kg N/100 m2/ yr may be necessary to produce acceptable quality on straight sand greens in regions with 6-7 months growing period". However, lower N-rates may be acceptable with the use of iron, especially at high pH. - Topdressing and vertical mowing had little effect in this 2 yr study, but in general, velvet bentgrass greens seems to need vertically mowing and topdressing at least one a month to avoid soft and "puffy" greens Statement: "The common perception that velvet bentgrass is a low maintenance species may not always be true, at least not on sandy greens". 4. Irrigation research, Rutgers University, New Jersey: The water consumption increased in the order velvet bent
Forfattere
Trygve S. AamlidSammendrag
Konklusjoner: 1. Grasplanten er bygd opp av ulike typer overjordiske lysskudd, underjordiske utløperskudd og røtter. 2. Når graset klippes, klipper vi alltid vekk den eldste delen av planta. Vekstpunktet holder seg normalt ved jordoverflata. 3. Under uheldige forhold (for eksempel ved mangel på lys) kan vekstpunktet strekke seg. Dersom vi klipper bort vekstpunktet, dør skuddet og grasmatta blir tynnere. 4. Engrapp og noen andre grasarter danner rhizomer (utløpere) og har dermed større reperasjonsevne. Andre arter, bl.a. raigras, danner tuer. 5. Grasplanter har et grunt rotsystem. Lav klipping, mangel på luft i jorda, lite lys og høy temperatur fører til dårlig rotsystem og lite slitesterke grasmatter. Komprimert sandjord kan hindre røtter og utløpere i å bre seg. 6. De viktigste artene på fotballbaner er tunrapp, engrapp, raigras, og rødsvingel. 7. Tunrapp prøver vi å unngå ved riktige skjøtselstiltak. 8. Både raigras og engrapp har klare fordeler, men også ulemper. - Raigrasets fordel framfor engrapp er raskere etablering og bedre slitasjetoleranse. - Engrappens fordel framfor raigras er bedre reperasjonsevne og bedre overvintringsevne 9. Rødsvingelsorter uten utløpere eller med korte utløpere kan blandes inn med inntil 30% i engrappblandinger. Dette gir større tetthet og går ikke ut over slitestyrken. Særlig viktig er dette for fotballbaner som ikke alltid får optimalt stell m.h.t. vatning og gjødsling.
Sammendrag
Most fungicide applications targeting apple scab aim to control primary infections caused by ascospores and spraying is thereby linked to ascospore availability. We investigated the effect of pre bud break climatic conditions on seasonal patterns of ascospore release. Apple leaves bearing pseudothecia of Venturia inaequalis were overwintered at orchard sites in 8 countries for up to 3 years. Leaf samples were collected 2 to 5 weeks before bud break and again at bud break, air dried, and sent via airmail to Norway. The samples were stored at -18 ºC upon arrival until tested. Disks cut from each replicate leaf sample were incubated moist at 20 ºC to allow ascospore maturation but prevent discharge. Matured ascospores were induced to discharge twice a week and enumerated until the supply was exhausted. The proportion of ascospores ejected was fitted against degree day accumulation using logistic regression. The regression intercept (onset maturation), slope (maturation rate), as well as the absolute number of spores counted differed significantly (P < 0.001, P = 0.05, P < 0.001 respectively) among sites and sampling dates. There was a significant interaction between site and sampling date, indicating that climatic conditions prior to bud break differentially impacted the subsequent ascospore availability. Observed differences could perhaps be used to further refine previously described models of ascospore maturity.
Sammendrag
In Central-Norway, Anthriscus sylvestris, Deschamspia cespitosa and Alnus incana are well known re-growth species in abandoned areas. They often dominate abandoned areas and reduce the species biodiversity. Objectives of these field-studies were to find proper management strategies that reduce the plant cover of A. sylvestris, D. cespitosa and A. incana in semi-natural grasslands and thereby conserve or increase the biodiversity. In road-verges dominated by A. sylvestris management studies by different mowing strategies was recorded during four years. The response of D. cespitosa, A. sylvestris and A. incana to four different grazing regimes was investigated in abandoned grasslands for four years. Results from the field studies show that areas dominated by these species request specific, extraordinary, intensive and long-term management strategies.
Sammendrag
Plant polyphenolics continue to be the focus of attention with regard to their putative impact on human health. An increasing and ageing human population means that the focus on nutrition and nutritional enhancement, or optimization of our foodstuffs, is paramount. Using raspberry as a model we have shown how modern metabolic profiling approaches can be used to identify the changes in the level of beneficial polyphenolics in fruit breeding segregating populations and how the level of these components are to what degree these are determined by genetic and/or environmental control. Interestingly, the Vitamin C content appeared to be significantly influenced by environment (growth conditions) whilst the content of the polyphenols such as cyanidin, pelargonidin and quercetin glycosides appeared to much more tightly regulated suggesting a rigorous genetic control. Preliminary metabolic profiling showed that the fruit polyphenolic profiles divided into two gross groups segregating on the basis of relative levels of cyanidin-3-sophoroside and cyaniding-3-rutinoside, compounds implicated as conferring human health benefits.
Forfattere
Anne Kari Bergjord Helge Bonesmo Arne Oddvar SkjelvågSammendrag
En canadisk model som simulerer utvikling av frost-toleranse i høsthvete under kontinental-klimatiske forhold ble videreutviklet for bruk i områder med et mer kystbasert klima. Forsøk med to sorter av høsthvete ble gjennomført i Midt-Norge gjennom to vintersesonger. Alle plantene ble herdet ved samme lokalitet, men etter herding, i midten av november, ble de distribuert til tre forskjellige lokaliteter med ulike vinter klima. Planter ble tatt inn fra felt til ulike tider gjennom høsten og vinteren og testet for frost-toleranse, uttrykt som LT50 (den temperaturen der 50 % av plantene ble drept). Resultater fra forsøkene ble brukt til å parameterisere og validere den nye modellen, kalt FROSTOL, som simulerer daglig utvikling av LT50 fra såing og utover gjennom vinteren. Frost-toleransen øker ved herding og reduseres ved avherding og stress, der stress forårsakes enten av lave temperaturer, eller av forhold med mer eller mindre telefri jord som er dekket med snø. Alle funksjonene i modellen styres av jordtemperatur i 2 cm dybde. En av funksjonene påvirkes i tillegg av snødybde, og to funksjoner av plantenes vernaliserings-status. De i alt fem koeffisientene tilhørende fire ulike funksjoner gav god korrelasjon mellom registrerte og simulerte LT50-verdier. En kryssvalidering av modellen indikerte at parameternes følsomhet i forhold til variasjoner i vintervær var tilfredsstillende liten.
Sammendrag
Carbon from complex and structural plant molecules has long been considered more efficiently retained in soils than that of soluble molecules. This dominant paradigm is now being challenged by data emerging from recent isotopic-labeling and compoundspecific isotopic studies. We recently demonstrated that large proportions of plantresidue lignin decompose within a year of incorporation to soils, and that soilextracted lignin has a turnover time of about 20 years (Rasse et al, 2006). In contrast, turnover time of soil-extracted polysaccharides can reach 40 years (Gleixner et al., 2002). Long-term incubation studies have shown that C from labeled glucose is better conserved in certain soil types than C from more complex molecules such as cellulose (e.g. Vinten et al, 2002). These studies suggest that the initial decomposability of plant molecules has limited impact on the long-term fate of their constitutive C in soils. Here we will present a new model where soluble molecules have a competitive advantage over structural molecules for the long-term preservation of their constitutive C in soils. Implementation of compound-specific data in quantitative soil models will also be discussed.
Forfattere
Stein Rune Karlsen Anne Tolvanen Eero Kubin Jarmo Poikolainen Kjell Arild Høgda Bernt Johansen Fiona S. Danks Paul Eric Aspholm Frans Emil Wielgolaski Olga MakarovaSammendrag
Northern Fennoscandia is an ecologically heterogeneous region in the arctic/alpine-boreal transition area. Phenology data on birch from 13 stations and 16-day MODIS-NDVI composite satellite data with 250 m resolution for the period 2000 to 2006 were used to map the growing season. A new combined pixel-specific NDVI threshold and decision rule-based mapping method was developed to determine the onset and end of the growing season. A moderately high correlation was found between NDVI data and birch phenology data. The earliest onset of the growing season is found in the narrow strip of lowland between the mountains and the sea along the coast of northern Norway. The onset follows a clear gradient from lowland to mountain corresponding to the decreasing temperature gradient. In autumn, the yellowing of the vegetation shows a more heterogeneous pattern. The length of the growing season is between 100 and 130 days in 55% of the study area.