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.
2016
Sammendrag
Norsk institutt for bioøkonomi (NIBIO) utførte sommeren 2016 en vegetasjonkartlegging basert på en enkel befaring i et beiteområde for sau i Lierne i Nord-Trøndelag. Området er inngjerdet med sekstråds strømgjerde for å tilfredstille krav om å være rovdyrsikkert. Målet med befaringa var å få oversikt over de ulike naturtypene og å estimere beitekapasiet i det avgrensede beiteområde. Det inngjerdete beiteområdet ved Nesset er på 3 205 dekar og består av ulike vegetasjonstyper og ulike hogstklasser av granskog med dertil ulik beitekvalitet for sau. Ut fra øvre tilrådelige antall sau per arealenhet på de forskjellige beitekvalitetene (tabell 1) og arealfordelingen av beitekvalitetskategorier i området (tabell 2) er øvre tilrådelige dyretall beregnet til å være 196 sau (søyer og lam).
Sammendrag
Rapporten gir en beskrivelse viktige naturtyper på Bliksvær i Bodø kommune samt en beskrivelse av det nyopprettede beiteområdet sør på øya. Skjøtselsplandelen tar utgangspunkt i nåværende drift. Anbefalte skjøtsels- og restaureringstiltak er beite med sau, fortrinnsvis på sommerhalvåret, sviing av kystlynghei, ferning av einer og rydding og tynning av bjørkekrattskog.
Sammendrag
Rapporten gir en beskrivelse av flere øyer på østsiden av Blomsøya i Alstahaug kommune som brukes til beite med gammelnorsk sau. På Trettøya og Langøyan er det kartlagt flere naturbaselokaliteter som kystlynghei, strandeng og strandsump. Skjøtselsplandelen tar utgangspunktet i nåværende drift. Anbefalte skjøtselstiltak er beite med GNS, sviing og fjerning av tistel.
Sammendrag
Rapporten gir en beskrivelse av inn- og utmarksarealene i Muddvær i Vega kommune på Nordlandskysten. Innmarka finnes på hovedøya Heimlandet og er i dårlig forfatning pga. erosjon og ugrasdominans som følge av våndangrep over flere år. Utmarksøyene består hovedsakelig av fattige utforminger av kystlynghei. Kystlyngheiarealer har blitt registrert og innmeldt til Naturbase. Eneste skjøtselsform per i dag er sporadisk slått på Heimlandet. Skjøtselsplanen anbefaler tiltak mot vånd og forebygging av erosjon samt innsåing og varig eng-etablering på Heimlandet. For kystlyngheiarealene i utmarka anbefales det lyngsviing.
Sammendrag
Rapporten gir en beskrivelse av inn- og utmarksarealene på øyan Skjærvær i Vega kommune på Nordlandskysten. De siste årene har større og større del av den opprinnelige slåttemarka blitt restaurert. Det ble kartlagt to naturbaselokaliteter, en slåttemark og et rikt strandberg. Skjøtselspnadelen tar utgangspunkt i dagens drift. Anbefalte skjøtselstiltak er slått av slåttemarkslokaliteten med supplerende restaureringsslått i fremdeles mjødurtdominerte partier.
Forfattere
Tomasz Leszek Woznicki Anita Sønsteby Kjersti Aaby Berit Karoline Martinsen Ola M. Heide Anne-Berit Wold Siv Fagertun RembergSammendrag
BACKGROUND Marked effects of the climatic environment on fruit chemical composition have often been demonstrated in field experiments. However, complex covariations of several climatic factors in the natural environment complicate the interpretation of such experiments and the identification of the causal factors. This can be better achieved in a phytotron where the various climatic factors can be varied systematically. Therefore, we grew four black currant cultivars of contrasting origin in a phytotron under controlled post-flowering temperature and photoperiod conditions and analysed the berries for their ascorbic acid, sugar and organic acid contents. RESULTS The analyses revealed significant effects of genotype on all investigated compounds. Particularly large cultivar differences were observed in the concentrations of l-ascorbic acid (AA) and sucrose. The concentrations of both AA and dehydroascorbic acid (DHAA), as well as the concentrations of all major sugars, decreased consistently with an increasing temperature over the temperature range 12–24 °C. Fructose and glucose were the predominant sugars with concentrations several fold higher than that for sucrose. AA was the main contributor to the total ascorbate pool in black currant berries. The AA/DHAA ratio varied from 5.6 to 10.3 among the studied cultivars. The concentration of citric acid, which was the predominant organic acid in black currant berries, increased with an increasing temperature, whereas the opposite trend was observed for malic and shikimic acid. Quninic acid was always present at relatively low concentrations. By contrast, photoperiod had no significant effect on berry content of any of the investigated compounds. CONCLUSION It is concluded that the post-flowering temperature has marked effects on the concentration of important chemical compounds responsible for taste and nutritional value of black currant berries, whereas photoperiod has no such effect in the studied cultivars. © 2016 Society of Chemical Industry
Sammendrag
The effect of fertility status and temperature conditions during floral induction on flowering, berry yield,and weight and drupelet numbers of individual berries were studied in ‘Glen Ample’ raspberries grownunder controlled conditions. Withdrawal of normal fertilization prior to and at various stages duringfloral induction did not affect yield and berry size, but marginally advanced flowering and fruit ripening.The successive stages of floral initiation and differentiation were studied and identified by scanning elec-tron microscopy of the uppermost lateral buds of plants grown for six weeks under naturally decreasingautumn photoperiods at temperatures of 9, 15 and 21◦C. Low temperature advanced floral initiation, andadvanced and enhanced flowering and berry yield in the following season. However, at variance fromearlier studies, the plants eventually initiated flower primordia even at 21◦C. Marginal low temperatureand short day conditions during the last days before the temperature treatments were started on 17September might possibly have reduced the subsequent induction requirements enough to explain thisunexpected result. Correlation analyses revealed an over-all positive correlation between fruit weightand drupelet numbers (r = 0.568, P = 0.01). In berries from the early harvests, the number of drupelets perberry increased with decreasing temperature, while the numbers converged to the same level regardlessof temperature in the later harvests. Based on the progress of the floral initiation process at the vari-ous temperatures, we interpret this to mean that only the early initiated flowers, that gave rise to theearly maturing berries, were differentiated during the actual period of controlled temperature exposure,whereas the remaining flowers were differentiated afterwards when all plants were exposed to identicallow temperature conditions. Increased femaleness under optimal floral induction conditions is in agree-ment with results in both monoecious and dioecious plants and circumstantial evidence suggest that,in the raspberry, this might be mediated by changes in gibberellin activity which acts as a male sexualhormone in plants and is known to inhibit growth cessation and floral initiation in raspberry.
Sammendrag
Berry yield and chemical composition of four commercial black currant cultivars were recorded in a field experiment in Norway over an 8-year period and related by linear regression analysis to temperature and precipitation conditions prevailing during the May-July preharvest period. Highly significant differences between cultivars and among years were found for all measured parameters. Fruit dry matter, soluble solids and pH were positively correlated with temperature and negatively correlated with precipitation during May-July, while yield, berry weight, and the concentration of total phenols and ascorbic acid showed the opposite relationship, being highly negatively correlated with temperature and positively correlated with precipitation. Similar black currant experiments elsewhere in Europe have often given deviating results, varying from opposite to no effects of the same weather variables, suggesting that fruit composition is influenced by several interacting genetic and environmental parameters. We conclude that differences in local weather and soil conditions and the use of different cultivars complicate direct comparison of such field experiments. Nevertheless, the observed strong and opposite correlations with precipitation and temperature suggest an inherently low drought tolerance of black currant plants.
Forfattere
Tomasz Leszek Woznicki Kjersti Aaby Anita Sønsteby Ola M. Heide Anne-Berit Wold Siv Fagertun RembergSammendrag
The effects of postflowering temperature and daylength on the concentration of individual phenolic compounds were studied in black currant (Ribes nigrum L.) berries under controlled phytotron conditions. The four cultivars studied varied greatly in their concentrations of individual phenolic compounds and temperature stability for accumulation. The concentrations of a wide range of identified phenolic compounds were strongly influenced by temperature over the 12–24 °C range, often with opposite temperature gradient patterns for compounds within the same subclass. Accumulation of anthocyanins and flavonols increased under natural long day conditions, which provided an increased daily light integral, while under identical light energy conditions, photoperiod had little or no effect on the concentration of phenolic compounds. Furthermore, with the exception of members of the hydroxycinnamic acid subclass, the concentration of most phenolic compounds was higher in berries ripened outdoors than in the phytotron, apparently due to screening of UV-B radiation by the glass cover.
Sammendrag
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