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.
2022
Forfattere
Lisa M. Schüler Juline Walter Hidehiko Kato Hirono Suzuki Christopher Jonathan Hulatt Ralf Rautenberger Sofia Navalho Benjamin Schmid Joao Varela Kiron Viswanath Peter Simon Claus SchulzeSammendrag
Phototrophic microalgae use light to produce biomass and high-value compounds, such as pigments and polyunsaturated fatty acids (PUFA), for food and feed. These biomolecules can be induced by flashing light during the final growth stage. We tested different exposure times (1–6 days) of flashing light (f = 0.5, 5, 50 Hz; duty cycle = 0.05) on biomass, pigment and fatty acid productivity in Diacronema lutheri and Tetraselmis striata. A three-day exposure to low-frequency (5 Hz) flashing light successfully increased the production of fucoxanthin, diatoxanthin, eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids in D. lutheri up to 4.6-fold and of lutein, zeaxanthin and EPA in T. striata up to 1.3-fold compared to that of continuous light. Biomass productivity declined 2-fold for D. lutheri and remained similar for T. striata compared to that of continuous light. Thus, short-term treatments of flashing light may be promising for industrial algal production to increase biomass value.
Forfattere
Randi Seljåsen Barbara Kusznierewicz Agnieszka Bartoszek Jørgen A.B. Mølmann Ingunn M. VågenSammendrag
Biosynthesis of phytochemicals in leaves of Brassica can be initiated by abiotic factors. The aim of the study was to investigate elicitor treatments to add value to waste of cabbage. A leaf waste fraction from industrial trimming of head cabbage was exposed to UV radiation (250–400 nm, 59 and 99 kJ∙m−2, respectively), photosynthetic active radiation (PAR, 400–700 nm, 497 kJ∙m−2), and ultrasound in water bath (35 kHz, at 15, 30 and 61 kJ∙l−1 water), in order to improve nutraceutical concentration. UV was more effective than PAR to increase the level of flavonols (2 to 3-fold higher) and hydroxycinnamate monosaccharides (1 to 10-fold higher). PAR was three times as effective as UV to increase anthocyanins. Interaction of PAR + UV increased antioxidant activity (30%), the content of five phenolics (1.4 to 10-fold higher), and hydroxycinnamic monosaccharides (compared with PAR or UV alone). Indoles were reduced (40–52%) by UV, but the other glucosinolates (GLS) were unaffected. Ultrasound did not influence any parameters. The results are important for white cabbage by-products by demonstrating that UV + PAR can be successfully used as an effectual tool to increase important phenolics and antioxidant activity of waste fraction leaves without an adverse effect on the main GLS.
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Book of Abstracts p. 225: Perennial sow-thistle (Sonchus arvensis L.) is a problematic weed in arable crops in northern Europe. To control S. arvensis, strategies which reduce both seeds and creeping root production are essential. Inducing repeated sprouting should result in depleting root reserves and reduction in the subsequent shoot emergence. Earlier studies of S. arvensis in the northern European countries have shown a restricted sprouting ability from July/August/ September to October/November. To better understand the sprouting patterns, we conducted joint outdoor pot experiments from March 2020 until July 2021 in three northern European regions: Northern Germany, Norway, and Finland. In each pot, root pieces of 5 cm from local plant material were planted at 5cm depth. Above-ground plants were cut at the soil surface in the growing season of 2020 at 1) flower-bud stage, 2) first visible open flowers, 3) start of seed production, and 4) withering stage. Shoots were counted monthly in 2020 and 2021. In the year 2020, in Germany, sprouting, flowering, seed-set, and withering started earlier than at the other two sites. Significantly more shoots showed up at the flower-bud stage in Germany and Finland compared to Norway. In Finland, significantly more shoots were observed at the later cutting stages compared to the first counts at the flower bud stage. As a subsequent effect, fewest shoots showed up in 2021 at the German and Finnish sites after cutting at flower bud and early flowering stage. The lowest emerged shoot number in 2021 for Norway tended to occur after cutting at the flower bud stage and the start of seed production. Accordingly, cutting at the flower-bud stage decreases the ability to produce shoots in the next year. Keywords: Perennial sow-thistle, sprouting, cutting, shoots Acknowledgements: This research was part of the project “AC/DC-weeds” which is funded by ERA-Net Cofund SusCrop/EU Horizon 2020, Grant no. 771134
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The three-dimensional structure of forest canopies is essential for light use efficiency, photosynthesis and thus carbon sequestration. Therefore, high-quality characterization of canopy structure is critical to improving our carbon cycle estimates by Earth system models and better understanding disturbance impacts on carbon sequestration in forested ecosystems. In this context, a widely used observable is the Leaf Area Density (LAD) and its integral over the vertical dimension, the Leaf Area Index (LAI). A multitude of methods exists to determine LAD and LAI in a forest stand. In this contribution, we use a mature Norway spruce forest surrounding an ICOS flux tower at Hurdal site (NO-Hur) to investigate LAD and LAI with six different methods: field campaigns using (1) the Plant Canopy Analyzer LAI-2000; (2) the LaiPen LP 110; (3) Digital Hemispheric Photography at a set of plots within the area; (4) a Lidar drone flight covering the footprint area of the tower; (5) an airborne Lidar campaign, and (6) a satellite LAI product (MODIS). The horizontal spatial structure of LAI values is investigated using marked point process statistics. Intercomparison of the methods focusses not only on biases and root mean squared errors, but also on the spatial patterns observed, quantifying to which extent a simple bias correction between the methods is sufficient to make the different approaches match to each other.
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Pathogenic wood decay fungi such as species of Heterobasidion are some of the most serious forest pathogens in Europe, causing rot of tree boles and loss of growth, with estimated economic losses of eight hundred million euros per year. In conifers with low resinous heartwood such as species of Picea and Abies, these fungi are commonly confined to heartwood and thus external infection signs on the bark or foliage of trees are normally absent. Consequently, determining the extent of disease presence in a forest stand with field surveys is not practical for guiding forest management decisions such as optimal rotation time. Remote sensing technologies such as airborne laser scanning and aerial imagery are already used to reduce the reliance on fieldwork in forest inventories. This study aimed to use remote sensing to detect rot in spruce (Picea abies L. Karst.) forests in Norway. An airborne hyperspectral imager provided information for classifying the presence or absence of rot in a single-tree-based framework. Ground reference data showing the presence of rot were collected by harvest machine operators during the harvest of forest stands. Random forest and support vector machine algorithms were used to classify the presence and absence of rot. Results indicate a 64% overall classification accuracy for presence-absence classification of rot, although additional work remains to make the classifications usable for practical forest management.
Forfattere
Monica JayesinghaSammendrag
KJ gruppen AS planlegger å bygge boligområde på Finstad i Nordre Follo kommune. Utbyggingen vil føre til nedbygging av dyrka mark på gnr. 137/bnr. 591, og jorda må derfor flyttes for å opparbeide nye jordbruksareal. Det er gjort vurdering av jordsmonnet på det dyrka arealet og en vurdering av hvor mye av jorda som egner seg til jordflytting. Ulike mottaksareal er befart og vurdert på tre eiendommer i Nordre Follo kommune (gnr./bnr. 78/2, 87/1 og 117/1). Det er sett på seks alternativer for jordflytting som omhandler større og mindre jordflytting i form av nydyrking og jordforbedring på eksisterende jorder. I forslaget til innspill til kommuneplanens arealdel er 15 dekar satt av til jordflytting, samt fire jordranker med jord av ulik kvalitet. Mottaksarealene på eiendommen gnr. 78, bnr. 2 har størrelser på 7 og 8 daa. Områdene består av skogholt med furuskog og grøftet myr med furuskog. På eiendommen gnr. 87 bnr. 1 er det to skogholt i tilknytning til et større jordbruksareal. På denne eiendommen er det også et større areal med plantet skog som kan nydyrkes. Arealene er henholdsvis 1,5 daa, 3,2 daa og 11,5 daa. På eiendommen gnr. 117, bnr. 1 er det et stort jordbruksareal med flere områder med fjell i dagen og svært lite jordsmonnsdekke. Her vil tilflyttende masser kunne brukes for å jordforbedre den eksisterende jordbruksenheten. Jordsmonnsundersøkelser på Finstadjordet viste at det var lettleire og siltig lettleire i matjordlaget. I undergrunnsjorda varierte teksturen og besto av lettleire, mellomleire og siltig mellomsand. Vurdering av de ulike alternativene for jordflytting resulterte i en prioritering av arealene på eiendommen gnr. 78, bnr. 2 for nydyrking. Disse arealene vil gi utvidelse av allerede eksisterende jordbruksarealer til større sammenhengende jorder med stor driftsverdi. Masser fra jordrankene kan brukes for å øke volumet av B-sjiktsmasser fra Finstadjordet for å gi tilfredsstillende jordsmonnsdybde. Overskuddsmassene fra jordrankene kan brukes for å forbedre jordene på eiendommen gnr. 117, bnr. 1.
Forfattere
Laura D. Ngau Sim S. Fong Kho L. Khoon Elisa Rumpang Harri Vasander Jyrki Jauhiainen Kim Yrjälä Hanna Marika SilvennoinenSammendrag
Water table conditions in drained peatlands affect peat decomposition, fluvial carbon and greenhouse gas emissions, and plant growth in oil palm plantations. This study illustrates the spatial heterogeneity of soil moisture profiles in cultivated tropical peat under oil palm plantation and uncultivated secondary forest, using maps. At a study plot under each land use the geographical coordinates of sampling points, tree locations and other features were recorded. Peat soil samples were taken at depths of 0–50 cm, 50–100 cm, 100–150 cm and 150–200 cm, and their moisture contents were determined. Overall, soil moisture content was higher in secondary forest than in oil palm plantation due to land management activities such as drainage and peat compaction in the latter. Significant differences were observed between the topsoil (0–50 cm) and deeper soil layers under both land uses. Soil moisture maps of the study plots interpolated using geographical information system (GIS) software were used to visualise the spatial distributions of moisture content in soil layers at different depths (0–50 cm, 50–100 cm, 100–150 cm, 150–200 cm). Moisture content in the 0–50 cm soil layer appeared to be inversely related to elevation, but the correlation was not statistically significant. On the other hand, there was a significant positive correlation between soil moisture content and the diameters of oil palm trunks. Palm trees with negative growth of trunk diameter were mostly located in subplots which were relatively dry and/or located near drains. The results of this study indicate that soil moisture mapping using GIS could be a useful tool in improving the management of peatland to promote oil palm growth.