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.
2023
Sammendrag
Levels of dissolved natural organic matter (DNOM) are increasing in our boreal watercourses. This is manifested by an apparent increase in its yellow to brown colour of the water, i.e., browning. Sound predictions of future changes in colour of our freshwaters is a prerequisite for predicting effects on aquatic fauna and a sustainable operation of drinking water facilities using surface waters as raw water sources. A model for the effect of climate on colour (mg Pt L-1) has been developed for two surface raw water sources in Scotland, i.e., at Bracadale and Port Charlotte. Both sites are situated far out on the Scottish west coast, without major impact of acid rain, with limited amounts of frost, and with limited recent land-use changes. The model was fitted to 15 years long data-series on colour measurements, provided by Scottish Water, at the two sites. Meteorological data were provided by UK Met. The models perform well for both sites in simulating the variation in monthly measured colour, explaining 89 and 90% of the variation at Bracadale and Port Charlotte, respectively. These well fitted models were used to predict future changes in colour due to changes in temperature and precipitation based on median climate data from a high emission climate RCP8.5 scenario from the HadCM3 climate model (UKCP18). The model predicted an increase in monthly average colour during growing season at both sites from about 150 mg Pt L-1 to about 200 mg Pt L-1 in 2050–2079. Temperature is found to be the most important positively driver for colour development at both sites.
Forfattere
Thilaga Sethuraman Shanmugam Munisamy Ganesan Meenakshisundaram Anicia Q. Hurtado Ganesh DossSammendrag
Regeneration of polyploidy from young thallus segments of Kappaphycus alvarezii was optimized for genetic improvement. Kappaphycus thallus segment cultured on sterile sea water supplemented with various combinations of Indole acetic acid, Kinetin and Acardian Marine Plant Extract Powder revealed differential response on callus proliferation and development of new thallus. Presence of Acardian Marine Plant Extract Powder (3 mg/l) in combination with Indole acetic acid and Kinetin (0.01 mg/l each) had induced the longest emerging thallus. Exposure of thallus to colchicine at 0.01% with above combination was optimal to induce high frequency regeneration of polyploidy mostly from the meristematic cells. Anatomical study of colchicine induced polyploidy revealed larger cortical cells with irregular thickening of epidermal layer. Phase contrast and Scanning Electron Microscopic study revealed increase in cell size in cortical region with significantly larger number of spherical shaped carrageenan globules in colchicine induced polyploidy than normal thallus. Single cells isolated using enzymatic treatments from colchicine induced polyploidy, shown chromosome number with a ploidy status of 4n ≈ 40. Whereas in normal thallus, only half the number of chromosomes (2n ≈ 20) were observed. Polyploidy were successfully acclimatized gradually using raft method for further evaluation. This is the first report reveals the induction and regeneration of polyploidy in Kappaphycus. The possible application of this finding in genetic improvement of Kappaphycus is discussed.
Forfattere
Thiago Inagaki Angela R. Possinger Steffen A. Schweizer Carsten W. Mueller Carmen Hoeschen Michael J. Zachman Lena F. Kourkoutis Ingrid Kögel-Knabner Johannes LehmannSammendrag
The spatial distribution of organic substrates and microscale soil heterogeneity significantly influence organic matter (OM) persistence as constraints on OM accessibility to microorganisms. However, it is unclear how changes in OM spatial heterogeneity driven by factors such as soil depth affect the relative importance of substrate spatial distribution on OM persistence. This work evaluated the decomposition and persistence of 13C and 15N labeled water-extractable OM inputs over 50 days as either hotspot (i.e., pelleted in 1 – 2 mm-size pieces) or distributed (i.e., added as OM < 0.07 µm suspended in water) forms in topsoil (0-0.2 m) and subsoil (0.8-0.9 m) samples of an Andisol. We observed greater persistence of added C in the subsoil with distributed OM inputs relative to hotspot OM, indicated by a 17% reduction in cumulative mineralization of the added C and a 10% higher conversion to mineral-associated OM. A lower substrate availability potentially reduced mineralization due to OM dispersion throughout the soil. NanoSIMS (nanoscale secondary ion mass spectrometry) analysis identified organo-mineral associations on cross-sectioned aggregate interiors in the subsoil. On the other hand, in the topsoil, we did not observe significant differences in the persistence of OM, suggesting that the large amounts of particulate OM already present in the soil outweighed the influence of added OM spatial distribution. Here, we demonstrated under laboratory conditions that the spatial distribution of fresh OM input alone significantly affected the decomposition and persistence of OM inputs in the subsoil. On the other hand, spatial distribution seems to play a lower role in topsoils rich in particulate OM. The divergence in the influence of OM spatial distribution between the top and subsoil is likely driven by differences in soil mineralogy and OM composition.
Sammendrag
The combination of preharvest treatments with calcium chloride and fungicides, and storage of maturity graded fruit were assessed in five European plum cultivars. At harvest, samples of fruit within a commercially suitable range in ripening were divided into two categories: less-ripe (tree ripe-) and more-ripe (tree ripe+). The fruit were stored for 10–14 days at 4 °C followed by 2–3 days at 20 °C before the assessment of fungal decay. If calcium chloride was applied six times each season, postharvest fruit decay was significantly reduced in four of nine experiments, with a total mean reduction of around 50%. Two calcium applications in combination with a fungicide treatment reduced decay by approx. 60% compared to the untreated in one experiment. In six of seven experiments there was no effect of preharvest fungicide applications. In six of 10 experiments, fruit of the category tree ripe- had fewer fruit with fungal decay after storage than the tree ripe+fruit. The higher incidence in the category tree ripe+fruit was primarily due to brown rot, Mucor rot, and blue mould. For the category tree ripe+, there was two to ten times more decay than on tree ripe- fruit after a simulated shelf-life period. To ensure low incidence of fungal decay, fruit of commercial harvest maturity may thus be separated in two ripening categories, one for rapid distribution to the market (tree ripe+) and another for extended distribution time (tree ripe-).
Sammendrag
Soil nutrient contents and stoichiometric ratios are determinants for soil biogeochemical cycling and functions. Variable rock fragment contents (RFC) may shape the soil nutrient status and availability in mountain ecosystems. We need to better understand how and why soil nutrients and stoichiometry shift across the RFC gradients. To investigate patterns of soil nutrient stoichiometry and underlying mechanisms in rocky soils, we conducted a field experiment involving four RFCs gradients (0%, 25%, 50% and 75%, V/V) and five vegetation treatments (four indigenous species, Artemisia vestita, Bauhinia brachycarpa, Cotinus szechuanensis and Sophora davidii, plus a non-planted treatment). Soil total carbon (C), total nitrogen (N), total phosphorus (P) and their molar ratios were measured. The contents of soil C, N and P, and C:N, C:P and N:P decreased with increasing RFC in all treatments, despite their trends were inconsistent in certain soil layers. The averages of soil N content significantly increased by 13.8% and 14.8% in C. szechuanensis and S. davidii, respectively. A. vestita and B. brachycarpa had higher soil C:N than C. szechuanensis and S. davidii. Soil nutrients and stoichiometry were positively related to soil water content (SWC) and soil capillary porosity, and negatively to bulk density and soil non-capillary porosity in all vegetation treatments, but varying relationships with biomass of plant components. These results demonstrated negative effect of RFC and discrepant effects of the plants on soil nutrients and stoichiometry. Soil structure, SWC and vegetation were the main drivers of variations in soil nutrient stoichiometry. We further concluded that soil nutrient stoichiometry in rocky soils is shaped by two influencing paths; effects of RFC on soil physical properties (SWC and soil structure) and effects of different vegetations. Our findings advance knowledge and mechanisms of soil nutrient stoichiometry in rocky soils and provide theoretical support for improving and restoring nutrient status in stony regions.
Sammendrag
NIBIO har taksert elgbeite på oppdrag av Grenland Landbrukskontor i 2022-2023. Det rikeste beitetilbudet var i sørøst, mens nord var spesielt fattig på buskbeite, og sørvest mer furudominert og variabel. I rapporten er regionen delt inn i Nord, Vest og Sør. Særlig Vest hadde høy dekning av blåbærlyng, mens Sør skilte seg ut med høy dekning av høge urter og bringebær. Også Nord hadde bra dekning av blåbærlyng, men lite annet attraktivt feltsjiktbeite. Vi fant lavere enn forventet tetthet av trær i beitehøyde (30-300 cm) i alle delområdene. Takst etter samme metodikk i Kjose i 2005 indikerer at både tetthet av beitetrær og ubeita skudd-cm/tre har gått ned, til tross for yngre skog i dag. Det skyldes trolig høyt beitepress fra hjortevilt, og skogskjøtsel over tid. Se anbefalinger i utvidet sammendrag. Vi har beregnet at det er mat til maks 0.6 elg per km2 (vinterbestand) i Nord og Vest, og 1.3 per km2 i Sør. Dette er et maks optimistisk anslag, gitt at beiteplantene ikke hadde vært kuet, og hvor det må gjøres fratrekk for hjort. Et svært grovt anslag er at hjorten tar 30-50% av bæreevnen i Nord og Vest, og 15-25% i Sør. De siste 5 årene har beregnet tetthet av elg i snitt vært 0.6-0.9 elg/km2 i Grenland som helhet. Uten mer presis kunnskap om hjortens beiting er det vanskelig å si hvilken tetthet av elg som vil bidra til å friskmelde beitene. Et friskmeldt beite er en nødvendighet, men ingen garanti, for elg i god kondisjon. Elg har også andre og økende utfordringer som kan svekke kondisjonen, som et varmere klima, men beitene er fortsatt en viktig brikke i puslespillet av faktorer som bidrar til den vedvarende dårlige kondisjonen på elg i Grenland.
Sammendrag
Global measures to bring net-zero-carbon and zero-waste emissions are expanding at a rapid pace. Currently, only 16% of the plastic waste from the food industrial sector is reprocessed and recycled, which is way lesser than its accumulation. Several countries have imposed a ban on single-use plastic derived from food and/or beverage industries. All these constraints and challenges have encouraged researchers to find a sustainable alternative to petroleum-based food packaging. The environmentally friendly substitute can be the bio-based polymer material derived from agri-food and marine wastes that connect the waste loop in the current economic model. This waste has the most valuable biopolymer mainly present in the cell wall matrix of plants, animals, bacteria, fungi, and algae. All these biopolymers are either accumulated in a landfill or not entirely harvested their high-value compounds as a potential feedstock. Nevertheless, bio-based polymers have better thermos-mechanical properties that can resist various conditions. They comprise superior functional properties when these biopolymers are coupled with other organic compounds such as composite films or multilayer packaging films which enhance the shelf-life of the food. Overall, biopolymers readily react with the soil microbes under specified environmental conditions that can significantly enhance the biodegradability of packaging material. This unique quality is envisaged to solve the existing problems and detrimental effects of synthetic polymer usage in the food industry. In this background, in this chapter, the origin of biopolymers and their potential functionality, mechanical property, and degradability as food packaging materials are discussed. Their current challenges and possible future prospects are also meticulously highlighted.
Forfattere
Trond HaraldsenSammendrag
Catastrophic floods have large effect on agricultural land both in short and long term. In this chapter, examples of impact of floods of different size in cold regions with glaziers have been presented. The largest floods occur as combination of heavy rainfall and melting and snow and ice in the mountainous areas. Periods of waterlogging by cold running water resulted in decreased yields, but N-fertilization after the soil no longer was water saturated could reduce the yield loss considerably. Although the floods cause severe erosion and sedimentation, results show that it is possible to find measures for reconstruction of the soils with the same productivity as undamaged soils, while the average result was about 85% of the original productivity.
Forfattere
Anders Nielsen Lawrence Richard Kirkendall Johan A. Stenberg Per Hans Micael Wendell Paul Ragnar Berg Anders Bryn Sonya Rita Geange Kjetil Hindar Lars Robert Hole Erlend Birkeland Nilsen Brett Kevin Sandercock Eva Bonsak Thorstad Gaute VelleSammendrag
Key words: apiculture, biological control, Norwegian Environment Agency, Norwegian Scientific Committee for Food and Environment, predatory mites, risk assessment, varroa Introduction The Norwegian Environment Agency (NEA) have asked the Norwegian Scientific Committee for Food and Environment for an assessment of adverse impacts on biodiversity concerning import and release of the predatory mite Stratiolaelaps scimitus as measure against varroa mites (Varroa destructor) in apiaries. The predatory mite is already in use in Norwegian greenhouses and polytunnels as a biological control agent against dark-winged fungus gnats in a various of plant cultures. The NEA has received an application for a new type of use: to combat varroa mites in apiaries. Background Varroa destructor (the varroa mite) is a species of parasitic mite that feeds externally on honeybees; it is considered one of the major threats to beekeeping world-wide due to its parasitic behaviour and because it acts as a vector for several viral and bacterial bee pathogens. Beekeepers in North America have begun experimenting with introducing Stratiolaelaps scimitus, a commercially available predaceous mite originally used for biocontrol in greenhouses and polytunnels, to control varroa mites, and several studies on the use of the mite in this context have been published recently. The Norwegian Environment Agency has asked VKM to assess the risk to biological diversity in Norway associated with this new use of S. scimitus, and to assess the effects of climate change on any risks that are proposed. Stratiolaelaps scimitus is a tiny (0.5 mm), soil-dwelling predaceous mite that in nature feeds on a wide variety of soil invertebrates, including fly larvae, nematodes, nymphs of thrips, potworms (oligochaetes), springtails, and other mites. For over three decades, Stratiolaelaps scimitus has been produced commercially and the species is now used globally for biological control. The mite is applied to control a wide variety of organisms harmful to food production or to the production of ornamental plants, but especially to combat infestations of fungus gnat larvae, spider mites, flower thrips, and certain plant-feeding nematodes. The species is already used as a biocontrol agent in Norway in greenhouses, open plastic polytunnels used for protecting crops, and in various indoor plantings and fungiculture. Methods VKM established a project group with expertise in entomology, invasion ecology, honeybee behaviour and ecology, and risk analysis of biological control agents. The group conducted systematic literature searches and scrutinized the relevant literature that was found. In the absence of Norwegian studies, VKM relied on literature from other countries. Results and conclusions This VKM assessment concludes with medium confidence that introducing S. scimitus for use in beehives would not significantly increase the probability of establishment and spread of S. scimitus above that of its current use. We point out that there is no evidence that continuous use of S. scimitus in Norway, over decades, has led to its establishment outside of enclosures, including open polytunnels. The optimal temperature for development and reproduction is far higher than what is normally observed in Norway (~28 °C). Although lethal temperature has been reported to be as low as –5.2 °C, we still conclude that S. scimitus would not be able to establish permanent populations in Norway, not even in the southern part of the country as such temperatures are expected to occur in some years throughout the country. Future climate change is not believed to alter this conclusion, since periods with lethally cold temperatures are expected to still occur in the future.
Forfattere
Arne Verstraeten Nicolas Bruffaerts Fabiana Cristofolini Elena Vanguelova Johan Neirynck Gerrit Genouw Bruno De Vos Peter Waldner Anne Thimonier Anita Nussbaumer Mathias Neumann Sue Benham Pasi Rautio Liisa Ukonmaanaho Päivi Merilä Antti-Jussi Lindroos Annika Saarto Jukka Reiniharju Nicholas Clarke Volkmar Timmermann Manuel Nicolas Maria Schmitt Katrin Meusburger Anna Kowalska Idalia Kasprzyk Katarzyna Kluska Łukasz Grewling Małgorzata Malkiewicz Lars Vesterdal Morten Ingerslev Miklós Manninger Donat Magyar Hugues Titeux Gunilla Pihl Karlsson Regula Gehrig Sandy Adriaenssens Agneta Ekebom Åslög Dahl Marco Ferretti Elena GottardiniSammendrag
The effects of tree pollen on precipitation chemistry are not fully understood and this can lead to misinterpretations of element deposition in European forests. We investigated the relationship between forest throughfall (TF) element fluxes and the Seasonal Pollen Integral (SPIn) using linear mixed-effects modelling (LME). TF was measured in 1990–2018 during the main pollen season (MPS, arbitrary two months) in 61 managed, mostly pure, even-aged Fagus, Quercus, Pinus, and Picea stands which are part of the ICP Forests Level II network. The SPIn for the dominant tree genus was observed at 56 aerobiological monitoring stations in nearby cities. The net contribution of pollen was estimated as the TF flux in the MPS minus the fluxes in the preceding and succeeding months. In stands of Fagus and Picea, two genera that do not form large amounts of flowers every year, TF fluxes of potassium (K+), ammonium-nitrogen (NH4+-N), dissolved organic carbon (DOC), and dissolved organic nitrogen (DON) showed a positive relationship with SPIn. However- for Fagus- a negative relationship was found between TF nitrate-nitrogen (NO3−-N) fluxes and SPIn. For Quercus and Pinus, two genera producing many flowers each year, SPIn displayed limited variability and no clear association with TF element fluxes. Overall, pollen contributed on average 4.1–10.6% of the annual TF fluxes of K+ > DOC > DON > NH4+-N with the highest contribution in Quercus > Fagus > Pinus > Picea stands. Tree pollen appears to affect TF inorganic nitrogen fluxes both qualitatively and quantitatively, acting as a source of NH4+-N and a sink of NO3−-N. Pollen appears to play a more complex role in nutrient cycling than previously thought.