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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.

2019

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This paper presents the water vapour sorption behaviour of degraded archaeological oak (Quercus robur L.) and the influence of methyltrimethoxysilane treatment on hygroscopicity. Wood samples (archaeological and undegraded recent oak) were treated with methyltrimethoxysilane using an oscillating pressure method. Moisture properties of the samples were determined using a dynamic vapour sorption system, and the surface area and porosity of treated and untreated waterlogged wood, previously dried using different methods, were characterised using a nitrogen sorption method. It was found that the silane modification resulted in a decrease in the equilibrium moisture content of archaeological oak samples from 23.7 to 19.4% for heartwood and from 23.3 to 10.0% for sapwood, respectively. After correction for silane content, however, the maximum equilibrium moisture content of the treated samples was 23.6% for heartwood and 21% for sapwood, which points rather at a bulking mechanism than chemical modification by silane. The results of the surface area and porosity measurements indicate that methyltrimethoxysilane is deposited in the cell wall and thus helps to preserve the microstructure of archaeological waterlogged wood.

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EDU-ARCTIC is an open-schooling project, funded by the EU for the years 2016-2019 and managed by scientists, nature educators and IT technicians. The main aim is to attract young people (13-20 years old) to the natural sciences. Further, to raise awareness of how everything in nature is connected, and that STEM education therefore in part must be interdisciplinary across normal school curricula. To achieve these goals, EDU-ARCTIC uses innovative online tools with open-access, combined with nature expeditions. Four main modules complement each other, but can also be used independently: 1) Webinars, where scientists conduct online lessons about their own field of expertise. The lessons comes as packages with worksheets and online games. The lessons brings youth close to scientists. They can ask questions what it means to work with science. It is also a valuable tool for teachers to brush up their STEM knowledge and get inspiration for their own teaching. 2) Polarpedia, which is an online encyclopaedia of scientific terms used in the webinars. The science is kept easy-to-grasp, with the aim to stimulate the pupils’ curiosity to look for more information. 3) Monitoring system, which uses citizen science and the project’s own app to record observations of meteorology and phenology. Observations are open for everybody to use in their own teachings. 4) Arctic Competitions, which is the module that has engaged the pupils the most. They submit their idea for a science project in late autumn, work with the project over the winter and present it in spring as an essay, a poster or a video. Teachers come up with innovative ways to fit this work into the normal curricula. A few lucky winners get to join scientists on expeditions to polar research stations. After 2.5 years, EDU-ARCTIC has engaged at least 1093 teachers from 58 countries. There is a language barrier for some teachers, and it is difficult to fit webinars into the school timetable. However, the challenges are minor compared to the interdisciplinary success of having teachers meet across countries and curricula. Here we illustrate this in detail by presenting a way of interdisciplinary teaching (“the beauty of poetry and maths”) developed by one of the teachers in the project, Mr. Francisco José Gómez Senent. Starting from a single poem published in Nature, it innovatively combines mathematics, literature, history and linguistic competence. The teacher originally used it to stimulate curiosity about the aesthetic criterion in science. Science is not only about facts! The approach can be generalized to cover a wide range of curricula, and different teachers can use it in a team effort across classes. Conclusion: The EDU-ARCTIC project has demonstrated that letting teachers meet across countries and teaching fields facilitates inspiring and innovative cross-overs in the normal school curricula. When teachers are inspired we believe it creates a happy teacher – happy teaching effect. keywords: interdisciplinary, natural science, open schooling, research, transdisciplinary.

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Accurately positioned single-tree data obtained from a cut-to-length harvester were used as training harvester plot data for k-nearest neighbor (k-nn) stem diameter distribution modelling applying airborne laser scanning (ALS) information as predictor variables. Part of the same harvester data were also used for stand-level validation where the validation units were stands including all the harvester plots on a systematic grid located within each individual stand. In the validation all harvester plots within a stand and also the neighboring stands located closer than 200 m were excluded from the training data when predicting for plots of a particular stand. We further compared different training harvester plot sizes, namely 200 m2, 400 m2, 900 m2 and 1600 m2. Due to this setup the number of considered stands and the areas within the stands varied between the different harvester plot sizes. Our data were from final fellings in Akershus County in Norway and consisted of altogether 47 stands dominated by Norway spruce. We also had ALS data from the area. We concentrated on estimating characteristics of Norway spruce but due to the k-nn approach, species-wise estimates and stand totals as a sum over species were considered as well. The results showed that in the most accurate cases stand-level merchantable total volume could be estimated with RMSE values smaller than 9% of the mean. This value can be considered as highly accurate. Also the fit of the stem diameter distribution assessed by a variant of Reynold’s error index showed values smaller than 0.2 which are superior to those found in the previous studies. The differences between harvester plot sizes were generally small, showing most accurate results for the training harvester plot sizes 200 m2 and 400 m2.

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Wild animal populations experience selection pressures from both natural and anthropogenic sources. The availability of extensive pedigrees is increasing along with our ability to quantify the heritability and evolvability of phenotypic traits and thus the speed and potential for evolutionary change in wild populations. The environment may also affect gene expressions in individuals, which may in turn affect the potential of phenotypic traits to respond to selection. Knowledge about the relationship between the genetic and environmental components of phenotypic variation is particularly relevant, given ongoing anthropogenically driven global change. Using a quantitative genetic mixed model, we disentangled the genetic and environmental components of phenotypic variance in a large carnivore, the brown bear (Ursus arctos). We combined a pedigree covering ~1,500 individual bears over seven generations with location data from 413 bears, as well as data on bear density, habitat characteristics, and climatic conditions. We found a narrow‐sense heritability of 0.24 (95% CrI: 0.06–0.38) for brown bear head size, showing that the trait can respond to selection at a moderate speed. The environment contributed substantially to phenotypic variation, and we partitioned this into birth year (5.9%), nonadditive among‐individual genetic (15.0%), and residual (50.4%) environmental effects. Brown bear head circumference showed an evolvability of 0.2%, which can generate large changes in the trait mean over some hundreds of generations. Our study is among the first to quantify heritability of a trait in a hunted large carnivore population. Such knowledge about the degree to which species experiencing hunting can respond to selection is crucial for conservation and to make informed management decisions. We show that including important environmental variables when analyzing heritability is key to understanding the dynamics of the evolutionary potential of phenotypic traits.

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The measurement network Integrated Carbon Observation System (ICOS) is dedicated to the quantification of fluxes of CO2, H2O, N2O and CH4 at the boundary between vegetation surfaces and the lower atmosphere. The implementation of observations sites follows strict protocols and a challenging labelling process to ensure standardized intercomparable observations. We report on our experiences in attempting to establish the only Norwegian ICOS Ecosystem site thus far, NO-Hur, located in an old-growth spruce forest at Hurdal in Southeast Norway. NOHur is planned as a class 2 site, with the option to an upgrade to class 1 later. The instrumentation and sensors needed, the requirements for spatial homogeneity and a detailed analysis of a digital terrain model are presented. The current status of the tower construction, the preliminary measurements obtained with the existing ICOScertified equipment at a test site, and the plans for integrating the measurements operationally into the network are shown

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Plant biology in Norway. Some main aspects; 1. Major efforts on micro and macro algae are now ongoing in Norway (lots of funding goes this way) 2. The pure basic plant biology research with molecular aspects are mostly at the major universities (exemplified here by Prof. Grini and Haman and in smaller groups at other institutions (exemplified by the TOPPFORSK project in epigenetics at NIBIO). 3. A lot of the plant biology in Norway is related to evolution, biodiversity and ecology in general, including climate change (Exemplified by studies in clinal variation and phenology) 4. There is a lot of applied research related to feed and food crops as well as forestry (including invasive species. abiotic stress, plant pathogen interactions insects and fungi with importance for agriculture). 5. There is a National Network for Plant Biology Research in Norway (led by Paul Grini from UiO). This network holds annual/biannual Norwegian Plant Biology conference (NorPlantBio) conferences. 6. Examples from the various institutions in Norway will now be presented.

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Etter oppdrag fra Nye Veier AS har NIBIO med samarbeidspartnere laget et program for forundersøkelser i vassdrag og sjø for ny E18 Arendal - Grimstad. Programmet omfatter forslag til 41 stasjoner og aktuelle undersøkelser. Det har blitt samlet inn informasjon om berørte vannforekomster, deriblant dagens tilstand, aktuelle forurensningskilder, naturverdier og nytteverdi. Programmet er diskutert og forankret hos Fylkesmannen i Agder, samt vannområdeleder for berørte vassdrag.

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Prøving av nye og eldre sortar og lovande seleksjonar av bærartene har vore særleg omfattande i Noreg etter 1950. Arbeidet har vore meir eller mindre organisert og det meste gjennomført ved dei regionale forskingsstasjonane (forsøksgardar, Statens forskingsstasjoner i landbruk, Planteforsk, Bioforsk, Nibio) og ved Norges landbrukshøgskole (NMBU). Matforskingsinstituttet Nofima As på Ås (tidlegare Norsk institutt for næringsmiddelforsking og Matforsk) har tidvis også vore viktig i samarbeidet. Arbeidet gjev oversyn over alle sortar og kjende seleksjonar av jordbær, bringebær, solbær, rips, stikkelsbær og bjørnebær som har vore prøvde i Noreg. Tabellane syner kva som har vore dei viktigaste sortane i dei ulike artene, kvar sortane har vore prøvde og når sortsforsøka har vore gjennomførde. Talet i parantesen syner til referansen i litteraturlista der ein kan finna nærare omtale av sortane.

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In the past decade, China imported massive quantities of soybean from the international market to meet its increasing domestic demand for protein[1]. However, China’s soybean imports from US decreased from 32.86 Mt (Million tons, 34% of the total 95.54 Mt) in 2017 to 16.64 Mt (19% of the total 88.03 Mt) in 2018[2] due to the China-US trade war. To reduce China’s reliance on imports, the Chinese government has been making policy incentive, e.g. higher subsidies, to encourage farmers for soybean cultivation. Traditionally Northeast China is the key production area for soybean. Soybean cultivation is tightly linked to the regional climate and environment. On the one hand, the local soybean growth is vulnerable[3] to the frequent meteorological hazards (e.g. droughts, floods) in the Northeast China[4]. The meteorological risks for soybean production in this area still remain unknown. On the other hand, albeit with relatively high production cost[5] and low water use efficiency[6], the local soybean cultivation is expected to effectively improve the nitrogen use efficiency and therefore alleviate the growing environment pollutions in this region[7]. Yet so far there are few quantitative research being reported on this environmental issue. Our research aims to explore both the meteorological risks and environmental costs of the policy-driven soybean expansion. We have developed a new version of the soybean growth algorithms within the DNDC (DeNitrification-DeComposition) model including nitrogen biogeochemical processes and performed regional simulations for soybean-related cropping systems in Northeast China. We will present the following results by combining model outputs and observations: (i) potential yield and the meteorological risks of soybean cultivation; (ii) fertilizer reduction in different crop rotation systems and the corresponding benefits to water ecosystem; and (iii) consequences of different policy scenarios (e.g. change in subsidy, GMO permission) to soybean production and environment.

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Potato soft rot Pectobacteriaceae (SRP) cause large yield losses and are persistent in seed lots once established. In Norway, different Pectobacterium species are the predominant cause of soft rot and blackleg disease. This work aimed to evaluate the potential of real-time PCR for quantification of SRP in seed tubers, as well as investigating the status of potato seed health with respect to SRP in Norway. A total of 34 seed potato lots, including certified seeds, was grown and monitored over three consecutive years. All seed lots contained a quantifiable amount of SRP after enrichment, with very few subsamples being free of the pathogens. A high SRP prevalence based on a qPCR assay, as well as a high symptom incidence in certified seeds were observed, suggesting that current criteria for seed certification are insufficient to determine tuber health and predict field outcomes. Pectobacterium atrosepticum was the most abundant species in the examined seed lots and present in all lots. Consistently good performance of first generation seed lots with respect to blackleg and soft rot incidence, as well as low quantity of SRP in these seed lots demonstrated the importance of clean seed potatoes. Weather conditions during the growing season seemed to govern disease incidence and SRP prevalence more than seed grade. The impact of temperature, potato cultivar and Pectobacterium species on tuber soft rot development were further examined in tuber infection experiments, which showed that temperature was the most important factor in nearly all cultivars. Large-scale quantification of latent infection and predictive models that include contributing factors like weather, infecting bacterial species and cultivar are needed to reduce soft rot and blackleg.