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
Det er ikke registrert sammendrag
Sammendrag
Uncoated wood is increasingly used in building façades in Northern Europe. The benefits can be both low maintenance and low environmental impact. An even, grey color of the façade is often the intention, but in several cases, an uneven pattern of light, grey and dark/black areas is the result. The effect of weathering and the influencing factors have to be considered when designing and building uncoated and coated wooden façade to avoid unwanted weathering effects. Wood weathering is commonly described to be caused by: accumulation of extractives on the surface, photo-degradation of lignin, staining by dark colored mould fungi, checking, cracking and splitting due to moisture fluctuation and erosion. This paper reviews, analyzes and exemplifies weathering as a finishing system and design option for uncoated wood. Furthermore, it also discusses and exemplifies the main influencing factors and weathering effects on coated wood in facades.
Sammendrag
The root rot pathogens in Norway spruce (Picea abies) Heterobasidion ssp. cause substantial loss in carbon sequestered in forest and economic revenue for forest owners. To facilitate strategic breeding planning for increased resistance against this pathogen in particular, the blue stain fungus Endoconidiophora polonica, growth and wood quality traits (wood density and spiral grain), we estimated additive genetic parameters, correlations and the potential response from selection. Parameters were estimated from a progeny trial series established at two sites (25 years from planting) and their parents in a seed orchard (43 years from grafting). A standard half-sib analysis based on progenies and a parent–offspring regression was used for estimation of heritabilities. Resistance against the pathogens was measured as lesion length under bark after inoculations in phloem. Heritability values varied with site and estimation procedure from 0.06 to 0.33, whereas the phenotypic variance (as CV P ) is high and fairly stable around 40–50 %. Heritability values for wood density and spiral grain in the same material varied from 0.32 to 0.63. The highest heritability values were generally obtained from parent–offspring regression. There is no evidence of resistance traits being genetically correlated with growth or wood quality traits. Wood density is negatively correlated with stem diameter. Implications for breeding are discussed.
Forfattere
Lise Dalsgaard Rasmus Astrup Clara Antón Fernández Signe Kynding Borgen Johannes Breidenbach Holger Lange Aleksi Lehtonen Jari LiskiSammendrag
Boreal forests contain 30% of the global forest carbon with the majority residing in soils. While challenging to quantify, soil carbon changes comprise a significant, and potentially increasing, part of the terrestrial carbon cycle. Thus, their estimation is important when designing forest-based climate change mitigation strategies and soil carbon change estimates are required for the reporting of greenhouse gas emissions. Organic matter decomposition varies with climate in complex nonlinear ways, rendering data aggregation nontrivial. Here, we explored the effects of temporal and spatial aggregation of climatic and litter input data on regional estimates of soil organic carbon stocks and changes for upland forests. We used the soil carbon and decomposition model Yasso07 with input from the Norwegian National Forest Inventory (11275 plots, 1960–2012). Estimates were produced at three spatial and three temporal scales. Results showed that a national level average soil carbon stock estimate varied by 10% depending on the applied spatial and temporal scale of aggregation. Higher stocks were found when applying plot-level input compared to country-level input and when long-term climate was used as compared to annual or 5-year mean values. A national level estimate for soil carbon change was similar across spatial scales, but was considerably (60–70%) lower when applying annual or 5-year mean climate compared to long-term mean climate reflecting the recent climatic changes in Norway. This was particularly evident for the forest-dominated districts in the southeastern and central parts of Norway and in the far north. We concluded that the sensitivity of model estimates to spatial aggregation will depend on the region of interest. Further, that using long-term climate averages during periods with strong climatic trends results in large differences in soil carbon estimates. The largest differences in this study were observed in central and northern regions with strongly increasing temperatures.
Sammendrag
Nutrients for food production are traditionally extracted from natural resources, most importantly as nitrogen from the air, and phosphorous from limited mineral resources. They can also be recovered and recycled from human waste products. There is generally a low P status in the world’s soils, while Norwegian soils are rich in phosphorous. Most recyclable P is in human and animal waste products as wastewater and manure, but also municipal solid waste and more recently, organic waste contain a considerable amount of P that ideally can be utilized.
Forfattere
Heidi Udnes Aamot Ingeborg Klingen S.G. Edwards May Bente Brurberg Guro Brodal Toril Eklo Hege Særvold Steen Jafar Razzaghian Elisa B. Gauslå Ingerd Skow HofgaardSammendrag
The plant pathogenic fungus Fusarium langsethiae produces the highly potent mycotoxins HT-2 and T-2. Since these toxins are frequently detected at high levels in oat grain lots, they pose a considerable risk for food and feed safety in Norway, as well as in other north European countries. To reduce the risk of HT-2/T- 2-contaminated grain lots to enter the food and feed chain, it is important to identify factors that influence F. langsethiae infection and mycotoxin development in oats. However, the epidemiology of F. langsethiae is unclear. A three-year survey was performed to reveal more of the life cycle of F. langsethiae and its interactions with oats, other Fusarium species, as well as insects, mites and weeds. We searched for inoculum sources by quantifying the amount of F. langsethiae DNA in weeds, crop residues, and soil, sampled from a predetermined selection of oat-fields. To be able to define the onset of infection, we analysed the amount of F. langsethiae DNA in oat plant material sampled at selected growth stages (between booting and maturation), as well as the amount of F. langsethiae DNA and HT-2 and T-2 toxins in the mature grain. We also studied the presence of possible insect- and mite vectors sampled at the selected growth stages using Berlese funnel traps. All the different types of materials were also analysed for the presence F. graminearum DNA, the most important deoxynivalenol producer observed in Norwegian cereals, and which presence has shown a striking lack of correlation with the presence F. langsethiae in oat. Preliminary results show that F. langsethiae DNA may occur in the oat plant before heading and flowering. Some F. langsethiae DNA was observed in crop residues and weeds, though at relatively low levels. More results from this work will be presented at the meeting.
Sammendrag
Sustainable forest management in an era of global changes has always been a central thematic area for the International Boreal Forest Research Association (IBFRA). At the 17th IBFRA conference held on 24–29 May 2015 in Rovaniemi, Finland, the theme of global change was accompanied by a new theme related to the use and value of big data in boreal forest management and research. Keynote presentations had a clear message that sustainably managed boreal forests and peatlands play a significant role in climate change mitigation. However, the choice of the most efficient mitigation options will vary with regional differences in ecology, institutional strength, and management intensity. In addition to changes in greenhouse gas fluxes linked to ecosystem dynamics, the design of climate change mitigation strategies should also account for the fate of harvested wood products and for the substitution of more energy-intensive materials such as concrete and steel. For climate change mitigation, it is therefore not only forest management that matters, but also ensuring the best possible end use for the produced biomass. Key note presentations on use and value of big data in the forest sector demonstrated the role of time series of remote sensing data in forest monitoring and research. In addition, new technologies and methods including terrestrial laser scanning are starting to provide detailed three-dimensional information from forest stands from which management tools and scientific understanding will be developed. Finally, citizen science was shown to offer a vast potential for the generation of forest-based data. Thus, new means are being developed by which forest scientists and managers will be able to obtain new, more frequent, and more detailed information on the forest. The ensuing development of knowledge will benefit the forest sector, create new opportunities for furthering boreal forest science, and finally benefit the society as a whole...
Forfattere
Belachew Gizachew Zeleke Svein Solberg Erik Næsset Terje Gobakken Ole Martin Bollandsås Johannes Breidenbach Eliakimu Zahabu Ernest William MauyaSammendrag
Background: A functional forest carbon measuring, reporting and verification (MRV) system to support climate change mitigation policies, such as REDD+, requires estimates of forest biomass carbon, as an input to estimate emissions. A combination of field inventory and remote sensing is expected to provide those data. By linking Landsat 8 and forest inventory data, we (1) developed linear mixed effects models for total living biomass (TLB) estimation as a function of spectral variables, (2) developed a 30 m resolution map of the total living carbon (TLC), and (3) estimated the total TLB stock of the study area. Inventory data consisted of tree measurements from 500 plots in 63 clusters in a 15,700 km2 study area, in miombo woodlands of Tanzania. The Landsat 8 data comprised two climate data record images covering the inventory area. Results: We found a linear relationship between TLB and Landsat 8 derived spectral variables, and there was no clear evidence of spectral data saturation at higher biomass values. The root-mean-square error of the values predicted by the linear model linking the TLB and the normalized difference vegetation index (NDVI) is equal to 44 t/ha (49 % of the mean value). The estimated TLB for the study area was 140 Mt, with a mean TLB density of 81 t/ha, and a 95 % confidence interval of 74–88 t/ha. We mapped the distribution of TLC of the study area using the TLB model, where TLC was estimated at 47 % of TLB. Conclusion: The low biomass in the miombo woodlands, and the absence of a spectral data saturation problem suggested that Landsat 8 derived NDVI is suitable auxiliary information for carbon monitoring in the context of REDD+, for low-biomass, open-canopy woodlands.
Sammendrag
This paper presents peer-reviewed studies comparing the content of deoxynivalenol (DON), HT-2+T-2 toxins, zearalenone (ZEA), nivalenol (NIV), ochratoxin A (OTA) and fumonisins in cereal grains, and patulin (PAT) in apple and apple-based products, produced in organically and conventionally grown crops in temperate regions. Some of the studies are based on data from controlled field trials, however, most are farm surveys and some are food basket surveys. Almost half of the studies focused on DON in cereals. The majority of these studies found no significant difference in DON content in grain from the two farming systems, but several studies showed lower DON content in organically than in conventionally produced cereals. A number of the investigations reported low DON levels in grain, far below the EU limits for food. Many authors suggested that weather conditions, years, locations, tillage practice and crop rotation are more important for the development of DON than the type of farming. Organically produced oats contained mainly lower levels of HT-2+T-2 toxins than conventionally produced oats. Most studies on ZEA reported no differences between farming systems, or lower concentrations in organically produced grain. For the other mycotoxins in cereals, mainly low levels and no differences between the two farming systems were reported. Some studies showed higher PAT contamination in organically than in conventionally produced apple and apple products. The difference may be due to more efficient disease control in conventional orchards. It cannot be concluded that any of the two farming systems increases the risk of mycotoxin contamination. Despite no use of fungicides, an organic system appears generally able to maintain mycotoxin contamination at low levels. More systematic comparisons from scientifically controlled field trials and surveys are needed to clarify if there are differences in the risk of mycotoxin contamination between organically and conventionally produced crops.
Sammendrag
Flere studier har avdekket store forskjeller i lønnsomhet mellom gårdsbruk. Usikkerhet knyttet til indre og ytre faktorer i gårdsdrifta gir en kompleks og skiftende beslutningsprosess som krever tilgang til mange informasjonskilder. At det er også variasjon på bruk med samme produksjon og like ressurser er en indikasjon på at indre faktorene som kan påvirkes av bonden er viktige for det økonomiske resultatet. Selv om bønder kan ha svært forskjellige mål for virksomheten, er det rimelig å anta at det er forbedringsmuligheter på de fleste brukene. Det er derfor viktig å prøve å avdekke årsakene til den store variasjonen i økonomisk prestasjon i primærlandbruket. I dette prosjektet har vi undersøkt hvordan lønnsomhet varierer mellom gårdsbruk i det enkelte år og på enkeltbruk mellom år. Vi har sett på forskjeller mellom driftsformer, regioner og bruksstørrelser. Hensikten med dette har vært å identifisere de variablene som synes å ha størst betydning for variasjon i lønnsomhet, og i hvilken grad dette er faktorer som kan påvirkes av den enkelte bonde. Prosjektet er gjennomført som en kvantitativ undersøkelse av datamaterialet fra driftsgranskingene i perioden 2010 – 2014, med driftsformene melk, sau og korn. I tillegg har vi undersøkt variasjonen innen bruk mellom år, gjennom en panelstudie av de brukene som var med i samtlige år i 2010 – 2014. Vi har brukt driftsoverskudd per enhet som resultatmål i prosjektet, fordi det mulig å sammenligne bruk fra hele landet med ulike størrelser og produksjonsvilkår. Datamaterialet ble undersøkt med hjelp av beskrivende statistikk. Det ble også utført en regresjonsanalyse på melkebrukene for å kunne si noen om hvordan ulike faktorer påvirker lønnsomheten. Vi har sett på variasjon og spredning i driftsoverskudd i forhold til produksjonsstørrelse for hver av de tre driftsformene i 2014. Alle brukene ble deretter delt i tre grupper ut fra oppnådd resultat i hvert enkelt år i perioden 2010 – 2014, der vi sammenligner resultatene for den beste tredelen med den tredelen med svakest lønnsomhet.