Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2025
Forfattere
Mostafa Hoseini Helle Ross Gobakken Stephan Hoffmann Csongor Horvath Johannes Rahlf Jan Bjerketvedt Stefano Puliti Rasmus AstrupSammendrag
RoadSens is a platform designed to expedite the digitalization process of forest roads, a cornerstone of efficient forest operations and management. We incorporate stereo-vision spatial mapping and deep-learning image segmentation to extract, measure, and analyze various geometric features of the roads. The features are precisely georeferenced by fusing post-processing results of an integrated global navigation satellite system (GNSS) module and odometric localization data obtained from the stereo camera. The first version of RoadSens, RSv1, provides measurements of longitudinal slope, horizontal/vertical radius of curvature and various cross-sectional parameters, e.g., visible road width, centerline/midpoint positions, left and right sidefall slopes, and the depth and distance of visible ditches from the road’s edges. The potential of RSv1 is demonstrated and validated through its application to two road segments in southern Norway. The results highlight a promising performance. The trained image segmentation model detects the road surface with the precision and recall values of 96.8 and 81.9 , respectively. The measurements of visible road width indicate sub-decimeter level inter-consistency and 0.38 m median accuracy. The cross-section profiles over the road surface show 0.87 correlation and 9.8 cm root mean squared error (RMSE) against ground truth. The RSv1’s georeferenced road midpoints exhibit an overall accuracy of 21.6 cm in horizontal direction. The GNSS height measurements, which are used to derive longitudinal slope and vertical curvature exhibit an average error of 5.7 cm compared to ground truth. The study also identifies and discusses the limitations and issues of RSv1, which provide useful insights into the challenges in future versions.
Forfattere
Rasmus Bang Stine Samsonstuen Bjørn Gunnar Hansen Mario Guajardo Hanne Møller Jon Kristian Sommerseth Julio C. Goez Ola FlatenSammendrag
CONTEXT Researchers have identified numerous strategies to improve economic performance and reduce greenhouse gas (GHG) emission intensity in combined milk and beef production on dairy farms. However, there remains a need to better understand how the effectiveness of these strategies varies under different operational conditions. OBJECTIVE This study aims to examine how the economic and GHG emission intensity mitigation effectiveness of increased milk yield, extended longevity of dairy cows, reduced age at first calving, and intensified beef production from bulls depend on operational conditions in dual purpose cattle systems. METHOD We present a quantitative framework to (1) economically optimize production at farm level under various constraints and (2) calculate corresponding GHG emissions. The framework is tailored for Norwegian dual-purpose cattle systems and used to assess the economic and GHG emission intensity mitigation effects of incremental adjustments in relevant decisions. RESULTS AND CONCLUSIONS The results show that increased milk yield, extended productive life of dairy cows, reduced age at first calving, and lower slaughter age of bulls can lead to economic and climatic win-wins in terms of higher gross margins and reduced emissions per kg of protein produced. However, they may also result in lose-win and win-lose outcomes depending on the operational conditions. All four measures free up roughage production capacity, which, if used to maintain/increase milk and/or beef production, typically results in economic gains. However, if e.g., the available milk quota or space prevent this, economic losses may occur. The climate impact also depends on how the freed-up capacity is used: if it boosts production, the effects vary based on the scale and type of increase and the farm's initial setup, while unused capacity leads to reduced emission intensity. Conflicts typically arise when: 1) the extra capacity increases less climate-friendly production, raising emission intensity despite economic gains, or 2) extra capacity cannot be used, causing economic losses despite climate benefits. Our results also show that what can be labeled a win in climate terms, and to what extent, depends on the selected target metric(s). SIGNIFICANCE Governments and societies strive to balance food production with environmental goals. In this context, it is essential to identify farm-level economic and climatic win-win and lose-win scenarios, not only for farmers but also for policymakers and the broader society. This study could inform decision-making and policy development, potentially enhancing economic and climatic performance in combined milk and meat production.
Sammendrag
Optimised contributions of green infrastructure (GI) to urban ecosystem services are strongly related to its multifunctionality. The challenge, however, is that the concept of multifunctionality still needs to be transformed into an operationalised assessment to evaluate current performance, which is instrumental in supporting spatial planning and policy strategies. Using the case of Stavanger City (Norway), the study conducted a spatial assessment of the multifunctionality of the urban green infrastructure. The study used a comprehensive set of 27 function indicators estimated for each of the 156 spatial units classified by their type, age, size, and biophysical characteristics. Correlation patterns among indicators and how the average and effective multifunctionality related to unit characteristics were analysed using correlation and multivariate approaches. The study demonstrated weak correlations between function indicators but revealed some potential trade-offs and function bundles. Notably, bundles related to tree cover (e.g. C sequestration, stormwater retention) had negative relationships with facilitation measures. There was a large overlap in functions between GI types associated with public green spaces and parks. Moreover, the characteristics of green infrastructure units, like size and age, primarily affected multifunctionality through effects on function indicators. Regarding the city-wide multifunctionality, we found some turnover and subsetting of functions among units, supporting multifunctionality at larger spatial scales. However, the average contributions from different GI types were similar. The study highlights the need to understand correlation patterns among function indicators and function bundles as critical to benefit from synergies and avoid unintentional trade-offs when designing and managing urban green areas.
Sammendrag
No abstract has been registered
Forfattere
Jian Liu Faruk Djodjic Barbro Ulén Helena Aronsson Marianne Bechmann Lars Bergström Tore Krogstad Katarina KyllmarSammendrag
No abstract has been registered
2024
Forfattere
Kari Straume EnerstadSammendrag
The climate is changing, and people and goods are crossing country borders more than ever. As a result, the number of alien plant species have increased worldwide, and it does not seem to be slowing down. This makes it even more important to find effective and sustainable management approaches to preserve the native species and habitats from the challenges invasive alien species may bring. This thesis explores the topic of alien plant species in the cultural landscape and how climate change and globalization impact the spread and establishment of these plants. The aim of the thesis is to identify the impacts climate change and globalization have on alien species and learn how they are managed. Additionally, investigate if discovered, alternative approaches could be applicable to the Norwegian management approaches on various levels of government. The thesis investigates how Norway manages alien plant species and explores the roles of national, regional and local government through theory and interviews. Three other nations are also studied, England, South Africa and Canada, to create a greater understanding of the variations in management and to compare the different approaches. The study found large variations in the municipal management approaches, limited collaboration between the stakeholders and decreased funding. A lack of knowledge and awareness among the public was also discovered. These factors collectively make managing alien plants difficult. Enhancing collaboration among national, regional and local management levels, alongside strengthening public awareness, has the potential to increase resources and enhance the effectiveness of management strategies.
Forfattere
Ingvild Alseth MolandSammendrag
This thesis explores an urbanized area in Norway, which is an important area for migratory birds both nationally and globally, through a case analysis. Together with knowledge base, the case analysis is used to develop some important measures for wader bird friendly urban landscapes. Urbanization and downsizing of nature put biodiversity under pressure, and many species are fighting for their survival. Bird populations are declining worldwide, and the species that are mostly affected by urbanization are often the species with special habitat requirements. In Europe, ground nesting birds experience a larger decline compared to other bird species. Wader birds are in rapid population decline and are therefore of conservation concern across Europe. Globally there are about 209 species of wader birds, and in Norway there are around 70 species registered. Population decline has been observed in several species of waders, and about 50 % of the waders in Norway are appearing on the Norwegian red list for species. Management decisions have the potential to influence important nesting and feeding habitats and protect wader birds in urban areas. Still, the wader birds have received a limited amount of attention and research in Norway. Fornebu, in Bærum municipality, is characterized as one of the most species rich localisations in Norway. Fornebu has gone through dramatic land use changes, transforming from an initial farming area to the primary airport of Norway, to a large housing project for business, housing, and recreation. The housing project is Northern Europe’s largest housing project and has affected the nature values through the construction of roads, housing, park-like landscapes, and increased human disturbance. The transformation has changed the natural landscape leading to a reduction of bird habitats. A document analysis reveals the municipality’s plans for future development of the landscape, and stakeholders’ perspectives on facilitating the landscape, through measures that might affect wader birds. The measures that emerge as most important is: to preserve the shoreline, restore wetlands, establish ponds, take care of meadows, facilitate edges with native vegetation, establish suitable habitats on green roofs, facilitate paths and signs for education amongst people, and facilitate protection against predators. The measures can help to protect and enhance the abundance of wader birds in urbanization processes and already urbanized landscapes and can help to raise awareness and promote education to citizens. The measures will also affect other species and can enhance the overall resilience of an urban environment.
Forfattere
Sigrid Esmeralda ArnestadSammendrag
På norske gravplasser er plassmangel et problem grunnet svært treg nedbrytning av menneskekropper som fremdeles kan være intakte etter flere tiår i en kistegrav. Ved etablering av nye gravfelt har masseutskifting med blandinger av maskinelt knust sand blitt benyttet for å sikre god drenering. Det eksisterer derimot lite kunnskap om langtidseffekten av denne type kunstig jord på nedbrytning i kistegraver. Knust sand fra stein har troligere høy pH og skarpere overflater som sannsynligvis pakkes annerledes enn naturlig rundet sand, hvilket kan ha betydning for jordfysiske egenskaper og påvirke transport og innhold av vann og luft. De antatte egenskapene kan påvirke forhold som styrer den mikrobielle aktiviteten, som er avgjørende for god nedbrytning. Oppgaven har derfor som formål å bidra til økt kunnskap om egenskaper til knust sand gjennom å karakterisere fysiske, hydrauliske og kjemiske egenskaper, samt å undersøke jordmassenes påvirkning på organisk mikrobiell nedbrytning. Ulike tester ble gjennomført i et lysimeteranlegg på følgende utvalg av sand; to typer knust sand, to naturlige sand, og fire typer blandinger av disse. Teposer ble begravd i to dybder med kontrollert vannstand og standard fysiske og kjemiske analyser samt vannlagringskapasitet ble undersøkt på jordprøver i lab. I tillegg ble infiltrasjonshastighet målt på jordmassene i lysimetrene. Resultatene fra studiet viste at massetap av te var signifikant mindre i knust enn naturlig sand, forholdsvis i det øvre jordlaget. Det antas at dette i hovedsak skyldes redusert mikrobiell nedbrytning, trolig som følge av høyere pH, lavt innhold av organisk materiale og for lite fuktighet i de knuste massene. Sistnevnte antakelig på grunn av lav vannlagringskapasitet. Nedbrytning av te var generelt lavere i det nedre jordlaget, trolig grunnet redusert oksygen som følge av mer fuktighet fra den nærliggende vannstanden. I de groveste kunstige og naturlige sandtypene ble det derimot ikke observert redusert nedbrytning i det nedre jordlaget, mulig som følge av fravær av kapillært vann fra den nærliggende vannstanden og antakelig fremdeles opprettholdelse av aerob mikrobiell aktivitet. Samtidig bør det bemerkes at forskjellene i nedbrytning stort sett ikke var signifikante mellom noen av jordtypene i dette jordlaget. Sandpartiklene ser ut til å være betraktelig mer kantet enn de naturlige, men studien viste ingen overbevisende forskjell i total porøsitet og det er behov for mer forskning på langtidseffekten av konsolidering som følge av forskjeller i partikkelform. I alt indikerer resultatene at mikrobiell nedbrytning kan begrenses i knust sand sammenliknet med naturlig, noe som vil være ugunstig dersom massene benyttes på kirkegårder der det er ønske om høy mikrobiell aktivitet og nedbrytning.
Forfattere
Hanna Marie KjernsbySammendrag
Finansiert av Statens Vegvesen
Forfattere
Elias GarvikSammendrag
The Norse built their hulls from oak boards hewn from cleaved or ‘rived’ logs. We know this through artworks and texts as well as archaeological finds describing the ships as well as their construction from the latter half of the early-medieval period. However, we know summarily little when it comes to the pre-production of hewn boards. I ask, - How could the Norse have possibly cleaved? - Which properties in white oak affect cleaving? - Which simple truths can be found of cleaving. Which direction of cleaving is best for oak? This is done by showcasing the differences in cleaving from the top, side, and bottom of a series of white oak logs. Namely why cleaving from each direction fails. To summarize the results. Cleaving from the top shines in cases where there is a large difference in the diameter at the top and bottom of the log. Cleaving from the side can act as a mitigator in the case of knots or to pierce directly through a knot or burl. Cleaving from the top or bottom falls more naturally in the cases where the pith is off-centre. With a log bent like an arch, cleaving from the side fell more naturally. The direction of the cleave ought to be thought of less as an immutable truth and more of as another tool to extract as many boards from a log as possible. We found that no direction of cleaving was inherently better in all scenarios. It is a case of risk-mitigation, which benefits from taking a thorough look at the log and making an informed choice. In cases where the angle of the twisting fibres of a log is significant, all cleaving directions struggle and fail, in cases where there are few natural faults, cleaving from all sides succeed.