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.
2024
Forfattere
Audun With AasgårdSammendrag
The focus on increasing timber in Norwegian forests has led to a doubling in volume the last 100 years, the harvesting on the other hand has been stagnating. An increase in demand of timber has on the other hand led to an increased harvesting focus. Harvesting in steep terrain is an easy way to increase the harvesting in Norway, especially since these areas have been left untouched until now. Since the volume in these areas have increased and the demand for timber is high, the operational costs have gone down, making the economical gain of harvesting these areas higher. An alternative that has grown in popularity the last years is winch assisted harvesting with T-winch. This harvesting method has shown good results both for economy and ecology compared to the traditional ways of harvesting in steep terrain. However, there is an uncertainty for how long a the time usage is for rigging in this harvesting method. In this study the main goal is to establish an model that can tell the time usage of rigging a T-winch for whole harvesting area. The study is also going to figure out if slope has an impact of the movement speed of the winch. The data was collected with the help of a GPS that was mounted on the T-winch. The data registered by the GPS was used to analysing the movement speed of the winch on the roads and in terrain of the harvesting area. The time usage of the winch will depend on the distance the winch will have to travel and which speed it has while moving over these distances. To calculate time usage, we need the movement speed of the winch while it moves over a variety of distances with different factors. The model should give an estimate of the time usage over the different phases of the rigging of a T-winch during a harvest. This will help the forestry leaders and machine entrepreneurs to make decisions based on knowledge of both how the harvest should be performed, but also if the harvesting method even is relevant for different sites. The model is adaptive since all the different phases operate separately from each other and some might not have to be used in certain harvest areas. The model also has weaknesses, especially as phases for both planning and securing the winch is missing. The planning phase may make a significant difference in time usage of rigging as bad planning will lead to an increase in time used. The securing of the winch is done to secure both machines and operators of the harvest and should also have been included in the study. These factors were not taken into consideration in this study. Slope did not have a significant effect on speed in the study.
Forfattere
Mads Haugom ØverstuenSammendrag
The interest of planting pine (Pinus Sylvestris) has increased in Norway over the last few years. The latest numbers from, among other, Statsforvalteren i Innlandet has shown an increase from 1,6 million planted pine plants in 2020 to 2,4 million pine plants in 2023, with a top year in 2022 with 2,6 million plants in Innlandet. The increasing interest, as well as the importance of planting the right species at the right location regarding the ongoing climate change makes it interesting to understand how we can make plants grow and survive better. In this study, I’m therefore going to examine how short-day treatment affects the field performance of pine plants. I’m also testing how well the plants perform when planted on different planting dates. In a field trial at Stange, located in Innlandet, Norway, we established three plots where we planted 900 pine plants in total. 450 of these where short-day treated for 3 weeks in June, where they got 14-hour nights. The other 450 plants were non-treated. The plants where thereafter outplanted at three different times during late summer and autumn to test the effect of late autumn planting on pine. I registered height, diameter, vitality and cause of damage when they were planted and after the following growing season. The short-day treated plants showed better growth and survival compared to non-treated plants. Planting later in the autumn affected the diameter growth negatively but had no effect on height growth. Planting later in the autumn led to more dead plants, but the death ratio for all planting dates was relatively small, ranging from 4,3 – 15,3%, regardless of the treatment. The short-day treated plants handled the later planting dates better than the non-treated ones. The only cause of damage that was considered important in this study was browsing damage. Short-day treated plants were less damaged than the non-treated ones. The distribution of damaged plants between the planting dates were relatively even.
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
Magnus Barnes EngSammendrag
The forests of Northern Østerdalen in Central Norway are deteriorated as a result of intensive exploitation in pre-industrial times. Large amounts of timber were used to produce charcoal for the Røros copperworks, and this activity has left clear impressions on the landscape. The soil which is greatly disturbed by the charcoaling, called a charcoal hearth, is marked by large amounts of charcoal in the soil. This thesis researched how soil properties and forest productivity on charcoal hearths differ from the surrounding area. Historical research has made it possible to indentify charcoal hearths of different ages, and this thesis is presumably the first to compare charcoal hearths along a gradient of time. I measured pH and C:N-ratio in the O-horizon, site index and basal area on 36 charcoal hearths and controll plots, with an age since charcoaling between 372 and 172 years. Further, I measured wood density and wood chemical concentration on a smaller sample of plots. The results show an increase in pH on charcoal hearths, which can be explained by the liming effect of ash. The increase in pH in the O-horizon has persisted over a long time, which might be caused by lasting increase in base saturation. The site index was lower on the charcoal hearths, perhaps as a result of dryer conditions. The basal area, on the other hand, was greater on the charcoal hearths, indicating better conditions for regeneration. No effect of charcoaling was found on wood density or wood chemical concentration. Although an age-dependent effect could not be demonstrated, the results indicate improving regeneration conditions with age. To study the effect of age, the data should ideally include equal numbers of plots for each age since charcoaling, and include more sites. The results show that charcoal hearths have differing soil properties and growth conditions, compared to surrounding areas. There still remains to research what effect charcoaling has had on greater spatial scale.
Forfattere
Sarah Lise HjelleSammendrag
Closed landfills have received increased attention in recent years due to their environmental impacts and challenges related to construction on or near such areas. In the past, waste management was less regulated, and there were less structural requirements for the design of landfills as there are today. This thesis is a research project within earthresQue and aims to increase the knowledge about older landfills in Norway. The Brånåsdalen landfill in Lillestrøm municipality was in operation from 1971 to 1991, where gas and settlement damage have been the main issues following the closure of the landfill. In this study, a combination of various methods was used to map the top cover and sealing layer, as well as the boundaries of the landfill. Electrical resistivity tomography (ERT) is a geophysical method used to investigate lateral and vertical changes in resistivity or conductivity in the ground, providing information about the electrical properties of different types of materials. In several areas, it was not possible to distinguish between the top cover and the sealing layer with ERT, even though field observations showed a clear layering. A possible reason for this could be that the top cover is thin, varying between 9 and 40 cm, and an average of 20 cm. Another reason could be that the distance between the electrodes is too large and with the resolution being too low. The thickness of the sealing layer varies greatly, and the depth down to the waste masses is between 1.5 to 6 meters. Overlapping resistivity values between the top cover, the sealing layer, and the waste masses make it challenging to distinguish the layers. Additionally, no clear distinction is observed between the inside and outside of the landfill in the horizontal direction. The sealing layer appears to be more heterogeneous than the top cover based on grain size analysis and statistical analysis. Infiltration measurements showed that the saturated hydraulic conductivity (Ksat) has spatial variations and that there is no difference in Ksat between the top cover and the sealing layer. The values vary both within and between different locations, where the median for the hydraulic conductivity in the top cover was 4,0 ∗ 10−5 m/s and in the sealing layer 6,8 ∗ 10−5 m/s. The top cover has a satisfactory grain size distribution and an average content of organic matter of 4%, which means that the soil can maintain good growing conditions. Because the soil layer is thin, it does not fall within what is recommended under current legislation with a thickness of 1 meter, which may result in the sealing layer being less protected and more susceptible to erosion.
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.
Forfattere
Einar Lyche LebesbyeSammendrag
Land-based wind power is considered one of the most applicable sources of renewable energy for the future. While cost effective, the knowledge of ecological consequences associated with construction and operation is limited. This thesis investigates how vegetation and cervid animals at Lista Wind Park were affected by its construction and operation. Vegetation data in revegetated and control plots were compared over a twelve-year period and tested for variation in species richness, species diversity and foliar coverage. Dispersal of alien species, as a result of infrastructure construction, was also investigated. Cervid habitat use was mapped one year before, during construction and several different years after the wind park was set into operation. This data was considered unreliable due to inconsistency in sampling circumstances and lack of calibration between observers, and not analysed further. Rather, inter-observer discrepancies in species identification were investigated. Vegetation in revegetated plots seems to converge towards control plots after twelve years. Differences in species richness, species diversity and foliar cover are no longer significant. However, models fail to account possible variations due to climate. The construction of the wind park resulted in dispersal of alien species. In general, experienced observers had trouble identifying species though photographs of feces, only being certain in ca. 50% of the cases. In cases where observers were certain, species ID was different compared to another observer in 19% of the cases. More studies are needed to determine land-based wind powers ecological consequences, especially on cervids.
Forfattere
Elise Lyng MonssenSammendrag
Wildlife-train collisions are a widespread issue, leading to significant costs to society, reduced animal welfare and potential impacts on species' population sizes. Understanding how ungulates respond to oncoming trains and what affects their detectability is crucial for developing effective mitigation strategies. Building upon the work of Bhardwaj et al. (2022), this study investigates how various factors influence flight behaviour in fallow deer (Dama dama), roe deer (Capreolus capreolus) and moose (Alces alces), as well as wildlife detection from the train driver's perspective. By utilizing films from driver-activated scare systems (DASS) mounted on the front windshield of trains on Norwegian and Swedish railways, this study offers insights into both wildlife reactions and the viewpoints of train drivers. Based on approximately 1000 observations of ungulates, each individual encounter with trains was analysed in relation to railway features, train speed, the train driver’s use of typhoon warning, the ungulates’ location within the terrain and biotic and abiotic factors in the surrounding landscape of the railway. Detection distance and flight initiation distance (FID) was calculated based on the video footage. The results showed that with increasing distance from the railway tracks, ungulates in total were less likely to flee from an approaching train and more likely to increase their FID. Generally, there was a higher probability of flight when the typhoon was used to warn the ungulates, but the effect of this signal was not significant in any of the separate analyses on each species alone. There was also a higher likelihood of flight during dusk/dawn. Flight behaviour of fallow deer was significantly influenced by herd size, with a greater likelihood of flight in smaller groups separated from a large herd. In contrast to roe deer and fallow deer, moose were significantly affected by train speed, with flight likelihood and FID decreasing with increasing speed. All species showed a significantly higher probability of flight across track with closer distance to the track, and in areas where the rail embankment was covered by vegetation with exception of roe deer. Additionally, ungulates in total had a higher probability of an early flight, before detected by the train driver, when visibility was obstructed by vegetation, terrain and curvature of the railway. Lastly, detection distance from the train driver’s perspective was significantly obstructed by vegetation along the railroad embankment. Further studies are suggested on a warning system that could be activated before the animals are detected by the train driver to increase animals’ FID, alongside the implementation of night vision cameras for improved detection of animals during nocturnal hours.
Forfattere
Lars Sandved DalenSammendrag
En viktig del av vårt samfunnsoppdrag er å kommunisere vår kunnskap og delta i samfunnsdebatten. Kronikken er et godt verktøy. Forfatteren er fagperson som bidrar med sin fagkunnskap. En levende og åpen samfunnsdebatt krever at dokumentasjon og oppdatert kunnskap blir gjort tilgjengelig for allmennheten. Og fagpersoner bør delta – med sin kunnskap og fakta. Kunnskap og fakta har imidlertid i flere sammenhenger kommet i miskreditt (fake news, klimadebatten), og det vil være av stor betydning at fagpersoner og forskere evner å nå frem med sin kunnskap til landets innbyggere. Bli bedre til å skrive og formidle forskningen din. Kommunikasjonsrådgiver Lars Sandved Dalen ved NIBIO har siden 2010 hjulpet forskere og fagpersoner med å få over 100 kronikker og debattinnlegg på trykk i norske aviser. I 2023 fullførte han det nyopprettede, fireårige deltidsstudiet i journalistikk og sakprosa ved Institutt for journalistikk og mediefag, OsloMet, med en masteroppgave om kronikken som sjanger. Sammen med forfatter og journalist Dag Kullerud skal Lars Sandved Dalen skrive en lærebok/håndbok om kronikken. Foredraget gir et unikt innblikk i kronikkens utvikling fra den danske avisa Politikens første kronikk i mai 1905 til dagens debattjournalistikk - med er særlig blikk på utviklingen de siste 50 år i de norske avisene Aftenposten, Dagbladet og VG. I tillegg får du de beste kronikkskrivetipsene fra Norges fremste debattredaktører - blant annet Erik Tornes i Aftenposten, Hans Petter Sjøli i VG, Tollef Mjaugedal i Klassekampen, Vidar Ivarsen i Dagens Næringsliv og Trønderdebatts Snorre Valen - og spesialoppfølging slik at nettopp du får din tekst på trykk akkurat der du ønsker.