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
Sammendrag
The decision support indicators (DSIs) are specifically designed to inform local and regional stakeholders on the characteristics of a predicted event to facilitate decision-making. They can be classified as conventional, impact-based and event-based DSIs. This study aims to develop methodologies for calculating event-based DSIs and to evaluate the usefulness of different classes of DSIs for climate impact assessment and climate actions by learning about users' perceptions. The DSIs are calculated based on an ensemble of hydrological projections in western Norway under two representative concentration pathway (RCP) scenarios. The definitions, methodologies and results of the indicators are summarized in questionnaires and evaluated by key stakeholders in terms of understandability, importance, plausibility and applicability. Based on the feedback, we conclude that the conventional DSIs are still preferred by stakeholders and an appropriate selection of conventional DSIs may overcome the understanding problems between the scientists and stakeholders. The DSIs based on well-known historical events are easy to understand and can be a useful tool to convey climate information to the public. However, they are not readily implemented by stakeholders in the decision-making process. The impact-based DSI is generally easy to understand and important but it can be restricted to specific impact sectors.
Sammendrag
The study investigated the production process and properties of a new wood-based material called Bioblocks. This sustainable composite is made from medium-density-fibreboard (MDF) residues, citric acid and either sorbitol or hexanediol. The process involves mixing in-water diluted chemicals with the MDF residues and curing the mixture in a laboratory oven to esterify the sorbitol and wood components with citric acid. A design of experiment was used to determine the influence and optima of the different process factors, and an optimised trial further investigated the material properties. The density distribution, compression strength, and TS after 24 h immersion in water according to EN 317 of the Bioblocks were tested. The first trial showed that mainly the amount of water added impacts the product’s properties. The optimised material achieved a sufficient density distribution with an average density of about 420 kg/m3, a compression strength of up to 3.5 N/mm2, and a TS of about 2%. Therefore, Bioblocks are a promising natural material to use waste MDF and substitute fossil, unsustainable materials.
Forfattere
Charles D. Minsavage-Davis G. Matt Davies Siri Vatsø Haugum Pål Thorvaldsen Liv Guri Velle Vigdis VandvikSammendrag
Northern European heathlands and moorlands dominated by Calluna vulgaris are internationally recognized for their conservation importance while also supporting traditional, low-intensity agriculture and game hunting. Managed burning plays an important role in maintaining these ecosystems but climate and land-use changes, including planned or unplanned transitions to forest and woodland, are now resulting in concerns about increasing wildfire frequency, intensity and severity. In combination with rapidly-changing regulations surrounding managed burning, this has highlighted the need to understand current and potential future fuel structures to effectively model fire behaviour and develop evidence-based regulations surrounding managed burning. We developed standardized heathland fuel descriptions and modeled associated fire behaviour for heathlands in the UK (England, Scotland) and Norway. Utilizing existing fuel and biomass data, we used cluster analysis to identify five distinct fuel models and assessed how they were represented across C. vulgaris life-stages, geographic locations and EUNIS habitat-types. We validated their independence by examining predicted fire rates of spread based across three representative fire weather scenarios. Fire rates of spread differed between C. vulgaris life stages, regardless of EUNIS community or country. Mature stage and taller building stage fuels produced the highest fire rates of spread and early, shorter building and pioneer stage fuels produced the lowest. Moss and litter fuel loads proved to be important determinants of fire rate of spread in a high-risk fire weather scenario. An understanding of links between fuel types and potential fire behaviour can be used to inform management and policy decisions. To aid in this, we used classification tree analysis to link fuel types to easily-observable characteristics. This will facilitate pairing the fuel models with fire behaviour prediction software to make evidence-based assessments of management fire safety and wildfire risk.
Forfattere
Sanjana De Zoysa Jeewanthi Sirisena Helani Perera Shalinda Fernando Miyuru Gunathilake Upaka RathnayakeSammendrag
Rainfall Intensity Duration Frequency (IDF) curves can be identified as a major role in the planning of urban drainage infrastructure. Sri Lanka, which is an island surrounded by the Indian Ocean, is frequently exposed to various climatic alterations. Sri Lanka has specific region-wise IDF relationships for the entire country, however, these IDF curves were developed more than 30 years ago. Many in-situ rainfall observations in Sri Lanka have insufficient record lengths and the absence of finer time scale records (e.g. 15 min, hourly) leading to unreliable IDF curve developments. Given this importance, the present paper demonstrates the application of Satellite-based Precipitation Product (SbPP) daily rainfall in developing IDF curves for Sri Lanka. Rainfall satellite estimates derived from Integrated Multi-satellite Retrievals for GPM (IMERG), Tropical Rainfall Measuring Mission (TRMM-3B42), and Precipitation Estimation from Remotely Sensed Information Using Artificial Neural Networks – Climate Data Record (PERSIANN-CDR) have been used to evaluate the ability of application of remote sensing data to develop IDF curves for Sri Lanka against rain gauge (RG) data. Our study breaks new ground by generating 50 IDF curves tailored to specific locations covering the whole county Sri Lanka, using daily rainfall data from RGs and three SbPPs during the period between 1990 and 2019. This marks a significant departure from the conventional approach, offering a more granular understanding of rainfall patterns in the country. By providing IDF curves for individual locations, our research presents a novel contribution to Sri Lanka's IDF history. At first, to evaluate the accuracy of SbPPs, statistical analysis was conducted using continuous and categorical evaluation indices. Second, IDF curves were developed and compared with the presently available IDF curves. Results showcased that IMERG outperformed all SbPPs, while PERSIANN-CDR showed dire performances. The IMERG and TRMM-3B42 products tend to overestimate light precipitation regions in high elevations and overestimate heavy rainfall in low elevations compared to rain gauge data. Rainfall intensities derived by rain gauge data depicted relative changes within ±30% for shorter durations and ±20% for longer durations while SbPPs showed beyond ±30% difference concerning the previously developed IDFs. It was apparent that these products have significant inaccuracies which cannot be neglected when utilizing them in developing IDF curves. This study will be beneficial in solving design problems associated with urban runoff control and disposal where knowing the rainfall intensities of different return periods with different durations is vital.
Forfattere
Nina Trandem Olle Anderbrant Glenn P. Svensson Christer Löfstedt Elisabeth Ôberg Ann-Kristin Isaksson Hanh Huynh Kimmo Rumpunen Line Beate Lersveen Sigrid Mogan Gunda Thöming Marja RantanenSammendrag
Det er ikke registrert sammendrag
Forfattere
May Bente BrurbergSammendrag
Det er ikke registrert sammendrag
Sammendrag
Genetic variation and performance of up to 40-year-old Norway spruce (Picea abies (L.) Karst.) families from half-diallel crosses made in natural populations where studied, and the results were compared with results from nursery test of seedlings (1-2 years from seed) and short-term farm-field tests at 6-10 years from seed. The diallel analyses revealed significant levels of additive genetic variance for growth and phenology traits. The non-additive genetic variance was generally small to moderate. Strong genetic correlations for growth performance were found between the short-term and long-term trials but not between the nursery and long-term trials. Similarly, genetic correlations for phenology traits were strong between short-term trials and long-term trials, whereas the nursery tests generally did not predict phenology at older age well. The findings indicate that early selection for growth and adaptive traits based on short-term trials is effective for improvement of long-term performance in field if the test site is not outside the normal range of deployment of the reproductive material.
Sammendrag
Female flowering and cone production took place in three Norway spruce progeny tests at ages 17 and 20 years, each planted with full-sib families from a half diallel. The number of cones on individual trees were scored in five classes. More than 50 % of the trees produced cones, and a considerable variation was found among families for the ability to produce cones (precocity) and for the number of clones scored in classes (fruitfulness). Both traits were strongly related to tree heights and diameters at the individual and at the family level. In general, tall trees produced the highest number of cones. However, some families produced many cones even if their average heights were low. In two of the half diallels, estimates of GCA variance components for the number of cones produced had twice the value of the SCA component, indicating additive genetic inheritance of cone production. Heritability estimates of cone scores were 0.10, 0.17 and 0.23, and the genetic correlations between cone production and tree heights were 0.40, 0.50 and 0.35 in the three half-diallels, respectively.
Sammendrag
Semi-natural grasslands are amongst the most species-rich habitats in Scandinavia and elsewhere in Europe. However, the ecological values of these habitats are threatened, by intensification of agriculture in some areas and by abandonment in others. A key question is whether current measures aiming to protect this biodiversity in Norway are in fact successful. We evaluated, in the field, the condition of 55 localities of semi-natural pastures and hay meadows recorded in the Norwegian nature database, Naturbase. We found that only 20 localities (36%) were receiving the agri-environmental subsidies for which they were all eligible. All but one of the localities receiving the subsidies were in fair to good condition, compared with just 41% of the localities that did not receive subsidies. However, only four the 16 most valuable localities, those classed as nationally important, received agri-environmental subsidies. Through a questionnaire to landowners, we found that many were not aware of the biodiversity value on their properties. Of 33 respondents, 20 (61%) knew that they had these valuable ecosystems on their property, whilst 13 (39%) did not. Further, twenty respondents were not aware that they were eligible for financial support to maintain their species-rich grasslands. We conclude that to achieve long-term conservation in habitats dependent on management, it is essential to improve dialogue with landowners.
Forfattere
Jaime Puértolas Pedro Villar-Salvador Enrique Andivia Ishita Ahuja Claudia Cocozza Branislav Cvjetković Jovana Devetaković Julio J. Diez Inger Sundheim Fløistad Petros Ganatsas Barbara Mariotti Marianthi Tsakaldimi Alberto Vilagrosa Johanna Witzell Vladan IvetićSammendrag
Drought hardening is a nursery technique aimed to enhance early forest plantation establishment under dry conditions, which is a main limiting factors for plantation success. However, the quantitative effectiveness of drought hardening remains unclear. We conducted a meta-analysis to evaluate the influence of different factors in the effectiveness of drought hardening on seedling post-planting survival and growth. Overall, drought hardening did not significantly affect survival or growth, as several factors induced great heterogeneity, but analyses of those factors explained its effectiveness, especially on survival. A longer time between hardening and transplanting strongly reduced survival. Indoor-grown seedlings did not benefit more from hardening than outdoor-grown seedlings. Evaluations of drought hardening effectiveness in pots showed positive effects on survival but negative effects on growth, while no effects were found in large bed experiments. In field experiments, hardening significantly increased survival and growth with site aridity. Survival benefits were independent of species drought tolerance, measured by osmotic potential at the turgor loss point (πtlp), in moderate to high aridity sites. However, in low aridity sites, hardening increased survival in drought-tolerant species but decreased it in drought-intolerant species. Field results showed that hardening benefited shrubs more than trees in angiosperms. In conclusion, drought hardening at the end of nursery cultivation tend to increase post-planting seedling performance particularly in scenarios limiting post-planting root growth such as in arid climates and pot experiments. Our findings highlight the importance of future research on modelling the interaction between these technical features and species water use strategies..