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.
2023
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Authors
Pia Heltoft ThomsenAbstract
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Authors
Madelen Cecilia Espino FjeldAbstract
Et essensielt tema innen økologi er at oppfostring av avkom hos mange arter krever tilgang på betydelige ressurser og at fødselstidspunktet synkroniseres for å treffe toppen til ressurstilgangen i sesongmessige miljøer. Dagens raske klimaendringer mot for eksempel høyere temperaturer og en tidligere vår i nordlige økosystemer, har ført til at mange planter har vist trender for tidligere fenologiutvikling. For plantespisende pattedyr kan dette føre til trofisk «mismatch» mellom tidspunkt for fødsel og den fenologiske utviklingen hos beiteplantene, og vil kunne føre til at fødselstidspunktet ikke lenger treffer tidspunktet med optimal tilgang på ressurser. Endring i de klimatiske faktorene kan føre til seleksjon for tidligere eller senere fødselstidspunkt. For hjortedyr har tidspunkt for brunst og parring påvirkning på kalvingstidspunktet, og en høyere bestandstetthet hos enkelte arter kan føre til senere unnfangelse. Få tidligere undersøkelser har dokumentert om kalvingstidspunktet til hjortedyr er blitt endret over tid. En av årsakene til dette er mangel på data, siden det er vanskelig å observere kalving og kalvingstidspunkt i skogsområder. På grunn av en endret atferd til hjortedyr under kalving, er det hos enkelte arter vist at det er mulig å sannsynliggjøre oppdagelse av kalving ved bruk av ny teknologi (posisjonsdata fra GPS-halsbånd). Målet for dette prosjektet var å undersøke om posisjonsdata kan brukes til å påvise kalving og kalvingstidspunkt hos hjort (Cervus elaphus), og deretter bruke metoden for å undersøke om kalvingstidspunktet har endret seg over tid og med bestandstetthet i Norge. I analysene ble det brukt GPS-data fra 188 hjort og 309 mulige kalvingshendelser fra perioden 2005-2021 fra Trøndelag og Møre og Romsdal i Norge. Tjue koller med observert kalvingstidspunkt ble brukt som utgangspunkt for endringspunktanalyse og maskinlæring, for å finne estimert kalvingstidspunkt og -status ved hjelp av kovariater knyttet til bevegelsesmønster. Observert og estimert kalvingsstatus ble sammenlignet, men det var kun 81% av kollene som ble riktig estimert, som var et svakere resultat enn forventet. Når metoden ble brukt på et større utvalg av hjort, var det ikke mulig å påvise klare trender i kalvingstidspunkt over tid, men dette kan skyldes svakheter med metoden. Hjorten er en art som har en gjemmer-strategi første uken etter kalving. Den intensive perioden rett etter kalving er kort for en gjemmer som fører til utfordringer ved deteksjon av kalvingshendelser, og maskinlæringsmetodene bør derfor utvikles ytterligere for å få sikrere resultater. Dette vil være et viktig tema med tanke på hvordan klimaendringer kan påvirke det fremtidige økologiske samspillet.
Authors
Nikolai Antonsen BiletAbstract
The size of the Norwegian red deer population is historically high and typical of the trend seen over much of Europe. Dense populations may cause damage to agricultural crops, and crop yield is drastically decreased by red deer grazing in certain areas. We know that red deer select actively managed meadows, i.e., frequently renewed by fertilisation and re-seeding, over other agricultural meadows. Despite its importance, information regarding spatial grazing patterns by red deer on agricultural meadows is limited. In this study, I aim to quantify how grazing on agricultural meadows by red deer varies across spatial scales in southwest Norway. I hypothesise that grazing on agricultural meadows is determined by three major effects: (H1) Factors affecting forage quality and availability in meadows relative to natural habitats, such as population density and seasonal change, (H2) meadow management, such as renewal of meadows, and (H3) perceived predation risk and human disturbance, such as distance to settlement and forest edge. Grazing levels were assessed across meadows in a hierarchical study design, and I analysed the data using a binary logistic regression that model absence of grazing and a beta regression that model the level of grazing given grazing occurred. This enabled me to quantify both variation among spatial hierarchical units and the mechanisms behind spatial grazing patterns. I found that the grazing variation was largest between meadows in the local area and smallest on broader scale. High red deer density areas received more grazing relative to low-density areas, more grazing occured when meadow grass was shorter, and early in summer relative to late, suggesting that red deer select meadows over natural habitat when the difference in quality and availability of forage are large enough. Newly refreshed meadows received more grazing than the older ones, implying that a large part of the local site effect was caused by meadow management. Evidence of trade-off effects also appeared important as spatial grazing patterns changed near roads, houses, and forests. Broad-scale variation in red deer density explained some of the variations in grazing. However, since the largest variation in grazing was found locally, population reduction at broad scales may not effectively lower damages. These results may affect the scale at which management should target mitigation efforts.
Authors
Nina Johansen Arne Stensvand Aruppillai Suthaparan Annichen Smith Eriksen Pål Johan From Ellen Altenborg Runa Gidske Thomas Petillon Carl Emil ØyriAbstract
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Norwegian apple production is a highly variable affair, and even more so facing the changing climate. Knowledge about which role the pollinator communities play in these systems may bring us closer to understanding why the between year variation is so large, and how to mitigate it. In this particular study we will use state of the art genetic methods (Genotyping-by-sequencing) to investigate how the genes are transported within the orchards, and how this is affected by variations in bee species diversity. In turn, we will look into how the fruit quality and seed set is affected by the observed gene flow.
Authors
Narta ElshaniAbstract
Sheep production systems in Norway present complexity in the same way as other systems partaking in the climate challenges. Sustainability of these systems cannot be defined through single-impact indicators; hence a broader range of sustainability dimensions and trade-offs must be assessed. The present research uses the Sustainability Assessment and Monitoring RouTine (SMART): a multi-criteria sustainability assessment based on the Sustainability Assessment of Food and Agriculture Systems (SAFA) Guidelines which gathers data on the farms’ performance through 327 indicators across 4 dimensions. Eight sheep farms in Norway were selected for assessment: four low-land coastal farms, and four inland mountain farms. Management practices which support sustainability were identified in all farms: high animal welfare, high number of days of access to pasture for the livestock, no/low use of synthetic chemicals, good water management, and high quality of life for farmers. Management practices which hinder sustainability and key areas for improvement were also identified: increased onfarm energy production, decreased use of externally sourced concentrate feed, and increased farmers’ knowledge about externally sourced inputs. Some differences between the coastal and inland farms were also identified which were related to number of days of access to pasture for livestock, water consumption, participation for farmers in trainings and additional education, and political involvement. Using the SMART-Farm tool aided the process of identifying practices and systematically evaluating them through a global sustainability perspective. Aggregated results from the SMART-Farm assessment indicated a high degree of goal achievement across dimensions. The farms scored on average above 80% on the Environmental Integrity and the Social Well-Being, and lower on the Economic Resilience and the Good Governance dimensions (76% & 71% respectively). To evaluate these results, a qualitative expert elicitation method was employed; this provided insight into shortcomings which were a result of the context-generic approach that the tool has and lack of inclusion of stakeholder participation in indicator selection and aggregation process. These shortcomings are important to consider when interpreting the results of numeral integration assessments which are used for decision-making. However, evaluating these scores was also a valuable outcome in itself since it uncovered knowledge gaps about the topic of sustainability of sheep farming in Norway.
Authors
Jorunn Elisabeth Olsen Marcos Viejo Torstein Tengs Igor A. Yakovlev Hugh Cross Paal Krokene Carl Gunnar FossdalAbstract
No abstract has been registered