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.
2025
Sammendrag
Large herbivores at northern latitudes often forage on agricultural farmland. In these populations, the presence of both resident and migrant individuals (termed partial migration) is common, but how migrants and residents differ in their selection of farmland is not well-understood. Higher access to farmland may provide benefits to residents compensating for not following the ‘green wave’ of emerging vegetation such as migrants. According to sexual segregation theory, males and females differ in body-size-related nutritional needs and risk sensitivity associated with farmland. Yet, how the sexes differ in the selection of farmland through an annual cycle remains unclear. We quantified seasonal variation in the selection of farmland by partially migratory red deer (Cervus elaphus) at broad, landscape scale and at fine, within-home range scale using 16 years of data (2005–2020) from 329 females and 115 males in Norway. We tested predictions related to the partial migration and sexual segregation theories using resource selection functions. We predicted higher selection for farmland by residents than by migrants, and higher selection by females than by males due to higher nutritional needs, but that higher perceived predation risk would impact their diurnal selection patterns. The time spent on farmland was higher in winter (14%–18%) than in summer (8%–14%). Residents selected farmland more than migrants mainly at broad, landscape scale, while differences were smaller and less consistent at a fine, within-home range scale. Females showed higher broad-scale selection for farmland in winter, whereas males showed higher selection in summer. At a fine, within-home range scale, females selected farmland more in summer during darkness, whereas sex differences were small otherwise. The fine-scale selection of farmland was markedly higher during low-light conditions than in daylight. A high population density index was correlated with high broad-scale selection of farmland, i.e. high farmland availability in the home ranges, whereas the effect of the density index was weak at a fine, within-home range scale. Our study emphasises how hypotheses deriving from the theories of partial migration and sexual segregation can improve our understanding of ungulates' selection of farmland. The higher selection by residents during summer highlights the importance of retaining landscape connectivity, allowing for migration and reducing pressure on local resources.
Forfattere
Richita Saikia Athanasios Kaldis Carl Jonas Jorge Spetz Basanta Kumar Borah Andreas VoloudakisSammendrag
Det er ikke registrert sammendrag
Forfattere
Wendy Wuyts Nhat Strøm-Andersen Shumaila Khatri Arild Eriksen Per F. Jørgensen Arild Øvergaard Emil Rygh Angelica Kveen Alexander Mertens Jannicke Stadaas Inger Gamme Veronique Vasseur Anders Q. Nyrud Kristine NoreSammendrag
Det er ikke registrert sammendrag
Forfattere
Erik J. JonerSammendrag
Det er ikke registrert sammendrag
Forfattere
Chloé GrieuSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
In 2024, spruce bark beetle (Ips typographus) catches decreased in all counties except Telemark, Sør-Trøndelag, and Nordland. The highest catches this year were observed in Telemark and Buskerud. In Telemark, the catches are the highest recorded since the major spruce bark beetle outbreak that started in the mid-1970s. In Buskerud, while catches have declined compared to last year, they remain historically high. In Oppland, the catches have decreased markedly from the record-breaking year of 2023 but remain at moderately high levels. Across Southern Norway, this year’s catches are slightly above the 46-year average. The relatively high catches in Buskerud and Oppland are likely a delayed response to the storm damage in November 2021, as municipalities heavily affected by the storm report especially high catches. Additionally, field reports in 2024 indicate attacks on standing trees in areas with much windfall after the 2021 storm. Many of these damage reports likely pertain to trees attacked by beetles in 2023 or earlier but that are only now showing visible symptoms. The 2024 bark beetle season was characterized by extremely dry and warm weather in May, followed by a very wet summer with normal to slightly below-average temperatures. The warm May weather coincides with the beetles' primary flight period, favoring beetle dispersal and egg-laying. Additionally, the dry conditions in May may have stressed spruce trees, reducing their resistance to beetle attacks. The wet weather later in the summer likely benefited the trees while being sub-optimal for the beetles. Overall, the weather conditions during the 2024 season were probably relatively favorable for the beetles. A temperature-based development model estimate that, by September 17, the spruce bark beetle could have completed two generations near the Oslofjord, along the southern coastline, and in low-lying inland valleys. However, these model results do not necessarily mean that the beetles completed two generations in 2024 but indicate that conditions were warm enough to make it possible.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Frøydis GillundSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er usikkerhet knyttet til fremtidig melkeproduksjon i Norge, både produksjonsvolum, geografisk fordeling, og hvilken struktur, lønnsomhet og robusthet som vil karakterisere næringen. En positiv økonomisk utvikling i melkeproduksjonen, kombinert med målrettede støtteordninger for små og mellomstore melkebruk, kan stimulere til økte investeringer også på gårder med mindre enn 30 kyr. Dette kan bidra til å opprettholde dagens produksjonsvolum, og potensielt gi en økning. Hvis lønnsomheten i melkeproduksjonen svekkes, kan det bli utfordrende å opprettholde dagens produksjonsvolum. En akselerert strukturendring i næringen kan resultere i at produksjonen konsentreres i regioner med høy dyretetthet og på gårdsbruk med større kapasitet.