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.
2021
Sammendrag
NIBIO har på oppdrag av Stjørdal kommune utført taksering av elgbeite i de skogkledde delene av kommunen i juli 2021, for å kunne si noe om beitetilbud og beitepress. Vi fant at den totale tettheten av beite-trær i elgens beitehøyde (30-300 cm) var over snittet for våre øvrige takster i Sør- og Midt-Norge. Mengde beitbar biomasse (årsskudd) var bare halvparten så stor i indre som i ytre sone (skille mellom soner satt fra Skjelstadmarka i nord til Elvran i sør). Ytre sone hadde mer biomasse enn snittet i øvrige takster, mens indre sone hadde betydelig mindre enn snittet. Bjørk utgjorde nesten alt buskbeitet i indre sone, mens det i ytre sone også var en del selje og furu. Tilbudet av viktig feltsjikt (blåbær, høge urter og til dels bregner) var høyest i lavereliggende skog, uavhengig sone. Av hensyn til elg anbefaler vi at disse delene av skogen holdes tilstrekkelig lysåpne gjennom hele skogens rotasjonsperiode. Alle våre indekser på beitepress tilsier at elgbestanden i Stjørdal per 2021 var for høy i forhold til plantenes tålegrenser. Det er viktigst å følge beitepresset på bjørk. Vi har estimert ernæringmessig bæreevne til å være maks 1.3 elg/km2 i ytre sone, og bare halvparten i indre: 0.7 elg/km2. Vi anbefaler å holde bestanden under maks en periode for å la beitene hente seg inn. Sett og felt elg data indikerer at bestanden etter jakt siste 5 år har vært en del høyere enn maks: om lag 1.5 elg/km2. Det kan likevel se ut som kommunen er i ferd med å få snudd trenden i tide, da pilene for elgtettheten peker i riktig retning og beiteplantene fortsatt produserer rimelig bra.
Forfattere
Chedly Kastally Alina Katariina Niskanen Annika Perry Sonja T. Kujala Komlan Avia Sandra Cervantes Matti Haapanen Robert Kesälahti Timo A. Kumpula Tiina M. Mattila Dario Isidro Ojeda Alayon Jaakko S. Tyrmi Witold Wachowiak Stephen Cavers Katri Kärkkäinen Outi Savolainen Tanja PyhäjärviSammendrag
Pinus sylvestris (Scots pine) is the most widespread coniferous tree in the boreal forests of Eurasia, with major economic and ecological importance. However, its large and repetitive genome presents a challenge for conducting genome-wide analyses such as association studies, genetic mapping and genomic selection. We present a new 50K single-nucleotide polymorphism (SNP) genotyping array for Scots pine research, breeding and other applications. To select the SNP set, we first genotyped 480 Scots pine samples on a 407 540 SNP screening array and identified 47 712 high-quality SNPs for the final array (called ‘PiSy50k’). Here, we provide details of the design and testing, as well as allele frequency estimates from the discovery panel, functional annotation, tissue-specific expression patterns and expression level information for the SNPs or corresponding genes, when available. We validated the performance of the PiSy50k array using samples from Finland and Scotland. Overall, 39 678 (83.2%) SNPs showed low error rates (mean = 0.9%). Relatedness estimates based on array genotypes were consistent with the expected pedigrees, and the level of Mendelian error was negligible. In addition, array genotypes successfully discriminate between Scots pine populations of Finnish and Scottish origins. The PiSy50k SNP array will be a valuable tool for a wide variety of future genetic studies and forestry applications.
Sammendrag
In the last century, local or individual-based forest management was introduced by various forest scientists including Schädelin, Abetz and Pollanschütz as an alternative to traditional global thinning methods. They suggested breaking large forest stands down into smaller neighbourhood-based units. The centre of each of these neighbourhood-based units is a frame tree (also referred to as final crop tree, elite tree or target tree) with clearly defined properties that depend on the management objectives. In each management intervention, trees in the neighbourhood of frame trees that in the next 5–10 years are likely to influence the frame trees negatively are removed selectively. In contrast to global methods, management is only carried out where there are frame trees. Local or individual-based forest management methods were first introduced in a commercial forestry context, but rather constitute generic methods that can be efficiently applied in management for conservation, carbon sequestration and recreation. They are also often applied in the context of continuous cover forestry (CCF). In this study, we analysed the behaviour of test persons selecting frame trees in 26 training sites, so-called marteloscopes, from all over Great Britain. Although the test persons were new to individual-based management, statistical performance indicators suggested that frame trees were selected in accordance with the theory of local or individual-based forest management. Unexpectedly the test persons even achieved a comparatively high degree of agreement. This result contrasts the low agreement and partly unsatisfying performance indicators incurred in the selection of frame-tree competitors, the second step of local forest management. The outcomes of this study highlight that training in individual-based forest management needs to put more emphasis on the identification of frame-tree competitors.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Trygve S. Aamlid Wiktoria Kaczmarek-Derda Trond Gunnarstorp Harald Solberg Trond Olav Pettersen Kristine Sundsdal Kjell Wærnhus Kirsten TørresenSammendrag
Det er ikke registrert sammendrag
Forfattere
Divina Gracia P. RodriguezSammendrag
Det er ikke registrert sammendrag
Forfattere
Geir-Harald StrandSammendrag
Det er ikke registrert sammendrag
Sammendrag
Pollinating insects are an inherent part of most terrestrial ecosystems as they provide a crucial service for most angiosperms, including numerous important crops. A decrease in pollinator populations can therefore have severe consequences for both natural ecosystems and agricultural yields. Pesticide usage has been pointed out as one of the drivers behind pollinator declines. Globally, neonicotinoids are one of the most commonly used insecticides and studies have shown that exposure at sub-lethal levels can alter foraging behaviour, ultimately negatively affecting survival. Using a custom-made bumblebee colony monitoring system, we examined how the number and duration of foraging bouts of bumblebees (Bombus terrestris) on an individual level, and hive growth rate, was affected by exposure to low (6.5 µg/L) and high (10.6 µg/L) sub-lethal concentrations of the neonicotinoid clothianidin via nectar. We also examined possible interaction between clothianidin exposure and abiotic factors (temperature and precipitation), and its impact on foraging bout number and duration. Exposure to sublethal concentrations of clothianidin increased foraging bout duration in bumblebees. Furthermore, the foraging bout duration decreased with increasing temperature at both exposure concentrations, whereas the unexposed control group was not affected by temperature. Neither number of foraging bouts nor the daily rhythm of foraging bout duration was affected by clothianidin exposure or temperature. The foraging bout duration decreased with increasing precipitation in both exposed and non-exposed groups. However, we did not find any interaction between precipitation and exposure, suggesting that precipitation does not affect toxicity. Our study shows the importance of semi-natural experiments and accounting for ambient factors when assessing the risk that pesticide exposure may present to pollinators. We conclude that the effect of clothianidin exposure on bumblebee foraging behaviour is temperature sensitive and that local climatic conditions and future climate change scenarios should be considered in risk assessments of clothianidin and other insecticides.
Forfattere
Cornelya Klutsch Simo Maduna Natalia Polikarpova Kristin Forfang Benedicte Lissner Beddari Karl Øystein Gjelland Paul Eric Aspholm Per-Arne Amundsen Snorre HagenSammendrag
Maintaining standing genetic variation is a challenge in human-dominated landscapes. We used genetic (i.e., 16 short tandem repeats) and morphological (i.e., length and weight) measurements of 593 contemporary and historical brown trout (Salmo trutta) samples to study fine-scale and short-term impacts of different management practices. These had changed from traditional breeding practices, using the same broodstock for several years, to modern breeding practices, including annual broodstock replacement, in the transnational subarctic Pasvik River. Using population genetic structure analyses (i.e., Bayesian assignment tests, DAPCs, and PCAs), four historical genetic clusters (E2001A-D), likely representing family lineages resulting from different crosses, were found in zone E. These groups were characterized by consistently lower genetic diversity, higher within-group relatedness, lower effective population size, and significantly smaller body size than contemporary stocked (E2001E) and wild fish (E2001F). However, even current breeding practices are insufficient to prevent genetic diversity loss and morphological changes as demonstrated by on average smaller body sizes and recent genetic bottleneck signatures in the modern breeding stock compared to wild fish. Conservation management must evaluate breeding protocols for stocking programs and assess if these can preserve remaining natural genetic diversity and morphology in brown trout for long-term preservation of freshwater fauna.
Forfattere
Ingunn M. VågenSammendrag
Det er ikke registrert sammendrag