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
Forfattere
Pia Marinček Jing Vir Leong Loic Pittet Ètienne Léveillé-Bourret Tommi Nyman Maria Tomoshevich Evgeny Banaev Li He Elvira Hörandl Martin Volf Natascha D. WagnerSammendrag
The spatio-temporal evolution of woody plant lineages in the Holarctic is still understudied, limiting our understanding of evolutionary processes that promote higher diversity at higher latitudes in some lineages, which contradicts the latitudinal gradient hypothesis which predicts higher species richness in the tropics. Shrub willows (Salix subgenus Vetrix) comprise about 350 species of which many are adapted to arctic-alpine ecosystems and thus form an important element across the Holarctic region. In this study, we utilized RAD sequencing to estimate the spatio-temporal evolution of the Vetrix clade based on about 140 species covering most of its morphological and geographical diversity. The resolved phylogeny revealed four lineages: the Pan-Himalayan clade, the North American clade and two clades containing species from Eurasia. Widespread circumpolar species form a hybridogenetic grade between the Eurasian and North American clades. Our results confirm that shrub willows originated in the Tertiary, probably in Asia, and that diversification coincided with the climatic cooling in the Pleistocene. At least two radiations were observed, in the Pan Himalayas and in North America. Speciation was further shaped by migration and dispersal in Eurasia, likely accelerated by the uplift of mountain chains, the closure of the Turgai Strait and expansion of suitable habitats. The dated phylogeny revealed that speciation of arctic lineages predates adaptation to high latitudes, as also evident from the fossil record. Small wind-dispersed seeds enabled shrub willows to colonize the expanding arctic tundra regions in the Miocene and their recolonization after the LGM. Given the high observed number of polyploid species equally distributed in all clades and indications of genetic admixture, we assume that species diversity in shrub willows was additionally increased by hybridization and polyploidization.
Forfattere
Ludmila Sromek Kevin P. Johnson Mervi Kunnasranta Aqqalu Rosing-Asvid Britt-Marie Bäcklin Aselle Tasmagambetova Adylkhan Tovassarov Olga Rusinek Heather L. Ziel Ana Rubio-García Tommi NymanSammendrag
We studied the drivers of population-genetic structuring and genetic diversity in specialist parasites based on whole-genome resequencing data from 82 Echinophthirius horridus seal louse individuals sampled from 12 ecologically and behaviourally different phocine seal species, subspecies and populations across the Holarctic. We found that the main genetic disjunctions in E. horridus lice occur across seal host species and subspecies, with a further level of population subdivision emerging among host individuals within some populations. Endemic and relict landlocked seal (sub)species host the genetically most distinct louse populations, while lice associated with sympatric marine seals show signatures of occasional gene flow across hosts. Within the latter, the most extreme case is seen in the near-panmictic lice associated with northern European grey and harbour seals, which aggregate in shared rookeries and colonies. Although the louse and seal phylogenies were overall statistically significantly congruent, evidence for similar host shifts in the past is reflected in several conflicts in the phylogenetic trees of the lice and their hosts. Population-level mean heterozygosity and theta in seal lice varied considerably, and both measures of genetic variation were statistically significantly related to host population size. Taken together, our results support a non-adaptive model of parasite diversification, in which geographic and behavioural isolation among hosts drives parasite genetic differentiation, and genetic erosion in bottlenecked hosts cascades up to their specialist parasites. Our results provide new insights into processes that generate parasite diversity and trigger parallel losses of genetic diversity in endangered host–parasite systems.
Forfattere
Vincent Biard Piia Mutka Mairi Young Marja Niemi Tommi Nyman Milaja Nykänen Mervi KunnasrantaSammendrag
While social network analysis was originally developed for human sociology studies, it is also a valuable tool for characterizing behavioural aspects in many animal populations. For instance, social network analysis can be used for assessing the transmission of diseases or information within groups. Here, we describe co-occurrences and potential social associations of ringed seals, Pusa hispida saimensis, in Lake Saimaa, Finland, from 2016 to 2022, based on photoidentification data. Throughout seven successive moulting seasons (April to June), we identified 425 individuals, of which 178 had pairwise co-occurrences in altogether 185 dyads. These seals had a variable number of associates (up to 10), and co-occurrences were observed in 1–7 years. In general, observations of pairs or larger groups of seals (up to five individuals) were rare, and mainly occurred in the two most densely populated basins of the lake. Most of the group observations occurred on ice rather than on rocks. Overall, the fragmented nature of the lake system, site fidelity and moulting habitat availability are key factors that probably affect the observed co-occurrences. Most of the dyads were observed during only one year, which may indicate social tolerance while using the same moulting site. However, 21 dyads were observed during multiple moulting seasons, with some at different sites separated by up to 3 km in different years, suggesting the existence of actual long-lasting associations. Our study represents the first description of co-occurrences and potential social associations in the endangered Saimaa ringed seal. These results can be used for designing and implementing mitigation strategies in case of unforeseen and sudden changes in the environment, such as a disease outbreak.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Runar Kjær David Kniha Andrea Gjestvang Marianne Liplass Svein Wara Victoria Gonzalez Paul Eric Aspholm Tommi Nyman Cornelya Klutsch Snorre HagenSammendrag
Det er ikke registrert sammendrag
2024
Forfattere
Cornelya Klutsch Juho Vuolteenaho Birk Schulze Runar Kjær David Kniha Ane-Sofie Bednarczyk Hansen Ida Marie Luna Fløystad Tone Roksvåg Aandahl Simo Maduna Tommi Nyman Paul Eric Aspholm Snorre HagenSammendrag
An overview of projects working on/with soil at NIBIO Svanhovd
Forfattere
Galina Gusarova Hedvig Elisabeth Mjøen Magali Corti Frédéric Mahé Pernille Meyer Lilja Steinthorsdottir Marie Kristine Føreid Merkel Stefaniya Kamenova Kamenova Gabriela Wagner Monica Alterskjær Sundset Lars Folkow Tove Hilde Ågnes Utsi Tommi Nyman Cornelya Klutsch Torkild Tveraa Anne Krag Brysting Sylvain Monteux Youri Lammers Eric Coissac Pierre Robert Michel Taberlet Roberto Cazzolla Gatti Inger Greve AlsosSammendrag
Det er ikke registrert sammendrag
Forfattere
Ludmila Sromek Kevin P. Johnson Mervi Kunnasranta Eeva Ylinen Stephany Virrueta Herrera Elena Andrievskaya Vyacheslav Alexeev Olga Rusinek Aqqalu Rosing-Asvid Tommi NymanSammendrag
Det er ikke registrert sammendrag
Forfattere
Saskia Wutke Stephan M. Blank Jean-Luc Boevé Brant C. Faircloth Frank Koch Catherine R. Linnen Tobias Malm Gengyun Niu Marko Prous Nathan M. Schiff Stefan Schmidt Andreas Taeger Lars Vilhelmsen Niklas Wahlberg Meicai Wei Tommi NymanSammendrag
Phylogenomic approaches have recently helped elucidate various insect relationships, but large-scale comprehensive analyses on relationships within sawflies and woodwasps are still lacking. Here, we infer the relationships and long-term biogeographic history of these hymenopteran groups using a large dataset of 354 UCE loci collected from 385 species that represent all major lineages. Early Hymenoptera started diversifying during the Early Triassic ∼249 Ma and spread all over the ancient supercontinent Pangaea. We recovered Xyeloidea as a monophyletic sister group to other Hymenoptera and Pamphilioidea as sister to Unicalcarida. Within the diverse family Tenthredinidae, our taxonomically and geographically expanded taxon sampling highlights the non-monophyly of several traditionally defined subfamilies. In addition, the recent removal of Athalia and related genera from the Tenthredinidae into the separate family Athaliidae is supported. The deep historical biogeography of the group is characterised by independent dispersals and re-colonisations between the northern (Laurasia) and southern (Gondwana) palaeocontinents. The breakup of these landmasses led to ancient vicariance in several Gondwanan lineages, while interchange across the Northern Hemisphere has continued until the Recent. The little-studied African sawfly fauna is likewise a diverse mixture of groups with varying routes of colonization. Our results reveal interesting parallels in the evolution and biogeography of early hymenopterans and other ancient insect groups.
Forfattere
Kate L. Wootton F. Guillaume Blanchet Andrew Liston Tommi Nyman Laura G. A. Riggi Jens-Peter Kopelke Tomas Roslin Dominique GravelSammendrag
Who interacts with whom is a key question in community and network ecology. The concept that these interactions may be driven by a match between the traits of consumer and resource species is known as trait-matching. If trait-matching would allow for general predictions of interaction structure based on sufficiently few and easily-measurable traits, then this approach could replace the laborious description of each individual pairwise interaction. To resolve imprints of trait-matching in a species-rich tri-trophic Salix–galler–parasitoid network, and to identify the most relevant traits, we applied five different methods, each approaching the same phenomenon from a different perspective. As traits, we used, body sizes, gall type (position on plant, structure of gall) and phenology, among others, as well as phylogenetic proxies. When jointly applied, the methods demonstrate distinctly different imprints of traits within the two bipartite network elements (Salix–galler versus galler–parasitoid interactions). Of the galler–parasitoid sub-network's interactions, approximately half were explainable by the species traits used; of the Salix–galler sub-network's interactions, traits explained at most two-fifths. Gall type appeared to be the most important structuring trait in both networks. Phylogeny explained as much, or more than did our tested traits, suggesting that traits may be conserved and phylogeny therefore an effective proxy. Overall, the more specialized structure of the Salix–galler network versus the more nested structure of the galler–parasitoid network meant that different methods were more effective at capturing interactions and interaction structure in the different sub-networks. Thus, our analysis reveals how structuring impacts may vary even between levels within the same multitrophic network, and calls for comparative analyses of trait matching across a wide set of systems and methods.