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.
2026
Abstract
No abstract has been registered
Abstract
Blue rings (BRs) are wood anatomy anomalies that present great potential in identifying cold spells during the growing season. In this study, we investigated the effect of temperature anomalies on the occurrence of two types of BR in Pinus sylvestris at its northern distribution limit in Norway. Of the 3508 individual tree rings from 1727 to 2022 analysed, we identified 206 BRs from a span of 85 years, the oldest formed in 1730. We distinguished two types of BR: Type A with normal earlywood and latewood ending with a thin blue layer; and Type B with the entire latewood zone replaced by earlywood-like tracheids. Our results demonstrate that the two types have a common climatic trigger – a cool spring and autumn. However, Type A is more linked to tree-ring width, whereas Type B is associated more closely with tree ontogeny and local environmental constraints. Although we observed the formation of BRs even in old trees, we found that they formed more frequently in young specimens. We showed that while the short-term cyclical drivers of Type A remained persistent, the climatic or environmental drivers associated with Type B gradually diminished under climate change. Our study demonstrates that the differentiation of BRs into types can contribute to a better understanding of their driving factors; however, detailed intra-annual phenological and xylogenetic monitoring will be crucial to achieve further insights.
Authors
Junbin Zhao Mounir Takriti Per-Erik Jansson Ed Jones Mikhail Mastepanov Erling Fjelldal Cornelya Klutsch David Kniha Runar Kjær Simon Weldon Kjetil Fadnes Knut Bjørkelo Jonathan Rizzi Christian Wilhelm Mohr Gunnhild Søgaard Jagadeesh YeluripatiAbstract
Abstract Peatlands drained for agriculture and other uses release substantial carbon dioxide. Many countries estimate these emissions using the 2014 IPCC Tier 1 emission factors. Here we calibrated an ecosystem model with data from two cultivated peatland sites in Norway and simulate carbon dioxide emissions at 50 sites nationwide for 2001–2022. Model results showed that carbon dioxide emissions were strongly controlled by water table depth and aligned well with observations from other European peatlands of similar climate zones. Crucially, the Tier 1 emission factor matched our simulations only under very deep water tables (< –0.7 m), but overestimated emissions by 31–88% when water levels ranged from –0.7 m to –0.3 m. This indicates that Tier 1 methods may overstate emissions from cultivated peatlands in cool temperate and boreal regions, inflating estimates of mitigation potential. Tier 2 or 3 approaches can reduce uncertainty but require more field data.
Authors
Anne Straumfors Anani Komlavi Afanou Oda Astrid Haarr Foss Abdelhameed Elameen Mikkel Meyn Liljegren Hans Geir EikenAbstract
Background: Pesticides are used in greenhouse cultivation to control fungi and pests and to shape plant growth. This influences microbial communities and may increase the selective pressure for resistant species development. Antimicrobial resistance (AMR) is a growing global health challenge, and while AMR dispersal through soil and water is well studied, the role of bioaerosols as AMR vectors remains insufficiently explored. Objectives: To explore the link between chemical pesticide and the prevalence of AMR genes in aerosols from greenhouses using pesticides and those not using them. Methods: Forty-nine fullshift personal samples of inhalable dust were collected in eight greenhouses from 2021 and 2024. Five greenhouses used chemical pesticides and three did not. DNA was extracted and screened for the presence of 45 clinically relevant AMR genes using HT-qPCR. Results: Twenty of the 45 screened genes were detected. Greenhouses using pesticides showed significantly higher AMR gene levels than those not using chemicals. Several genes, particularly β-lactam and tetracycline resistance genes, occurred in high concentrations, including extreme values exceeding 60,000 gene copies/m³. This suggest that pesticide-using greenhouses may represent a greater risk for AMR dispersal. In contrast, greenhouses without chemical pesticide showed lower and more stable AMR gene levels. Factors other than pesticide application may also contribute, such as import of treated plants, soil and fertilizer materials, plant types or individual workers. Further research is needed to assess the health risks for greenhouse workers and to support the development of effective strategies for preventing and controlling AMR spread.
Authors
Dalphy Ondine Camira Harteveld Abdelhameed Elameen Simo Maduna Adam Vivian-Smith Andrea Podavkova Sabine Oettl Stefanie Maria Primisser Jorunn BørveAbstract
Small, superficial rot spots occurring around lenticels postharvest on apple in Norway have not been identified but were assumed to be underdeveloped Neofabraea lesions. Fungal isolation from such spots on fruit from the 2022 season revealed both Neofabraea perennans and Ramularia spp., identified by B-tubulin and ITS sequencing, respectively. In the 2023 season, isolations were made from fruit with spots resembling dry lenticel spot caused by Ramularia mali. The aim of this study was to identify the Ramularia species associated with the postharvest fruit spots in Norway. Multiple gene regions of five Norwegian isolates (E20, E21 from 2022; 13,15 and 18 from 2023) and three reference isolates, R. mali, R. eucalypti, and R. collo-cygni, were sequenced and used for phylogenetic analysis. The Norwegian isolates were distinct from the included reference isolates, but clustered with other Ramularia species. Isolates 13, 18 and E21 clustered with Ramularia vizellae, while isolates 15 and E20 were most closely related to Ramularia phacae-frigidae. Isolate E20 was sequenced using the Oxford Nanopore Technologies MinION platform. Pathogenicity was assessed in a field inoculation study using isolate E21, resulting in typical spot development on inoculated fruit. Ramularia vizellae has previously been reported from dead apple leaf litter and other woody hosts in the Netherlands and Iran, while R. phacae-frigidae was originally described from Phaca frigida in Switzerland. Neither species has previously been reported in association with apple fruit spotting. While Ramularia mali has caused outbreaks on apple in several European countries, recent studies hypothesize that the symptoms may be caused by a species complex with regional variation. The present results identify candidate species contributing to this complex in Norway and highlight the need for further studies to improve species delimitation and pathogenicity.
Abstract
Accurate species identification is essential for conserving and managing plants that provide important ecosystem services and have ethnobotanical value. The Greyia tree genus ( G. sutherlandii , G. radlkoferi and G. flanaganii ) is endemic to South Africa and Eswatini, and certain genotypes have medicinal value for treating skin hyper‐pigmentation. However, distinguishing among species is difficult because of overlapping phenotypes and the limited resolution of standard DNA barcodes. To overcome these limitations, a robust molecular identification assay was developed using a two‐phase strategy. First, de novo SNP discovery using 3RAD sequencing identified 47,726 genome‐wide SNPs from two to three plants sampled from each species' core geographic range: G. radlkoferi in northern Limpopo, G. sutherlandii in eastern KwaZulu‐Natal, and G. flanaganii in the south‐eastern Eastern Cape. Principal component analysis and coancestry matrices revealed three discrete genetic clusters, supporting the recognition of the three species. Selecting a set of 200 SNPs with intermediate Fst values (0.2–0.5) resulted in optimal separation of the three clusters. This led to the final selection of a 23‐SNP panel that included five informative barcoding loci (ITS, trnL‐F , matK ). Second, the 23 SNPs were converted into allele‐specific fluorescent PCR assays (SNP Type) for genotyping on the BioMark HD platform. The panel was validated using genomic DNA from 17 individuals from the 3RAD population groups and successfully differentiated all three species. It was then applied to 73 trees sampled across a 1000‐km transect from the Eastern Cape to Limpopo. Genetic clustering (PCA, UPGMA and ADMIXTURE) assigned each tree to one of three species‐level groups matching their expected ranges. In a practical case study, the assay also identified the species origin of 33 Greyia trees of unknown provenance from production orchards. This study provides an efficient SNP‐based tool for accurate species identification, supporting conservation planning and the sustainable management of Greyia populations.
Authors
Tore Flatlandsmo Berglen Christine Forsetlund Solbakken Hilde Thelle Uggerud Jenny Lovisa Alexandra Jensen Guttorm Christensen Tone Roksvåg AandahlAbstract
Did you know that stairstep moss can be used as a sampler for air pollution? Researchers at NILU have collected this kind of moss on several occasions and examined it for metals and other pollutants.
Authors
Cornelya KlutschAbstract
A presentation on environmental monitoring and research in the border regions of Norway, Finland, and Russia
Authors
Eirik Inge Mikkelsen Cornelya Klutsch Gunnar Sander Patrick Berg Sørdahl Ingrid Kvalvik Sigrid Engen Charlotte Teresa Weber Camilla Carlsten Mittenzwei Vito De LuciaAbstract
No abstract has been registered
2025
Authors
Pia Marinček Jing Vir Leong Loic Pittet Ètienne Léveillé-Bourret Tommi Nyman Maria Tomoshevich Evgeny Banaev Li He Elvira Hörandl Martin Volf Natascha D. WagnerAbstract
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.