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
Vilde Lytskjold Haukenes Johan Asplund Line Nybakken Jørund Rolstad Ken Olaf Storaunet Mikael OhlsonSammendrag
A key property of the boreal forest is that it stores huge amounts of carbon (C), especially belowground in the soil. Amounts of C stored in the uppermost organic layer of boreal forest soils vary greatly in space due to an interplay between several variables facilitating or preventing C accumulation. In this study, we split C stocks into the organic layer and charcoal C due to their difference in origin, stability, and ecological properties. We compared organic layer C and charcoal C stocks in two regions of south-central Norway (Trillemarka and Varaldskogen), characterized by Scots pine and Norway spruce forests with varying fire histories. We used structural equation modeling to investigate how vegetation composition, hydrotopography, and soil properties interplay to shape organic layer C and charcoal C stocks. Pine forests consistently contained larger organic layer C stocks than spruce forests. Charcoal stocks, in contrast, were less consistent across both forest types and study regions as pine forests had higher charcoal C stocks than spruce forests in Trillemarka, while the two forest types contained equal charcoal C stocks in Varaldskogen. Charcoal and soil organic layer C stocks increased with higher fire frequencies (number of fire events over the last 600 years), but not with a shorter time since last fire (TSF). Additionally, vegetation composition, terrain slope, and soil moisture were the most important drivers of the organic layer C stocks, while charcoal C stocks were mainly controlled by the depth of the organic layer. Also, microtopography was of importance for organic layer C and charcoal C, since depressions in the forest floor had more charcoal C than well-drained minor hills.
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Forfattere
Pia Heltoft ThomsenSammendrag
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Forfattere
Samuel L. Zelinka Samuel V. Glass Natalia Farkas Emil E. Thybring Michael Altgen Lauri Rautkari Simon Curling Jinzhen Cao Yujiao Wang Tina Künniger Gustav Nyström Christopher Hubert Dreimol Ingo Burgert Mark G. Roper Darren P. Broom Matthew Schwarzkopf Arief Yudhanto Mohammad Subah Gilles Lubineau Maria Fredriksson Wiesław Olek Jerzy Majka Nanna Bjerregaard Pedersen Daniel J. Burnett Armando R. Garcia Frieder Dreisbach Louis Waguespack Jennifer Schott Luis G. Esteban Alberto García‑Iruela Thibaut Colinart Romain Rémond Brahim Mazian Patrick Perré Lukas EmmerichSammendrag
Automated sorption balances are widely used for characterizing the interaction of water vapor with hygroscopic materials. This paper is part of an interlaboratory study investigating the stability and performance of automated sorption balances. A previous paper in this study investigated the mass, temperature, and relative humidity (RH) stability of automated sorption balances by looking at the mass change of a non-hygroscopic sample over time. In this study, we examine the mass stability of wood samples held at constant RH for seven to ten days after a step change. The reason for the long hold times was to collect data to “operational equilibrium” where the change in mass is on the order of the inherent operational stability of the instrument. A total of 80 datasets were acquired from 21 laboratories covering absorption with final RH levels ranging from 10 to 95%. During these long hold times, several unusual behaviors were observed in the mass-vs-time curves. Deviations from expected sorption behavior were examined by fitting the data to an empirical sorption kinetics model and calculating the root mean square error (RMSE) between the observed and smoothed behavior. Samples that had a large RMSE relative to the median RMSE of the other datasets often had one of several types of errors: abrupt disturbances, diurnal oscillations, or long-term mass decline during an absorption step. In many cases, mass fluctuations were correlated with changes in the water reservoir temperature of the automated sorption balance. We discuss potential errors in sorption measurements on hygroscopic materials and suggest an acceptable level of RMSE for sorption data.
Forfattere
Radosav Cerović Milica Fotirić Akšić Marko Kitanović Mekjell MelandSammendrag
Apple production in Western Norway faces challenges due to climatic constraints and varying phenology. It is essential for cultivars to adapt to regional ecological factors, while suitable pollinators are necessary for successful cultivation. This study examined the reproductive biology of two newly introduced apple cultivars, ‘Eden’ (Wursixo) and ‘Fryd’ (Wuranda), over two years (2022–2023). Key qualitative and quantitative parameters of reproductive biology were analyzed, including in vitro pollen germination, pollen tube growth within the style and ovary locules, flowering overlap time, and fruit set. The study involved cross-pollination between the pollen recipient cultivars ‘Eden’ and ‘Fryd’, with various pollenizers: ‘Rubinstep’, ‘Red Aroma’, ‘Elstar’, ‘Asfari’ and ‘Professor Sprenger’, as well as self-pollination and open pollination. According to the results from the progamic phase of fertilization and fruit set, the cultivars ‘Rubinstep’, ‘Asfari’, and ‘Fryd’ were the best pollenizers for ‘Eden’. In contrast, ‘Rubinstep’, ‘Eden’, and ‘Elstar’ were the best pollenizers for ‘Fryd’. Looking only at the overlapping of the flowering time between pollen recipient and pollen donor, ‘Professor Sprenger’ and ‘Fryd’ were the best pollenizers for ‘Eden’, while ‘Professor Sprenger’ and ‘Eden’ were good pollenizers for ‘Fryd’.
Forfattere
Eric Watkins Dominic P. Petrella Trygve S. Aamlid Dominic C. Christensen Sigridur Dalmannsdottir Andrew P. Hollman Gary DetersSammendrag
Ice encasement is a major concern for turfgrass managers in cold climates; however, there is a lack of data about both which turfgrasses are best suited for survival under these conditions and the reasons behind the superior recovery of some grasses from long-term ice encasement. In this study, we encased golf course putting greens-height field plots of creeping bentgrass (Agrostis stolonifera L.), velvet bentgrass (Agrostis canina L.), annual bluegrass (Poa annua L. var. reptans Hausskn.), Chewings fescue (Festuca. rubra L. ssp. commutata Gaudin), and slender creeping red fescue (F. rubra L. ssp. littoralis (G. Mey.) Auquier) with ice for 90–120 days with the inclusion of CO2, O2, and temperature sensors at 2.5 and 12.5 cm depth to better understand environmental conditions under ice and factors related to winterkill. Velvet bentgrass had the best overall performance and recovery, while annual bluegrass did not survive. Differences in recovery among turfgrass taxa may have been affected by the length of the ice encasement period, higher CO2 levels (>40,000 ppm), and lower O2 values, particularly in the second experimental run. During the recovery period in both years, photochemical efficiency values began increasing 5–10 days before percent green cover, suggesting that visual performance of the turf surface is a lagging indicator of recovery. Overall, recovery from ice encasement was annual bluegrass < Chewings fescue < creeping bentgrass = slender creeping red fescue = velvet bentgrass. These results can guide turfgrass managers in making species selection decisions in areas where long-duration ice encasement is a risk. Plain Language Summary Turfgrasses on golf course greens in cold climates can be severely damaged or even die from ice encasement. Little is known about this stress, including why certain grasses can survive longer. As a first step to learn more about this problem, we tested five different turfgrasses for their ability to survive under ice. The study was done during two separate winters in Minnesota under field conditions, resulting in 98 days of ice in 2021–2022 and 112 days of ice cover in 2022–2023. Annual bluegrass died completely during both experimental runs, while Chewings fescue suffered some injury in the first year and did poorly in the second year. Velvet bentgrass was the best grass in both years. Under the longer duration of ice cover in the second year, carbon dioxide levels were very high, while oxygen gas levels slowly declined over the course of the ice encasement period.
Forfattere
Attiq Ur Rehman Jahn Davik Petteri Karisto Janne Kaseva Saila Karhu Marja Rantanen Ismo Strandén Timo Hytönen Alan H. Schulman Tuuli HaikonenSammendrag
Key message Multiple QTLs for powdery mildew resistance were identifed in a pre-breeding population derived from the octoploid progenitor species of garden strawberry, including a stable major novel factor on chromosome 3B. Abstract Powdery mildew (PM), caused by the biotrophic fungal pathogen Podosphaera aphanis, poses an increasing threat to garden strawberry (Fragaria×ananassa) production worldwide. While a few commercial cultivars exhibit partial resistance, fungicide application remains essential for managing PM outbreaks. However, breeding ofers a more sustainable approach for controlling PM. A better understanding of the genetics of resistance is required for informed breeding strategies, e.g. through identifying novel resistance factors derived from the progenitor species of garden strawberry, F. chiloensis and F. virginiana. We conducted genome-wide association (GWA) and multivariate analyses in a reconstructed (ReC) strawberry population to investigate PM resistance under natural infection. Leveraging multi-year feld trial data and 20,779 singlenucleotide polymorphism markers, we identifed a novel major quantitative trait locus (QTL) on chromosome 3B, designated as q.LPM.Rec-3B.2, that was consistently associated with high PM resistance in both leaves and fruits. Greenhouse validation with a subset of the ReC population confrmed that this QTL region was stable across feld and greenhouse environments. Promising candidate genes for resistance, including two for MLO and one for EXO70, were identifed within this major QTL. In addition, multi-locus GWA models and non-additive GWA revealed additional resistance QTLs on multiple chromosomes. Despite previous challenges in breeding for robust PM resistance due to its quantitative nature and complex genetic control, our results provide valuable insights into resistance-contributing QTL regions already existing in strawberry, novel wildderived resistance QTLs not previously known, candidate genes, and pre-breeding germplasm carrying resistance traits as resources for future genome-informed breeding eforts.