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
Authors
Yi Wang Junjia Qi Meihui Wang Zhenke Zhu Yong Li Zhenghui Lv Jinyi Yu Haolin Yang Jian Liu Yuchen Lv Ying ZhaoAbstract
Ecological stoichiometry offers a mechanistic framework for linking soil biogeochemical processes with nitrogen (N) and phosphorus (P; collectively, NP) runoff losses in agroecosystems. This review synthesizes recent advances to elucidate how soil carbon: nitrogen: phosphorus (C:N:P) ratios regulate NP runoff losses through coupled soil–microbial processes. Crucially, we highlight that agricultural practices reshape soil stoichiometry primarily through labile nutrient pools and microbial biomass, whereas total soil nutrient ratios generally remain stable due to strong buffering capacity. Due to the relatively weak stoichiometric homeostasis of soil microorganisms, these shifts in labile C:N:P ratios strongly constrain microbial growth, community composition, and enzyme production. Consequently, stoichiometric imbalance acts as a primary regulator of key biochemical pathways—specifically soil organic carbon (SOC) mineralization, nitrification, and denitrification—that determine the mobilization of inorganic NP forms prone to runoff. Stoichiometric regulation exhibits dual characteristics of integration and independence. Soil C:N:P ratios simultaneously influence multiple biochemical processes, while each process responds to stoichiometric constraints with distinct threshold behaviors. These thresholds can be described by process-specific stoichiometric boundary limits, expressed as (C : N/P)max, beyond which reaction rates approach zero under element-limiting conditions. Despite growing empirical evidence, most existing models fail to explicitly incorporate these microbial-mediated stoichiometric constraints or (C : N/P)max thresholds, leading to predictive uncertainties. By framing NP runoff losses as emergent outcomes of stoichiometrically constrained processes, this review provides a robust theoretical basis for improving runoff modeling accuracy and developing stoichiometry-guided soil management strategies to mitigate agricultural non-point source pollution.
Abstract
Introduction Leaf area index (LAI) estimation is sensitive to sensor field of view (FOV), within-plot spatial heterogeneity, and sampling layout. Because LAI influences canopy radiation transmission, microclimate and vegetation–atmosphere exchange, robust field estimation is important for biometeorological and ecosystem research. Methods We evaluated these effects in mature Norway spruce [ Picea abies (L.) H. Karst] stands in the Czech Republic across 15 sites at elevations of 407–1,019 m a.s.l., using a combined gap-fraction approach based on LAI-2200 PCA measurements and digital hemispherical photography. At each site, a measured 9 × 9 grid of 81 below-canopy measurement points with 2-m spacing was used as an operational within-plot benchmark for mean optically derived LAI and spatial structure. Monte Carlo subsampling was then used to compare how reduced layouts, including random, row-wise, column-wise, block-wise, and spatially balanced block–row–column layouts, reproduced the full-grid benchmark mean. Results Narrower FOVs produced higher stand-level optically derived LAI estimates and greater within-plot variability. The full grids also showed directional spatial structure, with stronger autocorrelation along the north–south column direction than along the west–east row direction, although this contrast weakened under the narrowest FOV. Reduced layouts with more even spatial coverage outperformed random sampling. The spatially balanced block–row–column layout performed most consistently, whereas the row-wise layout provided little improvement. Approximately 25–36 well-distributed below-canopy measurements were sufficient to keep reduced-layout LAI deviations within 0.15 m 2 m −2 of the full-grid benchmark, whereas 7–9 measurements were enough to remain within 5% of this benchmark in most stands. Discussion Spatially balanced sampling can therefore improve the robustness and efficiency of stand-level optically derived LAI estimation, with relevance to forest biometeorology, ecosystem monitoring, and the validation of satellite-derived LAI products.
Abstract
Semi‐natural grasslands are valuable habitat for bumblebees ( Bombus spp.) in Fennoscandia. These grasslands are often maintained by livestock such as free‐ranging sheep, but it is unclear if sheep grazing impacts bumblebee communities, and if so, which grazing intensity is best. We compared bumblebee species richness and abundance on semi‐natural grasslands in southeastern Norway at varying levels of disturbance by sheep (0–1680 initially released). We used Bayesian hierarchical models to test the intermediate disturbance hypothesis, that the highest bumblebee abundance and richness would occur at moderate grazing intensity, while considering other important habitat variables: distance to forest, meadow size, sward height, and availability of flowers, litter, and bare soil. We found no support for the intermediate disturbance hypothesis but rather a negative relationship between the number of sheep released and measures of bumblebee species richness and abundance from targeted netting. Effects varied among the most common species. B. pratorum and B. wurflenii were more sensitive to the number of sheep released than were B. jonellus . Bumblebee abundance estimated by two capture methods (blue vane trapping and targeted netting) was only weakly correlated and bumblebee species richness estimated from traps was unrelated to any of our predictor variables. Practical implication . Our results suggest a weak negative influence of any amount of sheep grazing on bumblebee abundance and richness. Targeted netting was a more reliable method than blue vane traps to assess effects on the bumblebee community.
Authors
Simone Bianchi Cornelia Roberge Johannes Schumacher Johannes Breidenbach Kari T. Korhonen Harri MäkinenAbstract
Sustainable forest management needs growth models. Few studies have explored regional models in Fennoscandia despite similar conditions and challenges. We examined the feasibility of regional models for basal area increment of Norway spruce (Picea abies (L.) Karst.), Scots pine (Pinus sylvestris L.), and birch (Betula pendula Roth. and Betula pubescens Ehrh.). We compiled over 880,000 growth observations and estimated competition indices, climate variables, and site fertility classes by integrating data from recent National Forest Inventories (2004–2023) in Finland, Norway, and Sweden. Using Random Forest models, we identified the main growth drivers across countries (tree size, accumulated temperature sum, latitude, competition, and site fertility), with minor differences in their responses across countries. However, periodic NFI measurements could not capture the effect of additional climate variables. Using species-specific nonlinear mixed models, we demonstrated that predictive regional models can be fitted using those main drivers. Although we achieved only moderate predictive performance (Weighted Absolute Percentage Error of 45–71%, depending on the species and country), there were no residual geographical biases. The results confirm the potential of Fennoscandian growth models to address shared challenges. Future work should better account for site fertility, integrate process-based approaches for climate responses, and carry out independent validation.
Abstract
The four main apple cultivars in Norway, ‘Discovery’, ‘Summerred’, ‘Red Gravenstein’, and ‘Red Aroma’, account for approximately 80% of the market volume. These cultivars provide good yields in a Nordic climate with a short growing season but have relatively limited storage and shelf life. The main challenges are the rapid loss of firmness and senescence-related disorders, both of which are connected to ripening and ethylene. Several projects investigated possible ways to secure fruit quality at the consumer level by improving conditions at the packinghouse. One of the factors to evaluate was ethylene levels in fruit storage rooms. Ethylene concentrations were measured in cold storage rooms with varying volumes of fruit using a portable instrument equipped with an electrocatalytic sensor for continuous, in-situ measurement of ethylene in the air. Ethylene concentrations between 10 and 35 ppm were measured in 18% of the rooms, whereas 82% had concentrations between 0 and 10 ppm. Fruit samples were assessed for ethylene production rates in their expected cold storage period. The values obtained were used to evaluate the risk of high ethylene levels in certain rooms before packaging, to recommend which cultivars could be kept in the same rooms, and for how long. Treatment with 1-methylcyclopropene (1-MCP) was also tested to improve fruit quality during storage further. The 1-MCP treatment revealed considerable potential for maintaining the postharvest quality of the tested Norwegian apples.
Authors
Geir Wæhler Gustavsen Philip Bester Van Niekerk Jonas Niklewski Christian Brischke Gry AlfredsenAbstract
This cross-country study examineed perceptions of maintenance for coated wooden cladding in residential buildings across Norway, Sweden, and Germany. As timber cladding gains popularity in European homes, understanding expectations around cleaning, recoating, and replacement intervals becomes increasingly important. An online survey gathered responses from over 3,000 participants aged 18–89, randomly selected from representative regional panels in each country. The survey focused on the perception of maintenance practices and intervals, while also collecting data on personality traits, risk aversion, and socioeconomic background. Perceived maintenance practices for coated timber cladding differed across countries, but individual characteristics were generally more influential than national context. Most respondents accepted longer cleaning intervals than recommended, while their preferences more closely aligned with guidelines for recoating. Acceptance of replacement intervals varied markedly by country. Longer acceptable maintenance intervals were associated with a higher preference for uncoated cladding, particularly in Germany and Sweden. Younger age, urban residence, limited experience, and selected demographic and personality traits were linked to more intensive maintenance preferences.
Authors
Binbin Xiang Maciej Wielgosz Stefano Puliti Kamil Král Martin Krůček Azim Missarov Rasmus AstrupAbstract
The segmentation of forest LiDAR 3D point clouds, including both individual tree and semantic segmentation, is fundamental for advancing forest management and ecological research. However, current approaches often struggle with the complexity and variability of natural forest environments. We present ForestFormer3D, a new unified and end-to-end framework designed for precise individual tree and semantic segmentation. ForestFormer3D incorporates ISA-guided query point selection, a score-based block merging strategy during inference, and a one-to-many association mechanism for effective training. By combining these new components, our model achieves state-of-the-art performance for individual tree segmentation on the newly introduced FOR-instanceV2 dataset, which spans diverse forest types and regions. Additionally, ForestFormer3D generalizes well to unseen test sets (Wytham woods and LAUTx), showcasing its robustness across different forest conditions and sensor modalities. The FOR-instanceV2 dataset and the ForestFormer3D code are publicly available at https://bxiang233.github.io/FF3D/.
Authors
Theresa Weigl Jorunn Børve Emily Follett Ingunn Øvsthus Carl Gunnar Fossdal Hanne Larsen Siv Fagertun RembergAbstract
The mid-early-ripening cultivar ‘Summerred’ is popular among consumers and widely grown in Norway. However, ‘Summerred’ fruit is prone to rapid softening and development of senescence-related disorders, especially senescent breakdown. Calcium can have a significant role in maintaining firmness and delaying senescence of fruits. In a two-year study, foliar application of calcium chloride (CaCl2) was conducted six times, with varying weather conditions between the growing seasons. Fruit was harvested at optimal commercial maturity and stored at 4°C for either 6 or 9 weeks, followed by simulated shelf-life conditions at 20°C. Ethylene levels were monitored during storage to detect ripening discrepancies. At harvest, CaCl2-treated fruit exhibited significantly lower ethylene production compared to untreated fruit, although no differences were observed at the end of the storage period. Senescent breakdown showed significant variability between the two seasons, with an incidence of up to 15% in the first season and nearly no incidence in the second. Senescent breakdown increased with storage duration but was unaffected by foliar CaCl2 application. Real-time PCR analysis of fruit flesh samples revealed increased expression of polygalacturonase and β-galactosidases genes after storage, indicating their involvement in apple softening. Notably, there were no differences in gene expression between CaCl2-treated and untreated fruit after storage. Expression patterns of genes involved in ethylene biosynthesis at harvest were different between the two seasons. Higher expression was observed in the year with greater disorder development, indicating greater maturity at harvest. There were no significant differences in the Streif index between the two years.
Abstract
Timothy is the primary forage grass seed crop in Norway, where effective control of dicot weeds and lodging management are critical to maximizing seed yield and meeting seed purity standards. Optimal timing of gibberellic acid–inhibiting plant growth regulators (PGRs), such as chlormequat chloride (CCC) and trinexapac-ethyl (TE), often coincides with spring herbicide applications, raising concerns about crop safety and herbicide efficacy when products are tank-mixed. Field experiments were conducted in 2022 and 2023 at two locations in Norway to evaluate the effect of tank-mixing PGRs with commonly used herbicides on seed yield and quality, weed control, and lodging in timothy. Plant growth regulators (CCC (1500 g ai ha⁻¹) and TE (150 g ai ha⁻¹) were applied either as split applications (herbicide at BBCH 25; PGR at BBCH 35) or tank-mixed (BBCH 30–35) with one of three herbicide combinations: fluroxypyr + florasulam, florasulam + diflufenican, or aminopyralid + 2,4-D + florasulam. Seed yield was affected by PGR (P ≤ 0.05) but not by herbicide treatments. TE reduced plant height and lodging more than CCC; however, relative yield responses varied with stand age. Tank-mixing did not reduce seed yield and herbicide efficacy. Crop injury from tank-mixtures was minimal and temporary, and no reductions in final seed germination were observed. Tank-mixing CCC and TE PGRs with herbicides provided effective weed control and maintained optimal seed yield and quality, offering operational flexibility for timothy seed producers.
Authors
Pia BorgAbstract
We compared written guidance on date marking on the websites of Norwegian Food Safety Authority, Swedish Food Agency, and the Danish Agriculture and Fisheries Agency. We also compared what the three authorities write about guidance as a tool .