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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.

2025

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Abstract

We studied the ability of extended rotations as a measure to promote sustainable management ofproduction forests in Nordic countries. We carried out scenario analyses for three large forestregions in Southern Finland, Central Sweden, and South-Eastern Norway, where forestry has a highsocioeconomic value. We analyzed the effects on wood production, carbon sequestration, and theamount of produced deadwood over the 50 years. In the reference scenario (BAU), the prevailingmanagement of production forests was applied. In the scenario for extended rotations (EXT),rotation lengths were extended by 30 years, on average. We used data from national forestinventories to represent the current stage of the regions’ forests and produced future forecastsusing local models, which have been widely applied in large-scale analyses. The increase in carbonsequestration and production of deadwood in production forests can be achieved by lengtheningrotations but only at the expense of harvesting removals. The increase in annual carbonsequestration is between 0.7 and 1.6 Mg CO2 eq ha−1. Natural mortality increases by 20–30% alongwith the amount of deadwood by 0.15 m3 ha−1 a−1, on average. The decrease in the mean annualharvesting removals varies from 0.4 to 1.6 m3 ha−1 a−1 from region to region.

Abstract

Boreal forest soils are a critical terrestrial carbon (C) reservoir, with soil organic carbon (SOC) stocks playing a key role in global C cycling. In this study, we generated high-resolution (16 m) spatial predictions of SOC stocks in Norwegian forests for three depth intervals: (1) soil surface down to 100 cm depth, (2) forest floor (LFH layer), and (3) 0–30 cm into the mineral soil. Our predictions were based on legacy soil data collected between 1988 and 1992 from a subset (n = 1014) of National Forest Inventory plots. We used boosted regression tree models to generate SOC estimates, incorporating environmental predictors such as land cover, site moisture, climate, and remote sensing data. Based on the resulting maps, we estimate total SOC stocks of 1.57–1.87 Pg C down to 100 cm, with 0.55–0.66 Pg C stored in the LFH layer and 0.68–0.80 Pg C in the upper mineral soil. These correspond to average SOC densities of 15.3, 5.4, and 6.6 kg C m−2, respectively. We compared the predictive performance of these models with another set, supplemented by soil chemistry variables. These models showed higher predictive performance (R2 = 0.65–0.71) than those used for mapping (R2 = 0.44–0.58), suggesting that the mapping models did not fully capture environmental variability influencing SOC stock distributions. Within the spatial predictive models, Sentinel-2 Normalized Difference Vegetation Index, depth to water table, and slope contributed strongly, while soil nitrogen and manganese concentrations had major roles in models incorporating soil chemistry. Prediction uncertainties were related to soil depth, soil types, and geographical regions, and we compared the spatial prediction against external SOC data. The generated maps of this offer a valuable starting point for identifying forest areas in Norway where SOC may be vulnerable to climate warming and management-related disturbances, with implications for soil CO2 emissions.

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In recent years, biochar loaded with urea has been proposed as a promising N-rich fertilizer with both high-N capacity and slow release. Understanding the interaction between urea and biochar at the molecular level is key to product design. Solid-state NMR (SSNMR) spectroscopy is a particularly powerful method to probe molecular composition and interactions within the bulk of materials. The objective of this work was to identify molecular structures and interactions when urea is loaded into and released from biochar. To do so, we carried out SSNMR investigations of biochar loaded with 13C and 15N isotopically enriched urea. Biochar-urea composites were prepared both with a saturated aqueous urea solution (BUs) and with molten urea (BUm). SSNMR analysis revealed that urea is predominantly in a paracrystalline form on the biochar surface or physically entrapped within biochar pores. In BUm, products of the thermal degradation of urea were also detected, mainly in the form of biuret. Water-immersion experiments showed that 78 and 64% of the urea contained in BUs and BUm is released, respectively, after 24 h, demonstrating substantial retention of urea. The residual urea is mainly physically confined in the biochar pores. In the case of BUm, urea thermal degradation species are also partially retained.

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Many countries have goals to reduce soil sealing of agricultural land to preserve food production capacity. To monitor progress, reliable data are needed to quantify soil sealing and changes over time. We examined the potential of the Imperviousness Classified Change (IMCC) 2015–2018 product provided by the Copernicus Land Monitoring Service (CLMS) to assess soil sealing in agricultural areas in Poland and Norway. We found very high overall accuracy due to the dominance of the area with no change. When we focused on areas classified as change, we found low user accuracy, with over-estimation of soil sealing. The producer accuracy was generally much higher, meaning that real cases of soil sealing were captured. This is better than under-estimation of soil sealing because it highlights areas where sealing may have occurred, allowing the user to carry out further control of this much smaller area, without having to assess the great expanse of unchanged area. We concluded that the datasets provide useful information for Europe. They are standardized and comparable across countries, which can enable comparison of the effects of policies intended to prevent soil sealing. Some distinctions between classes are not reliable, but the general information about increase or decrease is useful.

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This chapter explores the implementation of the smart city idea in Stavanger Municipality. While smart city ideas are internationally varyingly defined, Stavanger co-developed and adopted a local and national roadmap for smart city implementation in the municipality. This qualitative case study explores how the office, established for the smart city implementation in Stavanger, coped with the implementation process in practice, considering respectively rational, natural, new institutional, and translation theory perspectives of organizational change. Data were collected from spring 2019 to spring 2020, employing qualitative interviews and document analyses of semi-annual reports (2018–2019), to explore the research question: What happened with smart city ideas under their implementation in the Stavanger Municipality, in view of selected organizational change theory? The data were analyzed by applying pre-elaborated theory-derived checkpoints. Findings indicate that the Stavanger Municipality seems to have implemented the smart city idea during processes strongly related to established organizational culture. During various stages of the process, each of the considered organizational change theories were reflected, dependent on the time of evaluation, culminating in the establishment of translation competence in the organization. The study’s findings and view of understanding may inspire and critically prepare other medium-sized urban municipalities on their way to becoming smart cities.

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Abstract

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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Abstract

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