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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

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Forests can be established through active methods like planting or direct seeding, or passive approaches that rely on natural regeneration. Each method has its own advantages and challenges, especially in the context of climate change. The choice of forestation methods (afforestation, reforestation, and restoration) must consider environmental factors, including soil conditions and past land use, which significantly influence the likelihood of successful regeneration. Ecological objectives, such as promoting beneficial biodiversity and soil health, are increasingly recognized, as well as more traditional productivity-oriented objectives, in adapting to environmental pressures and altered climate. Increasingly, the aim is to establish mixed-species forests, which are more resilient to climate change, pests, and diseases. This chapter discusses forward-looking practices for climate-responsive site preparation, direct seeding, planting, and natural regeneration. Natural regeneration relies on the natural dispersal of seeds, while artificial methods allow for greater control over outcomes. Seedling characteristics and species traits must be aligned with site conditions to enhance establishment success. Direct seeding is a viable method for large-scale forest regeneration if the necessary conditions are met. Recent technological advancements in seed treatment and mechanical seeding techniques can improve germination rates and seedling survival. The main goal of site preparation is to create optimal conditions for young plants, and innovative approaches for assessing and improving these conditions are introduced, including precision seeding and enhancing beneficial microbiomes at planting sites. The presence or absence of an overstory significantly influences seedling establishment. Overstory cover can either enhance or suppress seedling growth through resource competition and microclimate regulation. Site preparation must balance light and moisture availability and temperature. Innovative strategies for improving forest regeneration have emerged, including the use of introduced species and selected genetic materials better suited to changing climatic conditions. Plant-associated and soil microbes enhance seedling establishment, and beneficial microbiomes that favor seedling growth and health can be introduced in the nursery or on sites to support sustainable forestation. Nurse trees can provide sheltered environments that mitigate abiotic stress on seedlings. Remote sensing and digital technologies are important in precision forestry. Drone-assisted techniques for site inventory and monitoring can potentially improve data collection and monitoring and provide practitioners with timely information for decision-making. Overall, this chapter provides a comprehensive overview of forward-looking practices that aim to enhance forest resilience and sustainability in the face of climate change.

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Seedling functional attributes (i.e., morphological and physiological traits driving water, carbon, and nutrient economy, as well as stress resistance and resilience) influence the early performance of forest plantings. Nursery environment and cultivation practices interact with species ecology to shape these attributes and potential outplanting success. Although extensive literature exists on these topics, studies that have quantitatively synthesized findings to generalize plant quality and nursery cultivation theory are almost nonexistent. This chapter quantitatively reviews the effects of (1) seedling size and shoot-to-root mass ratio (S/R) and (2) several nursery cultivation practices on outplanting survival and growth. Examined practices include stock type (container vs. bareroot (BR)), drought and blackout hardening, container properties in oaks and pines, and growing media alternatives to peat. For this, we developed different databases compiling information at a global scale from scientific and technical literature in different languages. Seedling size significantly enhances outplanting survival when comparing seedlings of the same age, while S/R does not. Stocktype and species-specific leaf area (SLA), a trait related to resource acquisition capacity and stress resistance in plants, modulate the effect of morphology on survival, particularly on arid sites. In dry climates, large seedlings have a survival advantage over small seedlings in low SLA species (i.e., slow growth and high stress resistance plants) cultivated in containers, if water stress is mitigated through intensive soil preparation, and using 1-year-old seedlings. When stock types differ in survival, container plants usually outperform BR stock, especially if soil preparation is performed, and under dry and high weed competition conditions. Drought hardening improves survival, especially in shrubs, but can negatively affect survival in drought-sensitive species on low aridity sites. Blackout reduces field growth, particularly in drought-tolerant species. The effect of container characteristics on survival differs between oaks and pines: for oaks, reducing plant spacing in small to moderate containers (<400 mL) is preferable to maximize survival, while for pines, increasing container depth is more effective. Peat alternatives, including manure, organic waste, and rice hulls, improved survival, whereas sludge performed poorly. Rice was most effective on humid sites, while manure and organic waste showed consistent benefits across climates. Our findings highlight the potential for peat alternatives, with effectiveness depending on local ecological and economic conditions. Based on these results, we provide recommendations to match seedlings’ size and S/R to species' SLA, stocktype, soil preparation intensity, and aridity of the planting site, along with cultivation guidelines for producing such a variety of seedlings.

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The increasing frequency of droughts and heavy rainfall is intensifying conflicts between agricultural water use and other human and environmental demands. Natural/Small Water Retention Measures (NSWRMs) can help mitigate these conflicts by enhancing water quality, improving agricultural resilience, and contributing to sustainable development goals. However, there are knowledge gaps about the effectiveness of these measures across different regions, scales, and climate conditions. The EU Horizon 2020 project OPTAIN aims to address these challenges in 14 European case studies. The project involves local stakeholders through Multi-Actor Reference Groups, which have identified and documented 235 potential NSWRMs, of which 66 from 29 categories have been selected for further evaluation. These measures are catalogued in collaboration with the WOCAT and NWRM.eu databases. To assess the impact of these NSWRMs at field and catchment scale, OPTAIN applies the SWAT+ model with a fully distributed routing scheme, accompanied by further field-scale simulations using SWAP in areas of high data availability. The project developed protocols and R scripts to standardize data preparation, model calibration, and evaluation across case studies, ensuring consistent analysis. Initial simulations in the German case study demonstrate positive effects of NSWRMs, such as low tillage and grassed waterways, in reducing peak water flows, increasing low flows, and enhancing nutrient and sediment retention. Furthermore, the project linked SWAT+ with an economic model using the CoMOLA platform to optimize NSWRM allocations based on environmental and economic criteria. Policy analysis is another important component of OPTAIN, with local and regional policies being reviewed to identify gaps and opportunities for harmonizing water and agricultural policies across Europe. Interim findings, shared through policy briefs, emphasize the need for better integration of agro-environmental policies, increased intersectoral collaboration, and awareness-raising among stakeholders. OPTAIN's overarching goal is to improve the acceptance and implementation of NSWRMs by harmonizing data, methods, and policies across the 14 case studies. While there are significant differences between countries, which pose challenges for comparative studies, the project is working to address these through data standardization and model improvements. The R scripts developed by the project will assist future SWAT+ users worldwide in setting up and calibrating models to evaluate the effectiveness of NSWRMs in water and nutrient retention. Ultimately, OPTAIN aims to optimize the spatial allocation and combination of NSWRMs, ensuring they are both environmentally and economically sustainable, while also promoting policy alignment at local, national, and EU levels.

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Invasive species are one of the greatest threats to biodiversity. However, our understanding of how these species persist and spread in novel environments remains limited. Specifically, the relative importance of species interactions versus environmental conditions and the role of rapid evolutionary adaptation are not fully understood. Here, we investigate the impact of these factors on the distribution of the invasive Himalayan balsam ( Impatiens glandulifera ). We examined whether the climatic niche of the species is pre-adapted to the environmental conditions in the introduced range through niche modeling. Field surveys were conducted to assess the importance of herbivory and competition, and greenhouse treatments were used to investigate local adaptation. We found that the species has not yet fully occupied the suitable climatic space in its introduced range in Europe. Our results suggest that the species may have experienced enemy release while also facing increased biotic pressure at the northern range edge. We identified adaptive differentiation in flowering time, which enhances reproductive success when plants grow in climates similar to their origin. Our results indicate that Himalayan balsam has rapidly adapted to differences in growing season length in its introduced range, with trait plasticity providing an adaptive advantage. Together, these findings suggest that the species may continue to spread across its introduced range in Europe.

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Schistidium pratense and S. heribertii, two distinctive and locally abundant components of the Alpine flora, are here formally described as new species from Europe. Although recognised for over two decades, their official taxonomic treatment has been long overdue. This paper provides an integrative account, combining morphological and molecular evidence, outlining their currently known distribution, and discussing their relationships to related species. Schistidium pratense is closely allied to S. dupretii in both molecular and morphological traits but differs in its larger overall size, including longer shoots and leaves, as well as in the absence of stomata. Schistidium heribertii resembles S. atrofuscum in its black coloration but is distinguished by its prominent leaf hairpoints and a pruinose appearance on the upper parts of the shoots. Molecular analyses place S. heribertii as the sister species to the clade comprising S. atrofuscum and S. helveticum. Both new species share similar ecological preferences, typically colonising calcareous substrates. Schistidium pratense is widespread and locally abundant in subalpine pastures, while S. heribertii has a more scattered distribution and predominantly inhabits warm sites across a broad elevational range in valleys with a continental climate. To date, S. heribertii is known only from the Alps, whereas S. pratense has also been recorded in Scandinavia, the Dinarides, the Apennines and the Black Forest in Germany

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Research on Sonchus arvensis  L. is underrepresented despite its status as a widespread perennial arable weed in the Northern Hemisphere. This study investigates, based on a comparison of literature data and recent plant metric data, whether there are indications of a problematic expansion in Germany and identified two knowledge gaps. The recent plant metric data were taken between 2019–2024 at various sites in Germany, Norway, and Finland. We structured the results in subchapters along the life-stages of S. arvensis given in their headings: ‘Propagules in the soil’, ‘Plant establishment’, ‘Rosette growth’, ‘Plant height’, ‘Seed production’ and ‘Plant senescence’. In Germany, S. arvensis has a rosette diameter measuring 34–58 cm and a height of 40–98 cm, although a height of up to 220 cm has been recorded in 2024 in Germany. Rosette diameter and plant height data indicate at least no smaller sizes compared to studies and plant metric data from other countries. Notably, 142 seeds per head were counted in Germany, indicating a source for successful spatial spreading. We address two knowledge gaps related to the research question in the title. One regarding whether vegetative growth contributes to the spread of S. arvensis , and another concerning how its phenological development is influenced by temperature and photoperiod. In addition, we recommend monitoring the species biology and ecology on agricultural fields in Germany.

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Norway has positioned itself as a climate policy forerunner by aiming to reach net-zero emissions already by 2030. However, the net-zero ambition is not well-defined, not legally binding, nor substantiated by action plans. In a first, interdisciplinary, analysis we scrutinise the net-zero concept and discuss unilateral options. Second, we provide an economic analysis with a global computable model, SNOW, of the costs and macroeconomic impacts of various policy scenarios. It explores how the net-zero ambition interacts with other 2030 goals and quantifies the impacts of emphasising domestic abatement and carbon removal measures vs. paying for emission mitigation abroad. Finally, the 2030 results are revisited to assess how well they align with Norwegian and global climate targets for 2050. The main findings are that pursuing the net-zero ambition, on top of other binding 2030 goals Norway is already committed to, will increase costs by 25–100% depending on the use of domestic measures. On the margin, domestic measures are found to have only small, uncertain, and costly mitigation potential, thus, buying international carbon credits will be inevitable. Besides being significantly cheaper, carbon trading can have the potential benefits of developing the credit markets and the individual projects’ qualities. Even if domestic measures can play but a modest part in the net-zero strategy towards 2030, we identify several steps governments unilaterally can take today to expand abatement opportunities towards mid-century. We also find measures that seem cost-effective in pursuing 2030 goals but look less attractive against a global 2050 backdrop.

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The multitasking lesser mealworm ( Alphitobius diaperinus ) is a special beetle known as a pest in poultry, a resource for waste degradation and an alternative for protein production. This study compares the predictive accuracy of correlative species distribution models (SDMs) with a risk index derived from a mechanistic model. The study derives the mechanistic‐based risk index from the ordinary differential equation that describes the population dynamics of A. diaperinus using the temperature‐dependent bio‐demographic rates, while the ensemble SDM is derived using well‐known algorithms such as maximum entropy, random forest and so forth. We finally propose a hybrid model combining both approaches using a weighted average approach. When overlaid on occurrence data, the predictive accuracy of the mechanistic model globally varied across temporal scales, with the highest performance observed in the October–December quarter (27% of occurrences were predicted correctly). The comparison across geographic regions model had the best performance in Asia (94.4% accuracy), outperforming the two scenario SDMs (78.3%). In contrast, the correlative ensemble SDM performed better in Europe (93%), where we have most of the data, but was very sensitive to data gaps, especially in Africa. Finally, the proposed hybrid model outperforms both individual models in the global scenario (86.5% accuracy). These findings highlight the strengths and limitations of both modelling approaches and provide critical insights to optimise pest management strategies, sustainable utilisation and ecological forecasting by refining SDM through the integration of biological realism and empirical data.