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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

Sammendrag

1. The results of nature restoration efforts have been characterized as notoriously unpredictable. Many variables impact the trajectory of species communities towards recovery, and ecological theory that takes traits, habitat configuration and scale into account, can improve models. However, the most important questions regarding the predictability of species community restoration may be related to stochasticity. 2. We investigated the assembly of a cyanolichen community in a chronosequence consisting of 88 new forest patches (30–140+ years old) comprising today 0.4% of a 170 km2 former treeless heathland area in south-western Norway. Two complete inventories were carried out 12 years apart, and we (1) tested inferences on colonization status and recovery time based on the first inventory only; (2) investigated the recovery of the lichen community by changes in species richness, species density and composition at three different spatial scales; and (3) discussed how dispersal capacity and stochasticity affect community recovery in general. 3. Colonization of sites by lichen species exceeded extinctions in young sites but not in old sites, and in the second inventory, the richness of species weighed by occurrences no longer differed significantly between young and old sites at landscape scale. However, the differences between old and young sites depended on the spatial scale and method of measurement. 4. In accordance with inferences based only on the first inventory, colonization and extinction dynamics indicated that recovery of species richness in our study system will take 90–120 years at the landscape scale, whereas recovery of species composition was difficult to determine due to idiosyncratic development among sites. 5. Synthesis and applications. Using species composition as a template for the evaluation of restoration recovery in systems with a high degree of stochastic colonization and extinction is problematic, particularly at finer scales. Ideally, comparisons of restoration and reference communities should therefore be at large enough spatial scale to cancel out the major effects of stochasticity at finer scales. Furthermore, we suggest that a complete recovery of species numbers may not be needed as an indicator of restoration success if species richness measurements indicate that communities are en route to recovery.

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Sammendrag

Large‐scale re‐/afforestation projects afford sizable atmospheric CO2 removals yet questionsloom surrounding their potentially offsetting biogeophysical radiative forcings. Forest area change alters notonly the surface albedo but also heat, moisture, and momentum fluxes, which in turn modify the atmosphere'sradiative, thermodynamical, and dynamical properties. These so‐called radiative forcing “adjustments” havebeen little examined in re‐/afforestation contexts, and many questions remain surrounding their relevance inrelation to the instantaneous forcing from the surface albedo change—and whether they can affect Earth'sradiative energy balance in regions remote from where the re‐/afforestation occurs. Here, we quantifiedbiogeophysical radiative forcings and adjustments from realistically scaled re‐/afforestation in Europe at highspatial resolution and found that adjustments with high signal‐to‐noise were largely confined to only a fewmonths and to the region of re‐/afforestation. Adjustments were dominated by perturbed low‐level clouds andrarely exceeded ±25% of the annual albedo change forcing.

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Sammendrag

Wood-degrading brown-rot fungi primarily target carbohydrates, leaving the lignin modified and potentially valuable for valorization. Here, we report a comprehensive comparison of how Gloeophyllum trabeum in vitro degrades hardwood and softwood, which have fundamentally different lignin structures. By harnessing the latest advancements in analytical methodologies, we show that G. trabeum removes more lignin from wood (up to 36%) than previously reported. The brown-rot decayed lignin appeared substantially Cα-oxidized, O-demethylated, with a reduction in interunit linkages, leading to formation of substructures indicative of Cα-Cβ, β-O, and O-4 cleavage. Our work shows that the G. trabeum conversion of hardwood and softwood lignin results in similar modifications, despite the structural differences. Furthermore, lignin modification by G. trabeum enhances the antioxidant capacity of the lignin and generates an extractable lower molecular weight fraction. These findings improve our understanding of lignin conversion by brown-rot fungi and highlight their biotechnological potential for the development of lignin-based products.

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Sammendrag

Climate change poses an unprecedented threat to forest ecosystems, necessitating innovative adaptation strategies. Traditional assisted migration approaches, while promising, face challenges related to environmental constraints, forestry practices, phytosanitary risks, economic barriers, and legal constraints. This has sparked debate within the scientific community, with some advocating for the broader implementation of assisted migration despite these limitations, while others emphasize the importance of local adaptation, which may not keep pace with the rapid rate of climate change. This opinion paper proposes a novel pollen-based assisted migration strategy as a potential middle ground in this debate. By leveraging existing seed orchard infrastructure for controlled pollen transfer, this approach aims to enhance forest resilience through the introduction of genetic material from climatically suitable sources while acknowledging local adaptation. We assess the genetic implications of the proposed strategy through computer simulation. Additionally, we examine the ecological implications of assisted gene flow, discussing the potential benefits of heterosis and the risks of outbreeding depression in intra-specific hybrid populations. We further explore the advantages of pollen-based migration in mitigating phytosanitary risks, reducing economic barriers, and simplifying legal considerations compared to traditional seed or seedling transfer methods. Regional perspectives on adapting pollen-based assisted migration are provided, with specific examples from Northern and Central Europe. We highlight how this approach could be integrated into existing forestry practices and regulatory frameworks within the European Union. We conclude by advocating for the inclusion of pollen-based assisted migration in future international projects and operational forestry, emphasizing the need for adaptable policies that can support innovative forest management strategies in the face of climate change.

Sammendrag

This study presents information about the variability between and within populations of Norway spruce in lammas shoot formation. Assessments of lammas shoots were conducted in two short-term trials involving full sib families of Norway spruce from two complete diallel crosses, each originating from a natural population. These assessments were made over two growing seasons when the trees were six and seven years from seed, during which early summer temperatures varied significantly. The trees were grown on former agricultural land with large variation in soil fertility across the field. The proportion of trees with lammas shoots varied among blocks, ranging from 1 to 14 %, with the highest values in the blocks with the most fertile soil conditions. A substantial variation was also found among families from each population regarding the percentage of trees with lammas shoots, varying among half-sib families from 2 to 20 % and 1 to 19 % in the two populations, respectively. The largest part of this genetic variation was additive, with high values for the general combining ability (GCA) variance components and low values of the specific combining ability (SCA), maternal and reciprocal components. Estimates of narrow sense heritability were 0.40 for transformed lammas shoot scores in both diallels. Generally, families with an early start and early cessation of shoot elongation had the highest frequency of lammas shoots. In one of the diallels, families with a high lammas shoot percentage also had the highest number of ramicorn branches in a field trial at age 12 and 26 years from seed.

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Observations of two apparent phenotypic expressions (morphodemes) of the composite thallus of the lichen-forming ascomycete species Ricasolia amplissima (Scop.) De Not. (formerly Lobaria amplissima (Scop.) Forss.) inspired us to investigate the morphological and genetic variation of the species in Norway. The morphodemes differ in thallus shape and occurrence of apothecia and/or cephalodia, each dominating in climatically different parts of southern Norway. We investigated the morphology of herbarium collections as well as fresh samples from various areas, including localities where the two morphodemes occur together. The nrITS barcode marker was sequenced to investigate the genetic variation along the climatic gradient of the Hardangerfjord area. We also included barcode sequences of specimens from other parts of the world in order to establish if the Norwegian pattern of variation has a wider geographical significance. Results suggest that the genetic variation found in Ricasolia amplissima corresponds to morphology independently of geography/climate. The two haplotype groups cluster in two distinct sister clades, however, the within-species variation is too small to justify taxonomic recognition. Specimens with the cephalodiate morphodeme and its haplotypes are mainly found in the oceanic west, whereas specimens with apotheciate morphodemes and its haplotypes occur mainly in the drier eastern parts. The results can be interpreted as 1) immigration to Norway from different gene pools in separate glacial refugia, or, 2) natural selection for water efficient cephalodiate morphodemes in the oceanic west and apotheciate (sexually reproducing) in drier suboceanic east parts of Norway. We argue that within-species genetic variation should always be considered before conservation actions such as transplants of lichen thalli are taken.

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Sammendrag

With increased focus on sustainable building materials and the growing popularity of uncoated wooden cladding, understanding consumer acceptance of aesthetic changes becomes crucial for sustainable architectural choices. This study investigated consumer acceptance of uncoated wooden cladding in Norway, Sweden, and Germany, focusing on personality traits and perceptions. Using an online survey with 3112 participants, the study found that preference for uncoated wooden cladding was similar (around 20%) across the three countries, despite diferences in the prevalence of wooden cladding. A natural consequence of weathering of wood exposed outdoors is greying of the surface. The survey presented participants with images of uncoated wooden cladding with varying degrees of grey discolouration. Participants rated the acceptability of these claddings based on their preferences. Acceptance of this discolouration difered by country, Norwegians preferred intermediatecoloured panels, Swedes preferred darker panels, and Germans accepted all panels. Personality traits measured using the Big Five personality inventory and socioeconomic factors infuenced preferences. In Norway and Sweden, those accepting the discolouration of uncoated wooden cladding included introverts, highly conscientious individuals, young people, females, and those with tertiary education. Additionally, in Norway and Germany, openness to experience was linked to acceptance, while strong emotional control was signifcant only in Norway. This study underscores the complexity of consumer preferences for uncoated wooden cladding, demonstrating that personality traits, in conjunction with cultural and demographic variables, jointly infuence perception. The fndings ofer valuable insights for architects, builders, and policymakers seeking to advance sustainable construction practices while optimising consumer satisfaction in the housing sector.