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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.

2024

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Abstract

Almost 10,000 of apple cultivars are described worldwide but only a few of them are dominating in commercial apple orchards. The decline in genetic diversity could lead to negative consequences in terms of adaptability, resistance and even consumption. Apple genetic resources in Norway are conserved in several local clonal archives. The aim of this study was to evaluate Norwegian heritage apple cultivars from a pomological, agronomical, and chemical point of view, identify the most important quality parameters, and select cultivars with desirable traits for modern markets and breeding purposes. In total 75 heritage and 4 standard apple cultivars were evaluated at the Norwegian Institute of Bioeconomy Research – NIBIO Ullensvang, during 2018–2020. Based on individual investigations of various fruit quality characters, cultivar groups with special properties were selected for the industry, for making concentrate and fresh juice, and for medical properties. According to the soluble solid content, sweetness index, fruit size, acid, dry matter, and phenolic content, several groups of cultivars have high potential value for modern breeding programmes. Based on overall fruit quality, heritage cultivars Løeeple, Raud Gravenstein, and Rondestveit were selected for fresh consumption.

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Abstract

Genetic analyses of host-specific parasites can elucidate the evolutionary histories and biological features of their hosts. Here, we used population-genomic analyses of ectoparasitic seal lice (Echinophthirius horridus) to shed light on the postglacial history of seals in the Arctic Ocean and the Baltic Sea region. One key question was the enigmatic origin of relict landlocked ringed seal populations in lakes Saimaa and Ladoga in northern Europe. We found that that lice of four postglacially diverged subspecies of the ringed seal (Pusa hispida) and Baltic gray seal (Halichoerus grypus), like their hosts, form genetically differentiated entities. Using coalescent-based demographic inference, we show that the sequence of divergences of the louse populations is consistent with the geological history of lake formation. In addition, local effective population sizes of the lice are generally proportional to the census sizes of their respective seal host populations. Genome-based reconstructions of long-term effective population sizes revealed clear differences among louse populations associated with gray versus ringed seals, with apparent links to Pleistocene and Holocene climatic variation as well as to the isolation histories of ringed seal subspecies. Interestingly, our analyses also revealed ancient gene flow between the lice of Baltic gray and ringed seals, suggesting that the distributions of Baltic seals overlapped to a greater extent in the past than is the case today. Taken together, our results demonstrate how genomic information from specialized parasites with higher mutation and substitution rates than their hosts can potentially illuminate finer scale population genetic patterns than similar data from their hosts.

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Abstract

The emergence of alternative stable states in forest systems has significant implications for the functioning and structure of the terrestrial biosphere, yet empirical evidence remains scarce. Here, we combine global forest biodiversity observations and simulations to test for alternative stable states in the presence of evergreen and deciduous forest types. We reveal a bimodal distribution of forest leaf types across temperate regions of the Northern Hemisphere that cannot be explained by the environment alone, suggesting signatures of alternative forest states. Moreover, we empirically demonstrate the existence of positive feedbacks in tree growth, recruitment and mortality, with trees having 4–43% higher growth rates, 14–17% higher survival rates and 4–7 times higher recruitment rates when they are surrounded by trees of their own leaf type. Simulations show that the observed positive feedbacks are necessary and sufficient to generate alternative forest states, which also lead to dependency on history (hysteresis) during ecosystem transition from evergreen to deciduous forests and vice versa. We identify hotspots of bistable forest types in evergreen-deciduous ecotones, which are likely driven by soil-related positive feedbacks. These findings are integral to predicting the distribution of forest biomes, and aid to our understanding of biodiversity, carbon turnover, and terrestrial climate feedbacks.

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Abstract

Vegetasjon langs bekker og vannveier er viktig for biologisk mangfold, jordvern, erosjonskontroll, reduksjon av risiko for flom og tørke, og for elvens hydromorfologi. Copernicus Land Monitoring Service tilbyr geografiske produkter til støtte for forvaltning av land og vann. I denne rapporten analyserer vi potensialet til Riparian Zones temakart (RZ) for bruk til kartlegging og overvåking av vegetasjon langs bekker og vannveier i Norge og Polen. Vi inkluderer også analyser av temakartet Small Woody Features (SWF) innenfor områder kartlagt i RZ. Vi sammenlignet RZ med nasjonale data og flybilder for å verifisere kvaliteten til datasettet, både for status og endringer i arealdekke og arealbruk langs bekker og vannveier. Vi konkluderer med at den tematiske nøyaktigheten var ganske god for vann, jordbruksareal og skog, men at andre klasser ikke korresponderte like godt med de nasjonale dataene. Mange av avvikene kan skyldes forskjeller i klassifiseringssystemene, kildedatene og kartleggingsinstruksene for de forskjellige datasettene. I tillegg fant vi at den romlige oppløsningen av RZ er utilstrekkelig for detaljert overvåking, særlig i jordbrukslandskap. Likevel gir RZ en standardisert og harmonisert metodikk for hele Europa, og er et steg i riktig retning for å kunne overvåke arealdekke og arealbruk i disse dynamiske og viktige områdene.