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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.

2021

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Sammendrag

Questions Which environmental factors influence fine-grain beta diversity of vegetation and do they vary among taxonomic groups? Location Palaearctic biogeographic realm. Methods We extracted 4,654 nested-plot series with at least four different grain sizes between 0.0001 m² and 1,024 m² from the GrassPlot database, covering a wide range of different grassland and other open habitat types. We derived extensive environmental and structural information for these series. For each series and four taxonomic groups (vascular plants, bryophytes, lichens, all), we calculated the slope parameter (z-value) of the power law species–area relationship (SAR), as a beta diversity measure. We tested whether z-values differed among taxonomic groups and with respect to biogeographic gradients (latitude, elevation, macroclimate), ecological (site) characteristics (several stress–productivity, disturbance and heterogeneity measures, including land use) and alpha diversity (c-value of the power law SAR). Results Mean z-values were highest for lichens, intermediate for vascular plants and lowest for bryophytes. Bivariate regressions of z-values against environmental variables had rather low predictive power (mean R² = 0.07 for vascular plants, less for other taxa). For vascular plants, the strongest predictors of z-values were herb layer cover (negative), elevation (positive), rock and stone cover (positive) and the c-value (U-shaped). All tested metrics related to land use (fertilization, livestock grazing, mowing, burning, decrease in naturalness) led to a decrease in z-values. Other predictors had little or no impact on z-values. The patterns for bryophytes, lichens and all taxa combined were similar but weaker than those for vascular plants. Conclusions We conclude that productivity has negative and heterogeneity positive effects on z-values, while the effect of disturbance varies depending on type and intensity. These patterns and the differences among taxonomic groups can be explained via the effects of these drivers on the mean occupancy of species, which is mathematically linked to beta diversity.

Sammendrag

Fiskeslam fra fem settefiskanlegg for smolt ble analysert i både 2019 og 2020: Fire produkter som var tørket med ulik teknologi, en flytende biorest og en tørket biorest. Gjødselkvaliteten til fiskeslam var mer variabel enn tidligere antatt, også for fiskeslam fra samme settefiskanlegg. De fleste produkter var i kvalitetsklasse II pga. sink og/eller kadmium. Næringsstoffsammensetningen var ubalansert, med lavt nitrogen/fosfor forhold og lavt kaliuminnhold. Bioresten viste god nitrogeneffekt, men tørking reduserte nitrogenkvaliteten. I tørket fiskeslam forelå nitrogen hovedsakelig som tungt tilgjengelig organisk nitrogen, uavhengig av type behandlingsteknologi. Inkuberingsforsøk er et relativt rimelig verktøy som kan gi en god indikasjon på nitrogenkvaliteten i fiskeslam...