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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

Sammendrag

Forest harvest residue is a low-competitive biomass feedstock that is usually left to decay on site after forestry operations. Its removal and pyrolytic conversion to biochar is seen as an opportunity to reduce terrestrial CO2 emissions and mitigate climate change. The mitigation effect of biochar is, however, ultimately dependent on the availability of the biomass feedstock, thus CO2 removal of biochar needs to be assessed in relation to the capacity to supply biochar systems with biomass feedstocks over prolonged time scales, relevant for climate mitigation. In the present study we used an assembly of empirical models to forecast the effects of harvest residue removal on soil C storage and the technical capacity of biochar to mitigate national-scale emissions over the century, using Norway as a case study for boreal conditions. We estimate the mitigation potential to vary between 0.41 and 0.78 Tg CO2 equivalents yr−1, of which 79% could be attributed to increased soil C stock, and 21% to the coproduction of bioenergy. These values correspond to 9–17% of the emissions of the Norwegian agricultural sector and to 0.8–1.5% of the total national emission. This illustrates that deployment of biochar from forest harvest residues in countries with a large forestry sector, relative to economy and population size, is likely to have a relatively small contribution to national emission reduction targets but may have a large effect on agricultural emission and commitments. Strategies for biochar deployment need to consider that biochar's mitigation effect is limited by the feedstock supply which needs to be critically assessed.

Til dokument

Sammendrag

Knowing how and to what extent environmental parameters affect threatened species facilitates the understanding of their specific microhabitat requirements. In this study, we examined the response patterns of four threatened tropical plant species to variations in temperature, precipitation, and physiographic variables, and analyzed the relative contributions of environmental variables to the observed distributions of the species. The studied species are Bursera coyucensis, Cryosophila argentea, Guatteria anomala, and Vatairea lundellii and are cataloged into specific risk categories in the Mexican Official Standard NOM-059-SEMARNAT. Our findings suggest differences in ranges of temperature and precipitation (for example, C. argentea exhibited narrower ranges compared to G. anomala and V. lundellii in precipitation) and similarity in ranges of slope across species distributions. We also found that most species distributions respond non-linearly to variations in environmental variables. These results contribute to defining the environmental spaces of these species. The partial and combined effects of climatic variables, and the range of environmental distributions reported here, have intrinsic implications for the adaptation capacity, plasticity, and survival of these species to environmental variation. This information could be useful to promote conservation activities such as the creation of microhabitats with optimal environmental preferences through sustainable silviculture.

Sammendrag

The aim of this study was to contribute to closing global phosphorus (P) cycles by investigating and explaining the effect of fish sludge (feed residues and faeces of farmed fish) and manure solids as P fertiliser. Phosphorus quality in 14 filtered and/or dried, composted, separated or pyrolysed products based on fish sludge or cattle or swine manure was studied by sequential chemical fractionation and in two two-year growth trials, a pot experiment with barley (Hordeum vulgare) and a field experiment with spring wheat (Triticum aestivum). In fish sludge, P was mainly solubilised in the HCl fraction (66 ± 10%), commonly being associated with slowly soluble calcium phosphates, and mean relative agronomic efficiency (RAE) of fish sludge products during the first year of the pot experiment was only 47 ± 24%. Low immediate P availability was not compensated for during the second year. Thus efforts are needed to optimise the P effects if fish sludge is to be transformed from a waste into a valuable fertiliser. In manure solids, P was mainly soluble in H2O and 0.5 M NaHCO3 (72 ± 14%), commonly being associated with plant-available P, and mean RAE during the first year of the pot experiment was 77 ± 19%. Biochars based on fish sludge or manure had low concentrations of soluble P and low P fertilisation effects, confirming that treatment processes other than pyrolysis should be chosen for P-rich waste resources to allow efficient P recycling. The field experiment supported the results of the pot experiment, but provided little additional information.