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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

Biochar is emerging as a promising solution for increasing carbon in soil, improving the fertility of selected soils, and mitigating N2O emissions from agricultural soils. In Norway,biochar is high on the agenda of potential actions to address climate change. Farmers, farmer organizations and authorities wish to know more about effects of biochar on Norwegian soils and environmental impacts. This Ph.D. thesis reports results from four field based studies, which document both agronomic and environmental impacts of biochar application in grain and vegetable production systems in Norway. Paper I:III report results from a 4 year field experiment in a silty clam loam in flat terrain in Ås, Norway. In Paper I, I assessed the impact of applying 11.6 and 31.5 t ha-1 miscanthus biochar on soil physical properties, soil microbial biomass and oat and barley yield. Soil volumetric water content was significantly higher and bulk density was significantly lower at the higher biochar application rate. However, there was no significant effect of biochar on soil aggregate stability, pore size distribution, penetration resistance, microbial biomass, basal respiration and barley and oat yields over four years. At the same field site in Ås, Paper II assessed the impact of new vs aged biochar on N2O and CH4 fluxes in two field seasons. New biochar additions at 31.5 t ha-1 significantly reduced N2O by 80% in a single peak event post-harvest in 2012 whereas 2-year aged biochar emitted 41% less N2O flux compared to the control (not significant). In 2014, new biochar application induced more N2O emission than the control whereas aged biochar did not differ. However, the magnitude of N2O emissions in 2014 was 2-6 times less than in 2012 due to much drier weather, so the net effect over two field seasons was that new biochar mitigated N2O more than it stimulated it. Analysis of aged vs new biochar shows that biochar loses its alkalinity over 2-4 years and this may explain the weaker N2O mitigation effect in aged compared to new biochar. In contrast to previous studies, I found that aged biochar did not reduce the soil CH4 sink capacity but instead improved it during peak CH4 emission events. New biochar did not differ from the control in CH4 flux. Cumulative emissions of CO2, N2O and CH4 did not differ between treatments in 2012 and 2014 due to the high standard deviation recorded within treatments, which is common in GHG field studies using closed chamber measurements. In Paper III, we documented the mobility and fate of biochar 5 years after application. We measured the vertical (0-60cm) and lateral (9 m from plot edge) transport of biochar in the field at Ås. After 5 years, we accounted for 92-107% ±6 of the applied biochar. Forty-five to seventy two percent of biochar was present in the 0-23 cm plough layer within plot boundaries, 22-31% was vertically transported to 23-60 cm depth, 0-21% had moved laterally within 9 m of the plot boundary and 4% was mineralized as CO2. Under laboratory tests, I found that biochar was easily released from soil aggregates when exposed to water slaking. However, considering the high recovery rates we achieved after 5 years we conclude that erosive loss of biochar via slaking was not a significant risk factor in this flat field site where biochar was well incorporated into the soil. Due to the moderate amount of biochar that is vertically transported below the plough layer I recommend that future soil sampling strategies designed to document biochar C stocks considers this vertical movement. In the final study, Paper IV, we cooperated with a commercial farmer to test the synergistic fertilization effect of biochar added as 20% and 40% (V/V) to liquid anaerobic digestate and applied the mixtures at 7 cm depth under spring onion planting rows in a coarse sandy soil.

Sammendrag

Subclinical parasite infections in livestock production have huge economic impact on the farming industry, leading to decreased animal welfare and reduction in meat, milk and wool production. The global spread of anthelmintic resistance has exacerbated the threat of gastrointestinal nematode (GIN) infections to small ruminant health and production. Phytochemicals, such as condensed tannins (CT), have shown promising anthelmintic potential, and could complement other management practices to reduce anthelmintic use for parasite control. Conifer bark is a rich source of CT. Studies have shown that the content of CTs in Norway spruce and Scots pine varies, but on average they contain around 4% CTs. This study explored the anthelmintic activity of bark from Norwegian conifers over two seasons, extracted with three different solvents (water, acetone, methanol), against two sheep GIN, Teladorsagia circumcincta and Trichostrongylus colbriformis. Bark extracts were analysed to determine their total CT content and tested in vitro, with the aim to quantify their impact on egg hatching and L3 larval motility. Results show significant variation in efficacy of the extracts on egg hatching in a dose dependent manner. The CT content of the bark extracts were not always associated with LD50 values, indicating that other plant compounds may have additional anthelmintic effects. Preliminary results of the L3 larval motility test showed that incubation in the bark extracts had a smaller impact on this parasite stage at the concentrations tested. This research brings new insights into the potential anthelmintic activity of different phytochemicals and discusses the potential of bark extracts as a tool in the sustainable control of GIN in small ruminants.

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In 2016, the Sustainable Development Working Group (SDWG) endorsed The Arctic as a Food Producing Region research project. Involving research teams from Iceland, Norway, Canada, Greenland, and Russia, the objective of the project was to assess the potential for increased production and added value of foods originating from the Arctic, with the overarching aim of improving food security, while enhancing the social and economic conditions of Arctic communities. Although the Arctic was recognised as an important food-producing region, there was a shared sense that the Arctic was not meeting its full potential, either in terms of satisfying local food needs or for maximising its domestic or international export potential. Yet beyond speculation, much of which was informed by individual or anecdotal experience, there was little understanding of the current production capacities of Arctic food sectors or where opportunities may lie for sustainable growth. The aim of the project was, therefore, threefold: (1) complete an inventory of the current levels of Arctic food production in terms of products, volumes, revenues; (2) identify the constraints and opportunities for increased production value-added opportunities; and (3) identify potential pathways and new value chains for expanding Arctic food production and distribution opportunities. .............

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(1) We document the invertebrate fauna collected from 24 oak canopies in east and west Norway as a contribution to the Norwegian Biodiversity Information Centre’s ‘The Norwegian Taxonomy Initiative’. (2) A snap-shot inventory of the canopies was recorded by means of emitting a mist of natural pyrethrum into the canopies at night using a petrol-driven fogger and collecting the specimens in butterfly nets spread on the ground under the canopy. (3) Almost the entire catch of more than 6800 specimens was identified to 722 species. Out of 92 species new to the Norwegian fauna, 21 were new to science and, additionally, 15 were new to the Nordic fauna. Diptera alone constituted nearly half of the species represented, with 61 new records (18 new species). Additionally, 24 Hymenoptera (one new species), six oribatid mites (two new species) and one Thysanoptera were new to the Norwegian fauna. (4) Our study emphasizes the importance of the oak tree as a habitat both for a specific fauna and occasional visitors, and it demonstrates that the canopy fogging technique is an efficient way to find the ‘hidden fauna’ of Norwegian forests. The low number of red listed species found reflects how poor the Norwegian insect fauna is still studied. Moreover, the implication of the IUCN red list criteria for newly described or newly observed species is discussed.

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The complete chloroplast genome sequence of wild sea mallow Malva wigandii (=Lavatera maritima) was determined and characterized in this study. The genome is 158,162 bp long, containing a pair of inverted repeats regions (IRs) of 25,166 bp, which are separated by a large single-copy region of 86,860 bp and a small single-copy region of 20,970 bp. The sea mallow chloroplast genome has 131 known genes, including 85 protein-coding genes, eight ribosomal RNA genes, and 37 tRNA genes. The phylogenomic analysis showed that M. wigandii forms a cluster with Althaea officinalis with a strong bootstrap support and is sister to sequences belonging to the tribe Gossypieae. All of them are grouped in a lineage with other members of the subfamily Malvoideae. This newly sequenced chloroplast genome sequence provides useful genetic information to explore the origin and evolution of the Mediterranean radiation that gave rise to the generic alliance of Malva.

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The CORINE Land Cover dataset for Norway for the reference year 2018 (CLC2018) was compared to detailed national land cover and land use data. This allowed us to describe the thematic composition of the CLC-polygons and aggregate the information into statistical profiles for each CLC-class. We compared the results to the class definitions found in the CLC mapping instructions, while considering the generalization and minimal mapping units required for CLC. The study showed that CLC2018 in general complied with the definitions. Non-conformities were mainly found for detailed and (in a Norwegian context) marginal classes. The classification can still be improved by complementing visual interpretation with classification based on the statistical profile of each polygon when detailed land use and land cover information is available. The use of auxiliary information at the polygon level can thus provide a better, thematically more accurate CLC dataset for use in European land monitoring.

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Springs are ecosystems influenced by the exposure of groundwater at the Earth's surface. Springs are abundant and have played important, highly interactive ecological, cultural, and socio-economic roles in arid, mesic, and subaqueous environments throughout human evolution and history. However, springs also are widely regarded as being highly threatened by human impacts. Cantonati et al. (2020a) recommended increased global awareness of springs, including basic mapping, inventory and assessment of the distribution and ecological integrity of springs. We conducted a preliminary global analysis on the ecological integrity of springs by reviewing information on the distribution, ecohydrogeology, associated species, kinds and intensity of human uses, and level of ecological impairment of spring ecosystems. We reviewed information on an estimated 250,000 spring ecosystems among 78 countries across much of the world. Available literature on spring ecological integrity is sparse, widely scattered, and spatially erratic, with major gaps in knowledge. We report large differences in the quality and extent of information among countries and continents, with only moderate data availability even among developed countries, and limited information across most of the developing world. Among countries with available data, ecological impairment of springs is everywhere rampant, sometimes exceeding 90% in developed regions. Impairment among Holarctic nations is generally negatively related to distance from human development, elevation, and latitude, but such patterns are less evident in Africa, Australia, and South America. Declining trends in ecosystem condition, compounding threat factors, and spring-dependent population declines, extirpation, and extinctions of plants, invertebrates, fish, and herpetofauna are widely reported. Overall, available information indicates a global crisis in spring ecosystem integrity, with levels of ecosystem impairment ranging from Vulnerable to fully Collapsed. The threats to aquifers and the ecological integrity of springs vary spatially. Many springs are impaired by local impacts due to flow diversion, geomorphic alteration, land use practices, recreation impacts, and the introduction of non-native species. These threats can be reduced through education, rehabilitation of geomorphology and habitat quality, and species reintroductions if the supporting aquifer remains relatively intact. However, springs also are widely threatened by regional to global factors, including groundwater extraction and pollution, as well as climate change. Such coarse-scale, pre-emergence impacts negatively affect the sustainability of spring ecosystems and the aquifers that support them. Improving understanding and stewardship of springs will require much additional systematic inventory and assessment, improved information management, and reconsideration of basic conservation concepts (e.g., habitat connectivity), as well as cultural and socio-economic valuation. Substantial societal recognition, discussion, and policy reform are needed within and among nations to better protect and sustainably rehabilitate springs, their supporting aquifers, and the spring-dependent human and biotic populations that depend upon them.