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.
2018
Abstract
No abstract has been registered
Authors
Michael Roleda Hélène Marfaing Natasa Desnica Rósa Jónsdóttir Jorunn Skjermo Celine Rebours Udo NitschkeAbstract
Seaweeds are increasingly used in European cuisines due to their nutritional value. Many algal constituents, such as polyphenols, are important antioxidants and thus considered beneficial to humans. However, many seaweed species can accumulate heavy metals and exhibit potential health risks upon ingestion. We investigated temporal and spatial variations in polyphenol and heavy metal (As, Cd, Hg, Pb) concentrations of three edible seaweed species. The brown algae Saccharina latissima and Alaria esculenta, and the red alga Palmaria palmata were sourced from natural populations and aquaculture in the NE Atlantic and processed as bulk biomass mimicking industrial scales. The mean polyphenol content was species-specific (Alaria > Saccharina > Palmaria), and highest in winter (for Alaria and Saccharina) and spring (for Palmaria); inter-annual and spatial variations were marginal. Heavy metal concentrations varied between species and depended on collection site, but seasonal variations were minimal. Our data suggest that all three species are good sources of antioxidants, and the heavy metal concentrations are below the upper limits set by the French recommendation and the EU Commission Regulation on contaminants in foodstuffs. A health risk assessment indicated that consumption of these seaweed species poses a low risk for humans with regard to heavy metals. However, an EU-wide regulation on maximal concentration of heavy metals in seaweeds should be established.
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No abstract has been registered
Abstract
This article aims to explore differences in motivation for and actual use of allotment gardens. Results from questionnaire surveys and semistructured interviews in two Norwegian and one Dutch garden show that growing vegetables and consuming the harvest is a fundamental part of gardening. The same is true for the social element—meeting and talking to other gardeners, and feeling as part of a community. Although gardeners with different socioeconomic backgrounds experience gardening to some extent similarly, access to an allotment seems more important for gardeners with disadvantaged personal backgrounds: both their diets and their social networks rely more on, and benefit more from, their allotments. This underlines the importance of providing easy access to gardening opportunities for all urban residents, and disadvantaged groups in particular. Public officers and policy makers should consider this when deciding upon new gardening sites or public investments in urban food gardens.
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No abstract has been registered
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No abstract has been registered
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No abstract has been registered
Abstract
I 2014 ble 22 øyer i Breiðaförður, Vest-Island, vegetasjonskartlagt. Hensikten med kartlegginga var å registrere vegetasjonstyper, artssammensetning og gjengroingsstatus på øyer som har ulik størrelse, topografi, geologisk sammensetning, brukshistorie, samt ulikt fugleliv. De fleste øyer i denne undersøkelsen har ikke blitt kartlagt før, slik at prosjektet har bidratt til ny kunnskap om deler av dette unike øyriket i Breiðafjörður. In 2014, 22 islands in Breiðafjörður, West-Iceland were mapped for vegetation. The purpose to this study was to map vegetation types, distribution of plant species and overgrowing status in islands which differs in size, topography, bedrock composition, land use and birdlife activity. Most of the islands in this study have not been mapped before. This project provides new knowledge to part of the unique archipelago of Breiðafjörður.
Abstract
This study addresses changes in visual appearance of unpainted wood materials exposed outdoors. Specimens of Norway spruce (Picea abies) Scots pine (Pinus sylvestris), aspen (Populus tremula), acetylated Radiata pine (Pinus radiata) and DMDHEU-modified Scots pine sapwood were exposed facing south in Ås, Norway for 60 weeks. During this period, surface mould growth development and wasp attack were assessed visually. Development in lightness (L*) and the uniformity of the weather grey colour were assessed by image analysis. The mould rating of the tested wood materials developed in varying speed, but all specimens had reached the maximum rating after 42 weeks. Our results indicate that most specimens continued to darken after the specimens had reached maximum mould rating, and that evaluation of L* can provide additional information about the surface mould growth. Furthermore, our results indicate that most materials developed a less uniform appearance than what was initially, except from DMDHEU which obtained a more uniform appearance as a consequence of the weathering. This study also shows that wasp attack can give a lighter appearance of the wood by chewing off the top weathered layer. Different wood substrates were attacked in varying degree. Aspen was the substrate most severely attacked by wasps while the acetylated wood was not attacked at all during the 60 weeks of exposure.
Authors
Frans-Jan W. Parmentier Daniel Rasse Magnus Lund Jarle W. Bjerke Bert G. Drake Simon Weldon Hans Tømmervik Georg Heinrich HansenAbstract
Extreme winter events that damage vegetation are considered an important climatic cause of arctic browning—a reversal of the greening trend of the region—and possibly reduce the carbon uptake of northern ecosystems. Confirmation of a reduction in CO2 uptake due to winter damage, however, remains elusive due to a lack of flux measurements from affected ecosystems. In this study, we report eddy covariance fluxes of CO2 from a peatland in northern Norway and show that vegetation CO2 uptake was delayed and reduced in the summer of 2014 following an extreme winter event earlier that year. Strong frost in the absence of a protective snow cover—its combined intensity unprecedented in the local climate record—caused severe dieback of the dwarf shrub species Calluna vulgaris and Empetrum nigrum. Similar vegetation damage was reported at the time along ~1000 km of coastal Norway, showing the widespread impact of this event. Our results indicate that gross primary production (GPP) exhibited a delayed response to temperature following snowmelt. From snowmelt up to the peak of summer, this reduced carbon uptake by 14 (0–24) g C m−2 (~12% of GPP in that period)—similar to the effect of interannual variations in summer weather. Concurrently, remotely-sensed NDVI dropped to the lowest level in more than a decade. However, bulk photosynthesis was eventually stimulated by the warm and sunny summer, raising total GPP. Species other than the vulnerable shrubs were probably resilient to the extreme winter event. The warm summer also increased ecosystem respiration, which limited net carbon uptake. This study shows that damage from a single extreme winter event can have an ecosystem-wide impact on CO2 uptake, and highlights the importance of including winter-induced shrub damage in terrestrial ecosystem models to accurately predict trends in vegetation productivity and carbon sequestration in the Arctic and sub-Arctic.