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Publikasjoner

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

Sør-Varanger kommune i Øst-Finnmark har vært utsatt for luftforurensning fra russisk smelteverksindustri siden 1930-tallet, særlig fra smelteverket i byen Nikel som ligger bare ca. 10 km øst for den norske-russiske grensen ved Svanvik i Pasvikdalen. I tillegg til svoveldioksid inneholder utslippene store mengder tungmetaller, særlig kobber og nikkel. Formålet med denne undersøkelsen var å kartlegge tungmetallinnholdet i multer og blåbær og sammenligne nivået med tidligere studier. Resultatene fra innsamling i 2020 viser et tydelig geografisk mønster i innholdet av nikkel i blåbær og multer med til dels betydelig høyere konsentrasjoner i de delene av grenseområdet som er mest utsatt for forurensing. For kobber var variasjonsmønsteret mindre tydelig. På nær alle flater der vi har gjentak over tid finner vi også høyere konsentrasjoner av kobber og nikkel i 2020 enn i 1992, og 2008. Tidlig i 2020 kunngjorde russiske myndigheter at smelteverket i Nikel ville bli stengt i løpet av året. Bærinnsamlingen i 2020 er den mest fullstendige som er foretatt på norsk side i grenseområdet og er derfor et godt utgangspunkt for å overvåke tungmetallnivåene etter at smelteverket i Nikel er lagt ned.

Sammendrag

Scots pine exhibits variations in ray anatomy, which are poorly understood. Some ray parenchyma cells develop thick and lignified cell walls before heartwood formation. We hypothesized that some stands and trees show high numbers of lignified and thick-walled parenchyma cells early in the sapwood. Therefore, a microscopic analysis of Scots pine sapwood from four different stands in Northern Europe was performed on Safranin — Astra blue-stained tangential micro sections from outer and inner sapwood areas. Significant differences in lignification and cell wall thickening of ray parenchyma cells were observed in the outer sapwood between all of the stands for the trees analyzed. On a single tree level, the relative lignification and cell wall thickening of ray parenchyma cells ranged from 4.3% to 74.3% in the outer sapwood. In the inner sapwood, lignification and cell wall thickening of ray parenchyma cells were more frequent. In some trees, however, the difference in lignification and cell wall thickening between inner and outer sapwood was small since early lignification, and cell wall thickening was already more common in the outer sapwood. Ray composition and number of rays per area were not significantly different within the studied material. However, only one Scottish tree had a significantly higher number of ray parenchyma cells per ray. The differences discovered in lignification and cell wall thickening in ray parenchyma cells early in the sapwood of Scots pine are relevant for wood utilization in general and impregnation treatments with protection agents in particular.

Til dokument

Sammendrag

This study explores cell wall changes in Radiata pine (Pinus radiata) after modification with acetylation or furfurylation and subsequent prolonged subjection to the brown rot fungus R. placenta with the aim of better understanding the modus operandi of these two modifications. Both modifications have shown good durability in field tests, but in order to learn from their possible limitations, we used optimal environmental conditions for fungal growth, and extended the testing period compared to standard tests. Hyphae were found in acetylated wood after two weeks, and after 28 weeks of decay abundant amounts of encapsulated hyphae were present. In furfurylated wood, mass loss and a few hyphae were seen initially, but no further development was seen during weeks 18–42. The general degradation pattern was qualitatively the same for unmodified, acetylated and furfurylated wood: carbohydrates decreased relative to lignin. Acetyl groups were lost from acetylated wood during decay (earlier results), while the furan polymer did not seem to be altered by the fungus. Based on these findings it is hypothesized that modifications such as furfurylation that enhance moisture exclusion within the cell wall through impregnation polymerization offer better long term protection compared to modifications such as acetylation that depend on the replacement of hydroxyl groups with ether bound adducts that can be removed by fungi.

2020