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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.

2005

Abstract

Seeds of Abies lasiocarpa (Hook.) Nutt. (subalpine fir) were dissected, and the different parts were analyzed for elemental composition. The data were used to design a novel growth medium for initiation of somatic embryogenesis. Embryogenic cultures were initiated from immature zygotic embryos from six open-pollinated families of A. lasiocarpa on three different media.The frequency of initiation was the highest in early to mid-July when the zygotic embryo explants were ca. 0.8 mm long. Thereafter the response declined rapidly.The culture media did not significantly affect the initiation frequencies, but the subsequent growth and culture survival was dependent on the culture medium. On the Schenk Hildebrandt medium, many cultures ceased to grow and died. Several of the decaying cultures were rescued after transfer to one of the new media. Proliferating cultures could be stimulated to produce mature embryos. Of 2510 mature somatic embryos, 212 (8.4%) converted to plants, and 35 plants have grown over two periods.

Abstract

Wood is prone to natural decay. Unless properly conserved, sawlog quality will deteriorate due to checks, blue stain, rot wood borers and other causes. Log spraying has proved an efficient method for softwood quality preservation. The method is used both for seasonal storing during spring and summer, and for log preservation, e.g. following storm felling, for periods up to three years. A description of wood quality aspects and environmental impacts as well as practical and technical remedies are given.Most timber quality features will be upheld provided some basic routines are followed. Wood strength seems unaffected. Some discoloration due to tannin diffusion and spots of increased permeability due to bacterial colonies might be experienced. It is suggested that the method might be advantageous for the Italian Alpine forest industry.

Abstract

Det er stor variasjon i fiberforløp når man betrakter en hel trestamme. Således må den gjengse oppfatning om en regulær tredimensjonal anisotropi i stammen nyanseres. Såvel trevirkets fysiske egenskaper som fiberretningen har betydning når tre skal bearbeides og for egenskapene til den bearbeidede overflate. Denne presentasjonen omtaler varierende fiberretning knyttet til vridd vekst, kvister og overgangssonene rundt kvister, margens svakt slyngende form og uregelmessigheter i årringmønster og stokkens ytre form. Simultane modeller blir komplekse og mye av variasjonen forblir uforklart.

Abstract

Wood samples treated with ammonium copper quat (ACQ 1900 and ACQ 2200), chromated copper arsenate (CCA), Tanalith E 3491 and Wolmanit CX-8 have been studied in accelerated weathering experiments. The weathering experiment was performed by cycles of 2 h UV-light irradiation followed by water spray for 18 min. The changes on the surface of the weathered samples were characterized by roughness and color measurements on the samples with 0, 200, 400 and 600 h of total weathering.The objective of this study was to investigate the changes created by weathering on impregnated wood with several different wood preservatives. This study was performed on the accelerated weathering test cycle, using UVirradiation and water spray in order to simulate natural weathering. Surface roughness and color measurement was used to investigate the changes after several intervals (0200400600 h) in artificial weathering of treated and untreated wood.

Abstract

The substitution of biomass for fossil fuels in energy consumption is a measure to mitigate global warming, and political action plans at European and national levels exist for an increased use. The use of forest biomass for energy can imply different economic and environmental advantages and disadvantages for the society, the energy sector and forestry. For the achievement of an increased and sustainable use of forest biomass for energy, the WOOD-EN-MAN project aimed at synthesis and creation of new knowledge within the field.

Abstract

The genus Leptographium was described in 1927 and currently includes 48 species, with L. lundbergii as the type species. In recent years, the taxonomic status of L. lundbergii has not been uniformly agreed upon and it has been the topic of considerable debate. The problem was compounded by the absence of a type specimen, and the species was epitypified at a later stage. Unfortunately, the whereabouts of the epitype is now unknown. In 1983, Wingfield & Marasas described L. truncatum, which is morphologically similar to L. lundbergii. Based on DNA comparisons and similarities in their morphology, this fungus was reduced to synonymy with L. lundbergii. The loss of the type specimen as well as variation in the morphology of strains identified as L. lundbergii prompted us to re-examine the taxonomic status of this species. A number of strains from various geographic areas were studied. These include a strain of L. lundbergii deposited at CBS by Melin in 1929 (CBS 352.29) as well as the ex-type strain of L. truncatum. The strains were compared based on morphology and comparison of multiple gene sequences. Three genes or genic regions, ITS2 and part of the 28S gene, partial â-tubulin and partial elongation factor 1-α were compared. Strains currently identified as L. lundbergii, represented a complex of species. Strains initially described as L. truncatum clustered separately from other L. lundbergii strains, could be distinguished morphologically and should be treated as a distinct taxon. L. lundbergii is provided with a new and expanded description based on a neotype designated for it. A third group was also identified as separate from the main L. lundbergii clade and had a distinct Hyalorhinocladiella-type anamorph, described here as H. pinicola sp.nov.