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.
2010
Authors
Wendy Marie Waalen Lawrence Gusta Karen Tanino Jorunn Elisabeth Olsen Odd Arne Rognli Ragnar EltunAbstract
No abstract has been registered
Authors
Wendy Marie Waalen Lawrence Gusta Karen Tanino Jorunn Elisabeth Olsen Odd Arne Rognli Ragnar EltunAbstract
No abstract has been registered
Abstract
No abstract has been registered
Abstract
The semi-individual tree crown approach (semi-ITC) was used to predict crown base heights (CBH) on the level of single crown segments based on airborne laser scanning (ALS) derived metrics. The root-mean-squared-differences (RMSD) on the segment level were smallest for spruce. However, they were larger than the standard deviation of the measured CBH for pine and birch. The RMSD values were also larger compared to other studies. This can in part be explained by the fact that the semi-ITC approach incorporates errors of the segmentation algorithm. As a consequence, all instead of only correctly identified trees were considered in modeling which results in more realistic RMSD values. After aggregating the individual segment predictions to the plot level, the RMSD values were smaller than the standard deviations of the field measurements and comparable to other studies. The relative RMSD values for birch, spruce, pine and all species were 51.61, 35.22, 49.28, and 13.89%, respectively.
Abstract
The furfurylation process is an extensively investigated wood modification process. Furfuryl alcohol molecules penetrate into the wood cell wall and polymerize in situ. This results in a permanent swelling of the wood cell walls. It is unclear whether or not chemical bonds exist between the furfuryl alcohol polymer and the wood. In the present study, five different wood species were used, both hardwoods and softwoods. They were treated with three different furfurylation procedures and leached according to three different leaching methods. The present study shows that, in general, the leachates from furfurylated wood have low toxicity. It also shows that the choice of leaching method is decisive for the outcome of the toxicity results. Earlier studies have shown that leachates from wood treated with furfuryl alcohol prepolymers have higher toxicity to Vibrio fischeri than leachates from wood treated with furfuryl alcohol monomers. This is probably attributable to differences in leaching of chemical compounds. The present study shows that this difference in the toxicity most likely cannot be attributed to maleic acid, furan, furfural, furfuryl alcohol, or 2-furoic acid. However, the difference might be caused by the two substances 5-hydroxymethylfurfural and 2,5-furandimethanol. The present study found no difference in the amount of leached furfuryl alcohol between leachates from furfurylated softwood and furfurylated hardwood species. Earlier studies have indicated differences in grafting of furfuryl alcohol to lignin. However, nothing was found in the present study that could support this. The leachates of furfurylated wood still need to be investigated further to identify the chemical differences between wood furfurylated with furfuryl alcohol monomers and furfuryl alcohol prepolymers.
Abstract
No abstract has been registered
Abstract
No abstract has been registered
Abstract
Scots pine (Pinus sylvestris) and especially its heartwood is one of the most common construction materials for general outer use e.g. windows or facades in northern Europe. It is considered being use class 3 and is according to EN 350-2 \"not treatable\". Reports from industry and researchers indicate that the heartwood treatability is not uniform. It is still unclear what causes these differences. To increase its durability by means of impregnation would be a contribution to extend the use of both a natural and native material. The understanding of a potential pattern analog to latitudinal/longitudinal origin or other forest or wood properties could help to improve the impregnation by better material selection. Scots pine samples from 25 different sites in 6 countries in northern Europe have been collected throughout autumn and winter 2009/2010. A circle of varying size containing approximately 30 trees was set up in a representative site of each stand. All diameters were measured and arranged in three classes. Three trees of each class were chosen randomly. Only the middle and upper diameter classes were used for studying heartwood permeability. The small diameter class had insufficient heartwood width to be processed. Samples of 20 x 20 x 50 mm were cut and conditioned in a climate chamber. The samples were impregnated with a water-soluble monomer furfuryl alcohol solution in a standard pressure/vacuum process. Results showed a generally low permeability but a few samples had an unexpected high ration of filling. Further on, the samples with the highest and lowest treatability will undergo anatomical and chemical tests to explain these properties.
Authors
Eivind Vangdal M. Vanoli P.Eccher Zerbini S. Jacob A. Torricelli L. SpinelliAbstract
No abstract has been registered
Abstract
The anamorph genus Leptographium Lagerberg and Melin includes species that are typically bark beetleassociated fungi, with teleomorphs in Grosmannia. During a survey of ophiostomatoid fungi in Norway, two unusual species, that fit the broader morphological description of Leptographium, were isolated directly from the rootfeeding beetles, Dryocetes authographus and Hylastes cunicularius, as well as from roots infested by these insects. The first of these could be distinguished from other described species based on a sparse sporulation, black spore drops and chlamydospores in older cultures. This species also produces a Hyalorhinocladiella synanamorph. The second species was characterised by distinctly curved conidia. Based on these unusual morphological characteristics and distinct DNA sequences, these fungi were recognised as new taxa for which the names Leptographium chlamydatum sp. nov. and L. curvisporum sp. nov. are provided.