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
Paul Aakerøy Bjørn KløveAbstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Christian Guido BrucknerAbstract
No abstract has been registered
Authors
Christian Guido Bruckner Hans-Peter Grossart Peter, G. KrothAbstract
No abstract has been registered
Authors
Arild AndersenAbstract
No abstract has been registered
Authors
Anne Moxnes Jervell Asbjørn VeidalAbstract
No abstract has been registered
Abstract
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
Currently, very little data exist on the exposure of soil biota to engineered nanoparticles (ENPs), in spite of soils being an important potential sink for ENPs. Though, data on exposure are essential to determine whether or not, or to which extent, a hazard constitutes a risk. This knowledge gap is mainly due to difficulties in tracing ENPs in soils where natural nanoparticles are abundant. We used neutron activated ENPs as tracers and examined the exposure (uptake, excretion and internal distribution) of nanoparticles of cobalt (Co NPs 3.9 ± 0.8 nm) and silver (Ag NPs 20.2 ± 2.5 nm) in the earthworm Eisenia fetida, and compared this to soluble cobalt and silver salts. Accumulation patterns were highly different for cobalt and silver. Concentrations of cobalt in worms after 4 weeks exposure reached 88% and 69% of the Co ions and Co NPs concentrations in food, respectively, while corresponding values for Ag ions and Ag NPs were 2.3% and 0.4%. Both Ag NPs and Ag ions in earthworms were excreted rapidly, while only 32% of the accumulated Co ions and Co NPs were excreted within a 4 months depuration period. High accumulation of cobalt was found in blood, and to a lesser extent in the digestive tract. Sequential extraction and centrifugal ultrafiltration provided useful information on metal speciation, dissolution and bioavailability of Co NPs and Ag NPs. Both Ag NPs and Ag ions were strongly bound to soil constituents, whereas Co NPs and Co ions were largely found as water soluble species, in good agreement with the results from the uptake study.