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.
2002
Authors
Erlend Ystrøm Haartveit Per Otto FlæteAbstract
Modulus of Elasticity (MOE) and Modulus of Rupture (MOR) were measured on lumber from trees originating from four stands in each of the countries Norway and Sweden. Half of the stands were monocultures of Norway spruce while the remainder were mixed stands of Norway spruce and birch species.No significant differences in MOE and MOR were found between Norway spruce lumber grown in monocultures and lumber originating from mixed stands. Furthermore, there were no significant differences between the two groups concerning wood density, mean annual ring width and diameter of the largest knot in each log.These three variables also yielded similar models for lumber originating from monocultures and mixed stands, respectively, when used as independent variables in simple regression models for MOE and MOR.PLS1 regression models, with a X-matrix of variables measurable with simple equipment on trees and logs, were used to sort logs according to predicted values of MOE and MOR. The models show promising results with respect to pre-sorting of logs in order to create a better fit between the quality of logs and the expected properties of the final products.When sorting logs, a high percentage is correctly classified, and the cumulative distributions of the two groups resulting from sorting are clearly different. Hence, PLS1 regression models using simple measurements on trees and logs seems potentially useful for predictions of MOE and MOR without the use of advanced technical equipment.
Authors
Toril Drabløs Eldhuset Arne SandnesAbstract
• Micro suction cups are useful for collecting soil solution at high spatial resolution, e.g. gradients in the rhizosphere. • Their success in the field depends on soil type and the soil water content. • Both inorganic ions, organic acids, and pH in the soil solution showed high variability through time. • Unexpectedly, the concentration of major cations and anions were higher in the rhizosphere than in the bulk soil. • Only four organic acids were detected with certainty, i.e. by use of retention times and spectra of known standards. • Low initial concentrations with subsequent microbial breakdown in the samples vials and analytical limitations of small volume samples are considered to be the main reasons for the small number of acids detected.
Authors
Toril Drabløs Eldhuset Arne SandnesAbstract
No abstract has been registered
Authors
G. van TolAbstract
No abstract has been registered
Authors
Nicholas ClarkeAbstract
Within ICP Forests, the question has arisen whether it is necessary to determine DOC or TOC in deposition. There are several possible reasons for doing so, which can be summarised under two headings: quality control and process studies.
Authors
Michael Weber Walter Schönenberger Gerhard Weiss Petter NilsenAbstract
No abstract has been registered
Authors
Gudbrand LienAbstract
A new non‐parametric method to estimate a decision maker's coefficient of absolute risk aversion from observed economic behaviour is explained. The method uses the expected value‐variance (E‐V) framework and quadratic programming. An empirical illustration is given using Norwegian farm‐level data.
Abstract
No abstract has been registered
Abstract
No abstract has been registered
Abstract
The purpose of this study was to test the activity of gibberellins and auxins for induction of parthenocarpic fruit development in cloudberry, Rubus chamaemorus L., a dioecious, northern wild berry with potential for cultivation. Plant hormones were applied directly to open flowers, either dissolved in ethanol or as an aqueous spray. Of the tested gibberellins (GA1, GA3, GA4, dimethyl-GA4, GA5, GA9, GA19, GA20 and GA24) only GA1, GA3, GA4 and dimethyl-GA4 were active and induced fruit development comparable to development of pollinated fruits. Lack of activity of GA20 and GA9, the immediate precursors of GA1 and GA4, respectively, suggests that 3 b-hydroxylation of gibberellins can be inhibited in unpollinated flowers of cloudberry. Auxin treatments induced an initial fruit development, but did not result in ripe berries. Based on these results, use of transgenic methods to regulate gibberellin or/and auxin biosynthesis in carpels of cloudberry could be used to develop a parthenocarpic cloudberry.