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.
2007
Authors
Erlend Nybakk Terje Birkeland Knut FinstadAbstract
This study is based on a certain case with the largest Norwegian Forest Association (Viken Skog BA) as timber seller and Haselstad Bruk AS buyer of saw logs. The objective of the study is to adopt a more effective, accurate and market-oriented timber production system in the south-east of Norway using bucking-to-demand. A bucking simulator called OptApt is further developed with the addition of a function for near-optimal bucking-to-demand, to evaluate this bucking regime in relation to the traditional bucking-to-value approach used under Norwegian conditions, which means large variations in forests when it comes to dimensions and quality between, but also within, regions and stands. ....
Abstract
Capercaillie Tetrao urogallus leks have repeatedly been reported to be located in old forest. However, two conditions may have biased this widely held view. First, leks are known to be continuously used over several decades, and therefore might have been established when forest stands were younger. Second, stand -replacement logging (clearcutting) was not widely applied until the 1950s, leaving even-aged regenerating stands too young for leks to have been established in the latter part of the 20th century. Here we report eight cases of lek formation in young plantations from south-central Norway. Stand age ranged within 2646 years when display activity started. At six of the sites, we confirmed that females were regularly feeding on pine trees in winter prior to lek establishment, and at four of these sites displaying males were observed courting the females in late winter. These findings support the hotspot model of lek formation put forward by Gjerde et al. (2000), and it offers promising options for managing capercaillie leks in commercially utilised forests.
Authors
Miguel D. Mahecha Markus Reichstein Holger Lange Nuño Carvalhais T. Grünwald Dario Papale G. SeufertAbstract
Characterizing ecosystem-atmosphere interactions in terms of carbon and water exchange on different time scales is considered a major challenge in terrestrial biogeochemical cycle research. The respective time series currently comprise an observation period of up to one decade. In this study, we explored whether the observation period is already sufficient to detect cross-relationships between the variables beyond the annual cycle, as they are expected from comparable studies in climatology. We investigated the potential of Singular System Analysis (SSA) to extract arbitrary kinds of oscillatory patterns. The method is completely data adaptive and performs an effective signal to noise separation. We found that most observations (Net Ecosystem Exchange, NEE, Gross Primary Productivity, GPP, Ecosystem Respiration, Reco, Vapor Pressure Deficit, VPD, Latent Heat, LE, Sensible Heat, H, Wind Speed, u, and Precipitation, P) were influenced significantly by low-frequency components (interannual variability). Furthermore, we extracted a set of nontrivial relationships and found clear seasonal hysteresis effects except for the interrelation of NEE with Global Radiation (Rg). SSA provides a new tool for the investigation of these phenomena explicitly on different time scales. Furthermore, we showed that SSA has great potential for eddy covariance data processing, since it can be applied as a novel gap filling approach relying on the temporal correlation structure of the time series structure only.
Abstract
The effectiveness against soft rotting micro fungi and other soil inhabiting micro-organisms was tested according to ENV 807 using different treated Scots pine sapwood and beech wood samples. The treatments differed in basic material, solvent, depolymerization agent, viscosity and post treatment. The chitosan treated Scots pine samples showed improved performance against soft rot, whereas a large amount of untreated pines sapwood samples failed during the test. The different chitosan treatments showed only slight differences in performance during the test.Further results of ongoing field tests should give more information about the life performance of the treated samples.
Abstract
No abstract has been registered
Abstract
The objective of this study was to examine the effect of clover species on milk fatty acid (FA) composition. Lactating dairy cows were allocated to two groups and fed grass-clover silage containing either white clover (WC) or red clover (RC), without or with concentrate supplementation. No significant interaction of clover species with concentrate supplementation could be observed. RC milk had significantly higher proportion of polyunsaturated FAs (P<0.001), particularly C18:3n-3 (P<0.001), and contained a higher n-3/n-6 FA ratio (P<0.05) than WC milk. It is concluded that RC silage, independent of concentrate supply, yielded milk with more beneficial FA composition than WC silage.
Abstract
No abstract has been registered
Abstract
No abstract has been registered
Abstract
In Norway exterior wood structures have traditionally nearly exclusively been made of treated and untreated Picea abies and Pinus sylvestris. In recent years there has been a tendency that other tree species, like various domestic hardwoods and imported species have been used in exterior above ground applications, often unfinished. For several wood species, especially hardwoods, information regarding the durability in use class 3 is lacking. The main objective of this paper is to evaluate natural durability of Norwegian wood species for above ground applications comparing two non-standard above ground tests with the European standard tests for soil contact (EN 252) and lab performance against basidiomycetes (EN 113). The European standard tests EN 113 and EN 252 gave quite similar results, and they also corresponded well with the natural durability classification in EN 350-2. The two non-standard above ground tests differed to some extend from EN 113, EN 252 and EN 350-2. The results indicate that natural durability classification for one single wood species can change depending on use class. However, the field trials need a longer period of time before a final classification can be performed. Four species not included in EN 350-2 were classified in this study: Juniperus communis (1), Salix caprea (5), Sorbus aucuparia (5) and Populus tremula (5).
Abstract
City planners need practical methods to assess and compare the sustainability of different alternatives for urban infrastructure. This article presents the consequences of selecting different methods to normalize the values of sustainability indicators, and the influence of selecting different indicators and different weighting techniques. A nature based sewerage system is compared to a conventional system. The article demonstrates that the method used to normalize the indicators, the choice of relevant indicators and the weighting technique have considerable influence on which system is found to be the most sustainable. By selecting particular indicators, weighting and normalization methods, it is possible to prove that virtually any infrastructure system is more sustainable than any other alternative system. Such a biased approach is difficult to reveal unless the most careful, expert scrutiny is applied. Because of this fact, it is of paramount importance that the consequences of different evaluation methods are discussed and sensitivity analyses are carried out honestly and objectively on the critical parameters. An evaluation process made in this way will enable those parts of the analysis that generate disagreement to be identified, and decisions taken on what is important and unimportant.