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
P Benoit J Perceval Marianne Stenrød C Moni Ole Martin Eklo E Barriuso Tore E. Sveistrup Jens KværnerAbstract
No abstract has been registered
Authors
Anders LunnanAbstract
Norway has strong and competent institutions and lobby organisations for hydro and oil/gas. It has been difficult for renewables to reach the political agenda. The situation in 2007 is quite different compared with 10 years ago, now the knowledge about and political power of bioenergy is improved. The demonstration value of the Gardermoen project and the informational, educational and public relations work of the Energy Farm are important contributions to this changed situation. Climate change is of course another factor of large importance. The two case-studies, Gardermoen bioenergy plant and the Energy Farm, demonstrate that there are many other factors that prices/costs that influences bioenergy implementation.
Authors
Stig Strandli Gezelius Karen RefsgaardAbstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Aaron SmithAbstract
No abstract has been registered
Authors
Torstein KvammeAbstract
No abstract has been registered
Authors
Liv S. Nilsen Asbjørn MoenAbstract
No abstract has been registered
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.