Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2008
Forfattere
Anders BrynSammendrag
The forest limits of south-east Norway have expanded to higher altitudes. Two main processes are believed to cause these changes; re-growth after abandonment of human utilisation and recent climate changes. This article aim at separating the effects of these two processes on the upper forest limits and recent forest expansion. The results show that raised forest limits and forest range expansion often attributed to recent climate change is rather the product of re-growth, a process that was climatically retarded from 1959 to 1995. From 1995 to 2006, the data indicate a preliminary effect of climate change escalating the re-growth and probably pushing the future forest limits to higher altitudes.
Sammendrag
Whereas lichen growth rates have received considerable attention, comparatively few detailed studies of growth patterns have been carried out. Generally, most lichens seem to grow apically, with pseudomeristomatic tissue confined to lobe margins and branch tips. However, some species appear to retain the capacity to expand throughout the thallus. Such intercalary growth processes have proved difficult to confirm in the field for two- and three-dimensionally growing folious and fruticose forms. Using transplants of the conspicuous, one-dimensionally growing Usnea longissima Ach., we document that intercalary growth actually does occur, with thalli expanding geometrically in length with a doubling time of less than a year under favorable conditions.
Forfattere
Bernt-Håvard Øyen Per Holm NygaardSammendrag
From the first plantings and experiences in the afforestation areas in West and North Norway it became evident that there was a large potential for increasing the yield by changing tree species, especially from mismanaged broadleaves and pine to dense spruce plantations. The focal point in this chapter will therefore be the experience in Norway, with some examplesfrom other countries.....
Forfattere
Asrun Elmarsdottir Arne Fjellberg Gudmundur Halldórsson Maria Ingimarsdottir Olafur K. Nielsen Per Holm Nygaard Bjarni D. SigurdssonSammendrag
Recently, there has been increased emphasis on conserving biodiversity, threatened habitats and ecosystems in the Nordic countries. The Nordic countries have signed the Convention on Biological Diversity, thus embracing the target of halting the decline in biodiversity by the year 2010. Therefore it is important to identify the effects that afforestation has on biodiversity and the functioning of ecosystems......
Forfattere
Olafur Eggertsson Per Holm Nygaard Jens Peter SkovsgaardSammendrag
The last late glacial from 22,000 up until just before 13,000 years ago was very cold and dry throughout Europe. Large ice sheets were present over much of northern Europe, and ice caps covered the Alps and the Pyrenees. Forest and woodland were almost non-existent, except for isolated areas of woodland vegetation and close to the mountain ranges of southern Europe. Instead, a sparse grassland or semi-desert covered most of southern Europe, at the same time as a mixture of the dry, open steppe tundra and polar desert covered the parts of northern Europe not occupied by ice sheets (Figure 1). Ice-wedge geomorphological features suggest that permafrost extended across most of Europe, down to about the latitude of central France. At this time drifting sand and wind erosion were common in north and central Europe.
Forfattere
Erik LarnøySammendrag
To evaluate the decay resistance of wood, treated or untreated, for hazard classes 3, 4 and 5, the mass loss due to fungal exposure needs to be calculated. The standards for calculating mass loss in wooden test samples (i.e EN 113 and ENV 807) require that the samples used in the test are pre-dried to 0 % moisture content, m0, for determination of the initial dry mass. The standards describe that the samples should be dried at 103±2°C for 18 hours. When drying wood samples to 103 °C the samples are altered. Literature describes that extractives are influenced at temperatures as low as 60 °C, and redistribution and/or evaporation of these, will change the characteristics of the wood samples...
Sammendrag
The treatability of Scots pine (Pinus sylvestris) sapwood is ranked in the European standard EN 350-2 as class 1 (easy to treat), although huge differences in sapwood penetration exist. To obtain full sapwood penetration, process parameters have to be adjusted to the material most difficult to treat. It is therefore of importance to understand the factors that are responsible for penetration differences. Scots pine sapwood was investigated for anatomical differences influencing the ratio of filling (RoF) when treated with the wood modifying agent furfuryl alcohol. The database for the study was samples from two test series including Scots pine from Norway and Denmark. Within these experimental series each sample can be reassigned to its original position in the stem. The RoF for each sample was evaluated, and the variation in treatability within trees, between trees and between different stands was studied...
Sammendrag
Norway spruce (Picea abies) is widely used not only in Norway but in many other European countries. Due to its refractory behavior after drying it is difficult to impregnate with wood protecting agents that makes it suitable for outside applications. In this research spruce wood samples are exposed to microwave radiation in order to improve the impregnability. The strength properties are evaluated after both microwave and impregnation treatment. The results show, that microwave treatment on spruce wood samples improves the uptake of impregnation agents. With increasing energy absorption due to microwave radiation the impregnability is improved. No differences could be found between the microwave treatments in radial or tangential direction, neither in uptake of wood preservative nor in strength properties. The uptake of impregnation agents in spruce wood is increased by using a pre-treatment with microwave radiation. However, some microwave treatments lead to cracks and a reduction in tangential strength. Most of the values of the process parameters used were obviously too high, which resulted in a distinct crack development.
Forfattere
Gert-Jan Nabuurs Esther Thürig Nanny Heidema Kestutis Armolaitis Peter Biber Emil Cienciala Edgar Kaufmann Raisa Mäkipää Petter Nilsen Richard Petritsch T. Pristova Joachim Rock Mart-Jan Schelhaas Risto Sievänen Zoltan Somogyi Patrick ValletSammendrag
This paper is the outcome of a group discussion held at the Savonlinna meeting ‘Management of forest ecosystems and its impact on the GHG budget’. The aim of this break-out group discussion was to ‘Characterize forest management impacts on the GHG budget of forest ecosystems in different European regions’. In this paper we briefly characterize different options that a forest owner has in order to maintain or maximize forest carbon pools and carbon sequestration. These hectare scale descriptions of measures are then regarded in connection to the current state of European forests and how they can be combined with ongoing management trends and local issues. We point out the various possibilities that exist in European forests, where they are located, and where they could possibly be combined with adaptation. We identify these hotspots for largest growing stocks, largest peat areas, and, e.g. largest risks for loss of carbon due to fire or urban sprawl. We conclude that one common strategy cannot be designed. Within each region, local solutions have to be found that optimize goals and aim at integrated and sustainable land use.
Forfattere
Nicholas Clarke Nathalie Cools John Derome Kirsti Derome Bruno De Vos Alfred Fuerst Anna Kowalska Rosario Mosello Gabriele A. Tartari Erwin Ulrich Nils KönigSammendrag
Over the past years considerable efforts have been made to improve the quality of laboratory analyses in the various monitoring programmes within the framework of the ICP Forests programme. The Soil and Soil Solution, Deposition and Foliage and Litterfall expert panels have carried out a number of ring tests and held discussions on quality control. The expert panels’ subgroup, \"Working Group on QA/QC in Laboratories\", has extended its activities from the quality control of water analyses to encompass all forms of laboratory analysis, and now also includes experts in the fields of soil, foliage and litterfall. This paper presents all the quality control methods that have been devised for the relevant fields of analytical chemistry. The aim is to provide those laboratories carrying out analyses within the ICP Forests programme with a complete overview of the possibilities of applying quality control in their laboratories.