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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

Sammendrag

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......

Sammendrag

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.

Sammendrag

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.

Sammendrag

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.

Sammendrag

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.

Til dokument

Sammendrag

Data series for bud burst, beginning of flowering and petal fall for 20 species of deciduous trees and conifers at four sites in different regions of southern Norway have been analysed and related to temperature series. On average, the spring phenophases occurred 7 days earlier during the period 1971–2005. The most significant linear trends were observed for the earliest phases. The trends in this period were compared with trends in other periods, the longest one starting in 1927. Those starting in cold decades and ending in 2005 were in most instances statistically significant, whereas hardly any significant trend appeared for series starting in warm decades. This fact showed that the results of trend studies are very sensitive to the choice of starting year. There were significant decadal variations in 40% of the series. The dates of occurrence of the phenophases, varying from the first days of May to the first days of June, correlated with seasonal temperature series, in most cases strongest to mean temperatures for the seasons March–May and April–May. The North Atlantic Oscillation Index (NAOI) for January and February appeared to have some predictive power for the date of occurrence of the recorded phases. The basis for this may be that the oscillations described by the index are of importance for the fulfilment of physiological chilling requirements needed to break bud dormancy. The same genotypes of the trees were grown in region West Norway and in Central Norwegian region; during the period 1965– 2005 the trends towards earlier bud burst were more pronounced and steeper at the western site.

Sammendrag

Patterns of tree mortality, rates and type of tree and snag fall, and relationships between snag characteristics and potential wildlife habitat value were estimated for hybrid spruce (Picea glauca (Moench) Voss x engelmannii Parry ex Engelm.) and subalpine fir (Abies lasiocarpa (Hook.) Nutt.) in eastcentral British Columbia in order to provide important parameters for deadwood modelling. We sampled 172 snags (52 spruce and 120 fir) for species, size, morphological, and habitat attributes, and used dendroecological techniques on a subsample of these (n = 158) to estimate year of death. Input of snags appeared to occur at a nearly constant rate in these stands. Estimated annual tree fall, including live trees and snags, was 5.3% for hybrid spruce and 6.1% for subalpine fir and stem breakage was more frequent than uprooting. Long-term annual snag fall rates were 4.6% for hybrid spruce and 2.9% for subalpine fir. Discriminant analysis based on time since death correctly classified snags into three decay classes for 85% and 72% of spruce and fir, respectively. Snags that potentially could provide important functions for wildlife habitat were more prevalent in fresh and intermediate classes for hybrid spruce and in intermediate and old classes for subalpine fir. The results provide valuable parameters for further development of deadwood models, which are an important tool for development of best practices for deadwood management.