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.
2006
Forfattere
Volkmar TimmermannSammendrag
Monitoring on the forest officers\" plots in Norway has been running since 1988, with annual assessments carried out by local forest officers. In 2005 they assessed 30277 trees on 557 plots. For 15090 of these trees on 348 plots, there exist complete records of crown condition over the past 18 years. The plots are subjectively selected, mainly in Norway spruce dominated stands, and divided into four development classes. The results from 2005 show a slight increase in mean defoliation of Norway spruce to 16.4 %. There were small, but mostly negative changes in most regions without clear trends in the long term series. In southern Norway, a strong increase in defoliation was observed. Crown colour was improving in the western and northern regions of the country, whereas discolouration was increasing in south-eastern Norway. The mean discolouration was still very low in 2005, with 90 % of the spruce trees having normal, green colour. The mortality rate was low, on the average 3.4 ‰ for all trees. Only few causal agents of crown damage were reported. Data from 18 years of monitoring on the forest officers’ plots reveal some regional patterns for defoliation of spruce in Norway, with western Norway having the lowest mean defoliation through all years, and Mid-Norway the highest. In the other regions, the trends are not so clear with greater fluctuations in defoliation and discolouration.
Forfattere
Sanna Koutaniemi Tino Warinowski Anna Kärkönen Carl Gunnar Fossdal Lars Paulin Stephen Rudd Teemu H. TeeriSammendrag
Although a detailed description of the lignin biosynthetic pathway has been established in e.g. Arabidopsis, such an analysis has not been performed in tree species. We have used EST sequencing and quantitative real-time RT-PCR to explore lignin biosynthetic gene expression in Norway spruce (Picea abies).Altogether 7500 ESTs were sequenced from a lignin forming tissue culture and developing wood of spruce, and clustered into 3800 unigenes. According to a tentative annotation, 4% of the unigenes were potentially involved in lignin biosynthesis. For most catalytic steps, several gene family members were found, but only one unigene for each gene family contained ESTs from both the tissue culture and developing wood.Expression of the unigenes was studied in detail using quantitative real-time RT-PCR. Results highlighted the set of unigenes most likely responsible for monolignol biosynthesis in Norway spruce, also demonstrating that the same genes are expressed in all lignin-forming tissues.On the contrary, peroxidases and laccases, thought to be responsible for the oxidative step in lignin polymerisation, had distinct expression profiles in different tissues. Also a few genes induced by compression stress or Heterobasidion annosum infection were identified.
Sammendrag
This analysis is based on climatic data and increment cores from about 550 Forest officers from latitude 58-70N and longitude 6-18E. The strength of the data is the high number of plots scattering over most of the Norway spruce forest area in Norway. Tree ring-widths were transformed to ring indices to remove age disturbances and strengthen the climatic signal on the tree growth.We used regression analyses to examine the annually growth responses of these ring indices against 42 monthly climatic variables. The climatic variables we used were mean month temperature, precipitation and Palmer drought severity index (PDSI) with a range from previous year July to current years August.The results showed some correlations of climate on growth, with the June weather as most important. The most important variable in the lowlands (altitude 500 m) of southeastern Norway was the June precipitation, and the June temperature in the rest of the country.
Forfattere
Svein Johan Reid Wenche E. DramstadSammendrag
I kjølvannet av bruksnedlegging og nedgang i antall beitende dyr endres jordbrukslandskapet. Dette er ikke nødvendigvis et problem, men tempoet i etterkrigstidens bruksnedleggelse og generelle omstrukturering av landbruket er likevel av et sånt omfang at det de siste tiårene har vokst fram en økende bevissthet og bekymring for konsekvensene av disse endringene.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
There is a high correlation between methods for dynamic modulus of elasticity (MOEdyn) and static modulus of elasticity (MOEstat). MOEdyn methods have been found sensitive to detect early stages of decay and may be seen as an option for non-destructive wood durability testing.As the MOEstat measurements do not change after reaching the fibre saturation point, the uncorrected MOEdyn data from ultrasonic pulse excitation method provides increasin values after fibre saturation. This is due to the effect of free water in the cell lumen on ultrasonic waves. The aim of this study was to make a moisture calibration for the MOEdyn ultrasonic pulse excitation method using Scots pine (Pinus sylvestris L.) sapwood samples.MOE was measured at five different moisture levels. Three different MOE test methods were used: MOEdyn using ultrasound and vibration excitation and the traditional MOEstat. Sound Scots pine sapwood samples treated with two copper-containing wood preservatives and two chitosan solutions were evaluated, using untreated sapwood samples as control.In this study a correction value (\"k\") was calculated based on data from different moisture levels for water saturated samples using four different wood treatments and control. By measuring MOEdyn ultrasonic at wood moisture contents just below fibre saturation point, a minor effect of incipient water accumulation in the wood matrix was detected.Wood treatments influence the \"k\" value, and a \"k\" value needs to be calculated for all wood treatments when measuring MOEdyn ultrasound above fibre saturation. All the three MOE test methods in this study are applicable for all wood moisture levels as long as a \"k\" value is calculated for MOEdyn ultrasound above fibre saturation.
Forfattere
Birger VenneslandSammendrag
During the 1980s and the 1990s the tourism development in general increased rapidly. The term innovation has been used to describe this development. But how well can we adapt the traditional industrial understanding of innovation in the service sector? Especially it seems as we have to extend our understanding of innovation when comes to the development of nature based tourism. There is a need to discuss various definitions of innovation and look at a framework of understanding that distinguishes between various definitions of innovation in the service sector.
Forfattere
Øyvind Meland Edvardsen Halvor SolheimSammendrag
Det er ikke registrert sammendrag
Forfattere
Magnus Karlsson Ari M. Hietala Harald Kvaalen Halvor Solheim Åke Olson Jan Stenlid Carl Gunnar FossdalSammendrag
Norway spruce (Picea abies (L.) Karst.) has a natural distribution in the northern parts of Europe and Asia and is economically the most important tree species grown in the Nordic countries. A common threat to Norway spruce is the basidiomyceteous fungus Heterobasidion parviporum Niemelä and Korhonen. H. parviporum mainly attacks Norway spruce, although Siberian fir (Abies sibirica Ledeb.) and Scots pine (Pinus sylvestris L.) occasionally get infected. One obstacle to studying host/pathogen interaction in conifers has been the limited availability of mature clones for controlled inoculations, as genetic variation within the host material and the lack of replicates complicate interpretation of the results. Somatic embryogenesis, rooted cuttings, and tissue cultures may provide solutions for this problem. Tissue cultures from mature Norway spruce trees have been proposed as a possible model system for assessing resistance toward fungal pathogens. Recent data on chitinase isoform activity in the Norway spruce/H. parviporum pathosystem are encouraging; clonal variation was observed in the isoforms affected by inoculation, and the isoforms showing increased band intensity following bark inoculation by H. parviporum were also induced in the inoculated tissue cultures of the corresponding clones. To investigate the biological relevance of tissue cultures in host-pathogen interaction studies, transcript levels of selected host and pathogen genes in tissue cultures of Norway spruce were compared to those in bark of 33-year-old ramets of the same clones upon challenge by the pathogenic fungus H. parviporum. Similar transcript profiles of the pathogen and host genes were observed in both tissues, this supporting the use of tissue cultures as experimental material for the pathosystem. Higher transcript levels of the host genes phenylalanine ammonia lyase, peroxidase, and glutathione-S-transferase were observed in the more resistant clone #589 than in the less resistant clone #409 during the early stages of colonization. The most striking difference between the spruce clones was related to gene transcript levels of a class IV chitinase, which showed a continuous increase in clone #409 over the experimental period, with a possible association of this gene product to programmed cell death. Several of the fungal genes assayed were differentially expressed during colonization, including putative glutathione-S-transferases, laccase, cellulase, cytochrome P450 and superoxide dismutase genes. The transcriptional responses suggest an important role for the antioxidant systems of both organisms.
Forfattere
Anders Busse Nielsen Jasper Schipperijn Yngve Rosenblad Heldur Sander Mikk Sarv Kirsi Mäkinen Janis Donis Vegard Gundersen Ulrika Åkerlund Roland GustavssonSammendrag
Det er ikke registrert sammendrag