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
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
Forfattere
Clemens Reimann Arnold Arnoldussen Rognvald Boyd Tor Erik Finne Øystein Nordgulen Tore Volden Peter EnglmaierSammendrag
Forty terrestrial moss (Hylocomium splendens) samples were collected along a 120-km-long south–north transect running through Norway\"s largest city Oslo. Concentrations of 29 chemical elements (Ag, Al, Au, Ba, Bi, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, La, Mg, Mn, Mo, Na, Ni, P, Pb, Pt, S, Sb, Sr, Th, Ti, and Zn) and values for loss on ignition (475 °C) are reported. Silver (Ag), Al, Au, Bi, Cd, Co, Cr, Cu, Fe, Mo, Ni, Pb, Pt, Sb, Th, Ti, and Zn all show a characteristic Oslo peak when element concentrations are plotted against location of the sample site along the transect. Gold (Au) and Pt show the greatest relative enrichment of all elements in the city (ca. 10× “background”). Titanium (Ti), which is related to local minerogenic dust rather than anthropogenic emissions, shows a significant peak in Oslo. Loss on ignition, a measure of the amount of organic material in a sample, shows a negative peak in Oslo and at sites close to a known dust source. Input of fine dust thus appears to dominate many of the observed element concentrations in moss. The concentrations of Na are clearly influenced by the input of marine aerosols and show decreasing concentrations from south (near Oslo Fjord) to north (inland). The major plant nutrients Ca, K, Mg, P and S, as well as Hg, are the few elements displaying no spatial dependency along the transect. Element concentrations reach background variation levels at a distance of 20–40 km from the city centre.
Forfattere
Harald BratliSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Holger LangeSammendrag
Most phenomena in ecosystem research are assessed via repeated measurements of environmental variables. The dynamics of these time series is investigated with a variety of statistical techniques; in this article, we focus on modern nonlinear methods. They enable separation of short- and long-term components, show all types of trends and quantify the information contained and the complexity of the data sets.
Tidsskriftspublikasjon – Beitepress hemmer foryngelsen av barlind (Taxus baccata) i Norge
Tor Myking
Forfattere
Tor MykingSammendrag
Beitepress hemmer foryngelsen av barlind (Taxus baccata) i Norge Barlind forekommer i Skandinavia helt i ytterkanten av sin geografiske utbredelsen i Europa og danner i Norge sine mest nordlige populasjoner. Treslaget trenger varm sommer og mild vinter og vokser i spredte populasjoner i lavlandet langs kysten i det sørlige Norge. Det har lenge vært kjent at hjort og rådyr beiter sterkt på foryngelsen av barlind, og Genressursutvalget for skogtrær (http://www.genressurser.no/skogtrer/) initierte en kartlegging av beitetrykket. Undersøkelsen viser at beiting sterkt begrenser foryngelsen med frøplanter og at den har skadet bark og bar på trærne på et flertall av feltene som ble undersøkt. På kort sikt er ikke beitingen en trussel mot treslaget fordi trærne kan bli svært gamle. Men dersom den fortsetter på samme måte over lang tid, kan den påvirke den naturlige utbredelsen av barlind i denne nordlige utposten. En rapport fra første del av undersøkelsen er nå publisert og er tilgjengelig på http://skogforsk.pdc.no/pdf/2005/A-2005-6.pdf.
Forfattere
Joha W. Grobbelaar Michael J. Wingfield P. Bloomer Halvor Solheim Brenda D. WingfieldSammendrag
Det er ikke registrert sammendrag