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.
2000
Sammendrag
Measurement data on air, precipitation and canopy throughfall chemistry from a network of sites have been combined to study scavenging and deposition processes, with particular emphasis on the oxidised nitrogen species.High deposition rates of oxidised nitrogen occur in coastal areas of SW Norway. These are partly caused by high precipitation rates, partly also because a large fraction of the oxidised nitrogen is present as nitrate in large particles, which are rapidly removed by both wet and dry deposition processes.High wind speeds near the coast result in high concentrations of sea-salt particles in the air and high deposition rates of both nitrate and sea-salt particles, particularly in coniferous forest stands. HNO3 contributes on average only about 10-20% to the sum of aerosol nitrate and HNO3 (sNO(3)). Still, the combined dry deposition velocity of sNO(3) to these forest stands may be between 4 and 6 cm s(-1) on average.
Forfattere
Torstein KvammeSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Jenny Fäldt Halvor Solheim Bo Långström Anna-Karin Borg-KarlsonSammendrag
Det er ikke registrert sammendrag
Forfattere
Bjørn ØklandSammendrag
Det er ikke registrert sammendrag
Sammendrag
Siden 1980 har Norsk institutt for skogforskning overvåket bestanden av granbarkbiller ved hjelp av feller med feromoner. Registreringen skjer i samarbeid med skogbruksetaten i 10 fylker og kommuner i Sør-Norge og Trøndelag. Resultatene for 2000 i Sør-Norge viser at det stort sett er nedgang i fangstene, og i alle fylkene er trenden enten nedadgående eller stabil. Fangsttallene er likevel høye i enkelte kommuner. I Trøndelag er fangstene relativt små. Det er grunn til å tro at uvanlig kjølige forsomre de senere årene har virket negativt på billebestanden, etter som temperaturen bare leilighetsvis har overskredet det nivået som er nødvendig for billenes flukt (ca. 20°C). Tross denne relativt gunstige situasjonen er det grunn til å legge vekt på god skoghygiene, også der hvor fangstene er små i år.
Sammendrag
The anatomical response of Norway spruce bark polyphenolic parenchyma cells (PP cells) to inoculation with the phytopathogenic fungus Ceratocystis polonica and attack by its bark-beetle vector Ips typographus was examined.Fungal inoculation on the periderm surface had no effect, while inoculation just below the periderm or halfway into the phloem (mid-phloem) generated detectable responses within 3 wk. The responses included increase in PP cell size and in periodic acid - Schiffs staining of PP cell phenolics, wound periderm initiation from PP cells, and cambial zone traumatic resin duct formation. Fungi were not seen in samples 3 wk after subperiderm or mid-phloem inoculation, but were found in some samples 6 and 9 wk after mid-phloem inoculation.In contrast, inoculations into the cambium resulted in partial (3 wk) or complete (6 and 9 wk) fungal colonization and death of tissue in the infected area. This indicates that PP cells have defenses capable of inhibiting fungal growth. Samples taken near bark-beetle galleries had similar anatomical responses as inoculated samples, validating the inoculation approach to studying defense responses in spruce.These results show that PP cells represent not only a constitutive defense system, but are also involved in local and remote inducible defenses against fungal and beetle attack.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Dan AamlidSammendrag
Two fungi, V. heterodoxa and P. vaccinii, are found to have impact on the leaf coverage of bilberry plants. When studying vegetation or forest ecosystems, assessors should, therefore, be aware of the biotic impact of pathogens on plants.
Sammendrag
Det er ikke registrert sammendrag