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
Jenny Fäldt Halvor Solheim Bo Långström Anna-Karin Borg-KarlsonSammendrag
To identify chemical resistant markers induced by fungal or mechanical injury, young trees of Scots pine (Pinus sylvestris) were subjected to inoculations of blue stain fungi associated with the pine shoot beetles Tomicus piniperda and T. minor. Among the 20 trees selected for chemical analyses, 16 were divided into four groups: one as control and three were pretreated by wounding only, or by inoculation with either the blue stain fungus Leptographium wingfieldii or Ophiostoma canum.Four wk after pretreatment, all 16 pretreated trees were mass-inoculated with L. wingfieldii. The absolute and relative amounts, as well as the enantiomeric compositions of monoterpene hydrocarbons in the phloem, were determined via a small sample of the phloem before and after the pretreatment and mass inoculation, by using two-dimensional gas chromatography (2D GC) and GC-mass spectrometry (MS).After mass inoculation, the absolute amounts of most of the monoterpenes decreased in the phloem sampled 20 cm from the fungal infection, and were higher in the phloem sampled within the infected reaction zone.The relative amounts of both ()--pinene and ()-limonene increased in phloem samples taken 20 cm above the fungal inoculation in the preinoculated trees compared with phloem sampled from the remaining four control trees. The enantiomeric compositions of -pinene and limonene changed, after fungal growth, at defined distances from the inoculation site: the proportion of the ()-enantiomers was highest in the phloem sampled 20 cm from the fungal inoculation.Four wk after pretreatment, monoterpene production in the phloem at the site of inoculation was more enhanced by L. wingfieldii than by O. canum. However, the different virulence levels of the fungi did not affect the enantiomeric composition of the monoterpenes. The biosynthesis of monoterpene enantiomers is discussed in relation to induced pathogen resistance.
Forfattere
Per Otto FlæteSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Harald Bratli Erik Framstad Jogeir N. Stokland Odd Egil StabbetorpSammendrag
Det er ikke registrert sammendrag
Forfattere
Reidar Elven Torbjørn Alm Harald Bratli Arve Elvebakk Torstein Engelskjøn Eli Fremstad Marit Mjelde Bjørn Moe Oddvar PedersenSammendrag
Det er ikke registrert sammendrag
Forfattere
Bernt-Håvard ØyenSammendrag
Det er ikke registrert sammendrag
Forfattere
Halvor SolheimSammendrag
Treveps er store insekter som vekker oppsikt når de flyr rundt i skogen på jakt etter egnet materiale å legge egg i. Treveps i slektene Sirex og Urocerus har med seg råtesopp i mycangier. Siden dette ble oppdaga er fire sopparter blitt knytta til disse trevepsene. Først ble Stereum sanguinolentum antatt å være følgesvennen. Dette viste seg ikke å være tilfelle, men det har har hengt lenge ved i litteraturen. I stedet er tre Amylostereum-arter funnet å være assosiert med forskjellige arter av treveps; A. areolatum, A. chailletii (granlærsopp) og A. laevigatum (einerlærsopp). I denne artikkelen skriver jeg litt om treveps-sopp assosiasjonen og om de nevnte soppenes opptreden i Norge. Amylostereum areolatum er ikke rapportert fra Norge tidligere.
Forfattere
Risto Kasanen Jarkko Hantula Timo Kurkela Martti Vuorinen Antti Komualinen Johanna Haapala Henna Penttinen Egbert BeukerSammendrag
Det er ikke registrert sammendrag
Forfattere
Michael M. Müller Kari KorhonenSammendrag
Det er ikke registrert sammendrag
Forfattere
Rune Halvorsen Økland Harald Bratli Wenche E. Dramstad A. Edvardsen Gunnar Engan Wendy Fjellstad Einar Heegaard Oddvar Pedersen Heidi SolstadSammendrag
Knowledge of variation in vascular plant species richness and species composition in modern agricultural landscapes is important for appropriate biodiversity management. From species lists for 2201 land-type patches in 16 1-km2 plots five data sets differing in sampling-unit size from patch to plot were prepared.Variation in each data set was partitioned into seven sources: patch geometry, patch type, geographic location, plot affiliation, habitat diversity, ecological factors, and land-use intensity.Patch species richness was highly predictable (75% of variance explained) by patch area, within-patch heterogeneity and patch type. Plot species richness was, however, not predictable by any explanatory variable, most likely because all studied landscapes contained all main patch types ploughed land, woodland, grassland and other open land and hence had a large core of common species.Patch species composition was explained by variation along major environmental complex gradients but appeared nested to lower degrees in modern than in traditional agricultural landscapes because species-poor parts of the landscape do not contain well-defined subsets of the species pool of species-rich parts.Variation in species composition was scale dependent because the relative importance of specific complex gradients changed with increasing sampling-unit size, and because the amount of randomness in data sets decreased with increasing sampling-unit size. Our results indicate that broad landscape structural changes will have consequences for landscape-scale species richness that are hard or impossible to predict by simple surrogate variables.