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.
1997
Forfattere
Darrell W. Ross Halvor SolheimSammendrag
Pole-size Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) were inoculated with two fungi (Ophiostoma pseudotsugae (Rumb.) von Arx and Leptographium abietinum (Peck) Wingf.) associated with the Douglas-fir beetle (Dendroctonus pseudotsugae Hopkins) to evaluate their pathogenicity. Pruning the lowermost 30% of the live crown had no effect on host tree defenses. Inoculation with O. pseudotsugae produced significantly longer lesions in the phloem and resulted in a significantly greater percentage of necrotic phloem than inoculation with L. abietinum. The percentage of occluded sapwood was also greater following O. pseudotsugae inoculations, but the difference was not statistically significant. Individual lesion lengths declined significantly with increasing inoculation density, but the total percentage of necrotic phloem increased significantly. Both fungi appeared to be better adapted to grow in sapwood than in phloem. None of the inoculated trees were dead after 5 months, but some were chlorotic with less than 30% functional sapwood within the inoculation band. The results suggest that these fungi may assist the Douglas-fir beetle in overcoming the defenses of live trees.
Forfattere
Oddvar HaveraaenSammendrag
Det er ikke registrert sammendrag
Forfattere
Jan Mulder Petter Nilsen Arne Olav Stuanes Magne HuseSammendrag
Det er ikke registrert sammendrag
Forfattere
Knut SolbraaSammendrag
Det er ikke registrert sammendrag
Forfattere
Knut SolbraaSammendrag
Introduksjon til et avsnitt om lav funnet på Hirkjølen. Artikkelen omfatter også en artsliste.
Forfattere
Knut SolbraaSammendrag
Introduksjon til et kapittel om planter som er funnet i fjellskog på Hirkjølen. Artiklen inneholder også en liste over karplanter Introduction to a chapter dealing with plants found in mountain fores t at Hirkjølen, including a list of higher plants
Forfattere
Arild Vatn Lars R. Bakken Peter Botterweg Eirik Romstad Kjell Arne Brekke Øyvind Lone Tor RødsethSammendrag
Det er ikke registrert sammendrag
Redaktører
Petter NilsenSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
We compared diversity of birds in 35 study plots of equal size (58 ha) and productivity in western Norway, ranging from pure native pine Pinus sylvestris forests (n = 7), through different mosaics of native pine forests and spruce Picea spp. plantations (n = 21), to pure spruce plantations (n = 7). Diversity was evaluated by means of species richness, diversity indices, relative abundance curves and rarefaction. The diversity indices appeared to be less suitable for our purpose. Species richness was higher in pine forest than in spruce forest. However, a peak in species richness was found in mosaic forest. For pooled samples (408 ha), 11 bird species recorded in pine forest were not found in spruce forest, seven species were found in spruce forest but not in pine forest, and seven species were confined to the medium mosaics of pine and spruce forest (on average 56% pine and 44% spruce). We argue that, when mixing two habitat types A and B, the ratio of these habitats that maximize avian diversity depends on the ratio of species confined to habitat A and B, as well as the number of species favoured by the mixture of A and B. Existing spruce plantations (13% of the area) in native pine forests of western Norway have reduced the diversity of birds locally, but increased the diversity of birds on the landscape and regional scale.