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.
1999
Forfattere
A. TigerstedtSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Ketil KohmannSammendrag
Side effects of the permethrin formulations Gori 920 and Gori 920 L, the fenvalerate formulation Sumicidin 10 FW and the emulsifier of the Gori formulations have been studied in seedlings of Norway spruce. Whole plant treatment with the Gori formulations in early autumn resulted in a 5 - 10 C poorer frost tolerance (TDI) later in the autumn. Moreover, this treatment increased mortality by 30 % within two years of testing in field trials. A basal part treatment with the Gori formulations and whole plant treatment with Sumicidin 10FW containing 10 % fenvalerate, gave on the other hand no negative effects during two years of field testing. Late autumn treatment with Gori 920 and Gori 920 L. followed by cold storage for six months revealed poorer frost tolerance (3-4 C) in the spring than the control. These treatments also reduced leader shoot growth in the first year, and increased the frequency of plants lacking a dominant leader after two years by 20-40 %. The detrimental agent in Gori 920 L was found to be the emulsifier, ethoxylated nonylphenol, alone and in combination with the dispersal agent, the linseed oil. The linseed oil gave no significant additional negative effect on frost resistance and growth after the cold storage during the winter. The investigation demonstrates the necessity of testing for possible side effects before practical use of any commercial pesticide formulation. The experiments were conducted in Norway at the nursery of Buskerud Forestry Society and at The Norwegian Forest Research Institute at s
Forfattere
Svein Ola MoumSammendrag
The article presents a mapping system describing agricultural resources in scales ranging from 1:100.000 down to 1:300.000, with respect to a prototype covering an area of Nord-Gudbrandsdalen district. The maps cover all Norwegian land types grouped into 13 classes.Ancillary data is widely used and the area where new interpretation is needed was thus limited to dry land above the tree line. The land type of these areas was interpreted from Landsat TM images. Maps produced with this system offer a coherent overview of the landscape and land types for large areas. Land type statistics from these small-scale maps is only recommended when the claim of accuracy is low and statistical bias is acceptable. Use of the maps for regional and agricultural planning as well as for environmental impact assessment is discussed.
Forfattere
Torild Wickstrøm Ingrid Ann BergSammendrag
Det er ikke registrert sammendrag
Forfattere
Harald AaldeSammendrag
Det er ikke registrert sammendrag
Forfattere
Øystein Dale Morten NittebergSammendrag
Det er ikke registrert sammendrag
Forfattere
Oddvar SkreSammendrag
Seedlings of white birch seem to tolerate high winter temperatures to a higher degree than spruce seedlings, and were also more able to take advantage of elevated CO2 levels. Large differences were observed between provenances in response patterns. The southern provenance of birch was more tolerant against raised winter temperatures than the northern ecotype, and the southern spruce provenance seemed to differ from the two northern provenances in the same way. The Icelandic birch population seemed to have developed a low-growth strategy with strong CO2 acclimation and no significant CO2 responses in photosynthetic rates and growth parameters. This differing response may be explained by long-term selection pressure due to heavy grazing. One of the spruce provenences showed a similar pattern.
Forfattere
Svein SolbergSammendrag
On the local county monitoring plots located throughout Norway a reduction of crown density has been noted during 1988-97. The aim of this study was to determine whether this change could be attributed to normal effects from increased age on the plots.The dataset comprised around 580 plots and 27 000 single trees of Norway spruce, where each tree was provided with ten years of crown density measures. A two step approach was used, firstly to search for an expectancy for normal reduction of crown density by age derived from the dataset, and then to compare this with the actual reduction. The interpretation was somewhat complicated as the various results were tangled into each other.Highly significant correlations were found between crown density and age. The relationship indicated an annual reduction of crown density around 0.12%-units, however, the relationship varied both between years and between regions, and it was not possible to definitely determine whether the relationship was best described by linear or non-linear models.Of major importance here is that the relationship appeared to be influenced by the presence of stresses, which effects tended to be more severe in old stands. Based on this it seems questionable whether an expectancy for normal ageing can be properly defined. However, in the present study it could still be definitely determined that the mean crown density change of -0.41%-units annually was too negative to be attributed to normal ageing, as it was clearly below all the suggested expectancies from the various models.This suggests that the amount of stress in the period under study has been higher than normal, and this encourages the search for causal agents in further studies. Changes in silviculture may have had some influence.The results were valid for most of Norway, with the exception of western and northern regions. Crown density assessments are subjective, which may possibly give erroneous time trends, however, it is argued that this is less likely to be of major importance in the present data.
Forfattere
Tove M. Østensvik H. FossumSammendrag
Det er ikke registrert sammendrag