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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.

2015

Sammendrag

This paper reports on the performance of the red-listed Primula scandinavica, endemic to Scandinavia. The study took place in Jotunheimen, Norway. We evaluated occurrence, density and sexual reproduction variables (number of fertile individuals and number of seed capsules). Habitats were registered as land-cover categories (historical and current; broad habitat types) and habitat patch classes (semi-natural and natural; fine-grained habitat types). Spatial overlay analyses and maximum likelihood tests of generalized linear mixed models (GLMMs) were performed to assess the habitat quality of the land-cover categories and the habitat patch classes. In most (96%) of the observed occurrences the species was located at a site that had open vegetation 40 years ago but is now becoming forested or covered by shrubs. The highest densities of P. scandinavica were found in “heathland” and “grassland in transition into woodland”, while the potential for sexual reproduction was highest in “grassland” and lowest in “grassland in transition into woodland”. The results indicate that many of the populations in the study area are remnants and that the habitats of highest quality are semi-natural habitat patches. The changed land use practices in mountain areas have resulted and will result in fewer and smaller populations. However, as also climatic conditions will change it is not straightforward to predict the future performance of P. scandinavica.

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Sammendrag

This study compares the responses of two Swedish 5-year predictive stand-level functions with the observed responses in 721 fertilization experiment plots in Norway fertilized with nitrogen (N). All plots are single-species consisting of Norway spruce (Picea abies (L.) H. Karst.) or Scots pine (Pinus sylvestris L.) fertilized with ammonium nitrate (AN) or urea. The correlations between the observed and the two predicted responses were 0.34–0.40 for all plots taken together. One response function performed well on average, but underestimated the response in pine plots and overestimated the response in spruce plots. The second function overpredicted the response on the full dataset, in spruce plots and old forest, but performed well in pine plots. Both functions overestimated the growth response in high-productive plots. Higher N deposition in Norway than in Sweden may count for parts of the deviations. Testing of fertilization functions on new datasets is rare, but important part of the evaluation of functions. As the functions are not well fit for predicting the growth response in spruce and high-productive plots in our sample, new functions that include N deposition are welcome.