Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2012
Abstract
No abstract has been registered
Authors
Bernt-Håvard Øyen Petter Nilsen Fredrik Bøhler Kjell AndreassenAbstract
Models for predicting diameter increment in multi-storey spruce stands following mountain forest selective cutting (MFS) were developed. They were based on increment cores, tree ring analyses and stump registrations. The presented models rely upon time series data from 1600 trees in thirty-one Norway spruce stands in south-eastern and central parts of Norway. The selective cuttings were heavy; on average two thirds of the standing volume were cut. The increment following the interventions was highly variable, resulting in large random variability in the models with R2 varying between 0.18–0.31 for individual tree diameter growth and 0.40–0.50 for mean tree stand diameter growth. Dummy variables referring to three first 5-year periods after cutting were found to increase the precision and significantly reduce the random error. Selected models were validated using a test material from central Norway and also compared with the mostly applied Norwegian diameter increment models. Despite a large random variation in all models, the model performances appeared logical and the general fit to the data was acceptable. Based on tests, two diameter increment models are recommended for future yield prognoses in MFS. The models should also be of interest for wider use in other parts of the Nordic and Baltic boreal zone.
Authors
Stein Øvergaard Juan Antonio Fernández Pierna Vincent Baeten Pierre Dardenne Tomas IsakssonAbstract
No abstract has been registered
Authors
Audun Helge Nerland Aksel Bernhoft Per Brandtzæg Merethe Aasmo Finne Askild Lorentz Holck Olavi Junttila Heidi Sjursen Konestabo Richard Meadow Kaare Magne Nielsen Ville Erling Sipinen Hilde-Gunn Opsahl Sorteberg Rose Vikse Åshild Kristine AndreassenAbstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Adam ParuchAbstract
No abstract has been registered
Authors
Anders T Bråten Daniel Flø Sigmund Hågvar Oddvar Hanssen Christian Einar Mong Kjetil AakraAbstract
Spiders and beetles were pitfall-trapped in the foreland of the receding Hardangerjøkulen glacier in central south Norway. At each of six sampling sites, ages 3 to 205 years, twenty traps covered the local variation in moisture and plant communities. Thirty-three spider species and forty beetle species were collected. The species composition was correlated to time since glaciation and vegetation cover. A characteristic pioneer community of spiders and mainly predatory beetles had several open-ground species, and some species or genera were common to forelands in Svalbard or the Alps. While the number of spider species increased relatively constant with age, the number of beetle species seemed to level off after about 80 years. Half of the beetle species were Staphylinidae, and contrary to Carabidae, most of these were rather late colonizers. Most herbivore beetles colonized after more than 40 years, but the moss-eating Byrrhidae species Simplocaria metallica and also certain Chironomidae larvae developed in pioneer moss colonies after 4 years. The large Collembola Bourletiella hortensis, a potential prey, fed on in-blown moss fragments after 3 years. In the present foreland, chlorophyll-based food chains may start very early. Two pioneer Amara species (Carabidae) could probably feed partly on seeds, either in-blown or produced by scattered pioneer grasses.
Authors
Paal KrokeneAbstract
No abstract has been registered
Authors
M. Ashraful Islam Henrik Lütken Sissel Haugslien Sissel Torre Jorunn Elisabeth Olsen Dag-Ragnar Blystad Søren Rasmussen Jihong Liu ClarkeAbstract
No abstract has been registered
Abstract
No abstract has been registered