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.
2012
Forfattere
Bernt-Håvard ØyenSammendrag
Det er ikke registrert sammendrag
Forfattere
Lars Sandved DalenSammendrag
Et framtidig samfunn basert på fornybare energikilder krever at vi utnytter mer bioenergi fra skog. En ny doktorgrad omhandler hele kjeden fra skogsråstoff til ferdig brensel.
Forfattere
Finn-Arne HaugenSammendrag
Mange områder i Norge har svært gode utmarksbeiter, men mindre enn halvparten av dette utnyttes i dag.
Sammendrag
Askeskuddsjuke utvikler seg stadig til det verre og nå er store deler av Vestlandet også angrepet. Foreløpig har det gått verst utover de små trærne og mange er drept. De store trærne klarer seg bedre, men noen av dem har lite kronemasse igjen.
Forfattere
Kjersti Holt HanssenSammendrag
Selective cutting and other continuous cover forestry systems may be used in spruce forests where for instance environmental or recreational considerations are more important than forest production. However, in order for this system to be sustainable, successful regeneration must be achieved. The supply of both light and below-ground resources may influence the growth and development of seedlings. If a diverse tree species composition is desirable, knowledge of the gap sizes necessary to sustain seedling survival and growth of different species is important. We studied the growth of Norway spruce (Picea abies) and Scots pine (Pinus sylvestris) seedlings in the understory, using two Norway spruce sites with selective cutting and group fellings in SE Norway. 4-week old seedlings (henceforth: mini seedlings) were planted in plots with and without trenching in gaps of four different sizes, ranging from 20 to 500 m2. In addition, commercial seedlings of the two species were planted pairwise across the sites. After three years the mini seedlings were dug up and measured, while the survival and growth of the commercial seedlings were followed for eight years. Differences in seedling survival and growth characteristics due to gap size and (for mini seedlings) trenching were analysed using GLM. Mortality was high, especially for pine seedlings. This was due to grazing as well as competition for light and nutrients. Growth of both species was positively correlated with increasing gap size. This applied for height, diameter, shoot volume and needle biomass as well as total dry weight for both spruce and pine seedlings. However, trenching had a significant positive effect on growth too, also in the smallest gaps.
Forfattere
Lars Sandved DalenSammendrag
Regjeringen ønsker økt satsing på ny fornybar energi. Her spiller bioenergi en viktig rolle. Skog representerer en betydelig kilde til oppvarming, og riktig transport og tørking er viktig for å gi lønnsomhet.
Forfattere
Lars Sandved DalenSammendrag
Skogbunnplanter reagerer raskt på endringer i hogst. Store mengder hogstavfall på ett sted gjør at mange plantearter forsvinner nokså raskt.
Forfattere
Jørn Henrik Sønstebø Mari Mette TollefsrudSammendrag
Background: The conifer tree Abies lasiocarpa, is native to North America with a distribution range from Alaska in the north to Arizona and New Mexico in the south. The southern populations partly belong to the variety A. lasiocarpa var. arizonica, which has a distinct morphology. A. lasiocarpa is an important species for Christmas tree production in Norway and there is an increasing demand for seeds from proveniences known to produce high quality Christmas trees. Currently, seeds are imported from natural stands in the US and Canada or collected from plantations in Norway with unknown origin, but which are known to produce high quality trees. To increase the harvest potential of seeds in A. lasiocarpa both in natural stands and in seed production stands in Norway, it is important to know the population genetic structure in North America and identify the origin of the current seed producing trees in Norway. Population genetic structures will be used to identify new potential seed collection areas in North America.Main objectives: Investigate population genetic structure across the distribution range of A. lasiocarpa. Characterize genetic diversity in north American provenances and seed bearing stands in Norway. Assign Norwegian provenances to north American provenances in order to identify their origin and new potential seed collection zones.
Forfattere
Kjell Andreassen Bernt-Håvard ØyenSammendrag
Growth conditions in Fennoscandia are characterized by relatively short growth seasons and cold winters, from 130 growth days (T 5C) in the far north high mountains to more than 200 in south Sweden and Norway. Growth models from different regions predict different forest growth.In this study, we compare some models commonly applied in forest growth prognosis in pure even aged stands of Norway spruce, Scots pine and birch in Finland, Sweden and Norway. The objectives is to identify behavioural properties, accuracy and bias in selected Nordic growth models using a wide-ranging test data set from permanent research plots in Norway.Present tentative conclusions about the accuracy of growth outside the geographical range of the original base materials. With four different response variables in the tested models we emphasized relative deviations rather than absolute values as most suitable for comparisons. The models were compared by statistical tests, a visual inspection of the smoothed curve of the relative deviations in different stand properties and ranked due to their performance.We observed site index, stand density and mean tree size as the three main components in the models. For Norway spruce a basal area increment model from Sweden had the lowest standard deviation with 23 %. The mean R2 between residuals and stand characteristics from this model was also low (1.3 %), which indicates that variables are well included in the model. For Scots pine and birch, Finnish percent volume growth models showed the best fit to the Norwegian test data, with a R2 between residuals and stand characteristics of 2.8 and 6.7 %, respectively. Several of the models from Sweden and Finland predict the growth as well as stand models frequently in use in Norway.
Sammendrag
Grantrær og barkbiller har slåss i millioner av år. Kunnskap om granas forsvar kan gjøre det mulig å redusere barkbilleskader gjennom planteforedling og skogskjøtsel. Ny forskning viser at grantrær kan unngå å bli drept av barkbiller hvis de er raske til å produsere mye kvae.