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.
2006
Sammendrag
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Sammendrag
Hydrological time-series are known to depict long-term structures, and pronouncednonlinearities. Singular System Analysis (SSA) is one way to extract long-term componentsof these data-sets. Classical SSA is a principal component analysis (PCA) inthe time domain...
Sammendrag
Ecosystems commonly fall under the rubric of complex systems (West and Brown 2004). Nevertheless, in the practical management of certain ecosystems, we encounter simple heuristic rules of human interference that are often derived from cultural traditions rather than from scientific study. The increased technical power of computer-based simulation tools and their increased mathematical formalization may either remove former technical limits (e.g., of prediction) or, in contrast, reveal the fundamental character of some of these limits. Here, we shall argue that both cases occur, and that the main effect of simulation technology is to bring the distinction between these cases into scientific awareness.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Holger LangeSammendrag
Most phenomena in ecosystem research are assessed via repeated measurements of environmental variables. The dynamics of these time series is investigated with a variety of statistical techniques; in this article, we focus on modern nonlinear methods. They enable separation of short- and long-term components, show all types of trends and quantify the information contained and the complexity of the data sets.
Forfattere
Hans Geir Eiken Steinar Wikan Martin Smith Lars Jensen Henrik Brøseth Per Knappskog Tor-Arne Bjørn Leif E. Ollila Paul Eric AspholmSammendrag
Populasjonsovervåkning av brunbjørn (Ursus arctos) i Sør-Varanger, Finnmark ble gjennomført med hjelp av DNA-analyse av faeces. I 2004 og 2005 ble det samlet inn henholdsvis 104 prøver og 166 prøver, og DNA ble ekstrahert (62% og 49% positive prøver). Prøvene som gav DNA utbytte ble analysert med seks ulike mikrosattelitt markører (G1D, UarMU26, UarMU05, UarMu09, UarMU15 og G10B) og en kjønnstest.For 2004 gav DNA identifisering 33 ulike individer, mens i 2005 påviste en 26 ulike individer. Resultatene i rapporten blir vurdert opp mot feltobservasjoner samt mot feilkilder og begrensninger.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Fine root production, respiration, longevity and mortality are the major processes in carbon dynamics of the forest soils. The objective of the present work was to determine fine root biomass, respiration and root longevity. The study was carried out at a ten year-old stand of planted Norway spruce (Picea abies) (a clearcut, dominated by natural regrowth of Scots pine and birch) and three stands of Norway spruce, approximately 30, 60 and 120 years old, during 2001 and 2002. The stands were located at Nordmoen, a plain of sandy deposits in southeast Norway.Root biomass of both trees and understorey vegetation (0-1, 1-2 and 2-5 mm in diameter) in the humus layer and mineral soil horizons (to depth of 60 cm) was sampled by soil coring. Root respiration was performed in situ, by measuring the CO2 of excavated fine roots by using the CIRAS-I portable gas analyser. For the root turnover study, altogether 60 minirhizotrones were installed and images were processed. Root biomass and necromass (g m-2), specific root length (SRL, m g -1), root length density (RLD, cm cm-3), number of root-tips and mean longevity (y) were estimated.Root biomass was 2-3 times higher in the mineral soil than in the humus horizon. Compared with other stands, root biomass, SRL, RLD and the number of root tips were highest in the 30-year-old stand. At the 10 and 120 year-old stands understorey vegetation roots counted for 70 and 40% of total root biomass, respectively. The amount of necromass at 60 year-old stand was about twice as high (45%) compared to other stands.Root respiration (g C/min./g roots) was significantly lowest at 10-year-old stand. Root respiration among 30, 60 and 120 year-old stands was not significantly different, but it was highest in the 60-year-old stand. The respiration varied seasonally, with high peaks during the summer and lower values during the spring and autumn. Fine root longevity of tree and understorey roots at the 10-year-old stand were 1.2 and 1.4 years, respectively.It is concluded that stand age may influence the dynamics of the fine roots. The complexity of influences will be discussed.
Forfattere
Birger Vennesland Kåre Hobbelstad Torjus Folsland Bolkesjø Sjur Baardsen Jørn Lileng Jørund RolstadSammendrag
I 2005 kom Stortinget med en anmodning til Regjeringen om å legge fram nasjonale strategier for økt avvirkning. Landbruks- og matdepartementet (LMD) signaliserte i budsjettforslaget for 2006 at de ville komme tilbake til Stortinget med en slik strategi i forbindelse med statsbudsjettet for 2007. Norsk institutt for skogforskning (Skogforsk) og Norsk institutt for jord- og skogkartlegging (NIJOS) fi kk ansvaret med å utarbeide dette kunnskapsdokumentet med innspill fra skognæringen og skogforvaltningen. Institutt for naturforvaltning (INA) ved Universitetet for miljø- og biovitenskap (UMB) har vært en sentral bidragsyter i dette prosjektet. […]