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.
2011
Sammendrag
Remote sensing of the activity of vegetation in relation to environmental conditions provides an invaluable basis for investigating the spatiotemporal dynamics and patterns of variability for ecosystem processes. We investigate the fraction of Absorbed Photosynthetically Active Radiation (fAPAR) using SeaWiFS satellite observations from 1998 to 2005 and ancillary meteorological variables from the CRU-PIK dataset with a global coverage at a spatial resolution of 0.5o x 0.5o. A pixel-by-pixel spectral decomposition using Singular System Analysis leads to a global “classification” of the terrestrial biosphere according to prevalent time-scale dependent dynamics of fAPAR and its relation to meteorology. A complexity analysis and a combined subsignal extraction and dimensionality reduction reveals a series of dominant geographical gradients, separately for different time scales. At the annual scale, which explains around 50% of the fAPAR variability as a global average, patterns largely resemble the biomes of the world as mapped by biogeographical methods, and are driven by temperature and by pronounced rain seasons in the tropics. On shorter time scales, fAPAR fluctuations are exclusively driven by water supply, inducing, e.g., semiannual cycles in the equatorial belt of Africa or the Indo-Gangetic Plain. For some regions however, in particular South America, altitude, mean temperature, drought probability and fire occurrences are parameters that seem to shape the spatial patterns of fAPAR across time scales. Overall, we provide a first global multiscale characterization of fAPAR and highlight different mechanisms in land-surface-climate couplings.
Forfattere
Halvor Solheim Martti VuorinenSammendrag
Rødbandsjuke på furu er nå funnet i Norge. Sjukdommen, som på engelsk kalles “red band needle blight” eller “Dothistroma needle blight”, er forårsaket av en sopp som står på Mattilsynets liste over sjukdommer det er forbudt å innføre til Norge. Den ble først funnet i Troms, men soppen er også funnet i to fylker i Sør-Norge. Foreløpig er den bare funnet på trær i skog, men mange innførte furuarter er utsatt for smitte.
Forfattere
Ellen Merethe Magnus May SæthreSammendrag
Det er ikke registrert sammendrag
Forfattere
Tor J. JohansenSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Merete Wiken Dees Arild Sletten Ricardo Holgado Eldrid Lein Molteberg Tor J. Johansen May Bente Brurberg Vinh Hong Le Ragnhild Nærstad Arne HermansenSammendrag
Det er ikke registrert sammendrag
Forfattere
Tor J. JohansenSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
As in many countries throughout Europe, there has been a polarisation within the agricultural landscape of Norway during the last decades. On the one hand there is an increasing trend of intensified use of favourable areas, while on the otherhand there is an increase in the amount of land abandonment of extensively managed or marginal areas (Fjellstad Dramstad 1999, Robinson Sutherland 2002, Haines-Younget al. 2003). Among the main impact factors for biodiversity in agricultural landscapes are increased amount of built-up areas, intensification of agriculture and land abandonment. But different land use practices has been shown to have differential effects on biodiversity (Haines-Young 2009). Finding the relationships between land use practices and effects on biodiversity are fundamental to understand the links between people and their environment and development of sustainable agriculture ....