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.
2005
Forfattere
Per Gundersen Jan-Olov Weslien Bjarni D. Sigurdsson Magne Sætersdal Leena Finér Ingeborg CallesenSammendrag
Forest ecosystems provide many deliverables or benefits to society. The most obvious one is wood for the forest industry. Other benefits include berries, hunting, and recreation. More recently recognised benefits are environmental services such as carbon sequestration, water protection and biodiversity, which are without an immediate market value.On the other hand, there are pressures (e.g. climate change, air pollution, exploitation, and costs) on the ecosystem that may hamper the wood production or other benefits......
Sammendrag
About eighteen percent of the conventional dairy and cash crop farmers in Norway are considering to, and four percent are planning to convert to organic farming during the next five years. These two farmer groups can be considered as the potential for conversion to organic farming in Norway. In a questionnaire survey, this group rated attitudes on organic and conventional farming more similar to organic farmers than other conventional farmers did. For farmers considering or planning to convert, additional organic farming payments, organic farming laws and regulations and price premiums for organic products were more important sources of risk than for other conventional farmers. Most of these mentioned factors are influenced by agricultural policies, which thus represent an important factor for farmers? decision regarding the conversion to organic farming.
Sammendrag
About eighteen percent of the conventional dairy and cash crop farmers in Norway are considering to, and four percent are planning to convert to organic farming during the next five years. These two farmer groups can be considered as the potential for conversion to organic farming in Norway. In a questionnaire survey, this group rated attitudes on organic and conventional farming more similar to organic farmers than other conven¬tional farmers did. For farmers considering or planning to convert, additional organic farming payments, organic farming laws and regulations and price premiums for organic products were more important sources of risk than for other conven¬tional farmers. Most of these mentioned factors are influenced by agricultural policies, which thus represent an important factor for farmers` decision regarding the conversion to organic farming.
Forfattere
M. van der Sluijs Bent Christen Braskerud Ivan Digernes Inggard BlakarSammendrag
Det er ikke registrert sammendrag
Forfattere
M. van der Sluijs Bent Christen Braskerud Ivan Digernes Inggard Blakar Anne Grete BlankenbergSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Svein SolbergSammendrag
Forest damage will result in two general effects: defoliation and/or discolouration. The two available techniques in remote sensing of forests today, LiDAR and spectroscopy, are promising tools for monitoring these two, respectively. Merging data on foliar mass, estimated by LiDAR, with data on chlorophyll concentrations, estimated by spectroscopy, can provide data on chlorophyll mass pr area unit. Monitoring the temporal changes of this is likely to be a very good measure for variations in forest health.In order to check out the possibilities for this, we are now working on building relationships between foliar mass data and LiDAR data for single spruce trees. In total we have measurements of position and stem diameter on about 2000 trees distributed on 16 plots, where 64 trees are intensively sampled for estimating foliar mass, as well as crown size.We need to parameterize a relationship between the LiDAR data for each of these trees and their foliar mass (or leaf area). If we succeed to build this relationship, we will scale it up to provide foliar mass (or leaf area) estimates for every 10x10 m pixels in two SPOT images of the area.Together with a similar up-scaling of chlorophyll concentrations, based on spectroscopy, we will test the possibility of estimating chlorophyll mass per area from SPOT or other satellites. In addition, we have visually assessed data on crown density for all the trees, being a rough, but valuable data-set for validating the relationship.The work, being in progress now, includes several tasks:a) finding an appropriate canopy surface modelb) segmentation of treesc) estimating crown volume, and evt d) handling of smaller trees standing below (this is a heterogenous canopy layer forest) and e) handling of the relative influence of stem and branches.Additionally, we see some other benefits from using LiDAR together with airborne hyperspectral data and satellite data in general. Firstly, the combination of high resolution LiDAR and hyper-spectral data, is a good basis for separating the signals from ground vegetation and from the tree canopy. Secondly, LiDAR provides both a DTM and a canopy surface model, and they are two alternative surface models for the geo-referencing of other data, and for appropriate handling of effects of shadowing and obstacles from tall trees.
Forfattere
Kåre A. Lye Mary Namaganda Halvor B. GjærumSammendrag
Mt. Elgon is one of the largest volcanoes in the world, about 50 km across and with a 5-6 km wide crater. It is situated on the border between Kenya and Uganda between 1o and 2o north. From the Ugandan side of Mt. Elgon are reported 98 species of rust fungi (Urediniomycetes) from 13 genera. Out of a total of 153 collections, 79 are gathered by the authors. Based on this material nine species were described as new to science by the senior aothor (H.B.G.)
Forfattere
Kåre Lye Halvor B. Gjærum Mary NamagandaSammendrag
Det er ikke registrert sammendrag
Forfattere
Anne-Grete Roer Hjelkrem Jon Glenn Gjevestad SvendsenSammendrag
Prosjektet fokuserer på analyse av havnivået ved bruk av klassisk Fourier transform og wavelet transform. Både stasjonære og ikke-stasjonære komponenter av havnivået er funnet og gjenkjent som astronomiske og metrologiske komponenter. Hovedkonklusjonene av prosjektet er at den ene metoden ikke er bedre enn den andre. De supplerer hverandre og burde derfor brukes sammen og ikke istedet for hverandre.