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.
2013
Authors
Jihong Liu Clarke Gottschamel Johanna Hege Særvold Steen Sissel Haugslien Andreas G. Lössl Stephanie Ruf Ralph BockAbstract
No abstract has been registered
Authors
Ilse Geijzendorffer Felix Herzog Rob Jongman Stefano Targetti M. Knotters I. Staritsky Youssef Ammari Siyka Angelova Michaela Arndorfer Debra Bailey Katalin Balázs András Báldi Marion Bogers D. Brus R.G.H. Bunce Jean-Philippe Choisis Peter Dennis Tetyana Dyman Sebastian Eiter Wendy Fjellstad Mariecia D. Fraser T. Frank Jürgen Friedel Salah Garchi Tiziano Gomiero Philippe Jeanneret Gergely Jerkovich Max Kainz Esezah Kakudidi Eszter Kelemen Roland Kölliker Norman Kwikiriza Anikó Kovács-Hostyánszki Luisa Last Gisela Lüscher Gerardo Moreno Charles Nkwiine John Opio Marie-Louise Oschatz Maurizio Guido Paoletti Philippe Pointereau S. Riedel Jean-Pierre Sarthou Manuel Schneider Norman Siebrecht Daniele Sommaggio Siyka Stoyanova Erich Szerencsits Davide Viaggi J. Wilkes Sebastian Wolfrum Sergiy YashchenkoAbstract
No abstract has been registered
Authors
Debra Bailey Youssef Ammari Siyka Angelova Michaela Arndorfer Katalin Balázs András Báldi Marion Bogers Robert Gerald Henry Bunce Jean-Philippe Choisis Peter Dennis Tetyana Dyman Sebastian Eiter Wendy Fjellstad Thomas Frank Mariecia D. Fraser Jürgen Friedel Salah Garchi Ilse Geijzendorffer Tiziano Gomiero Felix Herzog Philippe Jeanneret Gergely Jerkovich Rob Jongman Max Kainz Esezah Kakudidi Eszter Kelemen Anikó Kovács-Hostyánszki Norman Kwikiriza Roland Kölliker Luisa Last Gisela Lüscher Gerardo Moreno Charles Nkwiine John Opio Marie-Louise Oschatz Maurizio Guido Paoletti Philippe Pointereau Jean-Pierre Sarthou Manuel Schneider Norman Siebrecht Daniele Sommaggio Siyka Stoyanova Stella Targetti Sebastian Wolfrum Varvara YashchenkoAbstract
No abstract has been registered
Authors
Lise SkrettebergAbstract
No abstract has been registered
Abstract
No abstract has been registered
Abstract
There is a need for monitoring methods for forest volume, biomass and carbon based on satellite remote sensing. In the present study we tested interferometric X-band SAR (InSAR) from the Tandem-X mission. The aim of the study was to describe how accurate volume and biomass could be estimated from InSAR height and test whether the relationships were curvilinear or not. The study area was a spruce dominated forest in southeast Norway. We selected 28 stands in which we established 192 circular sample plots of 250 m2, accurately positioned by a Differential Global Positioning System (dGPS). Plot level data on stem volume and aboveground biomass were derived from field inventory. Stem volume ranged fromzero to 596 m3/ha, and aboveground biomass up to 338 t/ha.We generated 2 Digital Surface Models (DSMs) fromInSAR processing of two co-registered, HH-polarized TanDEM-X image pairs – one ascending and one descending pair.We used a Digital TerrainModel (DTM) from airborne laser scanning (ALS) as a reference and derived a 10 m × 10 m Canopy Height Model (CHM), or InSAR height model. We assigned each plot to the nearest 10 m × 10 m InSAR height pixel. We applied a nonlinear, mixed model for the volume and biomass modeling, and from a full model we removed effects with a backward stepwise approach. InSAR heightwas proportional to volume and aboveground biomass, where a 1 m increase in InSAR height corresponded to a volume increase of 23 m3/ha and a biomass increase of 14 t/ha. Root Mean Square Error (RMSE) values were 43–44% at the plot level and 19–20% at the stand level.
Abstract
No abstract has been registered
Authors
Liv Østrem Birger Volden Arild LarsenAbstract
The potential of ×Festulolium as a forage species for Nordic conditions was investigated by comparing Norwegian candivars (LpFp-T, LmFp-T, LpFp-D-N, LpFp-D-UK) differing in parental origin and ploidy level with commercial cultivars of ×Festulolium (Hykor, Felopa), the parental species perennial ryegrass (Lolium perenne L.) and meadow fescue (Festuca pratensis L.), and timothy (Phleum pratense L.). Plant development was observed as leaf:stem ratio and standardised development stage, and dry matter yield and digestibility were studied throughout two consecutive harvest seasons (2007 and 2008) as an effect of taking the first cut at four maturity stages, namely: 1) vegetative growth, 2) early heading), 3) heading and 4) anthesis, and then consecutive cuts throughout the season. Observations were made at two locations in Norway (61°N, 67°N). Leaf:stem ratio and standardised development stage were affected by maturity stage, and the loloid types of ×Festulolium (Felopa and the candivars) grouped between the parental species as to developmental pattern. The most extreme changes across maturity stages 1-4 in first cut were seen in the festucoid type Hykor (smallest) and in timothy (largest). Across maturity stages 2 and 3, for two years Hykor obtained higher dry matter yield than the other entries, but overall digestible dry matter yield was equal in Hykor and LpFp-T due to the better digestibility in LpFp-T. The lower dry matter yield obtained in ×Festulolium Felopa, the diploid candivars and LmFp-T was mainly due to winter damages. Consistency was found between the locations for the entries investigated. For Nordic growing conditions, in which winter hardiness is required for commercial cultivars, the amphitetraploid breeding approach of perennial ryegrass and meadow fescue should be pursued. It is the parental origin of the candivar LpFp-T, which was comparable to Hykor, the best of the commercial ×Festulolium cultivars, and performed better than the cultivars of the parental species.
Authors
Peder Gjerdrum Birger EikenesAbstract
Strength properties are central for most wood applications. This paper describes variation of and co-variation between various strength parameters observed in clear wood. More than a dozen strength and density parameters were measured, each on ten samples from five different height levels from each of 21 planted, mature spruce trees. In general, strength and coefficient of variation comply with standard listed values. Between strength parameters usually modest, but always positive, correlation was found. Only 53% of the overall strength variation could be extracted in the first principal component, related to density. MOE and MOR are the two most closely correlated traits, and cleavage the one to show weakest connection to all other traits. Compression, MOR and hardness are closest correlated to density; however, the significance of density being partially masked by a considerable variation between samples from similar locations in the stem supposed to demonstrate parallel quality. All traits are stronger correlated to density than to ring width. In addition to density a substantial part, 5 to 30%, of strength variation could be attributed to tree effect, indication a potential for strength improvement by genetic selection. The finding confirms strength parameters to be far from collinear, i.e. strength is truly multidimensional.
Authors
Erik J. JonerAbstract
No abstract has been registered