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
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.
Authors
Trond Rafoss Jarle Skahjem John Atle Johansen Ståle Johannessen Sekhar Udaya Nagothu Inger Sundheim Fløistad Arild SlettenAbstract
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Darren J. Kriticos Robert C. Venette Richard H.A. Baker Sarah Brunel Frank H. Koch Trond Rafoss Wopke van der Werf Worner Susan P.Abstract
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Authors
Fuad Gasi Mirsad Kurtovic Belma Kalamujic Naris Pojskic Jasmin Grahic Clive Kaiser Mekjell MelandAbstract
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Authors
Marc Babut Gertie H. Arts Anna Barra Caracciolo Nadia Carluer Nicolas Domange Nikolai Friberg Vèronique Gouy Merete Grung Laurent Lagadick Fabrice Martin-Laurent Nicolas Mazzella Stèphane Pesce Benoit Real Stefan Reichenberger Erwin W. M. Roex Kees Romijn Manfred Röttele Marianne Stenrød Julien Tounebize Francoise Vernier Eric VindimianAbstract
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Abstract
The male and female genitalia characters of the European species of Monochamus Dejean, 1821, are described and compared in detail for the first time. The sclerites inside the median phallomer (internal sac) of M. sutor (Linnaeus, 1758) and M. galloprovincialis (Olivier, 1795) differ from those of all other examined species, and appear to be the best characters to separate M. sutor from M. galloprovincialis. There are no differences between the male or female genitalia characters of M. sartor (Fabricius, 1787) and M. urussovi (Fischer von Waldheim, 1805). Thus, M. urussovi is regarded as a subspecies of M. sartor: M. sartor urussovi nov. stat. The present results also support that the previously considered subspecies M. galloprovincialis pistor (Germar, 1818) is a true junior synonym of M. galloprovincialis galloprovincialis. No sclerites occur inside the internal sac of M. saltuarius (Gebler, 1830). The internal sac of M. sartor sartor (Fabricius, 1787), M. sartor urussovi and M. impluviatus impluviatus (Motschulsky, 1859) are distinctly different from the other European species of Monochamus: there is an elongated tube (terminal segment) inside the internal sac containing two very small and weakly sclerotized plates in M. sartor sartor and M. sartor urussovi and a larger sclerite in M. impluviatus impluviatus. A key to the European species and subspecies of Monochamus, incorporating male genitalia characters, is provided.
Authors
Eric N. Hansen Erlend Nybakk Rajat PanwarAbstract
The recent economic downturn severely affected the US forest sector from a macro-economic perspective but little is known about changes in firm-level performance. In this study we investigate the changes in financial, social and environmental performance of forest sector firms during a period approximately corresponding to the downturn. We also assess industry dynamism and industry’s view about social and environmental responsibility as a competitive tool. We conducted a national survey of wood, furniture and paper companies. Approximately sixty percent of our respondents reported a decline in financial performance during the downturn. With respect to social and environmental performance, customer oriented actions show mixed trends, employee matters remained somewhat unaltered, community engagement significantly decreased, and engagement in environmental activities significantly increased. Respondents view their operating business environment as highly dynamic and difficult and they do not view engagement in social and environmental responsibility activities leading to either financial or non-financial benefits.