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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.

2013

Sammendrag

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.

Sammendrag

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.