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.
2007
Sammendrag
In the context of an ongoing project on REMote sensing of FORest health (REM-FOR), we analyze airborne high-resolution hyperspectral images of a pine-dominated region in southeast Norway heavily attacked by the Pine sawfly Neodiprion sertifer, leading to severe defoliation. Leaf Area Index (LAI) is used as a proxy of the crown density, and comparing LAI maps from before and after the attack lead to indicators for damage extent. We discuss the application of the Forest Reflectance Model (FRT) of Kuusk and Nilson, which was designed for the application to (managed) Northern European Forests, to model the spectral response from the canopy. It is based on conventional forest inventory data, species-dependent parametrized crown shapes, canopy LAI, needle clumping index, and needle optical properties. Here, however, we run the model in an inverse mode, by iteratively minimizing the discrepancy between measured and simulated reflectances, and predicting the LAI, keeping known parameters of the model fixed. The LAI values are then compared to those obtained with either ground-based Licor LAI2000 measurements, or with airborne laser-scanning. Some preliminary results of this modelling concept for the case study are discussed.
Forfattere
Holger LangeSammendrag
The net ecosystem productivity (NEP) of a sequence of threemonoaged Norway spruce stands located in southeast Norway is modelled using the biogeochemical model Biome-BGC. For calibration, we use estimated biomass stocks at the plot level and Leaf Area Index measurements. The model is run for 30 years of historical temperature measurements as well as for a regional climate scenario. It is shown that under current conditions, NEP develops from negative values for a young stand (30 years) to clearly positive for a middleaged (60 years) to slightly negative again for a very old and decaying stand (120 years). However, the old stand benefits substantially from the predicted increased temperatures in the climate scenario, rendering NEP positive again. For the 30 and 60 years stands, almost no change is predicted from Biome-BGC.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Erik Trømborg Anders Nielsen Erling Thuen Odd Magne Harstad Torstein H. Garmo Harald Volden Øystein Holand Svein Jarle Horn Vincent Eijsink John Morken Petter H Heyerdahl Hanne Kathrine Sjølie Birger Solberg Lars Bakken Trine Aulstad Sogn Tormod Briseid Arne Grønlund Simen Gjølsjø Bjørn Langerud Nicholas ClarkeRedaktører
Hans Fredrik HoenSammendrag
Universitetet for miljø- og biovitenskap fikk i mai 2007 i oppdrag fra Norges Forskningsråd å kartlegge og beskrive kunnskapsstatus og forskningsbehov knyttet til bioenergi og klimagasser fra landbruket (jord, skog og utmark). Utredningen beskriver i korte trekk dagens status og hovedutfordringer når det gjelder produksjon av bioenergi og utslipp/binding av klimagasser i landbruket, og peker på sentrale forskningsbehov og forskningsoppgaver som kan bidra til å møte disse utfordringene. Rapporten er basert på bidrag fra forskningsmiljøene på Campus Ås.
Forfattere
Kjell Andreassen Volkmar Timmermann Nicholas Clarke Ingvald Røsberg Halvor Solheim Wenche AasSammendrag
Året 2006 må regnes som et stort skadeår for furu og bjørk i Norge der vel fire prosent av furutrærne var angrepet av furubarveps, og over ti prosent av bjørketrærne var angrepet av fjellbjørkemåler. Omfanget av trær med nye toppbrekk, vindfall og andre snø- og vindrelaterte skader var omtrent på samme nivå som i hele overvåkingsperioden. Skogens helsetilstand, registrert ved kronetetthet, misfarging og avdøing, påvirkes i stor grad av klimatiske forhold, enten direkte som ved tørke, frost og vind, eller indirekte ved at det påvirker omfanget av soppsykdommer og insektangrep. Langtransporterte luftforurensninger kan komme i tillegg til eller virke sammen med klimatiske forhold.....
Sammendrag
Det er ikke registrert sammendrag
2006
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
This document contains a summary of some techniques that can be used for CO2 monitoring considering a field laboratory site with an injection depth in the order of hundreds of meters. We will mainly focus on seismic: 3D and 4D surface seismic, acoustic image, multicomponent (MC) seismic, microseismic monitoring, boreholebased seismic, 4D cross-hole seismic surveying, 4D vertical seismic profiling (VSP); acoustic sonar bathimetry techniques; gravimetric techniques; electrical or electromagnetic techniques: electrical resistance tomography (ERT), ground penetrating radar, borehole radar, magnetotellurics; but geochemical techniques are included, like isotope methods, geochemical tracers, water chemistry. Finally, soil gas techniques and remote sensing methods area also described in this document. Storage of CO2 in geological formations is feasible on industrial scale. At the same time there is a requirement from Environmental and Health Authorities for documentation of subsurface behaviour of CO2. In this document we summarize different approaches for monitoring of subsurface migration, leakage and chemical reactions of CO2. We suggest performing studies at different scales including laboratory and field experiments. The methods we suggest has special emphasize on early detection of small amounts of CO2 migration. Of that reason the main focus of this report is on indirect geophysical monitoring (viz seismic, electrical and electromagnetic methods). To document subsurface reactions we also include geochemical methods. We suggest including ecological monitoring as an integrated part of the field experiments. Ecological monitoring will provide detection (or confirmation) of moderate CO2 leakage to the soil surface, and at the same time quantify effects on the vegetation of potentially leakages from geologically-stored CO2. In order to add value to the monitoring program, we recommend initiating simulation of monitoring experiments as early as possible in the project. Simulation of monitoring experiments should then be coupled to inverse flow simulations in order to optimize the monitoring program. Finally, monitoring of two specific field sites is suggested: The Brumunddal sandstone, and the Svelvik ridge in the outlet of the Drammensfjord. The preliminary budget for monitoring a field experiment on each side is 27.3 and 30.2 million NOK respectively. Recommendations for further work include: " Geological characterization of storage site and surrounding area. " Production of geological and numerical flow models of storage site and surrounding area. " Simulation of CO2 injection into the geological formation to identify potential migration and thus leakage points. This includes physical and chemical changes of the reservoir rock and surrounding strata. " Risk assessment to identify features, events and processes that might lead to the migration of CO2 and potential leakage. " Establish monitoring based on step 3 and 4 above. This includes monitoring of subsurface and surface area surrounding the storage site. " History matching of observations and simulation results (and if necessary modification of monitoring acquisitions).
Sammendrag
Inntill nylig har det vært liten oppmerksomhet om dyrket myr som kilde til CO2-utslipp og ingen systematisk kartlegging av C-tapet har blit foretatt. Beregneringer ved hjelp av tre forskjellige metoden tyder på at tapet kan være mellom 0,6 og 0,8 kg C m2/år, 2 - 4 million er tonn CO2/år, som er mellom 5 og 10 prosent av totalt menneskeskapt CO2-utslipp i Norge.
Sammendrag
Transient starch production is thought to exert a strong control over plant growth and response to elevated CO2. Here we tested this hypothesis with an experimentally-based mechanistic model in Arabidopsis thaliana. " Experiments were conducted on wild type (WT) of A. thaliana, starch-excess and starchless mutants under ambient- and elevated-CO2 conditions to determine parameters and validate the model. Central to the model, we experimentally demonstrated that dark respiration is directly proportional to soluble sugar concentration in A. thaliana leaves. " The model correctly predicted that: 1) mutant growth is about 20% of that of WT, and 2) absolute response of both mutants to elevated CO2 is an order of magnitude lower than that of the WT. " Our study demonstrates that effects of the diurnal starch cycle on growth can be captured by a fairly simple set of allocation equations. Our results further suggest that the maximum rate of leaf growth, and broadly the sink capacity, exert a strong control over the response to elevated CO2 of herbaceous plants such as A. thaliana.