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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.

2007

Sammendrag

The substitution of biomass for fossil fuels in energy consumption is a measure to mitigate global warming, as well as having other advantages. Political action plans for increased use exist at both European and national levels. This paper briefly reviews the contents of recommendations, guidelines, and other synthesis publications on sustainable use of forest biomass for energy. Topics are listed and an overview of advantages, disadvantages, and trade-offs between them is given, from the viewpoint of society in general and the forestry and energy sectors in particular. For the Nordic and Baltic countries, the paper also identifies the extent to which wood for energy is included in forest legislation and forest certification standards under the ?Programme for the Endorsement of Forest Certification? (PEFC) and the ?Forest Stewardship Council? (FSC) schemes. Energy and forest policies at EU and national levels, and European PEFC forest standards are analysed. With respect to energy policies, the utilisation of wood for energy is generally supported in forest policies, but forest legislation is seldom used as a direct tool to encourage the utilisation of wood for energy. Regulations sometimes restrict use for environmental reasons. Forest certification standards include indicators directly related to the utilisation of wood for energy under several criteria, with most occurrences found under environmental criteria. Roles and problems in relation to policy, legislation, certification standards, recommendations and guidelines, and science are discussed.

Sammendrag

The substitution of biomass for fossils fuels in energy consumption is a measure to mitigate global warming, as well as having other advantages. Political action plans for increased use exist at both European and national levels. This paper briefly reviews the contents of recommendations, guidelines and other synthesis publications on sustainable use of forest biomass for energy. Topics are listed and an overview of advantages, disadvantages and trade-offs between them is given, from the viewpoint of society in general and the forestry and energy sectors in particular. For the Nordic and Baltic countries, the paper also identifies the extent to which wood for energy is included in forest legislation and forest certification standards under the “Programme for the Endorsement of Forest Certification” (PEFC) and the “Forest Stewardship Council” (FSC) schemes. Energy and forest policies at EU and national levels, and European PEFC forest standards are analysed. With respect to energy policies, the utilisation of wood for energy is generally supported in forest policies, but forest legislation is seldom used as a direct tool to encourage the utilisation of wood for energy. Regulations sometimes restrict use for environmental reasons. Forest certification standards include indicators directly related to the utilisation of wood for energy under several criteria, with most occurrences found under environmental criteria. Roles and problems in relation to policy, legislation, certification standards, recommendations and guidelines, and science are discussed.

Sammendrag

available, especially in Norway. The objective of the present research was to estimate C losses from cultivated peatlands in West Norway by three independent methods: 1) long-term monitoring of subsidence rates, 2) changes in ash contents, and 3) soil CO2 flux measurements. Subsidence of cultivated peat soils averaged about 2.5 cm y-1. We estimated that peat loss and compaction were respectively responsible for 38% and 62% of the total subsidence during a 25-year period after drainage. Based on this estimate the corresponding C loss equals 0.80 kg C m-2 yr-1. The observed increase in mineral concentration of the topsoil of cultivated peat is proportional to their C loss, providing no mineral particles other than lime and fertilizers are added to the soil. Using this novel approach across 11 sites, we estimated a mean C loss of 0.86 kg C m-2 y-1. Soil CO2 flux measurements, corrected for autotrophic respiration, yielded a C loss estimate from cultivated peat soils of 0.60 kg C m-2 yr-1. The three methods yielded fairly similar estimates of C losses from Norwegian cultivated peatlands. Cultivated peatlands in Norway cover an estimated 63 000 ha. Total annual C losses from peat degradation were estimated to range between 1.8 and 2 million tons CO2 y-1, which equals about 3-4 % of total anthropogenic greenhouse gas emissions from Norway.

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Sammendrag

I det nasjonale «Overvåkingsprogram for skogskader» inngår det i Norge 8 intensivt overvåkede flater for å følge utviklingen av skogøkosystemet. Disse flatene er også en del av det europeiske nettverket av intensive skogovervåkingsflater i 37 land med til sammen 800 flater. Intensiv skogovervåking er utført her i landet siden midten av 1980-tallet, med verdifulle tidsserier som kan beskrive endringer i skogøsystemet. Hovedformålet er å beskrive skogens helsetilstand og belyse virkninger av langtransporterte forurensninger på skogøkosystemet. Resultater fra overvåkingen i 2006 presenteres i denne rapporten. Vi finner fortsatt de høyeste avsetningene av syre, svovel- og nitrogenforbindelser lengst sør i landet. Konsentrasjonen av svovelforbindelser i luft og nedbør har avtatt med 60-90% de siste 20 årene, og dette samsvarer med endringer av utslipp i Europa. Mengden av nitrogenforbindelser i nedbør har ikke endret seg like tydelig, men også her er det en nedgang de siste ti åra, særlig av NO2. Det ble observert betydelige overskridelser av enkelte grenseverdier for ozoneksponering av vegetasjonen i 2006. Ozonkonsentrasjonene påvirkes antagelig mest av meteorologiske forhold, og vi har ikke klart å påvise klare trender for denne eksponeringen i Norge. Graset smyle har økt i mengde på alle fire overvåkingsfelter på Østlandet de siste åra, mens mengden er redusert på overvåkingsflatene på Vestlandet. Smylemengden øker vanligvis med økt nitrogendeposisjon, og er derfor en viktig indikatorart. Kronetettheten for gran avtok sør og øst i landet, mens de vestligste og nordligste flatene viser en oppgang fra 2005 til 2006. Kronefargen hos gran ble også dårligere i 2006, og dette var gjennomgående på alle flater unntatt i Hurdal. Denne nedgangen i kronetetthet sør og øst i landet ble også observert på de regionale flatene og på de landsrepresentative Level 1 flatene. Tilbakegangen i kronevitalitet på Østlandet kan skyldes meteorologiske forhold eller biotiske skadegjørere som f.eks. granrust, og dette trenger ikke vise samme type negative trend som det vi observerte på 1980-tallet. For furu ble det bare observert minimal endring i kronetetthet, mens kronefargen ble betydelig dårligere.

Sammendrag

River floods may cause considerable damage. Water management strategies intend tomoderate or mitigate the severe effects of extreme discharge events. In this context,techniques for the detection and attribution of changes is of crucial importance. Extremeflood events seem to occur more frequently in recent decades in central Europe.It is anticipated that climate change and weather regime shifts may contribute to this...

Sammendrag

Characterizing ecosystem-atmosphere interactions in terms of carbon and water exchange on different time scales is considered a major challenge in terrestrial biogeochemical cycle research. The respective time series currently comprise an observation period of up to one decade. In this study, we explored whether the observation period is already sufficient to detect cross-relationships between the variables beyond the annual cycle, as they are expected from comparable studies in climatology. We investigated the potential of Singular System Analysis (SSA) to extract arbitrary kinds of oscillatory patterns. The method is completely data adaptive and performs an effective signal to noise separation. We found that most observations (Net Ecosystem Exchange, NEE, Gross Primary Productivity, GPP, Ecosystem Respiration, Reco, Vapor Pressure Deficit, VPD, Latent Heat, LE, Sensible Heat, H, Wind Speed, u, and Precipitation, P) were influenced significantly by low-frequency components (interannual variability). Furthermore, we extracted a set of nontrivial relationships and found clear seasonal hysteresis effects except for the interrelation of NEE with Global Radiation (Rg). SSA provides a new tool for the investigation of these phenomena explicitly on different time scales. Furthermore, we showed that SSA has great potential for eddy covariance data processing, since it can be applied as a novel gap filling approach relying on the temporal correlation structure of the time series structure only.

Sammendrag

Ecological studies are often confronted with short and fragmented or unevenly sampled time series. Examples are, e.g., time series of biogeochemical fluxes measured on a variety of scales. Characterizing the observed time series patterns, particularly the correlation structure is crucial for an integrated ecosystem assessment or possibly for improved processes understanding.