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.
2002
Forfattere
H. Mäkinen P. Nöjd H.P. Kahle U. Neumann Bjørn Tveite K. Mielikäinen H. Röhle H. SpieckerSammendrag
Regional and temporal growth variation of Norway spruce (Picea abies (L.) Karst.) and its dependence on air temperature and precipitation were compared in stands across latitudinal and altitudinal transects in southwestern and eastern Germany, Norway, and Finland.The temporal variation of radial growth was divided into two components: medium- and high-frequency variation, i.e. decadal and year-to-year variation, respectively. The medium-frequency component was rather different between regions, especially the southern and northern ones. However, within each region the medium-frequency growth variation was relatively similar, irrespective of altitudinal and latitudinal differences of the sample sites.A part of the high-frequency variation was common to all four regions, which suggests that some factors synchronising tree growth are common for the entire study area. The high-frequency component of growth was more strongly related to monthly air temperature and precipitation than was the medium-frequency variation. The limiting effect of low temperatures was more significant at northern as well as high-altitude sites, while the importance of precipitation increased in the south and at low altitudes.
Forfattere
Halvor SolheimSammendrag
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Sammendrag
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Forfattere
Magne SætersdalSammendrag
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Sammendrag
Concentrations and fluxes of dissolved organic carbon (DOC) and dissolved organic nitrogen (DON), together with pools of carbon and nitrogen in the soil and biomass, were determined along north-south and east-west transects across Norway, Sweden and Finland. The data were analysed statistically and modelled using the mechanistic model DyDOC.Concentrations of DOC and DON were greatest in the O horizon and decreased downwards in the soil. The highest production of dissolved organic matter appears to take place in the O horizon and any contribution from thoroughfall is probably small. A pronounced seasonal effect with peak DOC concentrations in late summer/early autumn may be due to a seasonal (largely temperature) effect on DOC production.The effect of acidic precipitation upon DOC concentrations and fluxes was unclear. DOC in the O horizon was mostly of recent origin, while DOC in the B horizon appeared to include some older material, possibly desorbed from the soil. A positive correlation was found with electrical conductivity and a negative correlation with pH in DOC concentrations from the O horizon.A lack of correlation between DOC concentrations and temperature is probably due to a time lag between peak temperatures and peak DOC concentrations. Modelling of DOC concentrations and fluxes using DyDOC gave rasonable results, suggesting that it might be possible to use DyDOC as a general tool for modelling and forecasting DOC concentrations and fluxes in Nordic forest ecosytems.Scenario analysis using DyDOC suggested that increased temperature without increased litter input might result in increased production of CO2 rather than DOC. An increase in both temperature and litter input would lead to increased DOC concentrations, with possible implications for drinking water quality. Increased precipitation will lead to increased fluxes of DOC.
Forfattere
Harald Kvaalen Ola Gram Dæhlen Ulrika EgertsdotterSammendrag
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Sammendrag
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Forfattere
David Wei Zheng M. Freeman J. Bergh Ingvald Røsberg Petter NilsenSammendrag
A process-based model was used to simulate biomass production of Norway spruce under both current climate and climate change scenarios. The model was parameterized for Nordmoen in south-east Norway using real climate data for the period 1987-1989. The model was applied to predict the biomass production responses to three climate change scenarios.The results showed that net primary production (NPP) increased by 7% under an elevated annual mean air temperature of 4C from the current 10.1 t dry mass ha-1 yr-1. A doubled current ambient CO2 concentration significantly increased NPP by 36%.The scenario of both elevated temperature and elevated CO2 concentration led to an increase in the NPP of 49%, higher than the sum of the two effects acting singly. The results also showed that forest production responses to climate change depend on the conditions of climate used for reference.
Forfattere
Erlend RolstadSammendrag
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Forfattere
Wenche E. DramstadSammendrag
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