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.
2022
Sammendrag
Klimaet forandrer seg, og vi vet at stigende temperaturer henger sammen med menneskeskapte utslipp av drivhusgasser til atmosfæren. Plantene tar opp rundt en fjerdedel av det vi slipper ut, men fluksene av drivhusgasser mellom atmosfæren og vegetasjon er komplekse og variable i rom og tid. For å kunne måle dem, må man ha et tårn med spesialutstyr. Siden september 2021 har NIBIO målt CO2-fluks i et tårn som står i skogen i Hurdal.
Sammendrag
Pollinerende insekter er i tilbakegang over store deler av verden. Denne globale nedgangen forventes å ha uheldige konsekvenser for biomangfold, økosystemtjenester og matproduksjon i fremtiden. Norge har utarbeidet en pollinatorstrategi hvor målet bl.a er å sikre levedyktige bestander av polline-rende insekter for å opprettholde pollinering i matproduksjon. Denne rapporten gir en bred oversikt over forskningsbasert kunnskap om faktorer som påvirker pol-linatorer og pollineringstjenester i ulike landskap, samt en oversikt over ulike modeller for å predi-kere forekomst av pollinatorer.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Inger Hansen Grete H. M. Jørgensen Christine K. Berge Gunvor Elise Nagel-Alne Marianne Gilhuus Solveig Marie Stubsjøen Kristian Ellingsen-Dalskau Cecilie Marie MejdellSammendrag
Det er ikke registrert sammendrag
Forfattere
Inger Hansen Grete H. M. Jørgensen Christine K. Berge Gunvor Elise Nagel-Alne Marianne Gilhuus Solveig Marie Stubsjøen Kristian Ellingsen-Dalskau Cecilie Marie MejdellSammendrag
Det er ikke registrert sammendrag
Sammendrag
Heat Field Deformation (HFD) is a widely used method to measure sap flow of trees based on empirical relationships between heat transfer within tree stems and the sap flow rates. As an alternative, the Linear Heat Balance (LHB) method implements the same instrumental configuration as HFD but calculates the sap flow rates using analytical equations that are derived from fundamental conduction-convection heat transfer theories. In this study, we systematically compared the sap flow calculated using the two methods based on data that were recorded using the same instrument. The measurements were conducted on four Norway spruce trees. We aimed to evaluate the discrepancies between the sap flow estimates from the two methods and determine the underlying causes. Diurnal and day-to-day patterns were consistent between the sap flow estimates from the two methods. However, the magnitudes of the estimated sap flow were different between them, where LHB resulted in much lower estimates in three trees and slightly higher estimates in one compared to HFD. We also observed larger discrepancies in negative (reversed flow) than in positive sap flow, where the LHB resulted in lower reversed flow than HFD. Consequently, the seasonal budget estimated by LHB can be as low as ∼20% of that estimated by HFD. The discrepancies can be mainly attributed to the low wood thermal conductivities for the studied trees that lead to substantial underestimations using the LHB method. In addition, the sap flow estimates were very sensitive to the value changes of the empirical parameters in the calculations and, thus, using a proper case-specific value is recommended, especially for the LHB method. Overall, we suggest that, despite the strong theoretical support, the correctness of LHB outputs depends largely on the tree individuals and should be carefully evaluated.
Sammendrag
As a way to estimate evapotranspiration (ET), Heat Field Deformation (HFD) is a widely used method to measure sap flow of trees based on empirical relationships between heat transfer within tree stems and the sap flow rates. As an alternative, the Linear Heat Balance (LHB) method implements the same instrumental configuration as HFD but calculates the sap flow rates using analytical equations that are derived from fundamental conduction-convection heat transfer equations.
Sammendrag
The municipalities of Tønsberg and Drammen have assigned NIBIO for the provision of a series of thematic maps on climate gas emissions and climate adaption capabilities from land cover and land use in conjunction with land use planning. This report is a guide to users of the various maps provided on climate gas emissions, water influx and water drainage, temperature regulation, biodiverstity and recreation of various areas of the municipalities.
Sammendrag
The municipality of Oslo have assigned NIBIO for the provision of a series of thematic maps on climate gas emissions and climate adaption capabilities from land cover and land use in conjunction with land use planning. This report is a guide to users of the various maps provided on climate gas emissions, water influx and water drainage, temperature regulation and biodiverstity in of various areas of the municipality.
Sammendrag
Det er ikke registrert sammendrag