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.
2001
Sammendrag
Med begrepet `landskap` forstår vi vanligvis et passe stort utsnitt av omgivelsene som er karakterisert ved områdets terreng, vegetasjon og menneskers bruk, f.eks. `det vi ser ut av et vindu med utsikt`. Den romlige fordelingen av ulike typer jordbruksareal, bebyggelse, kantsoner og andre fysiske elementer skaper landskapets struktur. Landskapet inneholder en rekke ulike verdier og representerer en ressurs for mange forskjellige formål. Landskapet er den arenaen der ville dyr og planter lever sitt liv, dvs der vi finner det biologiske mangfoldet. Landskapet er også viktig for å forstå forekomsten av kulturminner og for å forvalte disse riktig. Dessuten vil de fleste mennesker knytte ulike forestillinger til landskapet og oppleve forskjellige kvaliteter knyttet til landskapets elementer. Landskapet fungerer også som en ramme for menneskers ressursutnytting og forvaltning. Å forvalte landskapet og dets egenskaper medfører muligheter for å forvalte de verdiene vi finner i landskapet. Men det er mange ulike verdier i landskapet, og de har muligens helt forskjellig tilknytning til landskapets struktur og egenskaper. Det er dermed ikke selvsagt hvordan landskapet skal forvaltes for å oppfylle ulike mål, som dels kan være i konflikt med hverandre. ....
Forfattere
H. Saxe M.G.R. Cannell Øystein Johnsen M.G. Ryan G. VourlitisSammendrag
Det er ikke registrert sammendrag
Forfattere
Sondre Skatter R.R. ArcherSammendrag
Det er ikke registrert sammendrag
Forfattere
Ivar GjerdeSammendrag
Det er ikke registrert sammendrag
Forfattere
Petter NilsenSammendrag
Samarbeid NISK, NIVA, NINA, NILU Kalking av skog og utmark for å bedre vannkvalitet i vassdrag. Meldinga beskriver skoglige forhold i to nedslagsfelt i Suldal kommune.
Sammendrag
Understanding sulfate transport and retention dynamics in forest soils is a prerequisite in predicting SO4 concentration in the soil solution and in lake and stream waters. In this study forest soil samples from the Grdsjn catchment, Sweden, were used to study SO4 transport in soil columns from the upper three soil horizons (E, Bs and BC).The columns were leached using a sequential leaching technique. The input solutions were CaSO4 equilibrated with forest floor material. Leaching behavior of SO4 and concentration in the effluent were measured from columns from individual horizons.SO4 was always retained in the Bs and BC horizons, while the pattern for the E horizon varied. Attempts were also made to model SO4 breakthrough results based on miscible displacement approaches and solute convection-dispersion equation (CDE) in porous media. Several retention mechanisms were incorporated into the CDE in order to account for possible reversible and irreversible SO4 reactions in individual soil layers.The model was not successful in describing the mobility of SO4 in the top (E) horizon. Moreover, a linear equilibrium approach was generally inadequate for describing sulfate mobility in the Bs and BC horizons whereas improved model descriptions were obtained when non-linear equilibrium and kinetic approaches were utilized.We conclude that sulfate retention during transport in this forest soil is most likely controlled by kinetic reactivity of SO4 by reversible and irreversible mechanisms.
Forfattere
David Wei Zheng Petter NilsenSammendrag
Det er ikke registrert sammendrag
Forfattere
A. Sæbø Øystein JohnsenSammendrag
Det er ikke registrert sammendrag
Forfattere
Morten Ingerslev E. Mälkönen Petter Nilsen H.Ö. Nohrstedt H. Óskarsson Karsten Raulund-RasmussenSammendrag
Previous research has documented that nitrogen fertilization can lead to a significant tree growth increase in large parts of Scandinavia. Nutrient management of Nordic forests is currently under debate, mainly because environmental values are believed to be unnecessarily endangered by these actions. Nutrient management including fertilization, liming, recycling of wood ash or application of alternative nutrient sources can counteract nutrient deficiencies and imbalances, and be used for compensating the nutrients removed through harvesting. For successful implementation of nutritional management measures, several questions should still be studied. These questions mainly concern diagnosis of the need for applications, nutritional sustainability and treatment effects on the forest ecosystem and the surrounding environment.
Forfattere
Lars Sandved Dalen M. GriffithSammendrag
Adaptation to cold and freezing temperatures is crucial for survival in temperate and boreal areas. Compared with angiosperms, little is known about the mechanisms of freezing tolerance in gymnosperms. Coniferous species such as Norway spruce (Picea abies L. Karst.) have a wide distribution in boreal areas, indicating a strong ability to adapt to lasting periods of cold and freezing temperatures.Freezing-tolerant perennial plants survive subzero temperatures by forming ice in intercellular spaces and the xylem. Certain proteins associated with pathogen attack have been found to exhibit antifreeze activity, i.e. the ability to bind and modify the growth of ice.In order to study the possible role of pathogenesis-related proteins in development of freezing tolerance in Norway spruce, we looked at the accumulation of chitinases during hardening under both artificial and natural conditions.Our findings show that chitinases and other pathogenesis-related proteins, as well as antifreeze activity, are present in needles of Norway spruce, and that they increase in response to shorter daylengths and cold temperature. It is possible that pathogenesis-related proteins accumulated in conifers during cold acclimation could also exhibit antifreeze activity, and thus play an important role during development of freezing tolerance in perennial plants such as the gymnosperm Norway spruce.