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.
2006
Forfattere
Tore SkrøppaSammendrag
Det er ikke registrert sammendrag
Forfattere
Tore SkrøppaSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Vi registrerte plantenes utvikling og skader og målte høyder på 103 plantefelt med gran i Sør-Trøndelag, Nord-Trøndelag og Nordland, og på åtte kontrollfelt med flere plantepartier. Frøet kom enten fra Lyngdal frøplantasje eller lokale provenienser (bestandsfrø). Formålet var å beskrive effekter av krysningsmiljøet i frøplantasjen (ettereffekter), som er påvist i planteskoler og i forsøk, på utviklingen i plantefelt. Resultatene tyder på at tilstanden i plantefelt med planter fra lyngdalfrø og fra bestandsfrø gjennomsnittlig er noenlunde lik. Det er allikevel variasjon i resultatene både for regioner (kyst- og indre strøk) og for egenskapene som er studert. I kyststrøk er utviklingen omtrent den samme for planter fra de to gruppene, men med et litt høyere plantetall for feltene med bestandsfrø. I midtre og indre strøk er det noe bedre utvikling på feltene med planter fra bestandsfrø enn på de fra bestandsfrø. I Nordland og i høyereliggende strøk i Nord-Trøndelag har planter fra plantasjefrø klart seg like godt som lokal proveniens. Endelige konklusjoner om bruksområder for frø fra Lyngdal frøplantasje bør trekkes etter en total vurdering av alle resultater fra både tidlige tester, avkomforsøk og plantefelt.
Sammendrag
Det er ikke registrert sammendrag
Populærvitenskapelig – Sopp i norske bygninger!
Gry Alfredsen, Kolbjørn Mohn Jenssen, Halvor Solheim
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
In this study, forest treated with different strengths of selective cutting (2570 % of volume removed) was remeasured after twelve years in 2005. At each of the sixteen 0.2 ha plots, including four repeats of each treatment, all trees larger than dbh 2.5 cm were calipered. We investigated growth, changes in stand structure, tree age, tree damage and crown condition.The diameter distribution displayed a reverse J-curve at all plots both before and after the cuttings. Twelve years later the curve is only slightly changed. Increment cores from 300 trees were taken to analyse annual growth reactions in different diameter classes. Most trees reacted with increased growth from the second or third year after the cutting.This improved growth accelerated the following six or seven years with 20-80% increase. Both small and large trees reacted, including severely suppressed trees. The initial crown volume and crown vitality after cutting is essential for the increased growth since several years are necessary to build up a larger and better crown. The relationship between increased growth and reduced volume per hectare indicates less competition between trees regarding nutrients and light after the cutting.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
This analysis is based on climatic data and increment cores from about 550 Forest officers from latitude 58-70N and longitude 6-18E. The strength of the data is the high number of plots scattering over most of the Norway spruce forest area in Norway. Tree ring-widths were transformed to ring indices to remove age disturbances and strengthen the climatic signal on the tree growth.We used regression analyses to examine the annually growth responses of these ring indices against 42 monthly climatic variables. The climatic variables we used were mean month temperature, precipitation and Palmer drought severity index (PDSI) with a range from previous year July to current years August.The results showed some correlations of climate on growth, with the June weather as most important. The most important variable in the lowlands (altitude 500 m) of southeastern Norway was the June precipitation, and the June temperature in the rest of the country.
Sammendrag
This study is based on data from the Level I and from forest Officers plots. We combined three sets of data on growth, deposition and soil chemistry, totally 204 plots in south-eastern and mid-Norway. As response variable we used observed growth in % of estimated growth calculated from standard Norwegian growth models. In this way we filtered out the influence of site and stand properties as this were included in the model.The dependent deposition variable used was the N deposition from the national air and precipitation monitoring program. The dependent soil chemistry variables were N, C/N ratio, base saturation, pH, Al, and Ca/Al ratio. Soil chemistry variables should reflect the properties that most likely are influenced by S and N deposition, and that could influence the trees in the hypothesised ways.We used analyses of covariance as statistical method. Growth was positively correlated to nitrogen deposition and to soil nitrogen, and negatively correlated to the C/N ratio in the soil. Also, nitrogen deposition was positively correlated to soil nitrogen and negatively to soil C/N.It was concluded that N deposition probably has increased N availability and thereby growth in southernmost Norway with an order of magnitude around 25%. There were no relationships between growth and the soil acidification variables pH, base saturation, Al concentration or Ca/Al-ratio, and we concluded that no evidence for negative effects of soil acidification on forest growth was found.