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
Forfattere
Peder GjerdrumSammendrag
Hensikten med forsøket har vært 1)å undersøke forskjellen i likevektsfuktighet og hysterese mellom trestykker av varierende størrelse og 2)skaffe erfaring for opplegg av eventuelle senere forsøk. Søsteriske sett med biter av sju ulike lengder fra 7 til 402 mm og to behandlinger (de- hhv. adsorpsjon) ble plassert i et klimaskap under konstant klima: 30ºC og tabulert likevektsfuktighet 18.5%. Bitene ble observert ved veiing over to måneder. Likevektsfuktigheten ble funnet å øke degressivt med økende lengde på prøvebitene. Effekten av kvist/virkesfeil, som forekom i de største lengdene 20 og 40 cm, kan ikke separeres fra selve lengdeeffekten. For kommersiell trelast ble likevektsfuktighet ved desorpsjon estimert å ligge ca. 2%-enh. høyere, og ved adsorpsjon ca. 0.5%-enh. lavere enn tabulert verdi. Størrelsen på hysterese ble funnet å være 2.6%-enh., uavhengig av prøvebitenes lengde. Antatt forskjell fra endelig likevektsfuktighet for de lengste prøvebitene var ca. 0.1%-enh. etter to måneder. Prøvene med endebeskyttelse viste delvis uforklarlige avvik fra prøver uten endebeskyttelse, og ved benyttet fyllingsgrad ble klimaskapets regulerings-kapasitet overskredet i en kort periode etter oppstart.
Sammendrag
Omfattende skader på skog i Ottadalen, karakterisert som tilbakedøing av skuddene i krone og topp, var forårsaket av bormangel (Kohmann 1997). En senere undersøkelse (Kohmann 1999) viste at gjødsling med borax økte konsentrasjonen av bor til nivå langt over det kritiske. For å få oversikt over hvor store arealer bormangel kan gjøre seg gjeldende på, tok Skogavdelingen ved Fylkesmannen i Oppland initiativet til en mer omfattende registrering i den sentrale Gudbrandsdalsregionen. Målsettingen var også å finne parametre knyttet til de geografiske, edafiske og biotiske forhold som kunne gi indikasjoner på forventet bormangel. Hovedtyngden av undersøkte felt ligger i kommunene Skjåk,Lom, Vågå og Sel hvor i alt 148 av de 167 felt felt ligger. Det er 68 felt hvor hovedtreslaget er gran og 99 felt hvor hovedtreslaget er furu. I alt er det funnet at 22 felt (13 %) har sterk bormangel (konsentrasjonen av bor i siste nåleargang mindre enn 4 ppm B), mens 52 felt (31 %) har verdier som er klassifisert som moderat bormangel (4-8 ppm B).
Forfattere
Maria Sørensen Arild Ernstsen Leidulf Lund Jarle Nilsen Anders Lönneborg Øystein JohnsenSammendrag
Det er ikke registrert sammendrag
Forfattere
Carl Gunnar Fossdal Nina Elisabeth Nagy Praveen Sharma Anders LönneborgSammendrag
Here we describe the detection, developmental accumulation and cellular location of the putative plant defensin SPI1 (spruce pathogen induced 1), in the gymnosperm Norway spruce [Picea abies (L.) Karst.], using specific antibodies. Contrary to what has been found in angiosperms, it was not detected in the embryo or other parts of the seed, but accumulated during root development. The protein was detected by immunolocalization along the cell membrane of cells forming the root cortex. Furthermore, a significant accumulation of the SPI1 protein was detected in roots during the first day of infection with the fungal pathogen Heterobasidium annosum, but not in response to the pathogens Pythium dimorphum or Ceratocystis polonica
Forfattere
Tove M. ØstensvikSammendrag
Det er ikke registrert sammendrag
Sammendrag
Materials and Methods: In the field, fresh samples were obtained from different sources. Lake samples were collected from Lake Årungen, which is located in Ås. Stream samples were collected from Ås and Birkenes in southern Norway. All the samples were filtered in the field through 0.45 um membrane filters using syringes. Then the samples were fractionated through Bond Elut SCX cartridges connected to a portable vacuum pump, based on the method of Wickstrøm et al. (2000). A portion of the sample was passed immediately through the cation exchange cartridge. After the fieldwork another portion of the sample was taken to the laboratory where the same fractionation procedure was applied. These two fractions were then analysed for non-labile aluminium. A portion of the unfractionated sample was also analysed for total dissolved aluminium. An additional laboratory fractionation with a time lag was also applied to observe storage effects. Subsequent determination of total elements was done using ICP-AES. Transport, pretreatment and storage can also have an effect on the pH and organic matter concentration of the samples and, through this, on the equilibrium between different Al fractions. To evaluate pH differences prior to analysis, pH values were also measured in the field and in the laboratory. DOC was also determined. Differences between fractionation in the field and fractionation in the laboratory: In this study, non-labile fractions of Al were compared instead of the labile fractions of Al (which can be removed from solution on passage through cation exchange column) that are believed to have the greatest toxic effect on organisms.
Forfattere
Petter NilsenSammendrag
The paper gives a brief overview of the background, history and main results of forest fertilization experiments on mineral soils in Norway. Positive results of initial phosphorus (P) fertilization on survival and growth of Norway and Sitka spruce have only been achieved in the coastal districts of western Norway. Other elements have seldom given any significant effect.In young and old stands of Norway spruce and Scots pine nitrogen (N) fertilization with 150 kg N ha-1 usually gave increment increases in the range of 1-2 m3 ha-1 yr-1, for a period of 6-8 yrs after application. Given individually, no other element has proved stimulating to stem growth in a similar way. In young Norway spruce stands P has often given additional growth response when given together with N. Liming has been shown to have no or negative effects on tree growth. Fertilization experiments have changed from being management orientated towards addressing the problems of possible nutrient imbalances.
Forfattere
Halvor TorgersenSammendrag
Det er ikke registrert sammendrag
Forfattere
Jan-Ole Skage Tormod Stavrum Terje PundsnesSammendrag
Together with Ryfylke forsøksring, Norsk Pyntegrønt applied for funds during the spring of 1998 for examination of stands of subalpine fir in USA and Canada. The application was forwarded based on observations in plantations in Rogaland county and elsewhere in Norway, were high quality trees from provenances in USA and Canada had been reported. The aim of the survey was to work out recommendations for suitable areas for seed collection in subalpine fir in three distinct regions, northeastern Oregon, southwestern Washington and southern British Columbia for Christmas tree production in Norway. The distinct regions includes Umatilla National Forest, Wallowa-Whitman National Forest, Mount Hood National Forest, Gifford Pinchot National Forest, Kamloops Forest District, Vernon Forest District and Salmon Arm Forest District. Within each region seed collection was recommended from one main and one alternative provenance. On the individual tree, 20 parameters with relevance to performance as Christmas trees were recorded, but most weight was devoted to number of whorl branches and occurrence of internodal branches, as these parameters properly express the density of the trees. Some weight was also given to needle morphology and growth. First priory collection is recommended from the provenances Tower Mountain from Umatilla National Forest, Red Mountain from Gifford Pinchot National Forest and Chuwhels Mountain from Kamloops Forest District in Oregon, Washington and British Columbia, respectively. Alternative provenances are Horse Meadows from Wallowa-Whitman National Forest, Sawtooth Mountain from Gifford Pinchot National Forest and Laurel Lake from Kamloops Forest District, respectively.
Forfattere
Jan BjerketvedtSammendrag
Det er ikke registrert sammendrag