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.
1998
Forfattere
Hugh RileySammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Arne Olav Stuanes O. Janne KjønaasSammendrag
Nitrogen has been added to a forested 0.52 ha headwater catchment (G2 NITREX) at Grdsjn, Sweden, to study the ecosystem response to elevated N deposition. The catchment is dominated by naturally regenerated, mixed-age conifers, mainly Norway spruce, with Scots pine dominating in dry areas. After a pre-treatment period of about 1 yr of soil solution sampling, N was added to the whole catchment as an NH4NO3 solution by means of sprinklers. Total N input as throughfall to the catchment increased from the ambient 13 kg N ha-1 yr-1 in the pre-treatment year to a total of about 50 kg N ha-1 yr-1 in the 4 treatment years. Soil solution was collected by tension lysimeters at 4 locations in G2 NITREX covering a moisture gradient from the dry upper to the lower wet parts of the catchment, at 2 locations in a nearby control catchment (F1 CONTROL), and at 2 locations in an adjacent catchment (G1 ROOF) at which ambient throughfall is excluded by a roof and replaced by unpolluted throughfall added by sprinklers. After 4 yr of N addition, the volume-weighted average NO3 concentrations in G2 NITREX were higher than the pre-treatment values. Concentrations showed a progressive increase over time. In the 2 first treatment years this increase occurred only in the rooting zone but during the second 2 treatment years a pronounced increase also came in deeper layers. The lack of these trends in the F1 CONTROL and G1 ROOF catchments precludes natural variations in climatic conditions as the main cause for this increase. Relative to inputs, NO3 concentrations in soil solution were low and showed large variations between the drier and wetter locations with peak concentrations in late fall and spring. Nitrate in soil solution generally constitutes less than 10% of the inorganic mobile anions and thereby contributes much less to the leaching of H, Al, and base cations than CI and SO4, the dominant mobile anions. Soil solution NH4 has not changed relative to the control and roof catchments. However, the system is changing. Increases in NO3 leaching indicate reduced immobilization of NO3 that can be due to episodic excess N supply of the microflora together with episodes of high waterflow.
Forfattere
P.I. KraftSammendrag
Det er ikke registrert sammendrag
Sammendrag
Artikkelen beskriver fire soppsjukdommer i dyrka bjørnebær. Sjukdommene er purpur stengelflekk (Septocyta ruborum), bjørnebærbladskimmel (Peronospora sparsa),bjørnebærrust (Phragmidium violaceum) og gråskimmel (Botrytis cinerea)
Forfattere
Gunhild BørtnesSammendrag
Prøving av sju sortar sitronmelisse i 1997 og 1998 dyrka på papir og plast. Dyrking på plast ga høgast avling. Det var stor skilnad i oljeutbytte mellom sortane
Forfattere
Dag Røen S.H. HjeltnesSammendrag
Artikkelen drøftar kva ein bør legge særleg vekt på ved val av sortar for økologisk dyrking av frukt. Det vert dessutan presentert liste over tilrådde sortar i eple, pære og plomme.
Forfattere
Leiv MortensenSammendrag
Det er ikke registrert sammendrag
Forfattere
Vincent R. Franceschi Trygve Krekling Alan A. Berryman Erik ChristiansenSammendrag
The bark anatomy of Norway spruce clones that were resistant or susceptible to Ceratocystis polonica, a bark beetle vectored fungal pathogen, was compared. The major difference concerned the axial parenchyma cells, called polyphenolic parenchyma (PP cells) because of their vacuolar deposits. The phenolic nature of the deposits was indicated by autofluorescence under blue light, and immunocytochemical studies demonstrating PP cells are enriched in phenylalanine ammonia lyase (EC 4.3.1.5), a key enzyme in phenolic synthesis. Susceptible clone PP cells occurred as single rows filled with dense deposits. The resistant clone had 40% more PP cells, which occurred in rows two cells thick with individual cells also scattered among the sieve cells, and had lighter deposits. Trees inoculated with fungus were analyzed but a distinct fungal response could not be separated from the general wound response. In the resistant clone, phenolic bodies were reduced in size and density or disappeared completely 12 day after wounding, and PP cell size increased. The susceptible clone phenolics and cell size changed only slightly. These data show that PP cells are active in synthesis, storage, and modification of phenolics in response to wounding, providing a primary site of constitutive and inducible defenses.
Forfattere
Anne Sverdrup-Thygeson Fred MidtgaardSammendrag
Det er ikke registrert sammendrag