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.
1994
Forfattere
T. Westby N. Vagstad O. NordalSammendrag
Det er ikke registrert sammendrag
Forfattere
Øistein Vethe Ø. Engen Roar LinjordetSammendrag
Det er ikke registrert sammendrag
Forfattere
Petter NilsenSammendrag
Rapporten gir en kort bakgrunn for de ulike oppfatninger omkring behovet for tiltak mot forsuring av skog. Videre gis et sammendrag over effekter på ulike deler av skogøkosystemet og økonomiske konsekvenser ved noen av tiltakene mot forsuring av skog. Mottiltak som er behandlet er kalking, vitaliseringsgjødsling (inklusive asketilførsel), mer bruk av lauvtrær (blandingsskog, generasjonsveksling), flatebrenning, radikal markberedning, forlengelse av omløpstiden og bruk av plukkhogst - bledningshogst. Rapporten er i hovedsak basert på en tidligere utgitt utredning omkring disse problemene (Nilsen 1994). Foreløpig ser det ut til at man ut fra forsuringshensyn kan satse mer aktivt på en innblanding av lauvtrær i barskogen, først og fremst bjørk. Vitaliseringsgjødsling bør utføres i områder hvor man med sikkerhet har fastslått at årsaken til skogens nedsatte vitalitet skyldes næringsmangel eller ubalanse. Vitaliseringsgjødsling som forebyggende virkemiddel bør avventes til bedre kriterier for dette er utarbeidet. Det samme gjelder for dolomittilførsel og kalking.
Forfattere
F. Engelstad Roar LinjordetSammendrag
Det er ikke registrert sammendrag
Forfattere
Knut Solbraa Jon Olav BrunvatneSammendrag
The project started in 1976/77 with a series of experiments in five burned areas. These were:Fyresdal, 80\" E and 591\" N, 610 m.a.s.l. on shallow moraine soilHeddal, 95\" E and 594\" N, 380 m.a.s.l. on shallow moraine soilElverum, 114\" E and 605\" N, 225 - 265 m.a.s.l., sites on shallow moraine soil and sandy, sedimental soil respectivelyDeset,\"113\" E and 612\" N, 300 m.a.s.l. on sandy, sedimental soilkrestrmmen, 112\" E and 614\" N, 300 m.a.s.l. in a rocky, former river bed. The site at Deset burned in 1959, krestrmmen in 1980 and the others in 1976. The experiments covered more than 30 000 plants, mainly of Scots pine (P. sylvestris), but also a few lodgepole pine (P. contorta). Direct seeding after scarification was tried as well, but in a small scale only. Mainly the last years results are fully reported here, because the others are published earlier.The following conclusions are drawn from the complete project.1. High soil temperatures in addition to fresh cut stumps and dead trees permitted the accumulation of pathogens after the fire. These cover Hylobius abietis and other insects feeding on bark or needles of the young conifer plants. Their attacks culminated the year after the fire, and were neglectible from the third year. Treating the plants with pyretroides before planting significantly reduced bark damages. Treatment against needle eaters should be repeated annually, but is not permitted in Norway.2. The fungus Rhizina undulata killed a great share of the transplants near fresh cut stumps in Elverum. These plants died within a few weeks after planting. Also this attack continued during the first two years only. The picture of attacks in Elverum was confirmed after a prescribed burning, close to the wild-fire area, in 1984. A suspension of systemic fungicides gave the plants a good protection against Rhizina undulata. The fungus was also found in high densities at krestrmmen and with a few specimen in Fyresdal and Heddal. It seems however, to be no relations between the presence of the fungus and mortality of plants these places.3. Direct seeding after ground scarification showed good results in areas not exposed to erosion. These small pine seedlings were not attacked to the same extent as older plants. Potential seedtrees should therefore be left in order to initiate natural regeneration.4. The combination of low temperatures during the growth season and the attack of the fungus Gremmeniella abietina was the main reason for total mortality of the Scots pine plants at Deset.5. If chemical protection against insects and fungi is unwanted, planting on sandy soil should be done in the spring the third year after the fire. Treatment with insecticides and fungicides may allow earlier planting.6. On sandy soil, the annual height increment culminated after 9 years, and decreased rapidly from about 35 to 10 centimeters. Planting later than three years after fire reduced growth compared to earlier planting. Application of nitrogen fertilizers initiated continued high growth rate. On sandy soil, fertilization with approximately 130 kg nitrogen should start 8 to 10 years after the fire. The nitrogen status of plants may be checked by needle analysis. A concentration of up to 1,6 - 1,8 % N is probably suitable at a tree age of 10 years. A mulch layer of 5 cm of crude sewage sludge gave the best growth of all treatments. On moraine, growth reductions were considerable less than on sandy soil.7. Application of nitrogen fertilizers increased damage both by Gremmeniella abietina and moose. Heavy fertilization may also increase the risk of climatic damages and reduces the final lumber quality. Therefore, fertilization should be limited to stands on deep soil layers, favourable climatic conditions and areas that are not exposed to heavy winter browsing by moose.
Forfattere
Hans Olav EggestadSammendrag
Det er ikke registrert sammendrag
Forfattere
Øistein VetheSammendrag
Det er ikke registrert sammendrag
Forfattere
E. WoldSammendrag
Det er ikke registrert sammendrag
Forfattere
Tor J. JohansenSammendrag
Det er ikke registrert sammendrag
Forfattere
Jens KøhlerSammendrag
Det er ikke registrert sammendrag