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.
2007
Forfattere
Andrezej Brunon Poplawski Lotta Mårtensson Ingvild Wartiainen Ulla RasmussenSammendrag
The aim of this study was to analyze a total euryarchaeal community at DNA and RNA levels in a Swedish barley field with relation to soil depth (0-10 and 20-30 cm layers), soil fraction (bulk soil and rhizosphere) and time (August and November sample collection). Amplification of 16S rRNA gene using the archaeal universal A2F and Euryarchaea specific EK510R/(EURY498) primer pair, combined with denaturing gradient gel electrophoresis (DGGE), revealed distinct differences between rDNA and rRNA DGGE profiles. The soil depth, time, or rhizosphere effects did not significantly influence Archaeal community structure. Surprisingly, sequence analysis of DGGE-derived amplicons revealed the presence of Euryarchaea as well as uncultured soil Crenearchaea affiliated with group 1. In agreement, sequence comparison analyses showed that the majority of uncultured Chrenearchaea group 1 had almost 100% sequence complementarity to the 3" end of the EK510R/(EURY498) primer. Therefore, we propose that EK510R/(EURY498) is a universal archaeal primer rather than a a Euryarchaea specific SSUrRNA primer. Hence, considerable care should be taken during application of this primer in studies of euryarchaeal biodiversity in soil environments.
Forfattere
Trygve S. Aamlid Arild Andersen Rolf Skuterud Gunvald Henning JonassenSammendrag
The application of insecticides and / or chemical growth regulators for the control of arthropod-induced silvertops (whitetops) and / or lodging in seed crops of common bent (syn. browntop, US: colonial bentgrass, Agrostis capillaris L. syn. A.tenuis Sibth.) `Leikvin" was investigated in twelve on-farm trials laid out according to five different experimental plans in SE Norway from 1993 through 1997. Seed yields on plots sprayed with insecticides were significantly higher than on unsprayed control plots in three out of nine trials, however, these seed yield increases were poorly correlated with silvertop frequencies which varied from 1 to 60% on untreated plots. Differences between various insecticides (two pyretroids and one organophosphorous compound) and single versus split applications were mostly not significant. While seed yields on plots sprayed with ethephone ("Cerone", 0.5 kg a.i. ha-1) were not significantly different from those on unsprayed control plots, chlormequat chloride ("CCC 750", 1.0 or 2.0 kg a.i. ha-1 plus surfactant) minimised lodging and increased seed yield by 21% on average for five trials. When chlormequat chloride and the pyretroid alphacypermethrin were combined in a tank mixture including surfactant at Z 31-32, the effects of the two products were mostly additive. Based on these results, the application of the growth regulator chlormequat chloride (1.0 kg a.i. ha-1) is now recommended in Norwegian seed production of common bent. Although the effects of insecticides were often not significant, seed growers are further advised to add an insecticide (e.g. alphacypermethrin, 150 g a.i. ha-1) to the growth regulator as a precaution against silvertops, which otherwise seem to strike quite randomly in seed production of common bent.
Forfattere
Bernt Johansen Stein Rune Karlsen Christian UhligSammendrag
Oppsummering og konklusjon Denne rapporten har vist vegetasjons- og beiteklartlegging basert på Spot 5 satellittdata og feltstudier. Den har i tillegg gitt en vurdering av jorderosjon. Vegetasjonskartet presentert har 26 kartlagte enheter, derav 17 med vegetasjonsinnhold. Kartet viser at impedimentstyper av forvitringsmateriale og morenemateriale med berg, stein og grus i dagen dominerer. Inkluderer vi de sparsomt vegeterte enhetene her dekker de til sammen over halvparten (51,5 %) av arealet innen Hammerfest kommune på Kvaløya. Den andre store enheten er ulike utgaver av fjellkreklingheier som dekker 35,0 % av arealet. Fukt- og grasheier dekker 6,8 % av arealet, mens skog og myrtyper utgjør hver bare omkring 1 % av arealet. Reinbeite i barmarksperioden preger vegetasjonen på Kvaløya sterkt, både med hensyn til art sammensetning, dekning og vekstform. Mest påfallende er det på den sparsomme utbredelsen av vierkratt og bjørkeskog. Reinbeite gir ett åpent, og etter manges mening ett naturskjønt landskap, som er lett å ferdes i. Skogspotensialet er derfor stort i de vindbeskytta områdene under et par hundre meter. Dette er typisk for flere sommerbeiteområder på finnmarkskysten, men få steder er det så iøynefallende som på Kvaløya. Beitekvalitetet er vurdert ut fra artsinnhold i vegetasjonstypene og fra produksjon målet med vegetasjonsindeksen NDVI. I tillegg er kart som viser start og slutt på grønnbeitene presentert. Ut fra dette har vi gitt vegetasjonstypene beiteverdi fra 0 til 10 og laget et beitekart. Beitekartet illusterer tydelig at spesielt de indre deler har liten verdi som sommerbeite for rein, mens gode sommerbeiter finner vi rundt Hammerfest by, I Storvikvannet-Middagsfjellet området, i Torskefjorddalen og dels i området Straumnestet-Molstrandneset. I mange tilfeller har beiting av vegetasjonen ført til jorderosjon, spesiell på opprinnelig lav- og moserik vegetasjon, samt dvergbjørk-krekling dominerte vegetasjonstyper på eksponerte lokaliteter. Men også lokale forekomster med mer næringsrike vegetasjonstyper er tydelig degradert og utsatt for jorderosjon. Det antas at reinens påvirkning på vegetasjon og jordmonn var størst for ca. 15-20 år siden ved høyest antall rein på beite, og at den siden har betydelig minket. Reduksjon av reinflokken, men også økt utnyttelse av de forholdsvis gode beite i Hammerfest by har nok minket beitepresset på store deler av Kvaløya, så at naturlig plantesuksesjon ved flere lokaliteter har sinket eller stoppet jorderosjonen. Hvilken konkrete konsekvenser dette medfører er avhengig av mange forskjellige faktorer og vanskelig å forutsi. Dermed er det anbefalt å følge den framtidlige utviklingen av jorderosjon på Kvaløya med nye registreringer i årene som kommer.
Forfattere
Oleg I. Shumilov Elena A. Kasatkina Paul E. Aspholm Natalia V. Lukina I. Yu. KirtsideliSammendrag
Records of growth rings in sub-arctic trees play an important role in reconstructing climate change in the past. Tree-ring chronologies collected from different parts of Arctic (Fennoscandia, Kola Peninsula and Northern Siberia) were investigated by spectral (MTM method) and wavelet analysis. Among them it was analyzed juniper tree ring chronology with extension more than 700 years (from about 1300 A.D. till 2004 A.D.) collected for the central part of Kola Peninsula (Keivy region: 67.77N; 36.52E). Results of spectral analysis allow us to select the main periods of solar variability (22-year, 30-33 year and 80-90-year solar cycles) in Kola and Fennoscandia tree-ring chronologies. Besides it was found that only periodicities of around 20 years are present in Siberian series. With respect to 11-year periodicity, which is the most prominent one in sunspot number spectrum (Schwabe cycle) it may be said that it hardly appeared in sub-arctic tree-ring records. It was obtained a rather good correlation between long-term climatic variation in Europe and at Kola Peninsula. The minima of solar activity during the Sporer (1416-1534 AD), Maunder (1645-1715 AD) and Dalton (1801-1816 AD) were accompanied by temperature decreases. The coldest conditions of the last 700 years in the Northern Europe were in the XVII century during the "Little Ice Age" period. It should be noted that the Kola Peninsula tree-ring chronologies analysed here did not show any extended growth at the end of the XX century. The result obtained give us information on local climate variations in the very important area influenced by Gulf Stream and Arctic ocean and located in the vicinity of the very important for whole Europe gas field at the shelf of Barents sea. The work was partially supported by the program "Biodiversity and dynamics of gene pool" of the Russian Academy and by RFBR grant N 05-04-97528.
Forfattere
Elena A. Kasatkina Oleg I. Shumilov Paul E. Aspholm Natalia V. LukinaSammendrag
Among some of the mysteries of the Tunguska meteorite event, is the cause of the accelerated tree growth after 1908 in the catastrophe area (about 2000-2500 km^2). The main explanation of accelerated growth of old trees, was a result of decrease of competition level due to falling of considerable part of neighbour trees. We analyzed all available tree ring records (more than 100) including our own ones collected in the Taymir Region of Northern Siberia (72N; 105E) at a distance of about 1500 km to the North from the Tunguska catastrophe epicentre (61N; 102E). It was found that there were a considerable increase of tree ring growth in 1908 over a vast area of Siberia (60N-75N; 80E-110E) that at much more vast area (10^3 times more) than had been earlier considered. The similar effect was detected after the Chulym bolide explosion in 1984 (57.7N; 85.1E). Of course, the Chulym forest response area was some smaller taking into account incomparable powers of Tunguska and Chulym events). It is obvious that the interpretation mentioned above, of tree growth observed too far from epicentre, could hardly be accepted. A more likely hypothesis is that the growth of the trees became stimulated by the matter from comet that where spread over a large territory of Eurasia. It is generally believed that meteorites and comets delivered large amounts of simple organic composites to the early Earth. Another hypothesis is connected to NO produced during the event analyzed. For example, in time the Tunguska event the comet (probably fragment of the comet Enke) tail started to influence the Earth atmosphere several days before the fall of the meteorite causing optical anomalies observed mainly westwards from the place of TO explosion (Western Siberia, European Russia, Northern Europe). We discuss as well the role of "small signals" in simulation of biological object response. The work was supported by a grant from the Russian Foundation for Basic Research (grant N 05-04-97528), by the Program "Biodiversity and dynamics of gene pool" of the Russian Academy and by the Regional Scientific Program of the Murmansk region.
Forfattere
Leiv Mortensen Hans Martin HanslinSammendrag
I 2004 startet et relativt omfattende klimaforskningsprogram i Bioforsk med en total ramme på ca. 20 millioner kroner over 5 år. I løpet av de tre årene som har gått, er det blit gjennomført en lang rekke forsøk for å belyse hva som kan skje ved en framtidig klimaendring, blant annet med høsthvete.
Forfattere
Marie Alexis Daniel Rasse C. Rumpel G. Bardoux N. Péchot P. Schmalzer B.G. Drake A. MariottiSammendrag
Fire profoundly modifies the terrestrial C cycle of about 40% of the Earth"s land surface. The immediate effect of fire is that of a net loss of C as CO2 gas and soot particles to the atmosphere. Nevertheless, a proportion of the ecosystem biomass is converted into charcoal, which contains highly recalcitrant molecular structures that contribute to long-term C storage. The present study aimed to assess simultaneously losses to the atmosphere and charcoal production rates of C and N compounds as a result of prescription fire in a Florida scrub-oak ecosystem. Pre-fire and post-fire charred and unburned organic matter stocks were determined for vegetation leaves and stems, litter and soil in 20 sub-plots installed in a 30-ha area that was subjected to prescribed fire. Concentrations of C and N were determined, and fluxes among pools and to the atmosphere were derived from these measurements. Soil C and N stocks were unchanged by the fire. Post-fire standing dead biomass contained 30% and 12% of pre-fire vegetation C and N stocks, respectively. In litter, post-fire stocks contained 64% and 83% of pre-fire C and N stocks, respectively. Most of the difference in relative losses between vegetation and litter could be attributed to substantial litter fall of charred and unburned leaves during the fire event. Indeed, an estimated 21% of pre-fire vegetation leaf C was found in the post-fire litter, while the remaining 79% was lost to the atmosphere. About 3/4 of the fire-induced leaf litter fall was in the form of unburned tissue and the remainder was charcoal, which amounted to 5% of pre-fire leaf C stocks. Charcoal production ranged between 4% and 6% of the fireaffected biomass, i.e. the sum of charcoal production and atmospheric losses. This value is below the range of literature values for the transformation of plant tissue into stable soil organic matter through humification processes, which suggests that fire generates a smaller quantity of stable organic C than humification processes over decades and potentially centuries.
Forfattere
Bjørn Molteberg Frank EngerSammendrag
Dette er en forvaltningsoppgave som gjennomføres på oppdrag fra Mattilsynet (tidligere Landbrukstilsynet) ( www.mattilsynet.no ). Målet er å framskaffe resultater for godkjenning av nye sorter for opptak på norsk sortsliste. ( http://www.mattilsynet.no/planter/sortsgodkjenning/offisiell_registrering_av_plantesorter_10655 ) Prøvingen er en kontinuerlig, ikke tidsavgrenset prøving. Flerårige arter legges ut to ganger med tre registrerings- og høsteår etter hvert utlegg. Ettårige arter prøves i tre år. Artene blir som hovedregel prøvd i fem distrikter, Østlandet, Fjellbygdene, Vestlandet, Midt-Norge og Nord-Norge. I 2006 var det sorter av følgende arter med i prøvingen: Timotei, engsvingel/raisvingel/strandsvingel, engelsk (flerårig) raigras, strandrør, engrapp, rød- og hvitkløver og westervoldsk- og italiensk raigras. Totalt var det 50 sorter i prøving, ingen av disse var ferdig prøvd. I tillegg var det med 39 målesorter. Sorter som var ferdig prøvd i 2006 (24 stk.) kommer i tillegg til de nevnte 50. Disse er presentert i egen rapport. (Bioforsk Fokus Vol. 2 Nr. 5 - 2007).
Forfattere
Bjørn Molteberg Frank EngerSammendrag
Dette er en forvaltningsoppgave som gjennomføres på oppdrag fra Mattilsynet (tidligere Landbrukstilsynet) ( www.mattilsynet.no ). Målet er å framskaffe resultater for godkjenning av nye sorter for opptak på norsk sortsliste. ( http://www.mattilsynet.no/planter/sortsgodkjenning/offisiell_registrering_av_plantesorter_10655 ) Prøvingen er en kontinuerlig, ikke tidsavgrenset prøving. Flerårige arter legges ut to ganger med tre registrerings- og høsteår etter hvert utlegg. Ettårige arter prøves i tre år. Artene blir som hovedregel prøvd i fem distrikter, Østlandet, Fjellbygdene, Vestlandet, Midt-Norge og Nord-Norge. I 2006 var det sorter innen artene timotei, engsvingel, engelsk (flerårig) raigras, engrapp, rød- og hvitkløver og westervoldsk raigras som var ferdig testet. I alt 24 sorter var ferdig testet og av disse er 10 anbefalt godkjent, (2 engsvingel, 4 engelsk (flerårig raigras), 2 engrapp, 1 hvitkløver og 1 westervoldsk raigras.
Forfattere
Trygve S. Aamlid Nicholas JarvisSammendrag
Soil water repellency (hydrophobicity) is a common problem on sand-based golf greens. Due to this phenomenon, soil water may percolate as "finger flow" rather than uniformly through the soil profile. The objective of this project was to investigate the effect of a commonly used wetting agent, Primer 604, on turf quality and leaching of two fungicides from two contrasting rootzones. The preliminary conclusions are as follows: 1. The wetting agent (WA) improved turf quality of straight sand rootzones during the warm and dry summer. Rootzone containing compost were not affected by WA. 2. WA lead to more water retention in the thatch layer and thus a tendency to more fungi during the rainy fall season. Again, the effect was mostly expressed on straight sand rootzones. 3. Water droplet intiltration tests showed that straight sand rootzones were strongly hydrophobic, even at 3-5 cm depth, i.e. under the thatch layer. Compost-amended rootzones were less hydrophobic, and only in the thatch layer. 4. WA reduced the spatial variation in soil water content, notably in the 4-15 cm layer on straight sand plots. This suggest that water percolation was more uniform after use of WA. 5. Fungicide leaching did not occur from Green Mix rootzones, even for azoxystobin + propicionazole used at high "American" rates. 6. Use of WA significantly reduced leaching of the fungicides iprodione, azoxystrobin and propiconazole from straight sand rootzones.