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.
2011
Forfattere
Aparna Tiwari Adam Vivian-Smith Roeland E. Voorrips Myckel E.J. Habets Lin B. Xue Remko Offringa Ep HeuvelinkSammendrag
Background Parthenocarpy is a desirable trait in Capsicum annuum production because it improves fruit quality and results in a more regular fruit set. Previously, we identified several C. annuum genotypes that already show a certain level of parthenocarpy, and the seedless fruits obtained from these genotypes often contain carpel-like structures. In the Arabidopsis bel1 mutant ovule integuments are transformed into carpels, and we therefore carefully studied ovule development in C. annuum and correlated aberrant ovule development and carpelloid transformation with parthenocarpic fruit set. Results We identified several additional C. annuum genotypes with a certain level of parthenocarpy, and confirmed a positive correlation between parthenocarpic potential and the development of carpelloid structures. Investigations into the source of these carpel-like structures showed that while the majority of the ovules in C. annuum gynoecia are unitegmic and anatropous, several abnormal ovules were observed, abundant at the top and base of the placenta, with altered integument growth. Abnormal ovule primordia arose from the placenta and most likely transformed into carpelloid structures in analogy to the Arabidopsis bel1 mutant. When pollination was present fruit weight was positively correlated with seed number, but in the absence of seeds, fruit weight proportionally increased with the carpelloid mass and number. Capsicum genotypes with high parthenocarpic potential always showed stronger carpelloid development. The parthenocarpic potential appeared to be controlled by a single recessive gene, but no variation in coding sequence was observed in a candidate gene CaARF8. Conclusions Our results suggest that in the absence of fertilization most C. annuum genotypes, have parthenocarpic potential and carpelloid growth, which can substitute developing seeds in promoting fruit development.
Forfattere
Helmer BelboSammendrag
The theoretical potential for increased efficiency in early thinning by using accumulating harvester heads was investigated through simulation. Thinning was performed in corridors perpendicular to the strip road in 75 artificially generated stands with varying average tree size and density. The work pattern and work time in the crane work for five sizes of heads, with grapple diameters in the range of 10 to 50 cm, was estimated by the simulation model. The efficiency increased rapidly when the grapple diameter increased from two to four times the average diameter in the harvested stand, reducing the work time per tree by 15 to 50 percent compared to the single tree handling harvester head. Further increases in grapple dimension also increased the efficiency, but not at the same rate. In real work, the efficiency increase by an accumulating harvester head will probably be slightly lower due to less optimal harvesting conditions, operator skills and other non-productive work tasks that are not affected by work method.
Forfattere
Helmer BelboSammendrag
I denne rapporten gis en oversikt over tidsforbruk og kostnader i forbindelse med innsamling og bruk av halm som biobrensel i småskala fyringsanlegg. Rapporten er basert på data fra sju gårdbrukere med egne halmfyringsanlegg som i tre år har rapportert tidsforbruk og kostnader i sin halmforsyning. Seks av brukerne benyttet rundballer og sats-fyrte anlegg, mens en benyttet store firkantballer og anlegg med kontinuerlig innmating.....
Sammendrag
Langsiktige klippeforsøk ved Skog og landskap viser at både nobeledelgran og fageredelgran kan produsere mye dekorasjonsbar, mens fjelledelgran og nordmannsedelgran er svakere produsenter. Alle treslagene har imidlertid gitt mye flott bar til kransebinding. Edelgranene har god nåleholdbarhet, og nobeledelgran er i en særklasse.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
The species composition of wood-inhabiting fungi (polypores and corticoids) was investigated on 1138 spruce logs and 992 pine logs in 90 managed and 34 natural or near-natural spruce and pine forests in SE Norway. Altogether, the study included 290 species of wood-inhabiting fungi. Comparisons of logs with similar properties (standardized tree species, decay class, dimension class) in natural and managed forests showed a significant reduction in species number per log in managed spruce forests, but not in managed pine forests. The species number per log in managed spruce forests was 10–55% lower than on logs from natural spruce forests. The reduction was strongest on logs of large dimensions. A comparison of 200–400 spruce logs from natural and managed forests showed a 25% reduction in species richness corresponding to a conservative loss of ca. 40 species on a regional scale. A closer inspection revealed that species confined to medium and very decayed spruce logs were disfavored in managed forests, whereas species on early decay classes and decay generalists were unaffected. Similarly, species preferring large spruce logs were disfavored in managed forests. Forest management had strongest impact on low-frequent species in the spruce forests (more than 50% reduction), whereas common species were modestly affected. Corticoid fungi were more adversely affected than polypore fungi. These results indicate that wood-decaying fungi in pine forests are more adapted to forest disturbances than spruce-associated species. Management measures securing a continuous supply of dead wood are more important in spruce forests than in pine forests.
Sammendrag
Utvalget av biologisk verdifulle skogtyper er dels basert på viktige naturtyper etter DNs Håndbok 13, på livsmiljøer i skog med høy forekomst av rødlistearter, på prioriterte skogtyper for vern, samt Artsdatabankens rødlistete skogtyper etter inndelingen i Naturtyper for Norge (NiN). Identifi-kasjon og forekomst av disse ulike skogtypene kan dels baseres på underliggende økologiske gradienter, spesielt for næringstilgang og fuktighet, på bioklimatiske gradienter (oseanitet), på skogtilstand (alder) og på forekomst av spesielle terrengforhold eller voksesteder (som bekkekløf-ter). For å gjenkjenne tilsvarende skogtyper med utgangspunkt i Landsskogtakseringens data har vi forenklet kriteriene og tilpasset disse til Landsskogtakseringens parametere som vegetasjons-type, bonitet, alder/hogstklasse, bestandstreslag, og klimasone. Enkelte spesielle naturforhold som bekkekløfter finnes også hos Landsskogtakseringen. Med disse utvalgskriteriene utgjør summen av biologisk verdifulle skogarealer 27% av det totale skogarealet, der lavproduktiv eldre løvskog alene utgjør mer enn 15% av skogarealet og øvrige skogtyper hver utgjør 2-4%. Dette utvalget av skogtyper omfatter også skogarealer med begrenset verdi for biomangfoldet. De biologisk verdifulle skogtypene (definert for Landsskogtakseringens data) har omtrent tilsva-rende betydning som karbonlager og i opptak av CO2 som øvrig skog med tilsvarende produktivi-tet. De største karbonlagrene pr arealenhet finnes i gammel skog, spesielt gammel granskog og eldre løvskog med edelløvtrær, mens lavproduktiv eldre løvskog har lavest karbonlager pr areal-enhet. Summert over arealet av hver skogtype er det imidlertid eldre løvskog, både på lavproduk-tiv og mer produktiv mark, samt gammel gran- og furuskog som representerer de største karbon-lagrene. Årlig CO2-opptak pr arealenhet er knyttet til mer produktiv skog, som rik løv- og barskog og produktiv eldre løvskog, og lavest for lavproduktiv løvskog. Gammel gran- og furuskog og eld-re kystskog har middels CO2-opptak. Summert over hele arealet for hver skogtype er det eldre boreal skog og rik løvskog som har høyest årlig CO2-opptak.
Forfattere
Robin Engler Christophe E. Randin Wilfred Thuiller Stefan Dullinger Niklaus E Zimmermann Miguel B. Araujo Peter B. Pearman Gwenaëlle Le Lay Christian Piedallu Cécile H. Albert Philippe Choler Georghe Coldea Xavier De Lamo Thomas Dirnböck Jean-Claude Gegout Daniel Gómez-García John-Arvid Grytnes Einar Heegaard Fride Høistad Schei David Nogues-Bravo Signe Normand Mihai Puscas Maria Teresa Sebastia Angela Stanisci Jean-Philippe Theurillat Mandar R. Trivedi Pascal Vittoz Antoine GuisanSammendrag
Continental-scale assessments of 21st century global impacts of climate change on biodiversity have forecasted range contractions for many species. These coarse resolution studies are, however, of limited relevance for projecting risks to biodiversity in mountain systems, where pronounced microclimatic variation could allow species to persist locally, and are ill-suited for assessment of species-specific threat in particular regions. Here, we assess the impacts of climate change on 2632 plant species across all major European mountain ranges, using high-resolution (ca. 100 m) species samples and data expressing four future climate scenarios. Projected habitat loss is greater for species distributed at higher elevations; depending on the climate scenario, we find 36–55% of alpine species, 31–51% of subalpine species and 19–46% of montane species lose more than 80% of their suitable habitat by 2070–2100. While our high-resolution analyses consistently indicate marked levels of threat to cold-adapted mountain florae across Europe, they also reveal unequal distribution of this threat across the various mountain ranges. Impacts on florae from regions projected to undergo increased warming accompanied by decreased precipitation, such as the Pyrenees and the Eastern Austrian Alps, will likely be greater than on florae in regions where the increase in temperature is less pronounced and rainfall increases concomitantly, such as in the Norwegian Scandes and the Scottish Highlands. This suggests that change in precipitation, not only warming, plays an important role in determining the potential impacts of climate change on vegetation.
Forfattere
Fride Høistad ScheiSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag