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.
2017
Sammendrag
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Sammendrag
The Christmas tree industry in Norway is increasing and Abies lasiocarpa is, together with Abies nordmanniana, the most common exotic species for Christmas tree production. A. lasiocarpa today constitutes ca. 50% of the fir sold in Norway, and there is high demand for sufficient supply of high-quality seed and knowledge of seed sources with a potential for high Christmas tree quality. Two experimental plots were established to identify seed sources with potentially high survival and satisfactory Christmas tree quality. The high variation in traits on the two sites indicates promising possibilities for further selection of A. lasiocarpa clones for growing Christmas trees in Norway. Selection for late bud break to avoid spring frost is important. Pathogens were not found in any of the studied trials, but are an important factor to consider when selecting seed sources for Christmas trees. Due to the early bud break of this species, it is also of high importance to choose planting sites with minimal risks for spring frost. Good localities are slopes where the frost drains away during cold nights. In eastern Norway, A. lasiocarpa should be used with care in districts and sites where spring frost is commonly occurring.
Forfattere
Christian PedersenSammendrag
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Forfattere
Lone RossSammendrag
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Forfattere
Lone RossSammendrag
Det er ikke registrert sammendrag
Sammendrag
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Sammendrag
Fire blight, caused by Erwinia amylovora, was detected for the first time in Norway in 1986. It was a limited outbreak on the south-western coast, only on ornamentals, and particularly on Cotoneaster spp. An action group handling the eradication and containment of the disease was quickly established. Comprehensive statutory powers and resources were given by the government to do surveys and eradicate diseased or symptomless but highly susceptible plant species from contaminated areas. These activities have likely restricted fire blight to the western and southern coastal areas. Eastern and northern parts of Norway are considered free from fire blight. The disease has not been observed in important fruit-growing areas. Uncontrolled movement of beehives from areas with fire blight to areas free from the disease has contributed to its introduction to new areas. From 1969 to 2016 import of most host plants of E. amylovora from countries with fire blight was prohibited. A yearly program for annual surveys in parts of the country with commercial fruit-growing and nurseries, using digital maps on internet connected tablets with GPS and software for in situ registrations, proved to be an efficient method for discovering new outbreaks at an early stage, and to start eradication and thus limit further spread.
Sammendrag
Knowing the historical variation in fire regimes is instrumental in managing forests today and in predicting what may happen in the future. By cross-dating 745 fire scars in 378 samples of remnant Scots pines, we delineated 254 individual forest fires during the past 700 years in a 74-km2 section of Trillemarka-Rollagsfjell Nature Reserve in south-central Norway. Fire sizes, numbers, burn rates, and frequencies were compared with historical climate proxies, vegetation maps, and written sources. The results revealed patterns consistent with a predominantly climate-driven fire regime up to 1625, followed by periods of strong anthropogenic influence that increased fire frequency during 1600–1700s and diminished fires during 1800–1900s. This was documented by an abrupt increase in number of small fires from the early 1600s that markedly shortened fire intervals from a median of 73 to 37 yr. This shift in fire frequency coincided with a sudden appearance of early-season fires from 1625 and onward. Whereas late-season burn rate increased with summer temperature, no such relationship was found for early-season fires. These results were corroborated by written sources that describe anthropogenic forest fires and slash-and-burn cultivation expanding with the increasing population from the late 1500s and subsequently diminishing due to increasing timber values during 1700–1800s. Whereas human activity strongly influenced the fire regime at multidecadal to centennial scales, it was the interannual variability in climate that triggered large fire events, especially during the pre-1625 period. Prior to 1625, the percentage of years with fire tripled from 7% during cold summers (10–12°C) to 21% during warm summers (14–16°C). Burn rate increased even more, from 0.01% to 1.3% for the same temperature intervals. Ecologically, the post-1625 period is remarkable in such a way that human activity, first by greatly increasing fire frequency and subsequently almost eradicating fires, possibly influenced the fire regime to such an extent that it may be unprecedented for millennia.
Forfattere
Tatsiana Espevig May Bente Brurberg Marina Usoltseva Åslög Dahl Agnar Kvalbein Karin Normann Jo Anne CrouchSammendrag
Det er ikke registrert sammendrag
Forfattere
Tatsiana Espevig May Bente Brurberg Marina Usoltseva Åslög Dahl Agnar Kvalbein Karin Normann Jo Anne CrouchSammendrag
Dollar spot is a destructive and widespread disease affecting most turfgrass species, but until recently it has been absent from the Scandinavian countries of northern Europe. In the fall of 2014, disease symptoms consistent with dollar spot were observed on a golf course fairway in Sweden. A fungus was isolated from symptomatic turf and identified as Sclerotinia homoeocarpa on the basis of ribosomal deoxyribonucleic acid (rDNA) internal transcribed spacer (ITS) sequences, morphology, and culture characteristics. The ITS sequence was identical to isolates of S. homoeocarpa from the eastern and midwestern United States. Koch’s postulates were fulfilled, confirming the S. homoeocarpa isolate as the causal agent. This is the first report of turfgrass dollar spot in Sweden and only the second report of the disease from Scandinavia. Because pesticides are rarely used in the cultivation of Scandinavian turfgrass, dollar spot disease may prove difficult to control through conventional means and potentially represents a major threat to the industry.