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.
2019
Forfattere
Andreas Treu Katrin Zimmer Christian Brischke Erik Larnøy Lone Ross Foued Aloui Simon M. Cragg Per-Otto Flæte Miha Humar Mats Westin Luisa Borges John WilliamsSammendrag
Timber structures in marine applications are often exposed to severe degradation conditions caused by mechanical loads and wood-degrading organisms. This paper presents the use of timber in marine environments in Europe from a wood protection perspective. It discusses the use of wood in coastline protection and archeological marine wood, reviews the marine borer taxa in European waters, and gives an overview of potential solutions for protection of timber in marine environments. Information was compiled from the most relevant literature sources with an emphasis on new wood protection methods; the need for research and potential solutions are discussed. Traditionally, timber has been extensively utilized in a variety of marine applications. Although there is a strong need for developing new protection systems for timber in marine applications, the research in this field has been scarce for many years. New attempts to protect timber used in marine environments in Europe have mainly focused on wood modification and the use of mechanical barriers to prevent colonization of marine wood borers. The importance of understanding the mechanisms of settlement, migration, boring, and digestion of the degrading organisms is key for developing effective systems for protecting timber in marine environments.
Sammendrag
We grew young sweet cherry (Prunus avium L.) trees under controlled temperature and natural summer daylight conditions in order to study the control of flowering of the species. Two experiments with the cultivars ‘Lapins’ and ‘Van’, were conducted and compared with field results with the same cultivars at Ås in southeast Norway (59° 40′N, 10° 50′E, 90 m a.s.l.). Shoot growth increased with increasing temperature in the 12–21 °C range, but ceased in late summer (August) regardless of temperature conditions. A marked drop in temperature always induced an immediate cessation of growth. Under field conditions at Ås, both growth cessation and floral initiation took place by about 1 August. Low temperature (12–15 °C) significantly enhanced flowering of both cultivars compared with 21 °C, which tended to depress flower bud formation during the summer but stimulated the subsequent flower differentiation process. These results concur with earlier regression analyses, which revealed a close positive correlation between historical records of sweet cherry yields over a 40-year period in farmer’s fields in the fjord districts of western Norway and previous year August-September temperature, and a negative correlation with previous year July temperature. Practical implications of the results are discussed and it is suggested that inadequate temperature control in rain-protected cultivation in plastic tunnels might have negative consequences for next year’s flowering and yield.
Sammendrag
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Sammendrag
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Sammendrag
The genus Scapania comprises a group of leafy liverworts distributed throughout many bryophytic assemblages. While many Scapania species grow widely, some are assessed as endangered and appear to be specialists with distinct niche environments. Several are found only in alpine forest communities, inhabiting decaying logs in streams, typical of an environment that is threatened by both logging activity and changes to watercourses. Another species, S. nimbosa, has an unusual Oceanic-Montane distribution across Ireland, Scotland, Norway, China and Nepal. Since gemmae and sexual reproduction are absent the species is hypothesized to be primarily dispersed by fragmentation. In Norway S. nimbosa occupies an area of only 13 x 20 km, at altitudes between 300-980 m, and is frequently found with another more abundant asexual species, S. ornithopodioides. This makes S. nimbosa susceptible to local extinction through climate change or perhaps interspecific competition. Genomics is being increasingly used to infer demography and the evolutionary history of a species. Ascertaining levels of genetic variation can also contribute towards an effective conservation management plan. Besides, very little is known about the genomic organization and sexual determination in leafy liverworts. To generate new knowledge about the genus Scapania we sequenced the genomes of the sexual species S. nemorea (both male and female isolates), S. undulata (a single isolate), and several asexual S. ornithopodiodes and S. nimbosa isolates. Illumina paired-end (2x 300 bp) and Oxford Nanopore long reads were used to create genomic references. Initially organellar genomes were assembled, annotated and genetic variation was discovered. This revealed that variation is indeed present even for S. nimbosa and S. ornithopodioides at Norwegian sites. Next we focussed on creating a high quality nuclear reference genome for S. nemorea using the SPAdes assembler (v3.13). Qualities of each assembly and isolate were assessed with QUAST and BUSCO. While one assembly spans 202.6 Mb (10930 scaffolds; N50 of 66 Kb), other isolates of S. nemorea show larger assembled genome sizes and different Kmer distributions, consistent with the expected alternative sexual chromosome complement. We further analyse genomic synteny and diversity, but emphasize that difficulties in extracting DNA from herbarium specimens really hamper analysis.
Forfattere
Sille Rebane Kalev Jõgiste Eneli Põldveer John A. Stanturf Marek MetslaidSammendrag
Boreal and temperate forests cover a large part of the Earth. Forest ecosystems are a key focus for research because of their role in the carbon (C) balance and cycle. Increasing atmospheric temperatures, different disturbances (fire, storm and insects) and forest management (clear-cutting) will change considerably the C status of forest ecosystems. Using the eddy covariance (EC) method, we can define interactions among environmental factors that influence the C-balance and whether a forest ecosystem is functioning as a C-sink or C-source or possibly is C-neutral. In our review of published studies of different disturbances, we found that most of the post-disturbance studies based on EC method focused on the effects of forest fire and clear-cutting, only a few studies studies focused on the effects of storms and insects. Generally a forest is a C-source until several years after disturbance and then a forest is able to absorb C and become a C-sink. Recovery to C-sink status required up to 20 years in clear-cut areas. Recovery following wildfire disturbance was much longer, possibly more than 50 years. Recovery to C-sink status required approximately 5 years after storm and insect outbreak, however we can not predict overall recovery period because of the missing data.
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Forfattere
Milica Fotiric Aksic Uros Gasic Dabic Zagorac Dragana Milica Sredojevic Tomislav Tosti Maja Natic Mekjell MelandSammendrag
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Forfattere
Kjell Handeland Rebecca K. Davidson Hildegunn Viljugrein Anders Mossing Erling Meisingset Marianne Heum Olav Strand Ketil IsaksenSammendrag
Nematodes of the genera Elaphostrongylus and Dictyocaulus are associated with disease in semi-domesticated tundra reindeer and farmed red deer whereas less knowledge exists in the wild. Their first stage larvae (L1) develop to the infective third stage (L3) in the environment; Elaphostrongylus spp. within intermediate gastropod hosts and Dictyocaulus spp. as free-living larvae. Larval development of Elaphostrongylus is highly temperature dependent with a developmental minimum of 9–10 °C. Larval development of Dictyocaulus spp. may occur at low temperatures (5 °C) but the larvae are sensitive to desiccation. We examined the prevalence and intensity of Elaphostrongylus spp. and Dictyocaulus spp. infections in six wild reindeer and two wild red deer populations in relation to altitude, temperature and rainfall in their respective main summer pasture area over the 5 summers prior to sampling. The parasitological examination was based upon morphological identification of L1 in the faeces of hunted animals. Altitude was calculated from animal position data and temperature and precipitation by means of a nationwide gridded data set. Temperature decreased with increasing altitude, from 13.3 °C for the lowest located red deer population (300 m) to 6.1 °C for the highest located reindeer population (1400 m). No significant relationship between altitude and rainfall was identified. Elaphostrongylus spp. infection decreased in prevalence with increasing altitude, being identified in 89% of investigated samples from the lowest located population and in 3% of samples from the highest. The prevalence of Dictyocaulus spp. infection varied between 28 and 80% and no relationship with altitude was found. The intensity of Elaphostrongylus spp. infection was low in reindeer and moderate in red deer whereas the intensity of Dictyocaulus spp. infection was moderate in both species. Our results indicated that the climatic conditions in all areas studied were suitable for Dictyocaulus spp., whereas summer temperature was a restrictive factor for Elaphostrongylus sp. in reindeer.
Forfattere
David Natcher Yang Yang Jill Hobbs Kristin Beate Hansen Florent Govaerts Silje Elde Ingrid Kvalvik Bjørg Helen Nøstvold Rune Rødbotten Sigridur Dalmannsdottir Hilde Halland Eivind Uleberg Ólafur Reykdal Jón Árnason Páll Gunnar Pálsson Rakel Halldórsdóttir Óli Þór Hilmarsson Gunnar Þórðarson Þóra ValsdóttirSammendrag
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