Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2011
Authors
Ingun Tryland Lucy J Robertson Anne-Grete Buseth Blankenberg Markus Lindholm Thomas Rohrlack Helge LiltvedAbstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Roman Gebauer Daniel Volařík Josef Urban Isabella Børja Nina Elisabeth Nagy Toril Eldhuset Paal KrokeneAbstract
Conifers and other trees are constantly adapting to changes in light conditions, water/nutrient supply and temperatures by physiological and morphological modifications of their foliage. However, the relationship between physiological processes and anatomical characteristics of foliage has been little explored in trees. In this study we evaluated needle structure and function in Norway spruce families exposed to different light conditions and transpiration regimes. We compared needle characteristics of sun-exposed and shaded current-year needles in a control plot and a thinned plot with 50% reduction in stand density. Whole-tree transpiration rates remained similar across plots, but increased transpiration of lower branches after thinning implies that sun-exposed needles in the thinned plot were subjected to higher water stress than sun-exposed needles in the control plot. In general, morphological and anatomical needle parameters increased with increasing tree height and light intensity. Needle width, needle cross-section area, needle stele area and needle flatness (the ratio of needle thickness to needle width) differed most between the upper and lower canopy. The parameters that were most sensitive to the altered needle water status of the upper canopy after thinning were needle thickness, needle flatness and percentage of stele area in needle area. These results show that studies comparing needle structure or function between tree species should consider not only tree height and light gradients, but also needle water status. Unaccounted for differences in needle water status may have contributed to the variable relationship between needle structure and irradiance that has been observed among conifers.
Abstract
Twenty cypress accessions were tested for freezing tolerance. After freezing to −15°C, differences among cypress accessions were tested by measuring electrolyte leakage and chlorophyll fluorescence. Based on these data, cypress accessions showing contrasting freezing tolerance were subjected to transcript profiling of candidate genes upon the development of cold hardening, with the ultimate goal of providing a scientific basis for selecting/breeding cypress genotypes with higher tolerance to low temperature. Nine different cypress genes were selected: a heat shock protein, a putative chaperonin, a chlorophyll-binding protein, a serine/threonine protein kinase, a putative exonuclease, a dehydrin, and three senescenceassociated proteins. Transcript levels of these genes were profiled during cold hardening under controlled conditions using real-time reverse-transcription-polymerase chain reaction. While the genes showed regulation patterns common to both cypress accessions, in the case of chaperonin, exonuclease, and some senescence-associated proteins, clonal differences in gene regulation were found. The potential relationship of these differences with cold tolerance is discussed.
Authors
Juul Limpens Gunilla Granath Urban Gunnarsson Rien Aerts S. Bayley L. Bragazza J. Bubier A Buttler L. J. L. van den Berg AJ Francez Renato Gerdol P. Grosvernier M. M. P. D. Heijmans M. R. Hoosbeek S. Hotes Mati Ilomets I. Leith Edward A.D. Mitchell T. Moore M. B. Nilsson Jørn-Frode Nordbakken L. Rochefort Håkan Rydin L. J. Sheppard M. Thormann M. M. Wiedermann B. L. Williams B. XuAbstract
Peatlands in the northern hemisphere have accumulated more atmospheric carbon (C) during the Holocene than any other terrestrial ecosystem, making peatlands long-term C sinks of global importance. Projected increases in nitrogen (N) deposition and temperature make future accumulation rates uncertain. •Here, we assessed the impact of N deposition on peatland C sequestration potential by investigating the effects of experimental N addition on Sphagnum moss. We employed meta-regressions to the results of 107 field experiments, accounting for sampling dependence in the data. •We found that high N loading (comprising N application rate, experiment duration, background N deposition) depressed Sphagnum production relative to untreated controls. The interactive effects of presence of competitive vascular plants and high tissue N concentrations indicated intensified biotic interactions and altered nutrient stochiometry as mechanisms underlying the detrimental N effects. Importantly, a higher summer temperature (mean for July) and increasedannual precipitation intensified the negative effects of N. The temperature effect was comparable to an experimental application of almost 4 g N m−2 yr−1 for each 1°C increase. •Our results indicate that current rates of N deposition in a warmer environment will strongly inhibit C sequestration by Sphagnum-dominated vegetation.
Authors
Eric N. Hansen Erlend Nybakk Lyndall Bull Pablo Crespell Arnaldo Jélvez Chris KnowlesAbstract
Softwood sawmilling is important to the economy of many nations and huge volumes of softwood lumber are produced annually. Accordingly, the economic success of softwood sawmills, as they compete with substitutes such as steel and concrete, is of interest to various industry stakeholders, especially managers, and researchers. Given the strong connection between innovativeness and firm performance in the literature, this study investigates innovativeness in sawmills in Australia, Canada, Chile, Norway, and the USA. Mail surveys were used in each of the countries to collect data regarding product, process, and business systems innovativeness and firm performance. Findings suggest that sawmills focus equally on product and process innovativeness, firm size positively impacts innovativeness, and that overall, process innovativeness is what drives firm performance in this sector. Findings suggest that managers should focus on being innovative since this positively impacts firm performance.
Authors
Tao Zhao Halvor Solheim Bo Langström Anna-Karin Borg-KarlsonAbstract
Introduction: Windstorm is one of the most destructive environmental disturbance factors on forests, but its influence on conifer defense chemistry and susceptibility to insects and diseases is not well understood. Materials and methods: We selected groups of 10 Norway spruce trees with short leaders, leaning stems, or no apparent damage 17 months after the largest storm ever recorded in Sweden. Trees were mass-inoculated with Ceratocystis polonica, a virulent blue stain fungus associated with the spruce bark beetle (Ips typographus) to estimate tree resistance. Terpene and phenolic composition in the bark was analyzed by gas chromatography–mass spectrometry, two-dimensional gas chromatography, and liquid chromatography. Results: In contrast to our hypothesis, the results showed that trees with no apparent damage were more susceptible to C. polonica inoculation than short-leader and leaningstem trees. Chemical composition also differed between trees in different damage classes. (+)-3-carene and two unidentified stilbenes were higher, and taxifolin glycoside was lower in trees without apparent damage than in the others. The relative amount of (−)-α-pinene was negatively correlated, whereas (+)-3-carene, sabinene, (−)-germacrene D, thunbergol and two unidentified stilbenes were positively correlated with fungal performance. Conclusions: These results suggested that wind damage had increased resistance level of short-leader and leaning trees to C. polonica inoculation, and that change in terpene and phenolic composition in the bark could be at least partly responsible for the induced resistance. Different possible explanations for this unexpected finding are discussed.
Abstract
No abstract has been registered
Authors
Geir-Harald StrandAbstract
A landscape region can be drawn on a map as a geographic feature with distinct boundaries. Reality is, however, that the change from one landscape to another usually is gradual and that landscapes therefore have uncertain or undetermined boundaries. A thematic map of landscape regions is therefore a too simple model of the landscape. An alternative approach is to consider landscape categories as purely theoretical concepts. With this perspective, a particular geographical location can be more or less affiliated with a number of different landscape categories. Such a conception of landscape does not lead to a traditional thematic map of uniform, non-overlapping regions, but to a landscape model composed of multiple overlapping probability surfaces. This article shows how such a landscape model can be established using binary logistic regression. The method is tested and the result is assessed against an existing landscape map of Norway much used in policy impact analysis in this country. The overall objective is to develop a data driven landscape model that can supplement, elucidate and for some purposes maybe even replace, the qualitative landscape description represented by the traditional landscape map.
Authors
Stig Strandli Gezelius Maria HauckAbstract
No abstract has been registered