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.
2020
Authors
Ralf RautenbergerAbstract
The commercial cultivation of marine macroalgae is a young and rapidly growing industry sector in Norway. Although it is currently limited to a few brown macroalgae, other species such as the green marine macroalga Ulva fenestrata (formerly Ulva lactuca) has also a high potential for an industrial biomass production, for example to be used for the food marked. However, this process is strongly affected by the presence of marine diatoms transported along with the seawater into the cultivation system of U. fenestrata. These diatoms not only proliferate in the water tanks, they also colonise the green macroalgal biomass with many brown spots, which reduces its value for the food marked significantly. This presentation shows the results of a project that studied the use of germanium dioxide (GeO2) as a known growth inhibitor of diatoms to control their contamination during the biomass production process of U. fenestrata. First, the co-occurring diatom was morphologically identified as Fragilaria sp. using light microscopy. Thereafter, a dose-response experiment was conducted to reveal the concentrations of GeO2, resulting in an effective growth inhibition of Fragilaria sp. Based on this knowledge, the impact of different GeO2 concentrations was studied on how the photophysiolgy (photosynthetic characteristics, pigment patterns) and growth of U. fenestrata are affected in both small-scale (2 L) and large-scale (100 L) cultivation systems. An effective control of the proliferation of Fragilaria sp. during the cultivation process of U. fenestrata may result in the production a high-quality biomass with a high value for the food marked.
Authors
Melesse Eshetu Moges Arve Heistad Thorsten HeidornAbstract
No abstract has been registered
Authors
Haftamu Gebretsadik Gebrehiwot Jens Bernt Aune Jan Netland Ole Martin Eklo Torfinn Torp Lars Olav BrandsæterAbstract
No abstract has been registered
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No abstract has been registered
Abstract
The abstract classification system Nature in Norway (NiN) has detailed ecological definitions of a high number of ecosystem units, but its applicability in practical vegetation mapping is unknown because it was not designed with a specific mapping method in mind. To investigate this further, two methods for mapping – 3D aerial photographic interpretation of colour infrared photos and field survey – were used to map comparable neighbouring sites of 1 km2 in Hvaler Municipality, south-eastern Norway. The classification accuracy of each method was evaluated using a consensus classification of 160 randomly distributed plots within the study sites. The results showed an overall classification accuracy of 62.5% for 3D aerial photographic interpretation and 82.5% for field survey. However, the accuracy varied for the ecosystem units mapped. The classification accuracy of ecosystem units in acidic, dry and open terrain was similar for both methods, whereas classification accuracy of calcareous units was highest using field survey. The mapping progress using 3D aerial photographic interpretation was more than two times faster than that of field survey. Based on the results, the authors recommend a method combining 3D aerial photographic interpretation and field survey to achieve effectively accurate mapping in practical applications of the NiN system.
Authors
Andreas TreuAbstract
No abstract has been registered
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No abstract has been registered
Authors
Philipp Lehmann Tea Ammunet Madeleine Barton Andrea Battisti Sanford D. Eigenbrode Jane Uhd Jepsen Gregor Kalinkat Seppo Neuvonen Pekka Niemelä John S. Terblanche Bjørn Økland Christer BjörkmanAbstract
No abstract has been registered
Abstract
No abstract has been registered