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
Abstract
No abstract has been registered
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.
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.
Abstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Sara Alva-Lizarraga Karen Refsgaard Thomas G. JohnsonAbstract
No abstract has been registered
Editors
Sjur Baardsen John Marshall Bryden Karen Refsgaard Kjersti Nordskog Katja Strøm Cappelen Helene Lie Arezoo SoltaniAbstract
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Abstract
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Authors
Tibor Ferenczi Kenneth J. Thomson John Marshall BrydenAbstract
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Authors
Johannes BreidenbachAbstract
Digital aerial images over Vestfold county were acquired by TerraTec in summer 2007 with a Vexcel UltraCamX sensor. The flying height above-ground was approximately 2800-3000 m which resulted in images of approximately 1880x2880 m size. The images were acquired in north-south oriented flight strips with a 20% side and 60% within-strip overlap. Panchromatic image data were acquired in 20 cm ground sampling distance (GSD). Near infrared, red, green and blue image bands were acquired in 60 cm GSD but were pansharpened to a 20 cm pixel size by the data vendor. The original radiometric resolution of the images (12 bit) was resampled to 8 bit for archival storage. The plane location and orientation during image acquisition were logged using a GPS and an inertial navigation system (INS). To increase the accuracy of the external orientation, an aerial triangulation was performed based on 34 ground control points using the software Match-AT.