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.
2015
Authors
Zhibo Hamborg Gry Skjeseth Abdelhameed Elameen Sissel Haugslien Astrid Sivertsen Jihong Liu Clarke Qiao-Chun Wang Dag-Ragnar BlystadAbstract
No abstract has been registered
Authors
Peter Waldner Anne Thimonier Elisabeth Graf Pannatier Sophia Etzold Maria Schmitt Aldo Marchetto Pasi Rautio Kirsti Derome Tiina M. Nieminen Seppo Nevalainen Antti-Jussi Lindroos Päivi Merilä Georg Kindermann Markus Neumann Nathalie Cools Bruno de Vos Peter Roskams Arne Verstraeten Karin Hansen Gunilla Pihl Karlsson Hans-Peter Dietrich Stephan Raspe Richard Fischer Martin Lorenz Susanne Iost Oliver Granke Tanja G. M. Sanders Alexa Michel Hans-Dieter Nagel Thomas Scheuschner Primož Simončič Klaus von Wilpert Henning Meesenburg Stefan Fleck Sue Benham Elena Vanguelova Nicholas Clarke Morten Ingerslev Lars Vesterdal Per Gundersen Inge Stupak Mathieu Jonard Nenad Potočić Mayte MinayaAbstract
No abstract has been registered
Authors
Zhibo Hamborg YeonKyeong Lee Carl Jonas Jorge Spetz Jihong Liu Clarke Qiaochun Wang Dag-Ragnar BlystadAbstract
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Authors
Magnus Lund Jarle W. Bjerke Bert G. Drake Ola Engelsen Georg Heinrich Hansen Frans-Jan W. Parmentier Thomas Powell Hanna Marika Silvennoinen Matteo Sottocornola Hans Tømmervik Simon Weldon Daniel RasseAbstract
Creative Commons Attribution 3.0 license
Authors
O. Janne Kjønaas Nicholas Clarke Toril Drabløs Eldhuset Ari Hietala Hugh Cross Kjersti Holt Hanssen Tonje Økland Holger Lange Jørn-Frode Nordbakken Ingvald RøsbergAbstract
Tree harvest and different harvesting methods may affect the soil carbon (C) pool in forest ecosystems. In con- ventional stem-only timber harvesting (SOH), branches and tops that are left in the forests may contribute to the build-up of the soil carbon pool. In whole-tree harvesting (WTH), inputs of organic matter from branches and tops are strongly reduced. We established field experiments at Gaupen, SE and Vindberg, SW Norway, to study the short-term effects of SOH and WTH on processes affecting the accumulation and loss of soil C. Logging residues on the WTH plots were collected in piles that were removed after 6 months, rendering two sub treatments (WTH- pile and WTH-removal areas). We weighed selected trees and logging residues, surveyed understorey biomass production, quantified pre-harvest soil C and nutrient pools down to 30 cm. Soil respiration was measured and soil water sampled monthly during the growing season, while temperature and moisture were measured continuously. Organic and mineral horizons were incubated at different temperatures to estimate potential C and N mineraliza- tion, and deep sequencing of the ITS2 barcode region of fungal DNA was performed on the samples. Litterbags were deployed in the SOH plots. The logging residues amounted to 2.2-2.4 kg C m-2 At Gaupen, the mean in situ soil respiration rates increased following harvest with all treatments, but were significantly higher in WTH-pile and SOH relative to the WTH- removal areas in the first year as well as the fourth year of treatment. The former rates included aboveground decomposing needles and twigs but excluded coarser branches. The observed increase in the WTH-removal areas may be related to decomposing roots, as well as to increased C mineralization partly due to the higher soil tem- peratures following harvest. Soil temperature was the single most important factor explaining the variability in soil respiration rates over all treatments. At Vindberg, a decrease in soil respiration was observed with all treatments in the second and third years following harvest. At both sites, decomposition of logging residues from needles was more rapid relative to twigs and fine roots. The decomposing residues released a substantial amount of nitrogen which was gradually reflected in the soil water at 30 cm soil depth. A considerable increase in the NO3-N concen- tration also in the WTH-removal areas in the second year following harvest suggests an increase in N availability from decomposing fine roots and/or soil organic matter. The increased N availability in the WTH-removal areas was supported by results from short term lab incubations of undisturbed soil from the forest floor. The changes in the WTH-removal areas were also reflected in the soil fungal diversity: saprophytic ascomycetes on decaying plant material showed a striking increase in all treatments. For the WTH-removal areas, this may, again, be related to the increased input of root litter; however, the decrease in mycorrhizal basidiomycete species and the vigorous increase of ascomycetes following harvest may also affect the C mineralization of soil organic matter.
2014
Authors
O. Janne Kjønaas Nicholas Clarke Toril Drabløs Eldhuset Kjersti Holt Hanssen Ari Hietala Holger Lange Jørn-Frode Nordbakken Tonje Økland Ingvald RøsbergAbstract
No abstract has been registered
Authors
Tonje Økland Jørn-Frode Nordbakken Holger Lange Ingvald Røsberg O. Janne Kjønaas Nicholas Clarke Kjersti Holt HanssenAbstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
M Ashraful Islam Danuse Tarkowska Jihong Liu Clarke Dag-Ragnar Blystad Hans Ragnar Gislerød Sissel Torre Jorunn Elisabeth OlsenAbstract
No abstract has been registered
Authors
Zhibo Hamborg Sissel Haugslien Jihong Liu Clarke Carl Jonas Jorge Spetz Dag-Ragnar Blystad Qing Wang YeonKyeong Lee Astrid H Sivertsen Gry SkjesethAbstract
Chrysanthemum stunt viroid (CSVd) was first reported in US in the 1940s and is widespread in the world wherever chrysanthemum is grown. Cryotherapy of shoot tips, a new biotechnology developed in the recent years, is a novel application of plant cryopreservation techniques that allows pathogen eradication at a high frequency. Existing studies have proven that this technique can efficiently eradicate pathogens such as virus, phytoplasma and bacterium. However, up to now, there has been no report on viroid eradication. In the present study, we attempted to establish a droplet vitrification cryotherapy method for Argyranthemum and to apply it to eradicate CSVd. Results obtained so far demonstrated that cryotherapy of shoot tips alone failed to eradicate CSVd from the infected shoot tips of Argyranthemum maderense ‘Yellow Empire’. Using in situ hybridization of CSVd and histological analysis, we found that CSVd can invade meristematic cells and at the same time, these cells were able to survive following cryotherapy. These findings explained why cryotherapy of shoot tips alone could not be efficient enough to eradicate CSVd from the diseased materials. Further studies combining cold treatment with cryotherapy are under investigation for CSVd eradication.