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.
2007
Abstract
No abstract has been registered
Abstract
Studies of defense mechanisms in Norway spruce Picea abies against the spruce bark beetle Ips typographus show that inducible defenses are triggered by unsuccessful beetle attacks. Moreover, spruce trees can be vaccinated against bark beetle attacks through stem bark inoculation with Ceratocystis polonica, an aggressive fungal associate of Ips typographus. Artificial inoculation with certain other fungi has a similar effect, making treated trees a tougher mach for attacking beetles. A similar enhancement of resistance can be achieved by stem surface treatment with methyl jasmonate. Enhanced resistance is associated with the formation of traumatic resin ducts, and mobilization of phenolic substances in living parenchyma cells. The phenolics appear to mix with the traumatic resin. Similar mechanisms are operating in other conifers. We hypothesize that unsuccessful beetle attacks produce a vaccination effect in the trees, enhancing their resistance to later attack. Adding the effect of induced resistance as a model factor shows an immediate effect on the population dynamics of Ips typographus.
Authors
Inge Stupak Antti Asikainen M. Jonsell Erik Karltun Anders Lunnan D. Mizaraite K. Pasanen H. Pärn Karsten Raulund-Rasmussen Dominik Röser M. Schröder I. Varnagiryte L. Vilkriste Ingeborg Callesen Nicholas Clarke Talis Gaitnieks Morten Ingerslev M. Mandre R. Ozolincius Anna Saarsalmi Kestutis Armolaitis Heljä-Sisko Helmisaari A. Indriksons L. Kairiukstis K. Katzensteiner Mikko Kukkola K. Ots Hans Peter Ravn Pekka TamminenAbstract
The substitution of biomass for fossils fuels in energy consumption is a measure to mitigate global warming, as well as having other advantages. Political action plans for increased use exist at both European and national levels. This paper briefly reviews the contents of recommendations, guidelines and other synthesis publications on sustainable use of forest biomass for energy. Topics are listed and an overview of advantages, disadvantages and trade-offs between them is given, from the viewpoint of society in general and the forestry and energy sectors in particular. For the Nordic and Baltic countries, the paper also identifies the extent to which wood for energy is included in forest legislation and forest certification standards under the “Programme for the Endorsement of Forest Certification” (PEFC) and the “Forest Stewardship Council” (FSC) schemes. Energy and forest policies at EU and national levels, and European PEFC forest standards are analysed. With respect to energy policies, the utilisation of wood for energy is generally supported in forest policies, but forest legislation is seldom used as a direct tool to encourage the utilisation of wood for energy. Regulations sometimes restrict use for environmental reasons. Forest certification standards include indicators directly related to the utilisation of wood for energy under several criteria, with most occurrences found under environmental criteria. Roles and problems in relation to policy, legislation, certification standards, recommendations and guidelines, and science are discussed.
Abstract
River floods may cause considerable damage. Water management strategies intend tomoderate or mitigate the severe effects of extreme discharge events. In this context,techniques for the detection and attribution of changes is of crucial importance. Extremeflood events seem to occur more frequently in recent decades in central Europe.It is anticipated that climate change and weather regime shifts may contribute to this...
Authors
Carl Gunnar FossdalAbstract
In collaboration with the NARC platform at Ås, we have taken the Norway spruce phytochrome and PaChi4 promoters and introduced them into Arabidopsis using GFP and YFP expression vectors in order to study their effect on expression under long and short day treatment. Said in other words we use of GFP and YFP as reporters and Arabidopsis as a host for the Norway spruce promoters in order to study their possible regulation by day-length in this model plant system. In completely separate experiments in collaboration with the NARC platform at Ås, we have introduced the Norway spruce glycohydrolase PaChi4 into Arabidopsis to examine what effect this might have on the response to wounding and to pathogens. The PaChi4 enzyme is produced at very high levels in tissues with high level of host cell death (PCD) following fungal infections and it might be a marker for or directly involved in PCD. We have obtained transgenic plants and the first examination for any day-length dependent expression of the GFP and YFP reporters in the transgenic Arabidopsis lines is currently being pursued while the examination of the PAChi4 enzyme overexpressing lines are yet to be initiated.
Abstract
Ecological studies are often confronted with short and fragmented or unevenly sampled time series. Examples are, e.g., time series of biogeochemical fluxes measured on a variety of scales. Characterizing the observed time series patterns, particularly the correlation structure is crucial for an integrated ecosystem assessment or possibly for improved processes understanding.
Authors
John Derome Per Arild Aarrestad Paul Aspholm Vegar Bakkestuen Jarle Werner Bjerke Kjell Einar Erikstad Minna Hartikainen Ludmila Isaeva Martti Lindgren Antti-Jussi Lindroos Tor Myking Jarmo Poikolainen Pasi Rautio Ingvald Røsberg Maija Salemaa Hans Tømmervik Natalya VassilievaAbstract
No abstract has been registered
Authors
Pavel Cudlín Barbara Kieliszewska-Rokicka Maria Rudawska Tine Grebenc Odair Alberton Tarja Lehto Mark R. Bakker Isabella Børja Bohdan Konôpka Tomasz Leski Hojka Kraigher Thomas W. KuyperAbstract
No abstract has been registered
Authors
Holger LangeAbstract
The net ecosystem productivity (NEP) of a sequence of threemonoaged Norway spruce stands located in southeast Norway is modelled using the biogeochemical model Biome-BGC. For calibration, we use estimated biomass stocks at the plot level and Leaf Area Index measurements. The model is run for 30 years of historical temperature measurements as well as for a regional climate scenario. It is shown that under current conditions, NEP develops from negative values for a young stand (30 years) to clearly positive for a middleaged (60 years) to slightly negative again for a very old and decaying stand (120 years). However, the old stand benefits substantially from the predicted increased temperatures in the climate scenario, rendering NEP positive again. For the 30 and 60 years stands, almost no change is predicted from Biome-BGC.
Abstract
Furfurylated wood has shown to have promising properties for a wood modification agent during the last years. In this paper, an alternative curing method for furfuryl alcohol modified pine sapwood by means of microwave radiation was investigated. Different process parameters of microwave treatment such as output power, exposure time to microwave radiation, initial wood moisture content and evaporation during treatment, were tested. The weight percent gain of pine wood samples due to polymerised furfuryl alcohol was investigated by means of thermo gravimetric analysis. Leaching of furfuryl treated and differently cured samples gave information about the degree of fixation. No distinct influence of initial moisture content could be stated. A slight tendency of improving the degree of fixation by increasing the consumption energy of wood samples due to microwave energy was found. Changing the evaporation ability of samples during microwave treatment by using plastic foil had no distinct influence. Fixation of furfuryl alcohol could be improved by microwave treatment, and a degree of fixation above 90 % was calculated. However, the fixation was lower than in oven cured samples.