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.
2004
Authors
Christer Magnusson Hans Overgaard Hans Nyeggen Karl Thunes Solveig Haukeland Bonsak HammeraasAbstract
In this survey of 2002, 600 samples were collected from 83 forest blocks in the counties Akershus, Buskerud, Oppland and Østfold. The sampling activity involved 16 municipallities situated mainly within the three zone sites A, B, and C. Samples from Scots pine (Pinus sylvestris) formed 89%, while samples of Norway spruce (Picea abies) made up 10% of the total sample volume. Timber and forest debris were the most common objects sampled. Sixty-five percent of the pine samples and 81% of the spruce samples showed signs of Monochamus activity. Nematodes were common and occurred in 94% of the samples analysed. Thirteen samples of pinewood were positive for the genus Bursaphelenchus. Bursaphelenchus mucronatus was recorded for the third time in Norway, and was detected in forest debris attacked by Monochamus at Bjørdalen in the municipality of Eidsberg in the county of Østfold. The pine wood nematode Bursaphelenchus xylophilus was not detected in this survey.
Abstract
In this survey of 2003, 600 samples were collected from 96 forest blocks in the counties of Aust-Agder and Vest-Agder in southern Norway. The sampling activity involved 19 municipalities situated mainly within the two zone sites D and E close to Kristiansand and Arendal. Samples from Scots pine (Pinus sylvestris) formed 92%, while samples of Norway spruce (Picea abies) made up 8% of the total sample volume. Timber and forest debris was the most common objects sampled. Ninety-eight percent of the samples, regardless of tree species, showed signs of Monochamus activity. Nematodes were common and occurred in 90% of the samples analysed. Eight samples of pinewood were positive for the genus Bursaphelenchus. This genus did not occur in spruce. Bursaphelenchus mucronatus was detected in 6 samples of forest debris of pine attacked by Monochamus and collected in the county of Aust-Agder. In the municipality of Evje and Hornes B. mucronatus was detected at Skjerkelia and Sutestad. In the municipality of Froland the nematode was found in two samples from Budalsfjellet, and in one sample from Mjålandsvatn. In the municipality of Birkenes one sample from Vågsdalen contained B. mucronatus. This is the fourth report on the occurrence of B. mucronatus in Norway. The pine wood nematode Bursaphelenchus xylophilus was not detected.
Authors
Karl Thunes John Skartveit Ivar Gjerde Josef Stary Torstein Solhøy Arne Fjellberg Sverre Kobro Sueo Nakahara R. Zur Strassen Gijsbertus Vierbergen Ryszard Szadziewski Daniel V. Hagan William. L. Grogan Jr Terje Jonassen Kjetil Aakra Johannes Anonby Lita Greve Berend Aukema Kai Heller Verner Michelsen Jean-Paul Haenni Alexandr F. Emeljanov Per Douwes Kai Berggren Jutta Franzen R. Henry L. Disney Sabine Prescher Kjell Arne Johanson Boris Mamaev Sigitas Podenas Stig Andersen Stephen D. Gaimari Emilia Narchuk Geir Einar Ellefsen Søli Laszlo Papp Fred Midtgaard Arild Andersen Michael von Tschirnhaus Gerhard Bächli Kjell Magne Olsen Hans A. Olsvik Mihaly Földvari Jan Emil Raastad Lars Ove Hansen Per DjursvollAbstract
No abstract has been registered
Authors
Carl Gunnar Fossdal Øystein Johnsen Nina Elisabeth Nagy R Baumann Jørgen A.B. Mølmann Tore SkrøppaAbstract
Introduction: Survival and competitive successes of boreal forest trees depend on a balance between exploiting the full growing season and minimising frost injury through proper timing of hardening in autumn and dehardening in spring. Our research indicates that the female parents of Norway spruce adjust these timing events in their progeny according to the prevailing temperature conditions during sexual reproduction. Reproduction in a cold environment advances bud-set and cold acclimation in the autumn and dehardening and flushing in spring, whereas a warm reproductive environment delays these progeny traits by an unknown non-Mendelian mechanism. We are now looking for molecular mechanisms that can explain this “epigenetic” phenomenon. Material and methods: We have performed identical crosses with the same Norway spruce (Picea abies) parent, as discussed by Skrøppa & Johnsen (1994) and Johnsen et al. (1995), in combination with timed temperature treatments during shorter and longer periods from female meiosis, pollen tube growth, syngamy and embryogenesis and tested the progenies for bud-set and frost hardiness. We have followed the transcription of the spruce phytochromes PHYO, PHYP and PHYN and the class IV chitinase PaChi4 using Quantitative Multiplex Real-Time PCR. Results and conclusions: The effect of temperature on Adaptive properties is most likely a response to accumulated heat during embryogenesis and seed maturation. Our first attempt to look for a molecular mechanism has revealed that transcription of PHYO, PHYP and PHYN and the class IV chitinase PaChi4 (relative to alphaTubulin) all show higher transcription levels in progenies born under cold conditions than their full-sibs born under warmer conditions. This result is consistent with preliminary findings that methylation of cytosine in total DNA is higher in progenies reproduce under warm conditions than their colder full-sib counterparts. If these observations are related to methylation or other epigenetic effects, we may explain why progenies with a memory of a past time cold embryogenesis are more sensitive to short days than their full-sibs with a warmer embryonic history.
2003
Authors
Yi He Jixi Gao Haiying Liu Zhengtao Liu Feng Liu Xiaoshan Zhang Jingheng Guo Yanhui Wang He Shang Pengtao Yu Jianhua Zhu Jingjun Han Bin Yao Xiyon Hu Xiaoquan Zhang Min Shao Limin Zeng Lei Jin Lei Duan Quanru Liu Dawei Zhao Dongbao Zhang Shengliang Chen Renjun Xiang Yi Chang Jinhong Zhang Jiahai Luo Zhanyi Zhang Jinsong Xiao Xiaoyu Peng Rolf David Vogt Hans Martin Seip Wenche Aas Kjetil Tørseth Jan Mulder Trine Sogn Odd Eilertsen Tonje Økland Harald Bratli Valter Angell Svein Solberg Tor Myking Espen Lydersen Thorjørn Larssen Dagang TangAbstract
Sulphur deposition is high at all IMPACTS sites and exceed maximum levels observed in Europe and North-America. Dry deposition equals or exceeds wet deposition. The IMPACTS data, in particular those from the remote Lei Gong Shan site clearly document long-range transport of air pollutants. Due to the actual and future energy combustion and emission strategy in China, the long-range transport of air pollutants may significantly increase with subsequent increased environmental damage in rural and remote areas in China. In addition to sulphur deposition, depositions of reactive nitrogen (nitric acid and ammonia) and calcium are also important and clearly demonstrate that pH alone is not a good indicator for acid deposition. High concentrations of ground level ozone, above critical levels for vegetation and forest, are observed at the Liu Xi He site in Guangdong province. Soil acidification gives rise to high concentrations of toxic aluminium in soil water at several sites. At the Tie Shan Ping site in Chongqing aluminium occurs at a level where long-term harmful effects on trees might be expected. Defoliation and mortality have been severe, however, fairly stable. Insect attacks are apparently a major cause, but enhanced insect attacks might be an indirect effect of health weakening due to acidification. Defoliation has been considerable also in Liu Chong Guan in Guiyang, while the three other catchments had minor defoliation only. High foliar nitrogen concentrations are seen in Lei Gong Shan in Guizhou and Cai Jia Tang in Hunan, accompanied by low P/N-ratios. Statistical tests of vegetation change, so far only implemented in Liu Chong Guan, revealed minor changes in number and abundances of vascular plants, but a significant decline in number of bryophytes. This decline is probably related to climatic year-to-year variations. Data from other catchments and longer time periods are needed to identify vegetation changes related to soil acidification or direct effects of air pollutants. Modelling results from Tie Shan Ping suggest that the currently planned 20% reduction in sulphur emissions is far from sufficient to avoid further acidification. As more data are generated, dose-response relationships, critical load estimates and model predictions will obviously be improved.
Abstract
Establishment, survival and height growth of sown and naturally regenerated Picea abies (L.) Karst. seedlings were examined in a 6 yr period in eight stands on bilberry woodland in south- east Norway. Five harvesting treatments (shelterwoods of high, medium and low density, 253/25 m patch-cut, 503/50 m clear-cut) and three scarification alternatives (unscarified, patch scarification, inverting) were combined in a split-plot design. Establishment, survival and plant height after 6 yrs were positively affected by scarification. Significant differences between patch scarification and inverting were not observed, although mortality tended to be lower, and seedlings slightly taller, after patch scarification. Establishment after natural seedfall was least successful on the clear-cut, but more or less equal at the other stand treatments. Height growth increased with decreasing overstorey retention, while there was a tendency towards lower survival on the clear-cuts and patch-cuts. Natural regeneration in the unscarified plots was unsuccessful after 6 yrs, while the different combinations of harvesting and scarification treatments usually gave sufficient regeneration.
Authors
Dominik Röser Antti Asikainen Simen Gjølsjø B. Jaskelevicius D. Johansson P. Jylhä L. Kairiukstis I. Konstantinova Jørn Kristian Lileng Anders Lunnan M. Mandre Juha Nurmi H. Pärn T. Saksa L. Sikanen Kjell Suadicani M. Totopainen L. VilkristeAbstract
The report is investigating the current state of forestry, forest industries and the bioenergy sector in Denmark, Estonia, Finland, Latvia, Lithuania, Norway and Sweden. The main task of the research is to illustrate the current supply and use of wood based fuels in the Baltic and Nordic countries. Additionally the present use of forest fuels in the different countries in the private and industrial sector is analyzed and bottlenecks in the current supply of forest fuels are identified. The focus on energy policy has been on energy systems with less CO2 emissions in order to meet requirement of international agreements. Therefore, forest fuels offer great potential as a source of renewable energy. There has been a steady increase in the growing stock of European forests. Large amounts of residues are left unutilised both in Nordic and Baltic forests, especially in first thinnings and intermediate cuttings. They offer large potential to further increase the share of wood fuels in total energy consumption. Forest industries utilize a great share of wood residues at present but especially in Baltic regions there is potential to intensify the use of wood residues. An additional increase in wood biomass utilization is also dependent on future expansion of the district heating networks in Nordic and Baltic countries. Potential is available especially in the Baltic countries and Norway. The situation in regards to utilization of wood biomass in private dwellings is similar in all seven countries. Large amounts of fuelwood are consumed annually but new furnace and burner technology is necessary to use resources more efficiently. In regards to energy policy a lot has been done to improve the use of biomass utilization, but more has to be done to strengthen the position of forest fuels in the future. The main bottlenecks for the larger use of forest biomass were found to be a lack of utilisation of available technology for harvesting and transport operations and a lack of district heating. An improved use of technology would decrease the price of forest fuels, necessary to compete with fossil fuel prices on international markets.
Abstract
No abstract has been registered
Abstract
No abstract has been registered
Abstract
In this study of 130 sites with different management we investigated whether vascular plant species richness is significantly reduced when traditionally managed hay meadows are abandoned and reforested. We also compared the effects of reforestation with those of intensified land-use to see which have the largest effects on species richness. Finally, we investigated the relative importance of relevant ecological factors for species richness.While the use of artificial fertilizers in traditionally managed hay meadows has resulted in significantly lower species richness, and intensive cultivation in even lower species richness, abandonment with reforestation has not decreased the species richness significantly.Productivity and habitat diversity have determined the species richness of meadows on the scale (0.035.1 ha) of this study. Low productivity is a prerequisite for high species richness in meadows. Maximum species richness was observed in unproductive, old, traditionally managed hay meadows with a high soil pH and high habitat diversity. The high species richness of these meadows suggests that they are in urgent need of conservation.