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
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No abstract has been registered
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Abstract
Host tree terpenes can influence attraction of conifer-infesting bark beetles to their aggregation pheromones, and both synergistic and inhibitory effects have been reported. We tested a gradient of ratios of (–)-α-pinene, the predominant monoterpene in Norway spruce, to the pheromone of Ips typographus, a major pest of Norway spruce. Attraction of I. typographus increased as the release rate of (–)-α-pinene increased. The two highest (–)-α-pinene : pheromone ratios (526 : 1 and 2595 : 1) attracted twice as many I. typographus as pheromone alone, whereas low to intermediate ratios (56 : 1, 274 : 1) did not differ from pheromone alone. Our results are in agreement with a proposed model, which suggests that bark beetles display unique response profiles to host terpenes depending on the physiological condition of the host trees that they typically colonize. Ips typographus, which is an aggressive species capable of colonizing and killing healthy trees, showed an increased attraction to monoterpene : pheromone ratios, and this may be high enough to inhibit attraction of less aggressive beetle species typically colonizing dead, dying or stressed trees. Attraction of associates of I. typographus was also modified by (–)-α-pinene. Ips duplicatus, a competitor of I. typographus, showed increased attraction to the pheromone of I. typographus across all concentrations of (–)-α-pinene.
Authors
Guro Ådnegard Skarstad Laura Terragni Hanne TorjusenAbstract
No abstract has been registered
Authors
Sanna Koutaniemi Tino Warinowski Anna Karkonen Edward Alatalo Carl Gunnar Fossdal Pekka Saranpaa Tapio Laakso Kurt V. Fagerstedt Liisa K. Simola Lars Paulin Stephen Rudd Teemu H. TeeriAbstract
No abstract has been registered
2006
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No abstract has been registered
Authors
Ingerd Skow Hofgaard Leslie A Wanner Gunhild Hageskal Birgitte Henriksen Sonja Klemsdal Anne Marte TronsmoAbstract
No abstract has been registered
Abstract
Pulpwood has been imported to Norway since the beginning of the 20th century. However, exotic plant species hitchhiking with pulpwood were not observed before c.1985. Prior to this the imported timber was debarked, and the chances that diaspores would have attached to a debarked log (compared to a log with bark) are very small.A greenhouse germination experiment based on 385 dm2 of sifted bark from the holds of nine Estonian pulpwood ships yielded 3187 seeds of 201 species of vascular plants, few of which were typical of coniferous forests. Approximately 39% of the hitchhiking seeds did not germinate until after a period of cold treatment.Most of the species germinated in low densities, and those occurring in greater numbers are common and widespread in Norway. Six species were new to Norway: Agrostis clavata, Androsace filiformis, Bidens radiata, Carex montana, Melica picta, and Ranunculus cassubicus.During the last 20 years, pulpwood has been imported to Norway from many countries around the world, e.g. Russia, Scotland, Canada, and Zaire. While the present data do not indicate any immediate threat from aggressively invasive exotics, in order to avoid the introduction of non-native species and reduce the potential for biological invasion, timber should ideally be debarked prior to importation.
Abstract
The concentrations of carbon monoxide (CO) and other gases were measured in the emissions from solid waste degradation under aerobic and anaerobic conditions during laboratory and field investigations. The emissions were measured as room temperature headspace gas concentrations in reactors of 1, 30, and 150 L, as well as sucked gas concentrations from windrow composting piles and a biocell, under field conditions. The aerobic composting laboratory experiments consisted of treatments with and without lime. The CO concentrations measured during anaerobic conditions varied from 0 to 3000 ppm, the average being 23 ppm, increasing to 133 ppm when methane (CH4) concentrations were low. The mean/maximum CO concentrations during the aerobic degradation in the 2-L reactor were 101/194 ppm without lime, 486/2022 ppm with lime, and 275/980 ppm in the 150-L reactors. The presence of CO during the aerobic composting followed a rapid decline in O2 concentrations Significantly higher CO concentrations were obtained when the aerobic degradation was amended with lime, probably because of a more extreme depletion of oxygen. The mean/maximum CO concentrations under field conditions during aerobic composting were 95/1000 ppm. The CO concentrations from the anaerobic biocell varied from 20 to 160 ppm. The hydrogen sulfide concentrations reached almost 1200 ppm during the anaerobic degradation and 67 ppm during the composting experiments. There is a positive correlation between the CO and hydrogen sulfide concentrations measured during the anaerobic degradation experiments.
Abstract
No abstract has been registered