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.
2005
Abstract
At least three mechanisms are known to cause synchrony among spatially separated insect populations: 1) dispersal among populations, 2) synchronous stochastic effects, often referred to as the Moran effect, and 3) trophic interactions with other species that are either themselves synchronized or mobile.The present study brings in the role of insect taxa for spatial synchrony. The spatial synchrony observed in several North American and Eurasian epidemic bark beetles was compared with patterns of synchrony in outbreaks of defoliating forest Lepidoptera, revealing a marked difference between these two major insect taxa.The bark beetles exhibited a generally lower degree of spatial synchrony than the Lepidoptera, possibly because bark beetles are synchronized by different weather variables that are acting on a smaller scale than those affecting the Lepidoptera, or because inherent differences in their dynamics leads to more cyclic oscillations and hence more synchronous spatial dynamics in the Lepidoptera. Among the epidemic bark beetles tested, spatial synchrony of outbreaks in the Eurasian spruce bark beetle Ips typographus was significantly higher than for the other species.
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Authors
P. Neville Richard Fischer A.L. Axelsson Dan Aamlid Marco Marchetti T.B. Larsson Annemarie Bastrup-BirkAbstract
The joint network of tree crown condition monitoring under the EU and ICP Forests operates at two levels, a systematic extensive approach (Level I) based on a 16 km x 16 km trans-national grid of sample plots (>6000 plots) and an intensive approach (Level II) on more than 800 plots across continental Europe. Three ongoing projects embrace the different levels of monitoring, the above mentioned Level I and Level II systems, and the National Forest Inventories (NFIs). All of the three projects are based on a stand structure approach that assumes an increased potential for species diversity with increasing complexity of stand structure. An intensive test-phase of forest biodiversity assessment at more than 100 Level II plots, known as ForestBIOTA is underway during 2005. This project aims to test standardized methods of forest biodiversity assessment in the field and examine the relationship between stand structure, forest deadwood, ground vegetation and epiphytic lichens. A forest classification of the plots is also included. A separate approach, known as BioSoil (due to its combination with a detailed chemical inventory of the soils) is a demonstration project which aims to record indicators of forest biodiversity at the extensive Level I plots. Practical measures of stand structure, including records of tree species, lists of vascular plant species, and simple measures of forest deadwood are included for field assessment during 2006. A pan-European forest type classification elaborating on the EUNIS system and including the Natura 2000 habitat types is proposed. These initiatives are linked to a third project, COMON, operating at the level of the National Forest Inventories aiming to test the same core variables at national levels.
Abstract
Intensive monitoring plots of the ICP Forests gathered an amount of data about the ground vegetation in forest ecosystems throughout Europe. Each Country, applying different field techniques, conform to common rules of procedure, under the suggestions of a dedicated Expert Panel which implemented a Unified Coded Flora and comparability targets. Data series are foreseen to contribute to: definition of the forest ecosystem state and changes evaluation; assessment of the specific plant diversity at the ecosystems level. The contribution to scientific knowledge and to Global and Pan-European biodiversity initiatives and networks (ICP-IM, MCPFE, CBD, Forest BIOTA, ALTER-net, etc.) are also underlined. In spite of site-related data, first results (more than 670 plots, with large differences in plant diversity) depict the linkages with temperature, precipitation, dominant tree species and actual soil acidity. Nitrogen deposition seems to have some significant influence, which claims to further studies. Plant data series from ICP Forest’s plot, can be used for on-site confirmation of models including biodiversity k-factors and environment relations.
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*Strawberry Fragaria × ananassa (cv. Korona) was inoculated with Botrytis cinerea by dipping berries in a conidial suspension. *Colonization by the pathogen was monitored using real-time PCR, ELISA and ergosterol assays, the first showing the highest sensitivity. The expression of pathogen B-tubulin and six polygalacturonases (Bcpg1-6) and three host defence genes (polygalacturonase-inhibiting protein (FaPGIP) and two class II chitinases) were monitored using real-time RT-PCR. *The maximum transcript levels of the host defence genes occurred at 16 h postinoculation (hpi) at the presumed initial penetration stage. The unique transcript profile of Bcpg2 over the 96-h incubation time and its high transcript levels relative to those of the other Bcpgs at 8-24 hpi suggest that the gene has a specific role in the penetration stage. *Bcpg1 was expressed constitutively at a relatively high level in actively growing mycelia throughout the experimental period. Comparison of the transcript profiles indicated that Bcpg1 and Bcpg3-6 were coordinately regulated.
Authors
Erik Dybing Tore Sanner Jan Alexander Helle Katrine Knutsen Edgar Rivedal Bjørn Næss Hilde Kruse Ingolf Nes Janneche Utne Skåre Anne-Katrine Lundebye Martinus Løvik Wenche Kristin Farstad Lene Frost Andersen Georg Kapperud Øyvind Lie Judith Narvhus Leif SundheimAbstract
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