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.
2017
Authors
Paal KrokeneAbstract
No abstract has been registered
Authors
Rumen Tomov René Eschen Jean-Claude Grégoire Christo Nikolov Andrei Orlinski Alberto Santini Tiit Maaten Halldors Sverrisson Bjørn Økland Anna Maria VettrainoAbstract
Sentinel plantings are a powerful tool to identify harmful organisms before they arrive in a country, but the use of this novel tool is limited by reduced awareness. Another limitation for the establishment of sentinel nurseries are plant health regulations that affect the import of planting material of alien species for use in sentinel plantings. However, import of propagation material is often considered low risk compared to rooted plants and more relaxed regulations may apply. Import regulations may vary among countries and special conditions for import for scientific purposes may apply. We aimed to make an overview of regulations for import and planting of propagation material for use in sentinel plantings in countries around the world. During 2016 a questionnaire survey was conducted in more than 40 countries around the world to identify national legislation on the import of seeds of exotic tree species and their use for scientific purposes in open-field situations. This study will provide an overview on regulations that need to be observed while sentinel nurseries are settled both using seeds for planting and trees grown from these seeds. The results will be a useful tool to facilitate the selection of locations for future sentinel nurseries.
Abstract
Large-scale bark beetle outbreaks in northern conifer forests have already demonstrated huge impacts on forest economy, ecosystems and carbon dynamics. In North America, a historically unprecedented outbreak of the mountain pine beetle has expanded north- and eastwards beyond its historical range, and has reached epidemic levels in areas of northern British Columbia previously thought to be unsuitable for beetle survival. In Europe, the vast northern spruce forests have been spared from bark beetle outbreaks in the past, but here we review some recent observations and research results indicating that this may be undergoing change. For example, monitoring data of the most serious tree-killing bark beetle in Europe, Ips typographus, show a several-fold increase of the populations in its northern range during warm years. In the extensive spruce forests of northern Fennoscandia and Russia, a new phenomenon of tree-killing episodes by I. typographus has occurred in the last decade. Northern localities with one beetle generation per year in the past are now having more often two. Also other bark beetle species in the genus Ips have demonstrated a fast northward expansion in Europe, including one species contributing in bark beetle outbreaks of I. typographus in Central and Southern Europe.
Authors
Lorenzo Marini Bjørn Økland Anna Maria Jönsson Barbara Bentz Allan Carroll Beat Forster Jean-Claude Grégoire Rainer Hurling Louis Michel Nageleisen Sigrid Netherer Hans Peter Ravn Aaron Weed Martin SchroederAbstract
Bark beetles are among the most devastating biotic agents affecting forests globally and several species are expected to be favored by climate change. Given the potential interactions of insect outbreaks with other biotic and abiotic disturbances, and the potentially strong impact of changing disturbance regimes on forest resources, investigating climatic drivers of destructive bark beetle outbreaks is of paramount importance. We analyzed 17 time-series of the amount of wood damaged by Ips typographus, the most destructive pest of Norway spruce forests, collected across 8 European countries in the last three decades. We aimed to quantify the relative importance of key climate drivers in explaining timber loss dynamics, also testing for possible synergistic effects. Local outbreaks shared the same drivers, including increasing summer rainfall deficit and warm temperatures. Large availability of storm-felled trees in the previous year was also strongly related to an increase in timber loss, likely by providing an alternative source of breeding material. We did not find any positive synergy among outbreak drivers. On the contrary, the occurrence of large storms reduced the positive effect of warming temperatures and rainfall deficit. The large surplus of breeding material likely boosted I. typographus population size above the density threshold required to colonize and kill healthy trees irrespective of other climate triggers. Importantly, we found strong negative density dependence in I. typographus that may provide a mechanism for population decline after population eruptions. Generality in the effects of complex climatic events across different geographical areas suggests that the large-scale drivers can be used as early warning indicators of increasing local outbreak probability.
Abstract
No abstract has been registered
Authors
Jorunn Børve Antonio Ippolito Brankica Tanovic Monika Michalecka Simona Marianna Sanzani Anna Poniatowska Marta Mari Jovana HrusticAbstract
No abstract has been registered
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Authors
Ned B. Klopfenstein Jane E. Stewart Yuko Ota John W. Hanna Bryce A. Richardson Amy L. Ross-Davis Rubén D. Elías-Román Kari Korhonen Nenad Djuro Keča Eugenia Iturritxa, Dionicio Alvarado-Rosales Halvor Solheim Nicholas J. Brazee Piotr Łakomy Michelle R. Cleary Eri Hasegawa Taisei Kikuchi Fortunato Garza-Ocañas Panaghiotis Tsopelas Daniel Rigling Simone Prospero, Tetyana Tsykun Jean A. Bérubé Franck O.P. Stefani Saeideh Jafarpour Vladimír Antonín Michal Tomšovský Geral I. McDonald Stephen Woodward Mee-Sook KimAbstract
Armillaria possesses several intriguing characteristics that have inspired wide interest in understanding phylogenetic relationships within and among species of this genus. Nuclear ribosomal DNA sequence– based analyses of Armillaria provide only limited information for phylogenetic studies among widely divergent taxa. More recent studies have shown that translation elongation factor 1-α (tef1) sequences are highly informative for phylogenetic analysis of Armillaria species within diverse global regions. This study used Neighbor-net and coalescence-based Bayesian analyses to examine phylogenetic relationships of newly determined and existing tef1 sequences derived from diverse Armillaria species from across the Northern Hemisphere, with Southern Hemisphere Armillaria species included for reference. Based on the Bayesian analysis of tef1 sequences, Armillaria species from the Northern Hemisphere are generally contained within the following four superclades, which are named according to the specific epithet of the most frequently cited species within the superclade: (i) Socialis/Tabescens (exannulate) superclade including Eurasian A. ectypa, North American A. socialis (A. tabescens), and Eurasian A. socialis (A. tabescens) clades; (ii) Mellea superclade including undescribed annulate North American Armillaria sp. (Mexico) and four separate clades of A. mellea (Europe and Iran, eastern Asia, and two groups from North America); (iii) Gallica superclade including Armillaria Nag E (Japan), multiple clades of A. gallica (Asia and Europe), A. calvescens (eastern North America), A. cepistipes (North America), A. altimontana (western USA), A. nabsnona (North America and Japan), and at least two A. gallica clades (North America); and (iv) Solidipes/Ostoyae superclade including two A. solidipes/ostoyae clades (North America), A. gemina (eastern USA), A. solidipes/ostoyae (Eurasia), A. cepistipes (Europe and Japan), A. sinapina (North America and Japan), and A. borealis (Eurasia) clade 2. Of note is that A. borealis (Eurasia) clade 1 appears basal to the Solidipes/Ostoyae and Gallica superclades. The Neighbor-net analysis showed similar phylogenetic relationships. This study further demonstrates the utility of tef1 for global phylogenetic studies of Armillaria species and provides critical insights into multiple taxonomic issues that warrant further study.