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.
2016
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Lise Tingstad Siri Lie Olsen Kari Klanderud Vigdis Vandvik Mikael OhlsonAbstract
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Andrius Kuliesis Stein Michael Tomter Claude Vidal Adrian LanzAbstract
Key message Quality and reliability of forest resource assessments depend on the ability of national forest inventories (NFIs) to supply necessary and high-quality data. Over the last decades and especially since the 1990s, the NFIs in European countries have been rapidly developing. Possibilities for obtaining reliable and accurate data on annual increment from different inventory types were evaluated, and sample-based inventories have been found to be superior to standwise inventories in providing reliable data. Simplified methods may be employed when increment cannot be directly estimated from inventory data. Context An increasing intensity of forest resource use requires more accurate, detailed and reliable information, not only on forest area and growing stock but also on forest stand productivity, wood increment and its components. Aims The main objectives were to assess the capacities of forest inventories, the methods used for estimation of gross increment and its components and their accuracy and to demonstrate an effective method for estimation of increment when direct inventory methods are not available. Methods Data about national forest inventory methods were obtained from 30 responses to a questionnaire, distributed amongst national correspondents of all European countries; reports of COST Actions E43 and FP 1001, databases of Temperate and Boreal Forest Resource Assessment (TBFRA) 2000 and State of Europe’s Forests (SoEF) 2011 were used as well. Analysis and comparison of results from different forest inventories were used for evaluation of data reliability. Relationships between growing stock and gross increment in European forests were also analysed, and corresponding models were proposed. Results Seventy-nine percent of European forest area is covered by national forest inventories (NFIs) based on sampling methods and the rest on stand-level inventory and other inventory methods. Data obtained by aggregating standwise data usually underestimate growing stock by 15–20 % and gross increment even more. Almost half of the European forest area (47 %) is monitored using permanent plots, measured twice or more, allowing the estimation of gross increment and its components to be made directly. Conclusion Implementation of NFIs based on sampling methods, especially with permanent plots, resulted in an improvement of data quality and in most cases an increase of growing stock and gross increment. The estimation of natural losses is the weakest link in today’s NFIs and in the current assessment of European forest resources. The proposed default values for gross increment and its components is an option to be used in countries not having NFI at all or those which have started it only recently.
Abstract
Accurate estimation of winter wheat frost kill in cold-temperate agricultural regions is limited by lack of data on soil temperature at wheat crown depth, which determines winter survival. We compared the ability of four models of differing complexity to predict observed soil temperature at 2 cm depth during two winter seasons (2013-14 and 2014-15) at Ultuna, Sweden, and at 1 cm depth at Ilseng and Ås, Norway. Predicted and observed soil temperature at 2 cm depth was then used in FROSTOL model simulations of the frost tolerance of winter wheat at Ultuna. Compared with the observed soil temperature at 2 cm depth, soil temperature was better predicted by detailed models than simpler models for both seasons at Ultuna. The LT50 (temperature at which 50 % of plants die) predictions from FROSTOL model simulations using input from the most detailed soil temperature model agreed better with LT50 FROSTOL outputs from observed soil temperature than what LT50 FROSTOL predictions using temperature from simpler models did. These results highlight the need for simpler temperature prediction tools to be further improved when used to evaluate winter wheat frost kill.
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Jorunn BørveAbstract
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J.A.M. Janssen J.S. Rodwell M. García Criado S. Gubbay T. Haynes A. Nieto N. Sanders F. Landucci J. Loidi A. Ssymank T. Tahvanainen M. Valderrabano A. Acosta M. Aronsson G. Arts F. Attorre E. Bergmeier R.-J. Bijlsma F. Bioret C. Bita-Nicolae I. Biurrun M. Calix J. Capelo A. Carni M. Chytrý J. Dengler P. Dimopoulos F. Essl H. Gardfjell D. Petrucci Gigante G. Giusso del Galdo M. Hájek F. Jansen Jutta Kapfer A. Mickolajczak J.A. Molina Z. Molnár D. Paternoster A. Piernik B. Poulin B. Renaux Joop H.J. Schaminée K. Sumberova H. Toivonen T. Tonteri I. Tsiripidis R. Tzonev M. ValachovicAbstract
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The Eurasian spruce bark beetle Ips typographus is a major forest pest in Europe, capable of mass-attacking and killing mature Norway spruces over extensive areas during outbreaks. Recurring outbreaks over the last few centuries have affected Central and Northern Europe. Outbreaks tend to be periodic and are in many cases triggered by large wind-felling events. For example in Scandinavia several large outbreaks have been triggered by storm disturbances in the last 50 years. In Europe I. typographus is widespread where spruce hosts are found except for in the British Isles. Here we review the identification and biology of this insect and present information about its invasiveness and the potential of success in early detection and control of outbreaks. There are indications that a warmer climate will increase the risk for outbreaks in the northern range of spruce in Europe, where outbreaks so far have been rare. More outbreaks are also expected at the southern margin of the spruce distribution in Europe, where lower than average precipitation seems to generally favor infestations. Establishments outside Eurasia have not been found despite frequent interceptions at ports of entry. Our experiments showed that North American spruce species may be suitable hosts and we conclude that it cannot be ruled out that future establishment can result from repeated imports. The most efficient control option of storm-triggered outbreaks is removal of wind-felled trees before the new generation beetles emerge.