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
Authors
Ingrid Agathe Bay-Larsen Ingebjørg Vestrum Vibeke Lind Camilla Risvoll Margarita Novoa Garrido Michael RoledaAbstract
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The purpose of this study is to increase the basic understanding of outbreak dynamics in order to improve the management of bark beetle outbreaks. The spruce bark beetle Ips typographus is a major disturbance agent of European forests and is the continent’s most economically and environmentally damaging bark beetle. Outbreaks of the spruce bark beetle are often triggered by large windfall episodes, and we have utilized a unique opportunity to study a Slovakian outbreak where little salvage logging was performed in some areas after a 2.5 million m3 storm-felling in 2004. Our analyses focused on the first five years after the windfall, and we used a combination of empirical data and simulation models to understand the spatial patterns of beetle-killed forest patches developing during the outbreak. The univoltine beetle population used an increasing proportion of the windfelled trees during the two first seasons after the storm, but from the third season onwards our comparisons of inter-patch distance distributions indicated a transition from beetle production largely in windfall areas to a self-sustaining outbreak with infestation patches developing independently of the windthrows. The size of new infestation patches formed after this transition was modeled as a function of beetle pressure, estimated by the proportion of a circle area surrounding new patches that was covered by infestation patches the previous year. Our model results of patch size distribution did not correspond well with the empirical data if patch formation was modeled as a pure dispersal–diffusion process. However, beetle aggregation on individual trees appears to be important for patch development, since good correspondence with empirical data was found when beetle aggregation was incorporated in the modeled dispersal process. The strength of correspondence between the beetle aggregation model and the empirical data varied with the density of aggregation trees in the modeled landscape, and reached a maximum of 83% for a density of three aggregation trees per infestation patch. Our results suggest that efficient removal of windfelled trees up until the start of the second summer after a major windfall is important to avoid a transition into a patch-driven bark beetle outbreak that is very difficult to manage. Our results also indicate that the outcome of a patch-driven outbreak is difficult to predict, since the development of new infestation patches is not a simple function of beetle pressure but is also affected by beetle behavior and local forest conditions.
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Authors
Kjell AndreassenAbstract
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Authors
Marta Camino-Serrano Elisabeth Graf Pannatier Sara Vicca Sebastiaan Luyssaert Mathieu Jonard Philippe Ciais Bertrand Guenet Bert Gielen Josep Peñuelas Jordi Sardans Peter Waldner Sophia Etzold Guia Cecchini Nicholas Clarke Zoran Galic Laure Gandois Karin Hansen Jim Johnson Uwe Klinck Zora Lachmanová Antti-Jussi Lindroos Henning Meesenburg Tiina M. Nieminen Tanja G. M. Sanders Kasia Sawicka Walter Seidling Anne Thimonier Elena Vanguelova Arne Verstraeten Lars Vesterdal Ivan A. JanssensAbstract
Dissolved organic carbon (DOC) in surface waters is connected to DOC in soil solution through hydrological pathways. Therefore, it is expected that long-term dynamics of DOC in surface waters reflect DOC trends in soil solution. However, a multitude of site studies have failed so far to establish consistent trends in soil solution DOC, whereas increasing concentrations in European surface waters over the past decades appear to be the norm, possibly as a result of recovery from acidification. The objectives of this study were therefore to understand the long-term trends of soil solution DOC from a large number of European forests (ICP Forests Level II plots) and determine their main physico-chemical and biological controls. We applied trend analysis at two levels: (1) to the entire European dataset and (2) to the individual time series and related trends with plot characteristics, i.e., soil and vegetation properties, soil solution chemistry and atmospheric deposition loads. Analyses of the entire dataset showed an overall increasing trend in DOC concentrations in the organic layers, but, at individual plots and depths, there was no clear overall trend in soil solution DOC. The rate change in soil solution DOC ranged between −16.8 and +23 % yr−1 (median = +0.4 % yr−1) across Europe. The non-significant trends (40 %) outnumbered the increasing (35 %) and decreasing trends (25 %) across the 97 ICP Forests Level II sites. By means of multivariate statistics, we found increasing trends in DOC concentrations with increasing mean nitrate (NO3−) deposition and increasing trends in DOC concentrations with decreasing mean sulfate (SO42−) deposition, with the magnitude of these relationships depending on plot deposition history. While the attribution of increasing trends in DOC to the reduction of SO42− deposition could be confirmed in low to medium N deposition areas, in agreement with observations in surface waters, this was not the case in high N deposition areas. In conclusion, long-term trends of soil solution DOC reflected the interactions between controls acting at local (soil and vegetation properties) and regional (atmospheric deposition of SO42− and inorganic N) scales.
Authors
Marta Camino-Serrano Elisabeth Graf Pannatier Sara Vicca Sebastiaan Luyssaert Mathieu Jonard Philippe Ciais Bertrand Guenet Bert Gielen Josep Peñuelas Jordi Sardans Peter Waldner Sophia Etzold Guia Cecchini Nicholas Clarke Galić Galic Laure Gandois Karin Hansen Jim Johnson Uwe Klinck Zora Lachmanová Antti-Jussi Lindroos Henning Meesenburg Tiina M. Nieminen Tanja G.M. Sanders Kasia Sawicka Walter Seidling Anne Thimonier Elena Vanguelova Arne Verstraeten Lars Vesterdal Ivan A. JanssensAbstract
No abstract has been registered
Authors
Arne Melchior Ivar Alvik Tarjei Bekkedal Klaus Mittenzwei Ivar Pettersen Leo A. Grünfeld Marcus Gjems Theie Gabriel Felbermayr Frode Veggeland Hege MedinAbstract
This study analyzes TTIP, its implications for Norway and Norway’s trade policy choices. TTIP will hardly be concluded under Obama's presidency, but the agreement could become a reality within a few years. TTIP aims at comprehensive cooperation in the regulatory area. In the short term there will be limited harmonization of standards but regulatory cooperation between different systems. In the long term, the goal is stronger cooperation in the regulatory area. TTIP will from what we know not lead to a lowering of European health regulations or a "race to the bottom". If TTIP is realized and Norway remains outside, the EEA Agreement will be little affected and the overall economic impact is moderate. If Norway joins TTIP, there will be a significant real income gain, with estimates ranging from 2236 to 6772 NOK per capita in the various scenarios. There is considerable variation across sectors. With Norway outside TTIP there will be a moderate negative impact for a majority of the sectors, especially some manufacturing sectors that face tougher competition in the EU and USA export markets. The oil industry will benefit from increased demand and higher prices. If Norway joins TTIP, a clear majority of industries will benefit; especially business services and a number of other service industries. The public sector gains from TTIP, mainly due to cheaper inputs. TTIP will contribute to the dismantling of import protection for Norwegian agriculture and without compensating measures, production and employment will be reduced. TTIP will still allow some import protection and this margin of maneuver, which depends on future negotiations, is important for the outcome. With a larger margin of manoeuvre and unchanged budgetarty support, most of Norway’s agriculture can be maintained. With less margin of manoeuvre, it will be more challenging. Norwegian accession to TTIP may occur in the form of a standard trade agreement in which Norway or EFTA are formally equal to the EU and the United States. Alternatively, Norway may participate in a European pillar as in today's "Open Skies" agreement on air traffic. If TTIP succeeds in establishing comprehensive regulatory cooperation, the latter solution is most likely. Such a solution implies that Norway will become more closely integrated with the European Union also in trade policy towards third countries. Norwegian entry into TTIP implies that we have to accept the established rules and negotiate bilaterally with the EU and the USA on market access. The negotiations with the USA will apply to all aspects of market access, while negotiations with the EU will apply only to areas in which the EEA agreement is not already deeper. The negotiations with the EU for TTIP entry will thus include, among other issues, tariffs for seafood and agriculture. As an alternative to membership in TTIP, Norway or EFTA may initiate a trade agreement with the USA. Such an agreement would likely be less extensive in the regulatory area. Such an agreement will also provide an economic gain for Norway, but less than accession to TTIP. For Norway as a whole, accession to TTIP creates a real income gain between 12.5 and 35 billion NOK according to various scenarios, while a free trade agreement with the United States results in a gain of about 7.4 billion NOK. TTIP also includes negotiations on so-called Investor-State Dispute Settlement (ISDS), whereby foreign-owned companies can sue a state if they are unfairly or inappropriately treated. Such rights also exist in national law but international tribunals have to some extent extended the interpretation of what is considered unfair. The European Union has proposed a solution in TTIP with a permanent court as well as rules that discipline the interpretation of the principles, and thus avoids that ISDS unduly interferes into the states’ "right to regulate". This and many other issues are analysed in this report and six background papers.
Abstract
No abstract has been registered