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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.

2011

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Abstract

In recent years the harmonization of methods in the frame of the International Co-operative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (ICP Forests) operating under the UNECE Convention on Long-range Transboundary Air Pollution (CLRTAP) has been intensified. Among the C-actions of the FutMon project (LIFE07 ENV/D/000218; 2009-2010) the C1-Dep-22(SI) action was established with the goal to harmonize and develop the deposition monitoring procedures and sampling methods. The sampling equipment, spatial design of sampling plots and sampling frequency throughout Europe vary considerably. Therefore a step-by-step approach was made where the harmonized sampling equipment was developed and tested first. The selected collectors were installed at one observation plot of each participating country where measurements of throughfall and bulk deposition were run in parallel with the national collectors for a period of one year. To evaluate the agreement between methods, different statistical analyses were used including Altman-Bland plots, model II regression, and repeated measures ANOVA. Preliminary results from the “Intensive forest ecosystem monitoring plot” plot Brdo in NW Slovenia show a good agreement between national and harmonized bulk (both funnel-type) collectors, while comparison of throughfall measurements indicates systematic bias between harmonized (funnel-type) and national (gutter-type) collectors.

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Abstract

Dieback of European ash (Fraxinus excelsior), caused by the ascomycete Hymenoscyphus pseudoalbidus (anamorph Chalara fraxinea), started around 1992 in Poland and has since then spread over large geographical areas. By November 2010, the disease had been recorded in 22 European countries. The gradual expansion and high intensity of the ash dieback epidemic in Europe may suggest that H. pseudoalbidus is an invasive alien organism. In Norway, ash dieback was first reported in spring 2008, and a survey in early summer of the same year revealed that the disease had spread over large parts of the southern and eastern regions of the country. The distance from the southernmost to the northernmost infected stands was, at that time, about 400 km. Some old necrotic lesions were also observed, indicating that the ash dieback pathogen is likely to have been present in Norway since at least 2006. In 2009, a spore sampler was installed in a diseased ash stand at Ås, South-Eastern Norway. Sampling started in late July and continued until late September. Large numbers of ascospores resembling those of H. pseudoalbidus were observed, with the maximum number of spores occurring from the end of July to mid-August. The deposition of ascospores occurred mainly between 6 and 8 a.m. Ascospores are most likely to be the primary source initiating host infections and responsible for the rapid recent spread of H. pseudoalbidus in Europe.

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Abstract

In vitro dose responses of several calcium and potassium salts were determined on some commercially significant plant pathogens including: Helminthosporium solani, Fusarium oxysporum f. sp. pisi race 2, Colletotricum coccodes, Phytophthora cactorum, Phytophthora cinnamomi, Phytophthora erythroseptica, Phytophthora infestans, Phytophthora megasperma, Pythium ultimum and Venturia inaequalis. Mycelial growth inhibition was both salt-specific and dose-related. Pythium ultimum was completely inhibited by ≥75 mg·L-1 calcium propionate, but needed ≥ 300 mg·L-1 of calcium acetate and ≥ 40 mL·L -1 of potassium silicate for complete inhibition. Phytophthora infestans was completely inhibited by ≥150 mg·L-1 calcium acetate, ≥150 mg·L-1 calcium propionate or ≥ 5 mL·L-1 potassium silicate. Phytophthora cactorum was completely inhibited by ≥ 300 mg·L-1 calcium propionate, but required ≥ 600 mg·L-1 calcium acetate and ≥10 mL·L-1 potassium silicate for complete inhibition. Phytophthora cinnamomi was completely inhibited by calcium propionate at ≥ 600 mg·L-1, or by ≥10 mL·L-1 potassium silicate. Only potassium silicate inhibited Phytophthora megasperma, Phytophthora erthroseptica, V. inequalis and H. solani at concentrations of ≥ 5mL·L-1, ≥ 20 mL·L-1, ≥ 40 mL·L-1 or ≥ 80mL·L-1 respectively. Potassium acetate did not completely inhibit any of the pathogens in this study when tested at concentrations ≤ 1200 mg·L-1.