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.
2006
Abstract
Dissolved aluminium was fractionated in the field and the laboratory using a cation exchange method. Although absolute differences between results obtained from field and laboratory fractionations were generally small, relative differences, expressed as the ratio between labile aluminium determined after laboratory fractionation (Alll) and that obtained after field fractionation (Allf), could be large. The differences found were not statistically significant, although this may simply reflect the spread in the results. Alll/Allf had no apparent relationship with the temperature difference between the field and the lab. Although some significant correlations were found between Alll/Allf and H+, no significant correlations were found with the equivalent relative difference in {H+} between the lab and the field. Neither was any significant correlation found with dissolved organic carbon.
Authors
Aldo Marchetto Rosario Mosello Gabriele A. Tartari John Derome Kirsti Derome Pia Sorsa Nils König Nicholas Clarke Erwin Ulrich Anna KowalskaAbstract
Working Ring Test (WRT) was organised in the framework of the EU Regulation (EC) No 2152/2003 (`Forest Focus`) and of the UN/ECE Program `ICP Forests` in order to evaluate the overall performance of the laboratories monitoring atmospheric deposition and soil solution in European Forests, and to verify the improvement in the analytical quality as the results of the QA/QC work carried out in the laboratories which participated to a previous WRT. Seven natural samples of atmospheric deposition and soil solutions and 5 synthetic solutions were distributed to 52 laboratories, which analysed them using their routine method for the following variables: pH, conductivity, calcium, magnesium, sodium, potassium, ammonium, sulphate, nitrate, chloride, total alkalinity, phosphate, total dissolved nitrogen, dissolved organic carbon, aluminium, copper, iron, manganese, zinc, total phosphorus, total sulphur and silica. For each variable, a Data Quality Objective was defined, based on the results of the previous WRT, the comparison with the DQOs of other international networks, and the importance of the variable in deposition and soil solution monitoring. It resulted that 38% of the results do not meet the DQO, showing for which variables and in which laboratories improvement in analytical performance is needed. The results of the exercise clearly show that the use of data check procedures, as those described in the ICP Forests manual for sampling and analysis of atmospheric deposition, would make it possible to detect the presence of outliers or results not accurate, and would greatly improve the overall performance of the laboratories. Some analytical methods were found not suitable to the samples used in this WRT, nor to atmospheric deposition samples in European forests, and they include outdated methods, such as turbidimetry or nephelometry for the determination of sulphate, silver nitrate titration and ion selective electrode for chloride, Kjeldahl digestion for the determination of ammonium and organic nitrogen, and colorimetric titrations for alkalinity. A detailed discussion of the analyses of total dissolved nitrogen, dissolved organic carbon and total alkalinity is also provided, as they were the variables for which more analytical difficulty arose. Finally, a comparison between the results of this WRT and those of the previous exercise showed that the analytical performance of the laboratories participating in both WRTs improved as a consequence of the adoption of QA/QC procedures.
Abstract
The paper describes the development of the two involved nurseries and the reforestation efforts and results on the two experimental sites at Munda and in Mahamaya
Abstract
We describe the cloning and characterization of a single copy gene from Trichoderma atroviride P1 encoding a novel 30 kDa chitinase, Ech30. Ech30 is a family 18 chitinase showing low sequence similarity to other Trichoderma chitinases. Real-time quantitative RT-PCR studies revealed that expression of the ech30 gene was induced by the presence of Botrytis cinerea in plate confrontation assays, but hardly by chitin in liquid cultures. Studies of Ech30 purified from an Escherichia coli strain overexpressing the ech30 gene devoid of the leader sequence and a predicted intron, showed that the gene encodes an active chitinase, which, as expected for family 18 chitinases, is inhibited by allosamidin.
Abstract
Hydrological time-series are known to depict long-term structures, and pronouncednonlinearities. Singular System Analysis (SSA) is one way to extract long-term componentsof these data-sets. Classical SSA is a principal component analysis (PCA) inthe time domain...
Abstract
Ecosystems commonly fall under the rubric of complex systems (West and Brown 2004). Nevertheless, in the practical management of certain ecosystems, we encounter simple heuristic rules of human interference that are often derived from cultural traditions rather than from scientific study. The increased technical power of computer-based simulation tools and their increased mathematical formalization may either remove former technical limits (e.g., of prediction) or, in contrast, reveal the fundamental character of some of these limits. Here, we shall argue that both cases occur, and that the main effect of simulation technology is to bring the distinction between these cases into scientific awareness.
Abstract
No abstract has been registered
Authors
Holger LangeAbstract
Most phenomena in ecosystem research are assessed via repeated measurements of environmental variables. The dynamics of these time series is investigated with a variety of statistical techniques; in this article, we focus on modern nonlinear methods. They enable separation of short- and long-term components, show all types of trends and quantify the information contained and the complexity of the data sets.
Abstract
No abstract has been registered
2005
Abstract
No abstract has been registered