János Korponai

Analysis of Water Quality Data for Scientists

The most often used models are deterministic, although they are prepared from one sampling event. It must be stated that the statistics and model results obtained from this sampling event can significantly change if the sampling is to be reproduced because their results are probability variables (Kovacs & Szekely, 2006). In the case of deterministic models this problem is solved by means of sensitivity analyses, thus the uncertainty in the applied model remains. This may be the reason why the following can be found in the international literature regarding this question: “The future is stochastic modeling” (Kovacs & Szanyi, 2005; Wilkinson, 2006).

Spatial Optimization of Monitoring Networkson the Examples of a River, a Lake-Wetland System and a Sub-Surface Water System

Monitoring systems in general have to meet numerous requirements, the most important of which are representativeness and cost efficiency. The aim of the study, therefore, was to present the spatial optimization of the monitoring networks of a river (the Danube), a wetland-lake system (Kis-Balaton & Lake Balaton), and a sub-surface water system in the watershed of Lake Neusiedl/Fertő over a period of approximately two decades using a novel method, Combined cluster and discriminant analysis (CCDA). In the case of the river the results show that the monitoring network yields redundant information on certain sections, so that of 12 sampling sites 3 can be discarded. It was not, however, enough to consider just the tributaries when it comes to optimization. In the case of the wetland (Kis-Balaton) one pair of sampling sites out of 12, while in the case of Lake Balaton 5 out of 10 can be abandoned. For the sub-surface water system, however, all the 50 sites contained exclusive information; hence, all of these were shown to be necessary. In addition, neighboring sampling sites were compared pairwise using CCDA and the corresponding results were visualized in diagrams or so called “difference maps” indicating the location of the biggest differences. This approach also indicates the researcher where to place new sampling sites should the possibility arise. The discussed methodology proved to be highly useful in the optimization of the monitoring networks of the presented water systems.

A new European record of Diadesmis fukushimae and its transference to Humidophila genus (Bacillariophyta)

Abstract Diadesmis fukushimae, a rare oligotraphenic diatom, was found in some high mountain lakes of Romania. Its occurrence in the Parâng and Retezat Mountains is the second European record of the species. To date D. fukushimae has been known only from the type locality (Shenandoah National Park, Virginia, USA) and from a spring (Grotta Guernica, Dolomiti Bellunesi National Park (south-eastern Alps, Italy). Investigation by scanning electron microscopy showed that this species should be transferred to the recently established genus Humidophila. A new combination is proposed, Humidophila fukushimae. The morphological details of the European population are also presented.

Foreword: A virtual congress on palaeolimnology—palaeolimnological proxies as tools for environmental reconstruction in fresh water

The motivation for collecting recent knowledge in a special issue of Hydrobiologia derives from the recognition of the importance and applicability of palaeolimnological tools to help in defining ‘‘reference conditions’’ as designated within the Water Framework Directives and estimating influence of global climate change on surface waters. This volume was developed by inviting contributions from prominent experts in their respective fields. The compilation not only presents papers on palaeolimnological studies, focusing mostly on Eastern and Central Europe but also includes results from other regions. The use of palaeoecological analyses of sediments has a long tradition in Central Europe. In the nineteenth century, Lajos Lóczy (1849–1920) organized a systematic scientific research on Lake Balaton, the largest shallow lake of the region, and published the series of booklets (Lóczy 1897–1920) which are considered milestones in the development of limnology as a separate branch of science and which are comparable to Forel’s (1841–1912) seminal scientific heritage (Forel, 1892). Another milestone in the development of palaeolimnology was the first palaeolimnologial meeting which was held in Hungary in 1967. This meeting included some of the most prominent limnologists in the world including G.E. Hutchinson, D.G. Frey (Chairman), Nina V. Korde, D.A. Livingstone, O. Sebestyén, and W. Tutin who together formed the organizing committee. This committee decided to hold the symposium at the Biological Research Institute, Tihany, Hungary. The meeting profited from the excellent facilities and made the attendance of scientists from socialist countries possible. This location was also appropriate in celebrating the long tradition of geological and limnological studies on the lake including the early Guest editors: K. Buczkó, J. Korponai, J. Padisák & S. W. Starratt Palaeolimnological Proxies as Tools of Environmental Reconstruction in Fresh Water