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EN
Contemporary assessment of the ecological status of aquatic ecosystems is based on various groups of organisms, including diatoms. Biological assessment, implemented by the Water Framework Directive, has been applied worldwide for more than 15 years. Currently, the most basic “tool” used in biomonitoring are diatom indices, which are routinely applied in Europe and other countries around the world. In Poland, the diatom indices have been used for over 5 years, which is a period of time allowing to summarize and evaluate the effectiveness of these methods in the assessment of aquatic ecosystems. The purpose of this work was to analyse the use of diatom indices in the biomonitoring of surface water by collecting data on the possibilities and limitations of using diatom indices for the objective assessment of water quality. Attention was paid to mistakes made in the course of biological assessment performed with the use of diatom phytobenthos, which have a significant impact on the obtained results. The paper also contains suggestions for introducing several important changes in biological monitoring, which will improve its quality and efficiency in assessing the ecological status of various aquatic ecosystems.
EN
Pleodorina indica (Iyengar) H. Nozaki is a rare species from the Volvocaceae family (Chlorophyta, Volvocales), which naturally occurs in aquatic ecosystems of the tropical climate zones. This is the first record of this species I in Poland in a flow-through man-made reservoir on the Olechówka River in Łódź. The sampling site of P. indica in Łódź is the northernmost site in Europe. Among other records, the species has been also reported from Austria in 1996 and the Czech Republic in 2003. During the summer of 2015, abundant occurrence of this species was observed at the sampling site, at extremely high air and water temperatures. Physical parameters in the reservoir and the duration of the P. indica bloom were measured. In addition, morphological features of the species were observed with the use of light and confocal microscopy.
3
Content available remote First record of Prestauroneis tumida Levkov and accompanying species in Poland
EN
The paper presents morphological and ecological characteristics of Prestauroneis tumida Levkov recorded for the first time in Poland. The diatom Prestauroneis tumida Levkov was found in the microbenthos of the Czarna Staszowska River (left tributary of the Vistula River, south-eastern Poland). This diatom species was present in the upper section of the river (sampling sites: 1 – Drogowle, 2 – Raków) where saprobic state varied from oligosaprobic to beta-mesosaprobic. Dimensions of the valve were as follows: length 30-44 µm, width 8-11 µm and 13-16 striae in 10 µm. Our research updates the morphological diversity data such as measurements of valves in terms of width and the number of striae. The accompanying species of Prestauroneis tumida belonged to the group of good water quality indicators, from oligo- to mesosaprobic ones. Some of the identified species were indicators of alkaline, calcium-rich waters.
4
Content available remote Half a century of research on diatoms in athalassic habitats in central Poland
EN
Part of the geology in the Łódź province was formed during the Upper Permian period when rich Zechstein salt was deposited. Groundwater drains the deposits and flows out in the village of Pełczyska, creating a unique hydrogeological site in Central Poland. An inland, athalassic ecosystem can be a reference site for halophile microflora. The outflow with surrounding marshes has been an algological research site since 1964. The research reveals changes recorded in diatom assemblages from athalassic habitats, characterized by a wide range of salinity levels, and verifies the tolerance of taxa to salinity. The comparative analysis was based on the diatom material sampled in 1964-1965, 1992-1994 and on recently collected samples. The analysis revealed the temporal change in assemblages caused by a change in the chloride concentration, and the spatial change from one to another habitat type, characterized by varying salinity levels. The halophilic species in the studied habitats included e.g. Halamphora dominici, H. tenerrima, Navicula digitoconvergens, N. meulemansii, Staurophora salina. The analysis of changes allowed the verification of the species’ requirements and tolerance range to the salinity factor. Therefore, in the case of Fragilaria famelica and Halamphora sydowii, we propose a change in the halobion system classification.
EN
Simonsenia delognei is a diatom species which is relatively rarely recorded, but apparently widespread in Europe and other continents. This taxon has recently been discovered for the first time in springs of Central Poland, where it was found to occur abundantly. Somewhat later this species has also been identified and photographed in samples from the Eagean Region in Turkey. Light and electron microscopic studies were carried out on S. delognei populations from the Quaternary spring located near Łódź (Central Poland) and from the Porsuk and Felent Rivers and a spring in the Türkmen Mountains in Kütahya and Havuzdere Stream in Yalova (NW Turkey). Morphological studies were accompanied by environmental measurements and determination of changes in the seasonal distribution of S. delognei in a key area, i.e. the Porzeczkowe spring in Central Poland, which are included in the present study. Identification of S. delognei under a light microscope is difficult and hence an electron microscope is required for accurate taxonomic identification.
EN
The aim of the study was to compare the biological analyzes of the Linda River (Central Poland), which were based on three diatom indices: IO, GDI and IPS in order to select the best diatom index for the biological assessment of the lotic water quality. Additionally, the summary of the selected results of the biological and chemical analyzes was presented to show how precise the biological analyzes are as a basic tool in the assessment of the ecological status of the lotic waters. The results showed that each of the indices assessed the water in the Linda River to a specific but different quality class. The IO index showed class II of the water quality, while the IPS and GDI - class III. Statistical analysis conducted with the nonparametric Kruskal-Wallis test for independent samples (Kruskal, Wallis 1952) showed that differences in the values of individual indices at different sites were not statistically significant. It should be noticed that the IPS and GDI indices gave values that classify the water in the Linda River at least one class below. The obtained results confirmed that the biological methods are most reliable in the assessment of the water quality. These methods are less sensitive to a single impact of the environmental factors, therefore they permit accurate determination of the ecological status of the water ecosystems.
EN
Phytoseston studies were carried out at two sites near the town of Łask in the third orderstream segment of the Grabia River and the first order-stream segment of the Brodnia River, in two study periods: 1992-1993 and 2005-2006. Water and seston were sampled twice a month. The chemical parameters of N-NO3, P-PO4 and chlorophyll a were also determined. The aim of the studies was to determine the changes in the nutrient load of these ecosystems in the rivers studied over the course of 12 years and their influence on quantitative and qualitative phytoseston differentiation. No important differences in the taxonomic composition of the phytoseston between the two rivers were observed. A high participation of diatoms (over 50%), in relation to other algal groups, was recorded in both rivers. Vegetation in the Brodnia River begins to develop one month earlier than in the Grabia River. The greatest changes in the seasonal rate of algal succession occurred in the spring and summer periods, while no considerable changes in seston composition were recorded in the fall or winter periods. A decrease in phytoseston quantity was observed in the second study period. Chlorophyll a content was significantly lower in 2005-2006 than that in 1992-1993.
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