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EN
Habitat studies were conducted on three rare plant communities dominated by Nuphar pumila, Nymphaea candida and Hydrilla verticillata in lakes of north-eastern Poland. The comparison of habitat properties of these three types of phytocoenoses with those of Nuphar lutea common in the area under study was also performed. It was demonstrated that the plant communities studied were ecologically distinct. The habitats of the phytocoenoses of N. pumila differed most significantly from those of the other phytocoenoses. They often inhabited softer waters poor in Mg2+, dissolved SiO2, but rich in total Fe, PO43−, NO3−, and were associated with acidic substrates containing lower levels of Ca2+ and Na+, but greater amounts of total Fe and NO3−. The differences in the habitats of H. verticillata and N. candida phytocoenoses were most pronounced in the case of four properties of water: Na+, K+, Cl−, and Mg+. Their values were lower in waters of the H. verticillata phytocoenoses. The habitats of all the three types of rare phytocoenoses differed considerably from those of N. lutea. The most significant differences were found between the N. lutea and N. pumila phytocoenoses and the smallest differences were between the patches of N. lutea and N. candida. The properties of water were more important in differentiating the habitats of the phytocoenoses studied than the substrate properties. Due to alkalization and increase in water hardness in the lakes studied the stands of N. pumila are among the most threatened. The patches of N. candida and H. verticillata, which occur in waters with a wider range of hardness and tolerating a slight increase in trophy, can still continue to persist in the lakes for a long time.
EN
The present study showed the ecological differentiation of phytocoenoses dominated either by Myriophyllum alterniflorum or by Littorella uniflora, which in Poland are classified within the Myriophylletum alterniflori or Myriophyllo-Littorelletum association. The properties which best differentiated the waters of the above types of phytocoenoses were calcium and factors associated with the carbonate complex (pH, electrolytic conductivity, total and carbonate hardness), and pH in the case of substrates. The most distinct differences in the habitats were found between the phytocoenoses dominated by L. uniflora from the Pomeranian Lobelia lakes and those dominated by M. alterniflorum from the Łęczna-Włodawa Lake District, in which other species from the Littorelletea uniflorae class were absent. The L. uniflora phytocoenoses are associated with soft waters poor in Ca2+ and with the lowest values of pH, electrolytic conductivity, dissolved organic matter (COD-KMnO4) and dissolved SiO2. The substrates they inhabit are mineral and more acidic. By contrast, the values of the above-mentioned properties are considerably higher in the case of the phytocoenoses from the Łęczna-Włodawa Lake District. The habitats of the M. alterniflorum phytocoenoses from the Pomeranian Lobelia lakes occupy an intermediate position and are more similar to those of M. alterniflorum from the Łęczna-Włodawa Lake District. The results obtained in this study suggest that the phytocoenoses of L. uniflora and M. alterniflorum should not be included in the same association. Further studies are, therefore, necessary to resolve this problem. The comparative analysis of the present ecological findings and data obtained from other regions of Europe show that in Poland the phytocoenoses dominated either by L. uniflora or by M. alterniflorum, in which the contribution of Littorelletea uniflorae species is appreciable, are clearly associated with soft waters and their habitats are representative of the Littorelletea uniflorae class. The massive development of the phytocoenoses with both L. uniflora and M. alterniflorum in the Lobelia lakes is not always indicative of the increase in water hardness and euthrophication of waters typical of the communities of the Littorelletea uniflorae class. The M. alterniflorum dominated phytocoenoses without other Littorelletea species could be good indicators of the above processes taking place in such water ecosystems.
EN
Phytosociological and habitat studies of Sphagnum denticulatum and Warnstorfia exannulata phytocoenoses from Polish Lobelia lakes have been conducted. The present results were compared with data on Isoetes lacustris community. It is demonstrated that both communities of mosses are distinct with respect to their floristic composition. Moreover, they differ significantly from the patches of I. lacustris with regard to many properties of water and substrates. The phytocoenoses of S. denticulatum are associated with softer waters, poorer in Ca2+, Na+, NH4+ and dissolved organic matter, but richer in total Fe than those of I. lacustris. They are also distinguished by lower values of electrolytic conductivity. The substrates they inhabit are more strongly hydrated and richer in organic matter, total N, dissolved SiO2, Ca2+ and Na+, but poorer in PO43-. The W. exannulata phytocoenoses are also confined to softer waters with lower Ca2+, NH4+ and dissolved organic matter contents than those of I. lacustris. Their substrates are more strongly hydrated and have higher contents of organic matter, total N and Na+ but lower amounts of PO43-. In addition the waters of W. exannulata phytocoenoses are characterized by higher pH values and lower concentration of dissolved SiO2. The substrates are less acidic and richer in NO3-, but poorer in total Fe. The differences between the habitats of the S. denticulatum and W. exannulata phytocoenoses are also distinct. The former inhabit more acidic waters, richer in dissolved SiO2 and total Fe, but with lower values of electrolytic conductivity and concentration of Na+. Their substrates are distinguished by higher contents of organic matter and Ca2+, as well as by lower amount of NO3-. In view of the fact that the above phytocoenoses of mosses are distinct with respect to their floristic composition and are associated with specific habitats in which they form dense mats close to the bottom of the lake, they should be classified as distinct associations (Sphagnetum denticulati and Warnstorfietum exannulatae) in the system of aquatic communities (Class: Utricularietea intermedio-minoris).
EN
Pinguicula vulgaris (Lentibulariaceae) in north eastern Poland. Fragmenta Floristica et Geobotanica Polonica 8: 105–111. Kraków. PL ISSN 1640 629X. ABSTRACT: Pinguicula vulgaris L. has previously been recorded from four localities in the Suwałki Lakeland in the north easternmost part of Poland, but in at least at two of these stations the species has not been observed within the last decade. A new locality for this species was discovered in June 2000 in a small fen on the left hand side of the Kunisjanka stream in the village of Berżniki south east of Sejny. This is the richest locality for P. vulgaris in this part of the country and approximately 210 individuals were observed in an area of about 100 sq. m. The locality is described in detail and accompanying vascular plants and bryophytes are enumerated. Amongst the latter, four species are of special interest, namely Paludella squarrosa, Tomentypnum nitens, Helodium blandowii and Bryum weigelii which are considered to be glacial relicts in Central Europe. The local distribution of the species in north eastern Poland is presented and a distribution map showing its range in Poland as a whole is also provided.
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