The expansion and decline of charophyte communities in lakes within the Sejny Lake District (north-eastern Poland) and changes in water chemistry

AbstractOver the last 25 years, considerable changes have been observed in the littoral vegetation of 11 lakes within the Sejny Lake District. In eight lakes (Dowcień, Jurkowo, Kunis, Miałkie, Pilwie, Płaskie, Wiłkokuk, Zelwa) where Chara species dominated, their communities declined or disappeared completely. In four of these lakes (Dowcień, Jurkowo, Kunis and Miałkie), charophytes were replaced by communities of the class Potametea (mainly Nupharo-Nymphaeetum albae and Ceratophylletum demersi). In three other lakes (Pilwie, Płaskie and Wiłkokuk), the area covered by charophyte communities decreased. In Lake Zelwa, Charetum rudis and Charetum jubatae disappeared while Charetum tomentosae and Charetum fragilis expanded. A total area of charophyte communities remained approximately the same. A considerable increase in the water total hardness and PO43- concentration was noted in each of the eight lakes. In most of them increased levels of dissolved organic matter (measured as COD-KMnO4) and pH were detected as well. However, the increase in the PO43- concentration was smaller in Lakes Wiłkokuk and Zelwa in which only slight changes in the vegetation were observed. In the above two lakes, the concentration of dissolved organic matter decreased and low water colour values are now noted. In three lakes (Długie, Dmitrowo and Gajlik), the charophyte communities tended to expand under the condition of moderate or high (Lake Długie) PO43- concentration, while dissolved organic matter concentrations were low. These lakes are also characterized by low values of colour. Charophyte communities may persist in lakes for a long period of time even when there is a moderate increase in PO43- concentration until the colour of water distinctly increases (>20mgPtL−1)

Aneuploids in the shrub birch Betula humilis populations in Poland

Shrub birch (Betula humilis Schrk.) is endangered glacial relict growing in natural and drained fens and transitional mires. At present study we examined karyotypes of 103 individuals of B. humilis, collected in six populations from eastern and northeastern Poland. We found 60% of diploid individuals with 2n = 28. The rest of studied plants were aneuploids with 26, 27, 29, 30 and 31 chromosomes in their karyotypes. High frequencies of aneuploids in Polish populations of B. humilis could be a consequence of: (i) hybridization with congeneric species, (ii) stress resulting from range fragmentation, (iii) karyotype instability of individuals with 2n ≠ 28, or (iv) vegetative reproduction

Untersuchungen über Ökologie und Indikatorwert der Wasserpflanzengesellschaften in naturnahen Stillgewässern Polens

Die Arbeit ist eine Zusammenfassung von Untersuchungen über die Ökologie der Wasservegetation in naturnahen Stillgewässern in Polen, die am Lehrstuhl für Phytogeographie der Warschauer Universität durchgeführt wurde. Insgesamt wurden 532 Bestände von 18 Assoziationen aus den Klassen Lemnetea minoris Koch et Tx. 1954, Charetea fragilis (Fukarek 1961) Krausch 1964, Potamogetonetea Tx. et Prsg. 1942, Littorelletea uniflorae Br.-Bl. et Tx. 1943 untersucht. Es wird nachgewiesen, daß über das Vorkommen und die Entwicklung der Wasserpflanzengesellschaften im großen Maße die Wassereigenschaften entscheiden, die einmal mit dem Karbonatsystem zusammenhängen (Gesamt- und Karbonathärte, Gehalt an Ca, Mg), und außerdem mit denjenigen, die für Sauberkeit und Trophie des Wassers ausschlaggebend sind (Sauerstoffsättigung, Wasserfarbe, Gehalt an PO4-P, NH4-N, ges. Fe und gel. Si02). Unter den Bodeneigenschaften haben die größte Bedeutung: Wassergehalt, Oxydierbarkeit, Gehalt an organischer Substanz, Gesamtstickstoff, gel. Si02, SO4, pH-Wert, außerdem die Hauptbestandteile der Kalkgyttja (Ca, Mg, Na). Die pflanzensoziologische Einteilung der Wasserpflanzengesellschaften in selbständige Syntaxa nach dem Prinzip der floristischen Dominanz findet ihre Bestätigung in den Standortsbedingungen. Die einzelnen Gesellschaften oder Gruppen von Gesellschaften unterscheiden sich voneinander durch die Amplituden und Optima der Standortbedingungen; sie können daher einen Bioindikationswert haben.The present work aims to summarize the results of studies on ecology of aquatic vegetation conducted by the Department of Phytogeography of Warsaw University in natural water bodies in Poland. In total, 532 phytocoenoses of 18 associations from the following classes were investigated: Lemnetea minoris Koch et Tx. 1954, Charetea fragilis (Fukarek 1961) Krausch 1964, Potamogetonetea Tx. et Prsg. 1942, and Littorelletea uniflorae Br.-Bl. et Tx. 1943. It was demonstrated that the occurrence and development of aquatic plant communities is determined by following properties of water: factors associated with the carbonate complex (carbonate and total hardness, contents of Ca, Mg) and factors indicating water richness and purity (oxygen saturation, colour, concentrations of PO4-P, NH4-N, total Fe and dissolved Si02). The following substrate properties evidently influence the ecological distinctness of the plant associations studied: hydration, oxidability, content of organic matter, total nitrogen, dissolved Si02, SO4, pH and main components of calcareous gyttja (Ca, Mg, Na). Phytosociological differentiation of water plant communities on the basis of floristic dominance as distinct syntaxa was confirmed by the habitat differentiation. Individual associations or their groups vary with respect to amplitudes and optimum of the habitat conditions and consequently they can be considered as indicators of the various types of littoral habitats

Aquatic vegetation as an indicator of littoral habitats and various stages of lake aging in north-eastern Poland

The habitats of 356 phytocoenoses dominated by 15 species of aquatic plants were investigated. Among the properties of water, Na+, pH, total Fe, Ca2+, NO3−, SO42−, hardness and COD-KMnO4 were the most important in differentiating the habitats of the phytocoenoses studied. Considerable physicochemical differences were found between the waters of the phytocoenoses of Ranunculus circinatus (hard waters rich in Na+), Nuphar pumila (soft waters with high levels of total Fe), Elodea canadensis, Ceratophyllum demersum (alkaline waters) and Stratiotes aloides (waters containing high concentrations of Ca2+ and SO42−). The substrate properties that best differentiated the habitats compared were PO43−, hydration, organic matter content, total N, dissolved SiO2, Ca2+, Na+ and pH. Patches of R. circinatus inhabited substrates containing the highest levels of PO43−. Those of S. aloides were associated with substrates poor in PO43−. Patches of C. demersum were confined to substrates rich in total N. Phytocoenoses of R. circinatus were associated with large lakes, whereas those of N. pumila were restricted mostly to smaller lakes. The deepest parts of lakes were inhabited by Potamogeton lucens. Phytocoenoses of S. aloides occurred mostly in shallow waters, on thick sediments. The investigated phytocoenoses also represent different stages of succession. The phytocoenoses of Potamogeton perfoliatus, R. circinatus, Myriophyllum spicatum and Polygonum amphibium, which develop on mineral substrates, initiate the process of succession, whereas those of Myriophyllum verticillatum, Nymphaea candida, Nymphaea alba, N. pumila and S. aloides, which inhabit highly hydrated organic substrates, are characteristic of the late stages of succession

State of the Population of Gladiolus imbricatus L. in a Molinia Meadow after Extensive Management and Abandonment

The abandonment of seminatural Molinia meadows observed in Central and Eastern Europe during the 20th century started the secondary succession and threatened the state and persistence of populations of numerous meadow species. Considering this, the aims of the presented investigations were to study the abundance and selected traits of individuals of Gladiolus imbricatus L. in extensively used (EM) and unmanaged for at least 15 years (UM) Molinia meadows (Southern Poland, Central Europe). Altogether, 125 juvenile individuals, 21 vegetative individuals, and 119 generative individuals of Gladiolus imbricatus were investigated. The field studies showed positive correlation among the height of shoots and other traits of generative individuals in both study patches. Moreover, the greater abundance of population of Gladiolus imbricatus (especially the greater number of juveniles), as well as the greater dimensions of leaf blades, shoots, inflorescence, and number of capsules in the patch UM, indicates the appropriate state of the population. These data indicate a positive influence of abandonment and evolving secondary succession on the Gladiolus imbricatus population within the Molinia meadows

A New Approach to Use of Traction Power Network in Poland for Charging Electric Vehicles

Electric vehicles are increasingly appearing on Polish roads due to a number of technical, legal and marketing conditions. However, electromobility is developing primarily in urban areas, mainly due to the unevenly developed infrastructure for charging vehicle batteries and the power grid. Therefore, solutions should be created that use the existing power infrastructure, including the use of railway power infrastructure (RPI). The railway power network covers a significant part of the country, including forest areas, and, above all, it very often intersects with road infrastructure or runs along roads. This paper raises issues related to the possibility of using RPI to charge the batteries of electric vehicles. After characterizing the technical, operational and legal requirements related to these technical systems, a concept of an electric vehicle charging system using RPI was developed, along with a demonstration of the possibility of its implementation, which was simulated using mathematical models developed by the authors

Genetic diversity and sexual reproduction in relict populations of Betula nana

In the present study, the impact of geographical isolation and habitat conditions on genetic diversity and sexual reproduction was tested in four relict populations of dwarf birch L. in Poland and Belarus. Amplified fragment length polymorphism (AFLP) method revealed that the endangered central European stands were not genetically extirpated compared with the widespread localities from Finland and Russia, which can result from infrequent outcrossing events in long-living clonal populations. However, genetic clustering methods indicated significant differentiation of the Polish populations because of their small sizes and long-term geographical isolation. Considerable numbers of empty seeds were observed in both relict and central locations, although fully developed seeds germinated better in widespread populations. Analysis of groundwater chemical parameters indicated that two relict populations were significantly different from the remaining samples with respect to pH, electrical conductivity and concentrations of phosphorus ions, which can also influence the efficiency of sexual reproduction. In the light of results obtained it seems that endangered localities are relatively stable.Betula nanaB. nan