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PL
Celem badań było określenie wpływu wahań poziomu wód gruntowych, spowodowanych działalnością bobrów, na kształtowanie się składu florystycznego roślinności łąkowej na przykładzie bezleśnego fragmentu małej doliny rzecznej (rzeka Szum na Roztoczu Środkowym). Analizie poddane zostały również wybrane cechy populacji dwóch gatunków wieloletnich charakterystycznych dla zmiennowilgotnych łąk ziołoroślowych: Filipendula ulmaria i Cirsium oleraceum. Na stałych powierzchniach badawczych u znakowanych osobników odnotowywano liczbę pędów nadziemnych. Równolegle śledzono zmiany poziomu wód gruntowych w piezometrach. W płatach roślinności łąkowej w największym stopniu narażonych na podtopienie stwierdzono spadek różnorodności biologicznej oraz zmniejszenie się udziału gatunków charakterystycznych klasy Molinio-Arrhenatheretea. Reakcją populacji badanych gatunków na długotrwały stres wodny był spadek liczebności osobników i ramet oraz obniżenie się ich skupiskowości.
EN
The aim of the study was to determine the effect of fluctuation of the ground water level, caused by beaver activity, on the floristic composition of meadow vegetation in the fragment of small river valley (the Szum river, Central Roztocze). We analyzed selected traits of the populations of two perennial species characteristic of variously moist meadows: Filipendula ulmaria and Cirsium oleraceum. On permanent plots we noted the number of shoots (ramets) of marked individuals. Simultaneously, changes in the ground water levels were monitored in piezometres. In the patches of meadow vegetation under the greatest risk of flooding a decrease of biological diversity and reduce the share of species characteristic for the class Molinio-Arrhenatheretea was observed. The response of the populations of the species tested for long-term water stress was the decrease in the number of individuals and ramets, and reducing the degree of their clustering.
EN
In the studies on the metapopulation system two aspects are important: cognitive and practical. The former indicates that a metapopulation is a demographic structure of a higher level than coenotic or local populations and aims at recognition of relations between particular populations of a given species. The practical aspect reflects the issues of the dynamics and/or the extinction rate in particular populations and indicates potential habitats which can be colonized. The study of the Senecio rivularis metapopulation is created by relatively abundant population of ragwort in the Roztocze Highlands, Roztocze National Park, south-eastern Poland, recognized as the source population and three other called marginal or sink populations as well as potentially suitable habitats which are distributed as islands in adjacent hydrogenic areas. The distances between particular populations range from 1.3 to 6.5 km. As a long-lived, iteroparous rhizomatous clonal plant, insect-pollinated and anemoc anemochoric one, so having adaptations both for 'escape in time' and 'escape in space', S. rivularis may be treated as the model object of the study on the metapopulation level. The following hypotheses were put forward: (1) the spatial pattern, size and life-stage structures of particular populations reflect the time of their origin in the meta-system; (2) hydrochory is a complementary or alternative way of migration of anemochoric diaspores; (3) local watercourses and hydro-technical activity affect the formation and dynamics of S. rivularis metapopulation. The multi-aspect studies of the source population were conducted in the years 1987.2007. They aimed to establish the density, spatial pattern and life-stage structure of the S. rivularis population, both at a large scale, i.e. in the whole population (three times) and at a small scale, i.e. on the level of three particular clumps (four times). The size structure of generative genets and ramets in the whole population was aleborated five times. In the greatest of the other populations in the meta-system, the size structure was elaborated twice (2002, 2007) while the study of spatial and life-stage structures was done only once, in the first period, because of the disturbance of a greater part of the population in the next years. In the two remaining localities all plants were counted thanks to small abundance of the populations. Considerable changes in the spatial organization and life-stage structure of genets in the source and sink populations exhibited that colonization in the meta-system of S. rivularis proceeds in accordance with an island model of the 'stepping stone' type, downstream the river. Renaturalization of water relations of river catchment areas and construction of the so-called small retention objects affect the formation and dynamics of S. rivularis metapopulation which reflects at least some dynamics phases observed at the level of the source population: progressive, stable, fluctuation and/or regressive, and extinction phases. Knowledge of the density, life-stage and size structures of plants in a population facilitates a highly reliable determination of the development phase of a given local population in the meta-system and prognosis of its future.
EN
Our research was conducted in two different mire habitats . in the minerotrophic and ombrotrophic mires adjoining the lakes (LM) of the Łęczna-Włodawa Lakeland and in the eutrophic and calcium-rich mires of the river valleys (RM) of the Roztocze Highlands region (both study regions in Eastern Poland). The study aimed to evaluate (1) the position of mire phytocoenoses in the environmental gradient - from minerotrophic to ombrotrophic ones, (2) the influence of the species and life-form composition of plant communities on the density of bryophytes, and (3) the quantitative and sociological relations between the density of vascular plants and bryophytes. Phytosociological releves (180) were made in six lakeland mires and in four river valleys. The area of each phytosociological releves (16-25 m2) represented species composition and vertical structure of communities. In the study of the relation vascular plants-bryophytes we took into consideration the following parameters: species abundance, cover of particular plant layers (trees, shrubs, herbs, bryophytes), and the number of species in particular life-form groups. In the LM the cover of particular layers was correlated negatively with the abundance of Sphagnum mosses. Betula pendula, B. pubescens and Frangula alnus overgrowing the LM affect negatively the abundance of some peat mosses. Less distinct relations were found between the tree density and bryophyte cover in the RM, but there is a positive correlation between the shrub cover and its predominant species - F. alnus - and the abundance of Polytrichum commune. Taking into account the relations between the herbaceous cover and the abundance of bryophytes, the dependencies are also less pronounced in the RM phytocoenoses. A negative effect of the herbaceous cover and its species richness on the abundance of P. commune was observed, as well as positive relation between the number of herbaceous species and the abundance of Calliergonella cuspidata. In the LM phytocoenoses, a negative correlation was found in the case of S. palustre, while in the case of Aulacomnium palustre and S. cuspidatum the relations were positive. Among herbaceous plants of LM habitats the biggest number of statistically significant correlations were observed for abundance of Carex lasiocarpa and different bryophytes, while in the RM habitats the correlations between the abundance of bryophyte and vascular plant layers are less distinct.
EN
The idea of using ozone to disinfect root canals is of recent origin. The wide acceptance of epoxy resin-based sealers lead us to investigate whether ozone can influence the adhesion to the dentin. In this study, we tested the shear bond strength of AH Plus and EZ Fill. Forty freshly extracted bovine teeth were randomly divided into 5 groups. 16 of these samples were treated with ozone for 60 seconds (HealOzone, Kav)). 8 samples were conditioned with the G Bond bonding system. The groups tested were: (1) AH Plus, (2) AH Plus and ozone, (3) EZ Fill, (4) EZ Fill and ozone, (5) AH Plus and G Bond. 48 hours after being prepared the specimens were tested for shear bond strength. Statistical analysis showed significant differences between materials (AH Plus > EZ Fill) and significant, positive influence of ozone and bonding agent on the shear bond strength.
EN
The results of micropaleonthological studies of the Sarmatian (upper Miocene) Krakowiec Clays from primary deposit as well as re-deposited ones were applied to the analysis of the stratigraphic profile of the Sopot valley fills. The study site was at the break section of the Sopot River valley in a contact zone of southern escarpment between the central part of the Roztocze and Sandomierz Basin regions (SE Poland). Species of fossil microfauna (foraminiferans, radiolarians), sponges and mollusks, as well as residual deposits were used. The documented, even if apparently small change in the lithostatigraphic profile of the Sopot valley fills, i.e., the presence of pre-Pleistocene deposits in its floor, is very important for the valley history and for interpreting other problems of river breaks and the Roztocze escarpment zone itself, e.g., sclae of the Holocene movements elevating the Roztocze Region, and their effect on expected intensity of deep fluvial erosion. In the sub-scarp zone of the Tomaszów Roztocze subregion the Krakowiec Clays occur rather shallowly. In the Sopot valley (‘Czartowe Pole’landscape preserve) they are in contact with calcareous formations. In two levels of natural clays’exposures, a dozen or so foraminiferan taxa were found. They were also below the primary deposit on the floor levels of the Sopot valley fills. The residuum of the studied strata consists of glauconite and pre-Pleistocene quartz sands, without silicate and alumosilicate, typical for postglacial formations. The Sarmatian clays present in residue were redeposited at least in the pre-Pleistocene. From the clays top up to the surface of valley fills, are Holocene deposits. The study revealed that: (1) during the Holocene and earlier the Sopot valley fills were not removed completely; (2) the floor of the valley is made not of the youngest, Holocene strata, but much older; (3) the presence of the Sarmatian microfauna in the alluvia allows to date the studied deposits as pre-Pleistocene (Pliocene?); (4) fine quartz sands and glauconite (a specific form of hydromica) both forming the residuum of the studied valley fill levels, together with the absence of other silicates and alumosilicates that are common in the Pleistocene formations, exclude the studied Krakowiec Clays from the group of glacial or fluvioglacial (Pleistocene) formations; (5) the youngest (latest Pleistocene –Holocene) movements elevating the Roztocze Region and the resulting deep fluvial erosion do not correspond with shallow occurrence of the pre-Pleistocene valley fills; this requires further discussion.
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