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Individual marking is necessary for determining various elements of species ecology, but toe-clipping — a method frequently used in amphibian studies, is recently being questioned. Three water bodies (of 0.3 to 1.5 ha in size) used by common Bufo bufo for breeding, located within a large city (Warsaw, Central Poland), were chosen for the study. Captured toads had Passive Integrated Transponders (PIT) subcutaneously implanted under laboratory conditions. Marked toads were searched in consecutive breeding seasons. The recapture rate of males in particular ponds was up to 13% — much lower than in other studies carried out in non-urban habitats. 77% of re-trapped individuals were found in the next season after tagging. There were no differences in the frequency of re-trapped individuals in relation to the toe-clipping treatment, as some marked individuals had part of the toe (two phalanges) clipped for skelotochronological analyses. An individual from this group was observed to have regenerated the clipped toe after one year. We did not find any indication of better body condition among the re-trapped individuals when comparing them to the marked toads at the time they were first captured. The important advantage of PIT tagging is the fact that all individuals are marked in the same way and their handling is similar. This makes it possible to compare various demographic parameters (growth rate, survival etc.). In addition, the number of animals that can be permanently marked using PITs is several times higher than through the use of codes resulting from the clipping of fingers and toes.
The investigations were carried out in post-exploitation water bodies (subsidence pools, sand- and gravel pits) situated in urbanised and over-industrialised region of Upper Silesia. The least diversified leech (Hirudinea) communities occured in subsidence pools, because of the very high concentration of chlorides, sulphates and phosphates in their water, which is moreover very hard and of high BOD5 value. In other kinds of studied water bodies greater leech species diversity was observed. Most of the species found in studied water bodies occur commonly in various freshwater habitats, what may point out the lack of peculiarity of leech communities in these unnatural conditions.
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Inverse methods in hydrologic optics

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Methods for solving the hydrologic-optics inverse problem, i.e., estimating the inherent optical properties of a water body based solely on measurements of the apparent optical properties, are reviewed in detail. A new method is developed for the inverse problem in water bodies in which fluorescence is important. It is shown that in principle, given profiles of the spectra of up- and downwelling irradiance, estimation of the coefficient of inelastic scattering from any wave band to any other wave band can be effected.
The paper provides morphometric, physicochemical and vegetation structure of the 16 lakes in Drawieński National Park (DNP). These lakes showed considerable differentiation according to their morphometrical and physico-chemical variables. There are distinguished 4 groups of lakes: (1) throughflow lakes; (2) small, eutrophic non-throughflow lakes; (3) dystrophic lakes with humic water bodies; and (4) mesotrophic lakes. A dependence of the structure of the predominant vegetation types on morphometrical and physico-chemical variables was tested. Results of study of vegetation structure proves the initial classification of the lakes into several groups on the basis of environmental variables. The most important type of vegetation of throughflow lakes are helophytes and nymphaeids. The phytolitoral of eutrophic non-throughflow lakes is scanty. The vegetation of dystrophic lakes is dominated by species with floating leaves and mosses. The common vegetation of mesotrophic lakes is dominated by Chara species and elodeids.
The authors investigated the mycoflora developing on the carapace, muscles, brain and eggs of four species of crayfish. At total of 70 aquatic fungi was noted. Three species are new records for Poland. The highest number of fungus species develop on all body parts of crayfish in September, the lowest number in April.
Our paper proposes the evaluation of 5 select water bodies in Kraków (Bagry, Zakrzówek, Przylasek Rusiecki, and Kolna, and in the District of Krakóws water bodies formerly known as Kryspinów, currently “Zalew na Piaskach”). Their recreational values were assessed based on expert evaluation of 8 characteristics with the use of Saaty’s method to attribute weight to each characteristic. SWOT analysis was also applied, focussing on the problem of uncontrolled tourism. Kryspinow, Przylasek Rusiecki, and Kolna received the highest and very similar grades in terms of tourist attractiveness (2.475, 2.447, and 2.444, respectively), Bagry was slightly less attractive (2.224), and Zakrzówek received the worst score (0.796) due to its difficult access and lack of facilities.
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