Wyniki wyszukiwania - Biblioteka Nauki

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Cladoceran fauna from the archeological site vladar in Czech Republic

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Novakova K.

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tom Vol. 22

51-54

EN

The study described in this paper is a part of a multi-proxy project, which deals with sediments originating from a former artificial water reservoir situated at the large fortified hilltop site of Vladao. The oldest sediments were deposited around 350 BC and sedimentation continues till recent times. Number of palaeoecological analyses have been applied (pollen, macroremains, charcoal, wood, Cyanobacteria, algae, fungi, Cladocera, chemical elements, radiocarbon dating, archaeological artefact). The present contribution deals with analysis of chitinous fragments of Cladocera found within the trench. The results of this study clearly suggest a connection between the influence of human activity on the hilltop and the trophic status of the water in the cistern. Some phases of increased water eutrophication were distinguished on the basis of Cladocera species preferring nutrient rich water (Chydorus sphaericus, Bosmina longirostris).

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Development of the Kubłowo palaeolake, central Poland, during the Eemian Interglacial as against subfossil Cladocera analysis - preliminary results

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Niska M. , Roman M.

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2014

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tom Vol. 31, Nr 1

31--38

EN

The results of analysis of Cladocera occurrence in lacustrine sediments from the Kubłowo site have been presented. Lacustrine and peat deposits found there have been previously analyzed for pollen content (depth of 11.1-3.8 m) and represent a longest continuous Eemian-Vistulian succession in central Poland (Roman and Balwierz, 2010). Cladocera analysis was carried out on 25 samples from the depth of 9.20-10.5 m of an Eemian age section. The section consists of fine organic sand, silt with organic matter and gyttja. Identified were 19 species of subfossil Cladocera and five zones of fauna development were distinguished. In the early and mid-Eemian low frequency zooplankton in the palaeolake has been found. Best conditions for zooplankton development occurred in the late Eemian (R PAZ E6, E7). At the end of the Eemian a significant change of climate in a deterioration of environmental conditions and decreased presence of zooplankton has been noted. Cladocera results and the pollen data enable a reconstruction of the climatic and environmental changes in the Kubłowo palaeolake.

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Fossil Cladocera remains in the Eemian sediments - preservation, frequency and dominant species

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Niska M.

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tom Vol. 29

31--43

EN

This paper presents the results of fossil Cladocera analysis using material obtained from seven palaeolakes of the Eemian interglacial located in Poland. The main aim of this study was to investigate the state of preservation and diversity of species in the Eemian Cladocera. The studied Eemian lakes were formed at the end of the Wartanian Glaciation in tunnel and kettle holes. They had preserved a continuous record of environmental changes throughout the Eemian interglacial, until the Vistulian Glaciation. Cladocera fossils found in Eemian sediments were thinner and had a more damaged structure than fossils from the Holocene. Low degree of fossil preservation forced to develop an alternative method for preparation of the fossils for the microscopic analysis. Cladocera species found in the examined palaeolakes corresponded to the present-day species inhabiting Poland and Central and Northern Europe. The changes in species composition resulting from climate changes corresponded to the current geographic distribution of Cladocera. Despite the poor condition of the obtained fossil remains, the results showed that cladoceran fossils in sedtments of palaeolakes may be used in the reconstruction of environmental conditions from the period preceding the last glaciation.

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Fluvial processes under late Pleni-Weichselian environmental conditions: a case study from the Warenka site in central Poland

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Petera-Zganiacz J. , Brzozowicz D. , Pawłowski D. , Kaczmarek P.

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2024

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tom Vol. 30, No. 2

81--94

EN

Strong aggradational tendencies during the late Pleni-Weichselian have been noted in river valleys in central Europe. Thick series of mineral deposits were laid down, but also organic or mineral-organic horizons were formed under favourable conditions. The study area is located in the central section of the valley of the River Warta within an extraglacial area of the last glaciation. At the Warenka site alluvia, that attain thicknesses of 16 m, were analysed. Lithofacies analysis, OSL dating of mineral sediments and radiocarbon dating of organic and mineral-organic strata were performed. Organic and mineral-organic deposits were also subjected to pollen and Cladocera analyses. Together this set of analyses was used to determine fluvial processes and environmental conditions during the late Pleni-Weichselian. The results obtained allow the conclusion that these levels were deposited in the sedimentary environment of a low-energy, sand-bed braided river, which operated in the period from approximately 30 to 24 cal kBP – the late Pleni- Weichselian. During this time, there were periods when shallow water bodies were formed on the valley bottom, where deposition of organic material was possible. The presence of this type of sediment made it possible to reconstruct the vegetation cover; this had the character of a steppe-tundra, periodically shrubby steppe-tundra. Short-lived reservoirs were characterised by shallow-water settings with weakly developed vegetation and temporary influence of floodwaters as indicated by changes in cladoceran assemblages. Pollen spectra, low concentration of cladocerans, as well as the presence of the cold-tolerant Cladocera taxa are indicative of cold climatic conditions.