The Influence of the Zebra Mussel (Dreisena Polymorhpa) on Magnesium and Calcium Concentration in Water

In this study we examined changes in magnesium and calcium ion concentrations depending on Zebra Mussel biomass, pH values and temperature. We performed field experiments in years with different weather conditions using twelve 200 litre polycarbonate containers filled with 150 litres of non-filtered water from lowland, eutrophic reservoirs. Three treatments of the experiment were represented by: Phyto control with non-filtered water, Phyto+Dreis A with Zebra Mussel biomass of 500 g/m2, and Phyto+Dreis B with Zebra Mussel biomass of 1.000 g/m2. Magnesium and calcium ions concentrations were analyzed on an ion chromatograph (Dionex-1000). Results indicated a significant reduction in magnesium and calcium ion concentrations by Zebra Mussels (independent of mussel biomass), especially in the year with higher and more stable average temperatures. Mg concentration was significantly negatively correlated with temperature in this year. In both years of study the magnesium and calcium ion concentrations were negatively correlated with pH. Analyses of the Zebra Mussel's impact on magnesium and calcium loss from water, linked with the influence of physical factors (temperature and pH), may be valuable for the management of invaded ecosystems

A new find of mammoth tusk in loess-like sediments of the Zakliczyn Basin (Outer Western Carpathians, Poland)

In June 2007, in a valley side of a small stream close to Janowice in the Western Outer Carpathians of Poland, a 1.8 m long mammoth tusk was found within loamy-debris solifluction sediments, ca. 1 m thick. These discordantly overlie a 4-m-high strath built up of steeply dipping sandstones of the Krosno beds of the Skole Nappe, being in turn covered by 7.5-m-hick loessial silts and loess-like slopewash sediments. The latter are overlain at the top by another solifluction cover, ca. 1.5 m thick. The mammoth tusk belonged to an adult animal, probably 30-60 years old. The succession of malacofaunistic assemblages within loess-like sediments indicates a cold, polar climate, and an environment resembling tundra developed upon moderately moist substratum during the last glacial stage. The lower part of malacological sequence enriched in mesophile species probably refers to the Vistulian (Weichselian) interpleniglacial period. The middle part, indicative of more dry habitats, can be associated with the younger Pleniglacial, whereas the top part should represent the terminal phase of the latter. Sediments bearing the mammoth tusk were probably deposited at the turn of the Vistulian older Pleniglacial and Interpleniglacial time

Tracing human mobility in central Europe during the Upper Paleolithic using sub-seasonally resolved Sr isotope records in ornaments

Mobility of people and goods during the Upper Paleolithic has proven difcult to reconstruct given the relative rareness of remains. Nevertheless, archaeological contexts like the Late Pleistocene horizon of Borsuka Cave (Southern Poland) represent a unique opportunity to explore patterns of objects’ transportation across Central Europe. We investigated the origin of four ornaments made of European elk (Alces alces L.) incisors recovered at Borsuka Cave – the oldest known burial site in Poland, possibly a child grave. Laser-ablation plasma source mass spectrometric analyses of trace elements and Sr isotopic compositions revealed that one elk was roaming within a geologically uniform area while the others changed their pastures during their lifetimes. The non-local origin of the elk teeth is inferred from their exotic Sr isotopic compositions and the lack of evidence for the presence of elk in this territory during the Pleistocene. Instead, the elks’ Sr isotopic composition show good agreement with sites near the Austria-Slovakia border region and northern Hungary, ~250km away from the study site. We argue that the artefacts were most likely brought to Borsuka Cave by humans or by a network of exchange, so far never reported in the time range 32.5–28.8 ka cal BP for Southern Poland

Nonreceding hare lines: genetic continuity since the Late Pleistocene in European mountain hares (Lepus timidus)

Throughout time, climate changes have caused substantial rearrangements of habitats which have alternately promoted and disfavoured different types of taxa. At first glance, the mountain hare (Lepus timidus) shows the typical hallmarks of a cold-adapted species that has retreated to refugia since the onset of the current Holocene interglacial. In contrary to expectations, however, the species has a high contemporary genetic diversity with no clear differentiation between geographically isolated populations. In order to clarify the phylogeographic history of European mountain hares, we here analysed ancient DNA from the glacial populations that inhabited the previous midlatitude European tundra region. Our results reveal that the Ice Age hares had similar levels of genetic variation and lack of geographic structure as observed today, and the ancient samples were intermingled with modern individuals throughout the reconstructed evolutionary tree. This suggest a temporal genetic continuity in Europe, where the mountain hares were able to keep pace with the rapid changes at the last glacial/interglacial transition, and successfully track their shifting habitat to northern and alpine regions. Further, the temporal demographic analyses showed that the species’ population size in Europe appear to have been tightly linked with palaeoclimatic fluctuations, with increases and declines occurring during periods of global cooling and warming, respectively. Taken together, our results suggest that neither habitat shifts nor demographic fluctuations have had any substantial impact on the genetic diversity of European mountain hares. This remarkable resilience, which contrasts to a majority of previously investigated cold-adapted species, is likely due to its generalist nature which makes it less vulnerable to environmental changes

Diversity of muskox Ovibos moschatus (Zimmerman, 1780) (Bovidae, Mammalia) in time and space based on cranial morphometry

Muskox Ovibos moschatus is a Pleistocene relic, which has survived only in North America and Greenland. During the Pleistocene, it was widely distributed in Eurasia and North America. To evaluate its morphological variability through time and space, we conducted an extensive morphometric study of 217 Praeovibos and Ovibos skull remains. The analyses showed that the skulls grew progressively wider from Praeovibos sp. to the Pleistocene O. moschatus, while from the Pleistocene to the recent O. moschatus, the facial regions of the skull turned narrower and shorter. We also noticed significant geographic differences between the various Pleistocene Ovibos crania. Siberian skulls were usually larger than those from Western and Central Europe. Eastern Europeanmuskoxen also exceeded in size those from the other regions of Europe. The large size of Late Pleistocene muskoxen from regions located in more continental climatic regimes was probably associated with the presence of more suitable food resources in steppe-tundra settings. Consistently, radiocarbon-dated records of this species are more numerous in colder periods, when the steppe-tundra was widely spread, and less abundant in warmer periods

Investigating climate at the Upper Palaeolithic site of Kraków Spadzista Street (B), Poland, using oxygen isotopes

Between 50,000 and 20,000 years ago, Europe experienced a series of rapid climate change events known as the Dansgaard-Oeschger cycles, which may have made areas of northern Europe more attractive for occupation by early modern humans at certain times than at others. This paper investigates when humans were occupying northern Europe in relation to these climatic changes at the archaeological site of Kraków Spadzista Street (B), by applying oxygen isotope analysis of mammoth tooth enamel carbonates (d18O and d13C) found at the site. The new isotopic data suggest that mean annual temperatures at Kraków Spadzista were 4-9oC? colder than present and, based on comparisons with previously published isotopic data for mammoth in Europe, the Kraków assemblage most likely formed during a cold DansgaardeOeschger event. This suggests modern humans were able to occupy and survive in this area of northern Europe during the harsh cold phases that affected Europe at this time