Range expansion of an endangered beetle: Alpine Longhorn Rosalia alpina (Coleoptera: Cerambycidae) spreads to the lowlands of Central Europe

Rosalia alpina is an endangered and strictly protected icon of saproxylic biodiversity throughout its range. Despite its popularity, information on its habitats and host-plants is insufficient, which may compromise the adoption of suitable conservation strategies. R. alpina has been considered as montane and associated with beech in central Europe, whereas in southern Europe R. alpina has often been reported from lowlands and its host spectrum is broader. We present evidence of an elm-feeding population ofR. alpina occurring in a lowland (beechfree) forest in the Czech Republic. This plus other information available suggest, that R. alpina spreads into central European lowland forests along large rivers, and that spectra of hosts and habitats exploited by R. alpina in Central Europe are wider than generally thought. Alteration of its habitat preference has either occurred in Central European populations, or lowland-inhabiting populations from the South are spreading northwards, possibly due to climate change

Making a replica of cannon barell

The topic of the bachelor's thesis is the production of a cannon replica mainly on the basis of a suitably chosen technology. On the basis of a literary study, which consisted mainly of an examination of historical sources, gravitational casting was chosen. The mold was formed from the inorganic molding compound GEOPOL. The model of the barrel was created according to the historical model of the ship's cannon. The model was created by CNC machining and the material is artificial wood. Cast iron with flake graphite, which has suitable foundry properties, was chosen as the casting material. The conclusion of the thesis contains an evaluation of the selected technology

Making a replica of cannon barell

Tématem bakalářské práce je výroba repliky dělové hlavně podle vhodně zvolené technologie. Na základě literární studie, která se skládala převážně se zkoumání historických zdrojů, bylo zvoleno gravitační odlévání. Forma byla vyrobena z anorganické formovací směsi GEOPOL. Model hlavně byl vytvořen dle historické předlohy lodního děla CNC obráběním a materiálem je umělé dřevo. Litina s lupínkovým grafitem byla zvolena jako materiál pro výrobu odlitku, jelikož má vhodné slévárenské vlastnosti. Závěr práce obsahuje zhodnocení zvolené technologie.The topic of the bachelor's thesis is the production of a cannon replica mainly on the basis of a suitably chosen technology. On the basis of a literary study, which consisted mainly of an examination of historical sources, gravitational casting was chosen. The mold was formed from the inorganic molding compound GEOPOL. The model of the barrel was created according to the historical model of the ship's cannon. The model was created by CNC machining and the material is artificial wood. Cast iron with flake graphite, which has suitable foundry properties, was chosen as the casting material. The conclusion of the thesis contains an evaluation of the selected technology.

Organic matter and fine grains as possible determinants of spatial and seasonal variability in bed sediment fauna: A case study from a Hercynian gravel stream

AbstractThe spatial and seasonal distributions of organic matter and fine grains were tested as possible determinants of fauna distribution in bed sediment of a Hercynian gravel stream. Invertebrate densities and the amounts of fine grains and organic carbon were assessed in freeze-core samples taken along 70cm depth profiles at three different positions in the stream channel. Sampling was conducted on five occasions of low discharge over two years. The variability in invertebrate community composition was analysed using Detrended Correspondence Analysis with posterior projection of explanatory variables; Variation Partitioning was used to estimate the independent and shared effects of the explanatory variables. We found that the best predictors of the invertebrate community were spatial variables (depth, position in the channel) and then variables influenced by seasonal patterns (surface water temperature and discharge). The influence of organic matter and fine grain content was significant only after eliminating spatial autocorrelation. High amounts of organic matter, randomly accumulated in the sediment, improved the model by explaining high fauna densities. The fine grain content was not a limiting factor to fauna at our study site. It is possible that the large amount of mica flakes in the sediment has caused the arrangement of grains with a pore space sufficient for fauna even when fine grain content was high

Macroinvertebrate herbivores and epilithon algae community of a stream affected by mineralized heated mining water inflow

The main aims of this study were to analyse the effect of a mineralized heated water inflow from a uranium ore processing plant on the abundance and diversity of epilithon and macroinvertebrate herbivores as well as to identify changes in functional feeding groups. In total, four sampling sites were selected. One site was on the mining water tributary and three sites in a recipient natural stream (the Nedvědička River, Czech Republic): one of them upstream and two downstream from the mining effluent. Samples were taken monthly during the period 2008–2009. The number of species in the epilithon was higher downstream from the tributary and we also recorded a small increase in density. We observed significant changes in the taxonomical composition of epilithon and macroinvertebrate communities downstream from the tributary. Taxa richness of macroinvertebrates was similar between sampling sites. A small drop in macroinvertebrate abundance immediately downstream from the tributary was followed by a significantly elevated number of herbivores, especially scraper-collectors, at the more downstream site. Alteration of the species composition and abundance of herbivorous macroinvertebrates in the Nedvědička River could be explained by a combination of a change in food availability and the physico-chemical properties of the water.The mining water altered abundance and taxa richness of herbivorous macroinvertebrates and their food – epilithic algae. Changes in community composition and function were recorded, scraper-collectors and invasive species became dominant in affected sites. Understanding the ecological effects of mining water effluent is useful for river protection management

Hydroclimatic and hydrochemical controls on Plecoptera diversity and distribution in northern freshwater ecosystems

Freshwater ecosystems in the mid- to upper-latitudes of the northern hemisphere are particularly vulnerable to the impact of climate change as slight changes in air temperature can alter the form, timing, and magnitude of precipitation and consequent influence of snowmelt on streamflow dynamics. Here, we examine the effects of hydro-climate, flow regime, and hydrochemistry on Plecoptera (stonefly) alpha (α) diversity and distribution in northern freshwater ecosystems. We characterized the hydroclimatic regime of seven catchments spanning a climatic gradient across the northern temperate region and compared them with estimates of Plecoptera genera richness. By a space-for-time substitution, we assessed how warmer temperatures and altered flow regimes may influence Plecoptera alpha diversity and composition at the genus level. Our results show wide hydroclimatic variability among sites, including differences in temporal streamflow dynamics and temperature response. Principal component analysis showed that Plecoptera genera richness was positively correlated with catchment relief (m), mean and median annual air temperature (°C), and streamflow. These results provide a preliminary insight into how hydroclimatic change, particularly in terms of increased air temperature and altered streamflow regimes, may create future conditions more favorable to some Plecopteras in northern catchments