This classic area of Silurian and Devonian stratigraphy provided a number of ecological and paleoenvironmental observations during the last decade. Comparative studies of spontaneous successions in abandoned quarries demonstrated that natural processes provide their optimum revitalization. New archaeological records, paleozoological evidence from caves and the discovery of a Late Bronze Age hillfort confirmed that the high biodiversity of this landscape has resulted from a harmonious interaction of natural processes with human activities since the 5th millennium BC. and Vojen Ložek.
Faunistika není mrtvý obor zoologie. V prvním dílu diskutujeme záludnosti faunistiky a rozdíly mezi faunistikou a sběratelstvím. Měkkýši byli vybráni jako modelová skupina organismů, na nichž ukazujeme historii vývoje oboru v Českých zemích a vývoj měkkýší faunistiky., Faunistics is not a dead subject of zoology. The challenges of faunistics and the difference between faunistics and collecting are discussed. Molluscs were chosen as a model group to show the history of the subject in the Czech Republic and the development of mollusc faunistics., and Vojen Ložek, Lucie Juřičková.
Detailní výzkum recentní fauny umožňuje srovnání s výskytem jednotlivých druhů v období od glaciálu, přes oteplení na počátku holocénu, klimatické optimum holocénu i s nástupem zemědělství až po zhoršení podmínek v mladším holocénu. Fosilní záznamy mohou pomoci při vysvětlení absence konkrétních druhů na určitém místě v současnosti. Autoři článku také diskutují vliv ekologických fenoménů na lokální druhovou diverzitu - některé z nich druhovou bohatost zvyšují (říční, krasový a vrcholový fenomén), jiné ji snižují (hadcový a pískovcový fenomén). Faunistický výzkum musí probíhat ruku v ruce s taxonomickými studiemi. I v tak malakologicky prozkoumaných zemích, jako je Česká republika, jsou stále objevovány pro dané území nové druhy, včetně invazních – žádné území není prozkoumané jednou provždy. Článek zmiňuje některé důležité faunistické objevy na území České republiky, tak připomíná zásadní význam tohoto dnes podceňovaného oboru a nastiňuje také jeho výhled do budoucnosti., It is important to study the occurrence (presence vs. absence) of extant species; fossil records can help explaining the patterns. The role of ecological phenomena on local species diversity is discussed. The impact of ecological phenomena on local species diversity is discussed – some of them increase (river, karst and hilltop phenomena), while others decrease the species diversity (serpentine and sandstone phenomena). Faunistic research must go hand in hand with taxonomic research. Even in a well-explored country such as the Czech Republic, new species for this area are constantly being discovered including some invasive species, making faunistic research a never-ending story., and Lucie Juřičková, Vojen Ložek.
Cryptic immigrants are common species incorporated in near-natural biocoenoses that occur only in Holocene, mostly very recent deposits, being absent from older (Pleistocene) formations. This is true of Alinda biplicata, Oxychilus cellarius and other presented species. This also applies to isolated occurrences of Itala ornata or Cochlodina commutata that entered the Bohemian Uplands by aerial dispersal from the south. In the Pleistocene, the very early appearance of some southern species (e.g. Drobacia banatica) from the very be-ginning of the interglacial periods is reminiscent of modern snail invasions. How-ever, the former was initiated by the abrupt increase in temperature and moisture., Vojen Ložek, and 1 barev. fot., 10 čb. fot.
The importance of stream corridors and flood deposits for the spreading of molluscs is demonstrated using some examples from the Czech territory. Three types of floodplain debris, which contain shell accumulation, are distinguished: allochtonous debris accumulated by river flow on riversides, autochtonous accumulation in quiet parts of alluvium far from the main flow, and accumulation caused by strong turbulence during flooding. and Vojen Ložek, Lucie Juřičková.
The conditions for the use of snail shells from flood deposits are characterized. Snail s can spread up and/or down stream, but suitable flood deposits containing shells are usually found in the lowlands. Flood debris can contain shells of rare and subterranean species, occurring in a river environment in negligible numbers. Fossil shells in this material indicate nearby fossiliferous sediments. and Vojen Ložek, Lucie Juřičková.
Fossil continental molluscs have not hitherto been regarded as reliable paleoenvironmental indicators. Little was known about their ecological requirements or their position in characteristic biomes of the Quaternary climatic cycle, for instance in the loess steppe. Only recent analyses of their assemblages in a broad environmental context have shown that they are indicative of a number of important environmental phenomena in the same way as pollen grains or vertebrate remains. and Vojen Ložek.