Jan Divíšek

Refugial occurrence and ecology of the land snail Vertigo lilljeborgi in fen habitats in temperate mainland Europe

Vertigo lilljeborgi (Westerlund, 1871) is one of the rarest terrestrial snail species in temperate mainland Europe, where it is traditionally considered a glacial relict. This contrasts with its occurrence in northern Europe where it is a widespread species. This species prefers constantly wet habitats that are neutral to slightly acidic and avoids highly alkaline conditions, which is an extremely rare ecology for a Eurasian mollusc. Until 2012, only five historical records of this species were known in mainland Europe to the south of its main distribution in northern Europe. Since then, 20 new sites have been discovered, mostly located in the Hercynian Mountains (Bohemian Massif in the Czech Republic and Massif Central in France). In comparison with the boreal European and Alpine populations, those from the Hercynian Mountains inhabit acidic, rather soligenous and productive fens, strongly dominated by Sphagnum. Vertigo lilljeborgi does not occur in some sites with apparently suitable habitats as indicated by species composition of the vegetation. We observed a surprising correspondence between the occurrence of V. lilljeborgi and mean July air temperature and we report its first fossil record from the last glacial period from Central Europe. Although the number of its sites has increased recently, these sites represent highly unusual and unique habitats, vulnerable to drainage and destruction from human activities. This highlights the need for conservation efforts in most of the newly discovered isolated sites.

Distribution of alien animal species richness in the Czech Republic

Abstract Biogeographical barriers formed by natural forces over billions of years have been substantially disrupted by human activity, particularly in recent centuries. In response to these anthropogenic changes, global homogenization of biota is observed at an ever‐increasing rate, causing environmental and economic losses as well as emerging health risks. Identifying factors underlying alien species richness is essential for prevention of future introductions and subsequent spread. In this study, we examined the effects of environmental and human‐related factors on distribution of alien animal species richness in the Czech Republic (Central Europe). We compiled a set of maps showing the level of invasion of six categories of alien animal species in each of 628 grid cells (ca. 12.0 × 11.1 km) covering the Czech Republic. Relationships between alien species richness and 12 variables characterizing climatic conditions, topography, land cover, and human population size were calculated using the generalized least squares method. Species richness of all alien species, of invertebrates, and of terrestrial species showed the strongest positive relationship with mean annual temperature, while the number of black and grey (proposed prominent invaders) and aquatic species was most closely related to the presence of large rivers. Alien vertebrates showed a strong negative relationship with annual precipitation. The highest alien animal species richness was found in and near large population centers and in agricultural landscapes in warm and dry lowlands. The gateways for alien aquatic species are rather large rivers over sport fishing and aquaculture import. Compiled maps create a powerful visual communication tool, useful in development of programs to prevent future introductions.

Biogeographical patterns in vertebrate assemblages of the Czech Republic: regional division in the context of species’ distributions in Europe

Abstract. This study attempts to explore biogeographical patterns in vertebrate assemblages of the Czech Republic and to delineate faunal biogeographical regions of the country. We focused on native terrestrial species and first explored main gradients in the composition of their assemblages. The first gradient revealed by Principal Coordinate Analysis was best correlated with climatic variables, whereas the second gradient can be ascribed rather to longitude and to the associated habitat change. Using the spatially constrained clustering, the Czech Republic was divided into five cohesive regions and species above-average associated with these regions showed distinct distributions within the European continent. Delineated regions also significantly differed at least in three considered environmental variables. We provided clear evidence that species distribution data gathered by national mapping support main biogeographical patterns suggested by previously published expert-based classifications of the country. We also demonstrated that the fauna of the Czech Republic shows a biogeographical pattern very similar to that showed by natural habitats defined in terms of plant communities. This indicates that both fauna and flora of the Czech Republic yield to the same environmental forces and biogeographical processes such as spreading of faunistic and floristic elements from the adjacent Carpathian Mountains and the Pannonian Basin.

Biogeografické regiony České republiky

Kniha podrobně charakterizuje vsechny ctyři biogeograficke podprovincie a take 91 bioregionů CR. Každý bioregion je popsan z hlediska polohy, plochy, hornin, reliefu, půd, podnebi, aktualniho stavu krajiny, flory a fauny, vegetace potencialni i aktualni, dale pak dle geobiocenologicke typizace a kontrastů k okoli. Uvedena jsou i klicova chraněna uzemi. Soucasti publikace je podrobna mapa biogeografickeho cleněni CR v měřitku 1:500 000.