Michal Horsák

Masaryk University | MUNI · Department of Botany and Zoology

This book includes all know species of molluscs recorded in the Czech and Slovak Republics. All species and subspecies occurring in Czech and Slovak Republics are shown on 130 high-quality colour plates; their ecology, distribution and reliable identification is given in the text. Photographs of characteristic specimens in multiple views, often acc...

While the effects of contemporaneous local environment on species richness have been repeatedly documented, much less is known about historical effects, especially over large temporal scales. Using fen sites in the Western Carpathian Mountains with known radiocarbon-dated ages spanning Late Glacial to modern times (16 975-270 cal years before 2008)...

Aim Shells of fossil molluscs are important for palaeoecological reconstructions. However, the habitat requirements of snail species typical of central European full-glacial loess sediments are poorly known because most of them became very rare or extinct in Europe. The recent discovery of an almost complete extant assemblage of such species in mou...

Aims The aim was to identify the main drivers of aquatic macroinvertebrate species richness in spring-fen habitats (i.e. groundwater seepage wetlands) because these habitats are among the most threatened temperate biodiversity hotspots. Location Isolated spring fens in the western Carpathian Mountains. Methods Assemblages of Tricladida, Clitellat...

Mire terminology, subdivision and gradient structure have been subjected to an intense debate intensified in the last years. The conception of Wheeler and Proctor (J. Ecol. 88, 187–203), which divides mires into bogs, having pH<5.5, and fens, having pH>5.5, becomes generally accepted despite a certain critique from the Scandinavian perspective and...

Small streams in the temperate continental region of central Europe have been recently exposed to frequent drying. We investigated the effects of drying on clitellate communities in 25 small streams evenly distributed along the gradient of flow intermittence. We observed that the community exposed to both irregular and periodic drying could maintai...

Continentality is a globally significant gradient influencing broad-scale biogeographical patterns. An excellent example is the transition from the European temperate forest biome to the continental steppe and forest-steppe of Eurasia. One of the biogeographic crossroads where the two biomes meet is the Western Podillia in the western part of Ukrai...

While the importance of conservation mowing for mesic grasslands is generally accepted, its use for fens and fen grasslands interspersed within agricultural land is still controversial. Although fens may persist naturally, ongoing environmental changes increase productivity and accelerate succession. These processes can be mitigated through conserv...

We document realized and potential global species ranges based on empirically vetted species concepts in conjunction with global climate databases and climate suitability modelling. From this we investigate the nature of dispersal barriers and illustrate how they generate ecological uniqueness. Holarctic. Fifty‐two small body‐size (i.e. < 5 mm) lan...

The resting eggs of large branchiopods do not hatch all at once during a hydroperiod; instead, a fraction of the eggs are left dormant to cope with unstable conditions in temporary wetlands. In order to maximize fitness, the fraction that terminates diapause is modified by signals indicating habitat suitability and biotic interactions. Here, in a l...

Accurate ecological assemblage analysis requires that underlying taxonomic divisions reflect biological reality. However, the validity of many taxonomic hypotheses have never been rigorously confronted with replicable data. As a result, these categories might say more about human psychology than biology. We consider here the ways that statistically...

Aim: Trait-based approaches are being used increasingly in island biogeography, providing key insights into the eco-evolutionary dynamics of insular systems. However, the determinants of persistence of plant species after they have arrived and established on an island remain largely unexplored. Here, we used three edaphic island systems (i.e., habi...

Spring helocrenes are a unique aquatic environment with high biotic diversity. Although environmental heterogeneity has traditionally been assumed to explain the high species richness of spring habitats, this assumption has never been properly tested. Here, we sampled macroinvertebrates from two calcareous helocrenes in Slovakia with visually disti...

The presence of Last Glacial Maximum (LGM) biotic communities without modern counterparts is well known. It is particularly evident in central European fossil LGM land snails whose assemblages represent an odd mix of species that are currently limited to either xeric or wetland habitats. Here we document a genetically verified discovery of the mode...

The Kalábová (K1) and Kalábová 2 (K2) Nature Monuments are located in the central part of the White Carpathians PLA near the village of Březová. Both monuments protect treeless wet grasslands and tufa forming spring fens, which were originally part of a larger wetland complex. A total of 51 species were recorded in K1 (47 terrestrial and two aquati...

Increasing evidence for the effects of Holocene history on modern biotic communities suggests that current explanations of community patterns and conservation strategies require revisiting. Here we focused on Central European rich fens that are at high risk among mire habitats because of their relatively low environmental stability, and hence sensi...

The Hutě Nature Reserve is located in the central eastern part of the White Carpathians PLA, near the Žítková village. The reserve protects a preserved and topographically heterogeneous area composed of forest groves, meadows, pastures, and spring fens with a high diversity of submontane and thermophilic plant and animal assemblages. The species co...

Biological invasions are common among freshwater molluscs, with the North American planorbid gastropod Gyraulus parvus being reported from Europe (Germany) by the 1970s. It has since spread across Central and Western Europe, mostly living in artificial and highly modified habitats. However, considerable conchological and anatomical similarity exist...

This paper presents important faunistic records including location data with all details conducted in the Czech and Slovak Republics during 2020. Four new non-native species, Arion intermedius, Ambigolimax valentianus, Clathrocaspia knipowitschii and Krynickillus melanocephalus, were recorded outdoors in Slovakia. Radix lagotis was genetically conf...

The Western Carpathian Mountains have been attracting palaeoecologists for a long time, recently mainly to seek direct evidence of northern cryptic refugia in this region. We investigated a rich Holocene mollusc record in the White Carpathian Mountains, capturing a gradual development of forest malacofaunas under stable environmental conditions. To...

Groundwater-dependent ecosystems represent globally rare edaphic islands of scattered distribution, often forming areas of regionally unique environmental conditions. A stable groundwater supply is a key parameter defining their ecological specificity, promoting also soil thermal buffering. Still, a limited number of studies dealt with the importan...

The theory of island biogeography postulates that size and isolation are key drivers of biodiversity on islands. This theory has been applied not only to true (e.g. oceanic) islands but also to terrestrial island-like systems (e.g. edaphic islands). Recently, a debate has opened as to whether terrestrial island-like systems function like true islan...

Aim Trait-based approaches are increasingly implemented in island biogeography, providing key insights into the eco-evolutionary dynamics of insular systems. However, what determines persistence of plant species once they have arrived and established in an island remains largely unexplored. Here, we examined links between non-acquisitive persistenc...

Human activities have enormous impact on current biodiversity distribution across all spatial scales. Despite the numerous studies showing the difference between preserved and impaired sites, only little is known about the regional scale. Therefore, we selected four European regions differing in habitat conservation status (HCS) to explore if the v...

Water resources and associated ecosystems are becoming highly endangered due to ongoing global environmental changes. Spatial ecological modelling is a promising toolbox for understanding the past, present and future distribution and diversity patterns in groundwater-dependent ecosystems, such as fens, springs, streams, reed beds or wet grasslands....

Land snails are abundant invertebrates in many terrestrial ecosystems, playing an essential role in food webs and nutrient cycling. Although snails are commonly considered general grazers with a strong tendency to omnivory, their foraging strategy is well documented only for a few species. Virtually no data exist on trophic niche partitioning withi...

Le Vertigo septentrional (Vertigo geyeri Lindholm, 1925) est un Mollusque millimétrique inscrit à l’annexe II de la Directive Habitat-Faune-Flore. La Franche-Comté, qui constitue la limite occidentale de son aire de répartition continentale, abrite le principal bastion de cette espèce au niveau national, ce qui lui confère des responsabilités parti...

Soupis druhů nalezených během Speciálního botanicko-zoologického cvičení v terénu na Litomyšlsku (31. 8.-4. 9. 2020) Pořádající instituce Ústav botaniky a zoologie, Přírodovědecká fakulta, Masarykova univerzita, Kotlářská 2, 611 37 Brno, tel. 549491439, fax 549498331

Water resources and associated ecosystems are becoming highly endangered due to ongoing global environmental changes. Spatial ecological modelling is a widely used tool for understanding the past, present and future distribution and diversity patterns in groundwater-dependent ecosystems, such as fens, springs, streams, reed beds or wet grasslands....

Small lakes and ponds in karstic systems have received little attention in terms of mollusc research. Although these systems represent a refuge for lentic biota in most of the Mediterranean, there are virtually no ecological studies from many regions, including Albania. Therefore, we quantitatively studied mollusc assemblages at 58 sampling sites w...

Since the last comprehensive overview of the Czech and Slovak mollusc fauna, released in 2013, several records of species new for the countries or particular regions have appeared. In this paper, we summarize all such records and news collected in 2015-2019, including those affecting nomenclature and the national Check-lists made in 2013 and 2014....

Along the Calvados coast, peat deposit outcrops, rich in Holocene land-snails, represent a potential to reconstruct the evolution of the past environments, which are directly linked to the rise of sea-level. Dating and malacological investigation on the sequence of Graye-sur-mer (Calvados, Normandy) has shown a re-established palaeoenvironmental st...

Bioindication systems based on the occurrence of plant species are widely used in vegetation science, palaeoecology, community ecology, geographical modelling and global change biology. Although the existing systems are mostly regional, the development of large-scale vegetation databases calls for the establishment of a pan-European indication syst...

Our understanding of functional roles of aquatic invertebrate taxa is still limited even for common species, although being crucial for explanations of patterns observed in natural communities. As only recently shown, the common native European amphipod Gammarus fossarum , traditionally treated as a shredder of leaf litter, shows predatory behaviou...

The development of biotic communities since the last glaciation has been shaped by both dramatic climate changes and pathways of species colonisation from glacial refugia. Although the growing body of literature has emerged recently on possible scenarios of postglacial colonisation, less is known about the effect of climate. We analysed the dynamic...

Changing environmental conditions force species either to disperse or to adapt locally either genetically or via phenotypic plasticity. Although limits of plasticity can be experimentally tested, the predictability of genetic adaptation is restricted due to its stochastic nature. Nevertheless, our understanding of evolutionary adaptation has been i...

Despite the fact that native species of amphipods have been recognized as active predators similarly to invasive species, little is known about their predatory impact on aquatic communities. In this study, we used a laboratory experiment, a field enclosure experiment, and an analysis of natural community data to demonstrate how Gammarus fossarum af...

Bees and wasps inhabiting steppe formations are, according to recent red lists, among the most endangered species, quickly disappearing from local faunas of central European countries. Several species, which are specialised nesters in empty gastropod shells, show the opposite pattern. Based on their distribution maps, we found that these species ar...

Western-Carpathian travertine fens developed on deep-circulation groundwater are highly localised and harbour unique communities that combine rare species of calcareous fens and salt marshes, with many species considered glacial or Early-Holocene relicts. Using a multi-proxy palaeoecological approach, we tested the assumption of naturalness and Hol...

While among the most common Holarctic land snails, species of the Euconulus fulvus group have been subject to considerable recent taxonomic controversy. Based on 76 Euconulus populations collected across Eurasia and North America, we empirically evaluated these competing taxonomic hypotheses through an integration of nDNA and mtDNA phylogenetics, s...

1. Predation may significantly control number and density of coexisting species. The effects of predation on species diversity have traditionally been tested in experiments and theoretical models of simple trophic systems. In complex natural ecosystems, however, disentangling multiple sources of variation is difficult. In groundwater-fed environmen...

Research on past abrupt climate change and linked biotic response is essential for understanding of the future development of biota under changing climatic conditions, which, in turn, is necessary for adequate progress in ecosystem management and nature conservation. The present study presents the first comprehensive reconstruction of local and reg...

Current species‐richness patterns are sometimes interpreted as a legacy of landscape history, but historical processes shaping the distribution of species during the Holocene are frequently omitted in biodiversity models. Here, we test their importance in modelling current species richness of vascular plants in forest and grassland vegetation. West...

Calcareous fens represent an endangered type of peatlands, acting as refugia for stress-tolerant species in the currently changing landscapes. The resurveys across many regions have reported their recent disappearance or deterioration despite both the extreme habitat conditions (carbonate richness, presence of calcareous tufa, nutrient limitation,...

Groundwater‐dependent ecosystems are recognized as biodiversity hotspots being, apart many negative human impacts, highly threatened also by ongoing climate warming. Clitellata (Annelida) are dominant invertebrates of permanent fauna in spring habitats, representing a heterogeneous group including both specialized cold stenothermic and ubiquitous e...

Three native species of the Viviparidae are known in the Czech Republic, namely Viviparus acerosus, V. contectus and V. viviparus. The native range of V. acerosus includes the Danube and probably Dnieper and Dvina river basins. In the Czech Republic it inhabits slowly flowing rivers and canals in the floodplain of the Dyje and Morava rivers in Sout...

Shell formation is the main defensive strategy against predation for the majority of snails. Therefore, various predators have had to develop a variety of techniques how to overcome this barrier. As shells can persist in a calcium-rich environment for a long time, specific external or internal traces on shells left by predators indicate whether and...

The specific biota of isolated habitats is determined by habitat properties (e.g. age, size, environmental conditions), their spatial isolation, and the characteristics of the surrounding landscape matrix. In this study, we examine the contrast of Trichoptera assemblages between isolated island‐like Western Carpathian spring fens and nearby headwat...

Little is known about macroinvertebrate assemblages inhabiting aquatic-terrestrial transition zones, particularly at groundwater-fed wetlands. We studied diversity and vertical distribution of Dipteran assemblages in 27 spring fens characterised by variable groundwater chemistry ranging from acidic to extremely calcium rich. We sampled semiaquatic...

Freshwater mollusc diversity has repeatedly been found to peak in lowland stagnant waters, which are highly exposed to human-made degradation and the spread of non-native species. Despite the increasing loss of these habitats, little is known about the main predictors of their mollusc diversity patterns. Therefore, we aimed to determine the environ...

Surface coal mining severely affects natural ecosystems, though it might also result in an establishment of biologically unique anthropogenic habitats. We studied spontaneously created post-mining calcareous brooks located at the brown coal spoil heap in the Sokolov coal basin (Czechia). Despite their extreme water conditions, linked most to the io...

Studies on testate amoeba species distribution at small scales (i.e., single peatland sites) are rare and mostly focus on bogs or mineral-poor Sphagnum fens, leaving spatial patterns within mineral-rich fens completely unexplored. In this study, two mineral-rich fen sites of contrasting groundwater chemistry and moss layer composition were selected...

A countrywide data set of 1048 samples of the European land snail Cepaea nemoralis (L.) from Poland was assembled from both published and unpublished sources. Analyses of shell colour and banding polymorphism revealed distinctive patterns of variation. While the frequency of brown shells showed a clear geographical pattern related to climate, other...

Although Holocene mollusc succession has been described from many temperate European sites, no attempt to analyse diversity patterns across the continent from east to west has yet been done. Here, we assembled and quantitatively analysed 54 most representative Holocene successions categorized into five climatic and geomorphological regions. These w...

Calcareous tufas are great archives of geochemical information for the reconstruction of past climate. Their importance increases in the regions where other proxies are rare, such as Western Carpathians. Here, we present the first whole-Holocene palaeoclimatic reconstruction for this region based on geochemical proxies. We analysed δ 18 O, δ 13 C...

De part et d’autre des côtes de la Manche, la présence de formations tourbeuses est un héritage de l’histoire postglaciaire du nord de l’Europe. Sur les plages du Calvados (Normandie), au gré des marées, l’érosion dégage des bancs de tourbes. La topographie du littoral a permis la conservation de certains de ces affleurements riches en débris végét...

Naive use of molecular data may lead to ambiguous conclusions, especially within the context of “cryptic” species. Here, we integrated molecular and morphometric data to evaluate phylogenetic relationships in the widespread terrestrial micro-snail genus, Euconulus. We analyzed mitochondrial (16S + COII) and nuclear (ITS1 + ITS2) sequence across 94...

Corbicula fluminea, an invasive bivalve of SE Asian origin, has been recorded in the Morava River in Moravia (SE Czech Republic, Danube River basin) for the first time in 2018. Online at <http://mollusca.sav.sk>

Aquatic invertebrates of groundwater-dependent wetlands can be sensitive to a drop in the groundwater table, which is considered one of the possible impacts of climate change. We investigated whether aquatic clitellate species are able to dwell in waterlogged substrates without surface water, in 27 spring fens studied across the Western Carpathians...

1.The species richness–productivity relationship is one of the most debated patterns in ecology. Species coexistence theory suggests that it could be tightly linked to the type of nutrient limitation (NL: no limitation, single‐nutrient limitation, co‐limitation by several nutrients). Yet effects of NL on the species richness–productivity relationsh...

While spatial turnover in species composition is well documented (Whittaker 1975; Condit et al. 2002) much less investigation has been conducted over long‐time periods. Land snails provide a unique window to observe such patterns because their fossil shells not only allow for species‐level identifications and quantification of abundance (Schilthuiz...

The research of the Czech and Slovak mollusc fauna has a long tradition spanning the last 150 years. Particularly, in the last two decades, existing records were put in databases and distributional maps for most species are available on-line. The journal Malacologica Bohemoslovaca, which focuses on publishing faunistic studies from Europe, has been...

The Puścizna Wielka bog is situated in the Orawa-Nowy Targ Basin, surrounded by the Western Carpathians. It is a large raised bog (area over 480 ha, peat thickness up to 10 m) and represents an excellent peat archive of Holocene hydrological changes and climate variability in central Europe. We have collected a 6.3 m long peat sequence from the int...

There is still not enough palaeoecological data from the southwestern part of the Western Carpathians, where mountain ridges steeply rise from the dry and warm Pannonian basin. The reason is a low availability of sites with sediments harbouring fossil remains. In the Považský Inovec Mts, two small protected calcareous wetlands occur in different ge...