Drepanocladus lycopodioides rediscovered in the Czech Republic: Abandoned quarries as refugia for endangered fen species

Highlights

• Drepanocladus lycopodioides is semi-aquatic moss seriously declining in Europe.

• This species, considered extinct in the Czech Republic, was rediscovered.

• Waterlogged abandoned quarries serve as refugia for endangered fen biota.

Abstract

The moss Drepanocladus lycopodioides, considered extinct in the Czech Republic, has been rediscovered. The population occurs in an abandoned sandstone quarry with a shallow water pool; the site known as Lom Rasová is located in the Bílé Karpaty Mts (the White Carpathians) in the south-eastern part of the Czech Republic. The species has not been recorded in the country since the first half of the 20th century. The plant community with D. lycopodioides recorded in the Lom Rasová quarry resembles alkaline fens transient to intermittently wet meadows, i.e. the natural habitat of the species. We conclude that abandoned waterlogged quarries mimic the key environmental conditions that determine the natural occurrence of D. lycopodioides, i.e. high calcium richness, water table fluctuations, low productivity and irregular disturbances that prevent the dominance of competitively superior species. Such conditions no longer occur in current central-European agricultural landscapes. We encourage bryologists and mire ecologists to explore abandoned quarries and other post-mining habitats with shallow water bodies, as they may represent potential refugia for endangered fen species.

Introduction

Drepanocladus lycopodioides (Brid.) Warnst., syn. Pseudocalliergon lycopodioides (Brid.) Hedenäs, Scorpidium lycopodioides (Brid.) H.K.G. Paul, is a moss species of semi-aquatic calcareous habitats, including mostly calcareous and extremely rich fens, wet depressions in limestone areas and dune slacks (Hedenäs, 2003; van Tooren and Bruin, 2004). The distributional range of D. lycopodioides comprises Iceland, southern Scandinavia, Finnish Lapland, Denmark, the Baltic states, Ukraine, western Siberia, and western and central Europe (Hedenäs, 2003). Its core distribution area is the south Swedish Baltic area, i.e. Öland, Gotland, and the Stockholm Archipelago (Hedenäs and Bisang, 2015).

During the second half of the 20th century, the moss declined in many parts of Europe due to the intensification of agricultural management and degradation of suitable habitats (Hedenäs and Bisang, 2015). In view of its overall decline and current rarity, D. lycopodioides has been included among vulnerable taxa (VU) in the Red list of European bryophytes (Hodgetts et al., 2019). The species is often classified in higher categories of threat in national red lists, such as “critically endangered” in Norway and Slovakia (http://www.artsdatabanken.no, Mišíková et al., 2019) or “endangered” in Hungary and Romania (e.g. Papp et al., 2010; Ştefănuţ and Goia, 2012).

Historical data on the occurrence of the species in the Czech Republic is scarce (see Supplementary material for a list and further characteristics of known historical sites). According to Váňa (1981), a lowland calcareous mire nearby Hrabanov in central Bohemia represents the last place in the Czech Republic where the species was found in 1923. On the checklist and Red Lists of bryophytes of the Czech Republic (Kučera et al., 2012), D. lycopodioides is currently evaluated as extinct (RE). The species is also extremely rare in the surrounding countries. In Slovakia, for example, the species has been documented only in the Borská nížina lowland, where it was observed in the Abrod Nature Reserve until recently (Janovicová and Kubinská, 2002). In 2019, a population of D. lycopodioides was unexpectedly discovered by E. Šmerdová in the abandoned sandstone quarry known as “Lom Rasová” in the Bílé Karpaty (White Carpathian Mts) in the south-eastern part of the Czech Republic. The quarry currently represents the only known locality in the Czech Republic and one of two sites of D. lycopodioides in the Western Carpathians. The second confirmed record comes from the “Puścizna Rękowiańska” fen near Czarny Dunajec in the Orawsko-Nowotarska Kotlina basin in southern Poland (Ellis et al., 2016).

The aims of this study are (i) to describe the newly discovered locality, and first and foremost (ii) to draw the attention of bryologists and conservationists to quarries as potential refugia for endangered fen bryophytes in current landscapes.