HABITAT PREFERENCES AND CONSERVATION OF VERTIGO GEYERI (GASTROPODA: PULMONATA) IN SLOVAKIA AND POLAND

摘要

The tiny land snail Vertigo geyeri Lindholm, 1925 is a rare relict from the Late Glacial, inhabiting treeless spring fens. The main aims of this study were (1) to summarize present knowledge on distribution of V. geyeri in Slovakia and in Poland; (2) to analyse its ecology and habitat preferences; and (3) to suggest suitable conservation and management measures for this EUHSD Annex II species. In the course of field research on 122 fens in Slovakia and Poland, carried out between 2001 and 2011, we documented 33 Slovak and 24 Polish sites where this species occurred. Based on analysis of these populations, we identified a strong preference for permanently wet, but not extremely waterlogged, open fen sites with low-productivity nutrient-limited vegetation. The species displayed a unimodal response to calcium concentration in the groundwater, avoiding both calcium-poor Sphagnum-dominated fens and extremely mineral-rich and salt travertine fens. All sites in which V. geyeri occurs should be protected to prevent any hydrological changes resulting in successional shifts towards more productive and shrubby vegetation. Human-induced eutrophication should be also controlled to ensure the long-term maintenance of viable populations of the species. The locations of all Slovak and Polish fen sites in which V. geyeri has been recorded are provided to enable or maintain protection of the species at these sites.