Vertigo geyeri, Lindholm, 1925

Coufal, Radovan, Horsáková, Veronika, Peterka, Tomáš, Ryelandt, Julien, Skujienė, Grita & Horsák, Michal, 2024, Fig. 1 in Positive association between PTN polymorphisms and schizophrenia in Northeast Chinese Han population., Zoological Studies 63 (19), pp. 141-149 : 12-13

Vertigo geyeri

Distribution

Historical records of V. geyeri are summarized in Kerney et al. (1983), showing that it is widespread especially in Sweden, with relatively frequent but regionally restricted occurrence in Norway, Finland (see also von Proschwitz 2003; von Proschwitz et al. 2023 for distribution in Scandinavia), Denmark, Slovakia, United Kingdom, and in the Alps in Germany, Austria, and Switzerland. During the 1990s and after the 2000s, when the species was listed in Annex II of the EU Habitats Directive (92/43/EEC), the interest in the distribution of V. geyeri started to grow, and many new sites were discovered. The species is considerably more common in the Baltic States (data presented here; GBIF.org; Skujiene et al. 2019 2020 2021) than previously reported, like in the United Kingdom and Denmark ( Killeen et al. 2019; Conchological Society of Great Britain & Ireland 2020). Most of the findings from Poland come from the northeastern part (data presented here; Książkiewicz et al. 2015; Pokryszko et al. 2016), an area where the Scandinavian ice sheet advanced during the LGM ( Hughes et al. 2013). Outside of its main area of distribution in the arctic and boreal zones, many new sites were discovered. Since the first record in 2011, V. geyeri was discovered at several sites in Czechia (data presented here; Myšák et al. 2012; Schenková and Horsák 2013b; Horsáková and Horsák 2018; Coufal 2019; Čejka et al. 2020) and the originally known range in the Western Carpathians (mainly Slovakia) was repeatedly revisited and extended ( Schenková et al. 2012). Several isolated sites were discovered in the Romanian Carpathians (data presented here), probably marking the southeasternmost edge of the distribution. Several sites further south on the Balkan peninsula were explored, e.g., in Serbia, Montenegro, and Bosnia and Herzegovina, however, these yielded very poor mollusc communities without any demanding wetland species (unpubl. data). This is likely due to the young age of local groundwater-fed mires which originated later during the Holocene because the glacial period and the beginning of the Holocene were very dry ( Wright et al. 2003). However, it is possible that V. geyeri is more common in the Romanian Carpathians as there are more suitable unexplored sites (e.g., Hájek et al. 2021). The two records from Ukraine were published before 1950, as mentioned in Gural-Sverlova and Gural (2012). However, Balashov (2016) reported that these populations went extinct due to the destruction of the sites by illegal amber mining. Nevertheless, it is possible that the species still occurs in Ukraine elsewhere, for example in the Carpathian Mountains, as ecologically suitable sites are present there (e.g., Hájek et al. 2021). This is also supported by a record of subfossil shells from the sediments dated back to 621–256 cal. yrs BP near Yunashkiv, Western Podillia ( Hájková et al. 2022). In the calcareous areas of the Alps, mainly in Switzerland and France, but also in Austria (data presented here; Lecaplain 2013; Roy and Vanderpert 2016; Claude and Gonseth 2021; Lasne et al. 2021), the previously known range was extended. Nevertheless, the species is likely to be even more frequent there. The southernmost known records come from the Apennine Mountains in Italy (data presented here). However, ecologically suitable habitats also occur in the Pyrenees and in Cantabria ( Jiménez-Alfaro et al. 2014; Chytrý et al. 2020). Nevertheless, no records of the species are known from this area, possibly due to the lack of malacological surveys focusing on spring fens.

Ecology

According to older literature, Vertigo geyeri inhabits neutral to base-rich, calcareous groundwater-fed wetlands, while in Karelia it has also been found in wet, open deciduous forests ( Kerney et al. 1983; Cameron et al. 2003; Valovirta 2003; von Proschwitz 2003; von Proschwitz et al. 2023). Microhabitat preferences were studied by Kuczyńska and Moorkens (2010), while Horsák and Hájek (2005) and Schenková et al. (2012) studied its habitat preferences on the regional scale in the Western Carpathians. The latter two studies used data (n = 20; n = 57; respectively) that are a subset of this study (n = 222). Schenková et al. (2012) showed that climatic predictors have a significant contribution to the ecological gradient along a PCA axis. Although V. geyeri is often described as a boreo-montane species ( Kerney et al. 1983; Cameron et al. 2003; von Proschwitz 2003), i.e., occurring in areas with lower temperatures, it also frequently inhabits regions with low to intermediate (British Isles; Holyoak 2003; Killeen 2003; Killeen et al. 2019) and intermediate altitude (e.g., Western Carpathians and Czechia; Schenková et al. 2012; Coufal 2019). Accordingly, our data show that V. geyeri prefers sites with higher summer and winter temperature (in comparison with V. lilljeborgi and V. genesii ) while the abundances are highest at sites with summer temperature around 21°C. This is most likely one of the primary reasons why this species is substantially more common in temperate Europe than the other two relict species. Schenková et al. (2012) showed a decreasing abundance in response to increasing nutrient availability. The reason behind this is that the temperate sites used in the study are more productive (e.g., Horsák et al. 2017) compared to our dataset that includes sites from northern Europe, making this trend weak in our data. This might also be due to the wider ecological niche of northern populations as the species was reported to occur there in wet open deciduous woodlands ( Pokryszko 2003; Valovirta 2003; von Proschwitz 2003) whereas it has never been observed in such a habitat in temperate Europe. The decrease in openness in spring fens means encroachment by shrubs and trees which is often caused by habitat succession towards more productive ecosystems (e.g., Jensen and Schrautzer 1999; Jamrichová et al. 2014). Our results show that the species has a broad tolerance along the mineral richness gradient, as shown in previous studies ( Horsák and Hájek 2005; Vavrová et al. 2009; Schenková et al. 2012). Horsák and Hájek (2005) show a unimodal response of the species abundance peaking around 360 µS/cm while our data show a peak at 500 µS/cm, which is consistent with Schenková et al. (2012). The discrepancy is likely due to a smaller dataset used in Horsák and Hájek (2005). The results of our analyses do not show a significant relationship between the species occurrence/densities and moisture as shown in Kuczyńska and Moorkens (2010) and Schenková et al. (2012); however, this is likely due to the size of our dataset and the selection of sites that are well within the species’ ecological range.