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The paper presents data on 13 freshwater snail species: Theodoxus fluviatilis, Viviparus contectus, V. viviparus, Melanoides tuberculata, Bithynia tentaculata, B. leachii, Potamopyrgus antipodarum, Lithoglyphus naticoides, Marstoniopsis insubrica, Valvata cristata, V. pulchella, V. piscinalis and Borysthenia naticina, recorded over the last fifty years in the Wielkopolska district (W. Poland). Their distribution is shown on UTM/MGRS grid maps, and habitat information is provided. Among the discussed species, B. tentaculata (447 sites) and V. contectus (210 sites) are the most frequent in the region. Two alien species – M. tuberculata (two sites) and L. naticoides (seven sites) and the native B. naticina, recorded from five sites, are the least frequent.
Two localities of Pupilla pratensis were found in the environs of Gubin and Stęszew, W. Poland. Only one recent record of the species, earlier regarded as an ecotype of the widespread P. muscorum, was known from Poland. Consequently, the distribution and conservation status of the species are not well known. Our data indicate that P. pratensis is rare and has specific habitat requirements. In our study area it was found in only two out of 71 examined localities of a very similar habitat type and sampled on the same occasions. The two localities are wet meadows covered by sedges (mostly Carex acutiforis) growing on a calcareous peat substratum of lacustrine origin; the species is accompanied by two rare and legally protected vertiginids: Vertigo angustior and V. moulinsiana.
The terrestrial gastropod fauna of the Drawa National Park includes 39 species, of which 29 (74.4%) were present in quantitative samples and subject to quantitative analysis. Dominant species were Aegopinella nitidula (Drap.), Discus rotundatus (O. F. Müll.) and Vitrea crystallina (O. F. Müll.). Snail communities of acid beech forest and a ruderal site with park tree stands in a mixed forest with beech had the highest species diversity index H’, while those of a eutrophic lowland beech forest and acid oak forest showed the highest TDI index of species diversity, and equitability index (J). The mean snail density was 19.3 indiv. m-2. The presence of Macrogastra ventricosa (Drap.), Laciniaria plicata (Drap.), Bulgarica cana (Held) and Helicigona lapicida (L.) is noteworthy.
We present the list of molluscs recorded from Wielkopolska (W. Poland) during the last fifty years. It includes the 167 species (47 freshwater snails, 92 terrestrial gastropods, 28 bivalves) recorded from the region between July 1st 1958 and July 1st 2008. The number of localities recorded during the last 50 years is given for each species. The list is based on data from 4,155 localities described in 89 publications and 73 unpublished papers. Most of the information was published in Polish or not published at all, and thus inaccessible to a wider malacological audience.
We present the results of a terrestrial mollusc inventory in the Cybina River Valley (W.Poland). The species richness in 39 sites served as a biodiversity criterion for the whole area. The total number of 3,193 specimens collected represented 51 species (22 families), i.e. about 60% of terrestrial snail species of the whole Wielkopolska region. Species regarded as rare in the region and in the whole country constituted 22% of the whole material. Two of them are especially noteworthy: Vertigo angustior Jeffreys (Annex II, EU Habitats Directive), and Ruthenica filograna (Rossmässler) which is very rare in the region.
The aim of our study was to assess the small scale distribution (up to several m²) of hibernating forest-dwelling snails in relation to small-scale environmental factors, like litter composition, soil temperature and humidity or vegetation cover. The study was conducted in the ”Dębno nad Wartą” (local name) natural reserve, western Poland, in December 2006. A novel, cartographic method was applied for analysing and illustrating the small-scale distribution and habitat preferences of the snails. Four permanent study plots (15 m²) were established in 50 m intervals. Each plot was divided in fifteen 1m² squares, and from each square a litter sample was taken and analysed (60 samples in total). 17 snail species were recorded (6–13 species per plot; 0–8 per square). The distribution of particular species was clustered as its coefficients of variation were high (CV%> 150) as well as was the small-scale distribution of the total abundance of all the species (CV% = 122). The most uniformly distributed and frequent (C% of all samples) species were Trichia hispida (Linnaeus) (CV%= 153; C% = 45), Cochlodina laminata (Montagu) (206; 30) and Perforatella incarnata (O.F. Müller)(152; 37). Among frequent species the greatest value of CV% (425) and therefore the most patchy distribution was recorded for Ruthenica filograna (Rossmässler). According to the results of CCA, this species, together with Vitrina pellucida (O.F. Müller) (CV% = 296), and Clausilia bidentata (Ström) (CV% = 291), were the most stenotopic, wintering in specific microhabitats with low herb layer coverage, elm leaves prevailing in the litter and high percentages of hornbeam, ash, birch and alder leaves. In turn, for Perforatella rubiginosa (A. Shmidt) (CV% = 440) and Perforatella bidentata (Gmelin)(CV% = 440), also the species with patchy distribution – optimal wintering conditions were found in places with a higher soil temperature and the litter consisting mainly of oak leaves. The remaining snail species seem to be more eurytopic and winter in microhabitats with intermediate conditions. The results of the present study show that for the distribution of majority of species studied the most important factor is the proportion between the coverage of litter and herbaceous vegetation cover. The species richness of the malacocenoses studied strongly depends on the diversity of litter, since particular species prefer leaves of different trees.
This is the first publication of the series summarising the current state of knowledge on mollusc biodiversity and distribution in Wielkopolska (W. Poland). Here, we give a historical background of the research conducted so far in the region; we describe the geography and environmental conditions which hale determined the present shape of the region’s malacocoenoses. We also present a short summary of the results of the studies carried out in the region. Data from 89 publications and 73 unpublished papers (4,155 localities) show that 167 mollusc species were recorded from Wielkopolska during the last fifty years.
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