Spoločenstvá suchozemských mäkkýšov severnej časti Devínskej Kobyly (Malé Karpaty) [Land snail assemblages of the north part of the Devínska Kobyla hill (Malé Karpaty Mts., SW Slovakia)

Abstract

Present paper is focused on two topics. First topic is focused on evaluation of mollusc assemblages of northern part of the Devínska Kobyla hill (Malé Karpaty Mts.). The second topic was evaluation of all published data on molluscs of this area. The research was conducted during vegetation period of the year 1978. From 9 types of biotopes altogether 47 quantitative samples were sampled. The assemblages were evaluated on the base of constancy and dominance of the species. Altogether 7913 mollusc specimens were obtained from the samples. Composition and status of the forest mollusc assemblages in northern part of the Devínska Kobyla was shown to be determined by the substratum, age of forest stand and the degree of the biotopes disturbance. The species richest assemblage was detected within old grown forest (biotope 7) and calcareous substratum. The species poorest were assemblages found within clear-cut and young stand (biotopes 5, 8). Species rich community was found also in old growth forest with quartzite substratum, however a number of steppe species is absent within this biotope. The molluscan communities of open habitats were observed only in the northern part of the Devínska Kobyla foothill area. They occur mainly within xeric degraded grassland biotopes (vacant pastures, deforested fields). Within other non-limestone substratum biotopes only species poor coenoses composed of single or e few of species occurred (biotopes 2 and 6). The exception was the natural xeric grassland biotopes, which were typical biotopes for rich community of steppe molluscs (biotope 9). Extremely rich were limestone rocks, which are in addition partially covered by forest. The rich forest land snail community together with a number of xeric species was found here (biotope 3). In second part mollusc species composition of northern and southern part of the Devínska Kobyla massive and the Devínske Hradné Bralo hill are compared. Altogether 65 mollusc species (51 species in north part, 44 species in south part, 37 species in the Devín Castle hill) were found in whole area until nowadays. 10 mollusc species were found only in the southern part of the Devínska Kobyla massive (Bythinella austriaca, Chondrula tridens, Zebrina detrita, Vitrea subrimata, Nesovitrea hammonis, Limax cinereoniger, Limax maximus, Arion fuscus, Pisidium casertanum a P. personatum), 5 species were found only in northern part of the Massive (Platyla polita, Pyramidula pusilla, Vertigo pusilla, Vitrea crystallina, Monachoides vicinus) and 4 species were only found in the Devínske Hradné Bralo hill (Pupilla sterri, Balea perversa, Trichia striolata danubialis, Fruticicola fruticum). During our research 3 species new not published from this area were found (Platyla polita, Nesovitrea hammonis and Limax maximus).