ПРОСТОРОВА ДИФЕРЕНЦІАЦІЯ НАЗЕМНИХ МАЛАКОКОМПЛЕКСІВ НА РІВНИННИХ І ПЕРЕДГІРНИХ ТЕРИТОРІЯХ ЗАХОДУ УКРАЇНИ

Abstract

The peculiarities of the distribution of the land molluscs in the plain and foothill territories of Western Ukraine have been analysed on the basis of the personal long-term collections (1994–2017), the critical study of other collections and the literature data. The species lists were precised for 9 physical-geographical regions: Volhynian (Western) Polesia, Volhynian Upland, Male Polesia, Roztochia and Opillia, Western Podolia, Central (Northern) Podolia, Prut-Dniester Upland, Ciscarpathia, Transcarpathian Lowland. With due regard for the literature data, the records of 138 species of land molluscs (76 genera, 30 families) from the plain and foothill territories of Western Ukraine can be considered as reliable ones. The maximum species richness has been marked in Roztochia and Opillia (106 species), slightly less – in Western Podolia (95 species) and Ciscarpathia (94 species), the minimum – in Volhynian Upland (32 species). According to the taxonomic composition and ecological spectra of the land mollusc complexes, in the plain territories of Western Ukraine two faunistic complexes can be distinguished, the boundary between which passes along the northern edge of the Podolian Upland. The land mollusc fauna of Male Polesia and Volhynian Upland shows a greater similarity with the mollusc fauna of Western Polesia than with other parts of the deciduous forests zone, and is characterized by reduced taxonomic diversity, the lesser number of Carpathian species, the lesser part of the forest and, especially, stenobiontic forest species and an increased proportion of the hygrophilous species. In studied area a number of the land molluscs can be marked, which have penetrated to Western Ukraine exclusively due to the anthropochory (not less than 16 species). The most common of these at present are L imax maximus , Cepaea hortensis , Boettgerilla pallens , Krynickillus melanocephalus , Monacha cartusiana . A rapid spreading of the slugs from the complex Arion lusitanicus s.l. has been observed recently in Western Ukraine. The influence of anthropochory on shaping of present species composition of land mollusc complexes becomes the most apparent in Roztochia and Opillia, where the part of molluscs-anthropochores is not less than 11.3 %, and in the Transcarpathian Lowland (at least 12.2 %).