Distribution of photosynthetic species in grotto type caves of different regions

The article discusses the ecological significance of the phototrophic communities developing in entrance zone of grotto type caves as ecotones and refugiums. Species intrazonality and the dependence of cave species’ composition on geographic location were considered. The aim of present study was to identify similar caves of different regions based on the species composition of phototrophic communities using own data and data from literature. The empiric basis for investigation was present by phototropic species lists of own studies conducted by standard methods for phototropic species identification, as well as species lists from literature. The most frequently encountered phototrophs were species Chroococcus minutus and Chlorella vulgaris. Their occurrence in all the studied caves was revealed based on the taxonomic analysis. Thus, the intrazonal nature of the flora developed in grotto type caves is partially confirmed. Cluster analysis applying Euclidean distance was used to estimate similarity of the phototrophic communities developed in grotto caves of various genesis. Four clusters were identified: cretaceous caves of the Voronezh region; limestone grottoes of Ukraine and Abkhazia; monastic cells of Moldova and Ukraine; caves of Italy and Hungary. The dependence of the phototrophs biodiversity on the composition of the rocks and the genesis of the cavities was established. The geographical trend of photosynthetic species distribution in the grotto type caves was revealed.