Food partitioning between sympatric gerbils (genus Meriones) in arid conditions of the western part of the Caspian Depression

There are many patterns of coexistence in communities, including partitioning based on spatial, temporal, or food niches. This study considered the partitioning of food between two ecologically similar and sympatric species, the tamarisk gerbil and the midday gerbil, in the Terek-Kuma Lowland of the Republic of Daghestan. The qualitative and quantitative characteristics of the diets of both gerbils were revealed. The species have relatively wide diets; the tamarisk gerbil’s diet consisted of forty-six plant species, and the midday gerbil’s diet consisted of fifty plant species within the study areas. Thirty plant species were present in the diets of the two gerbils. The dietary breadths of both gerbils were similar. The dietary overlap of the two gerbils ranged from low to moderate (average Pianka’s dietary overlap index, 0.476?±?0.08). Finally, under conditions in which food resources are sufficient, the moderate abundance of gerbils and the high diversity of habitats and microhabitats in the study areas allow these two species of gerbils to coexist in a common location.     

Yeast Communities of Chestnut Soils under Vineyards in Dagestan

The study of yeast communities in chestnut soils (Kastanozems) under vineyards in the Republic of Dagestan made it possible to isolate 20 yeast species. Most of the yeasts under vineyards belonged to ascomycetes, among which species of the Saccharomycetaceae family (in particular, Saccharomyces cerevisiae) comprised a significant part. The obtained results indicate that the soils under vineyards keep the pool of microbial diversity and ensure preservation of many species typical for grapes. The method of enrichment culture on grape juice medium proved to be more efficient than other methods of analysis with respect to the number of isolated species and the rate of their detection. However, implementation of different techniques to study yeasts’ diversity can give somewhat different results; a set of methods should be used for an integrated analysis.