[The latitude-zonal and spatial-successional trends in the distribution of yeasts]

The distribution of yeasts in natural habitats is analyzed in the different nature zones of the former USSR (from tundra to desert) using the results of long-term research. Yeast community structure is changing in parallel to different stages of plant debris decay as well as to latitude-zonal gradient. These changes are not fluctuating but trend ones. As mineralization of plant debris proceeds the availability of sugars decreases and habitat become more extremal for yeasts which are typical saccharolytics. It causes decrease in species abundance and species diversity. At the same time in zonal gradient the most significant changes take place in the relative abundance of dominant species, genera or higher taxonomic groups. The thermotolerant species occurred more often in the southern regions while psychrophilic species dominate in the north. Soil yeast communities become more polytrophic in the north latitudes where mineralization of organic matter is rather low. Species inhabiting climatic pessimum areas usually form chlamidospores.