BACTERIAL COMMUNITIES OF SOLONCHAKS

Solonchaks are one of the most extreme environments; however, we have shown that bacterial population of solonchaks is characterized by well expressed spatial and taxonomic structure, whose main features are un even vertical and horizontal distribution of bacterial population dens ity and regular change in the taxonomic composition from layer to laye r. Maximal density of bacterial populations was found in salt crust in the sites covered with plant debris or algal films; minimal density w as recorded in deep mineral soil horizons and on the surface of green parts of plants. On plant leaves, the dominating groups were sporeform ing and coryneform bacteria, in plant debris, Gram-negative bacteria, in mineral soil horizons, sporeforming bacteria. In salt crust, obliga tely halophilic archaebacteria were constantly present, which, however , were not a prevailing group there.