ECOLOGICAL STATE OF THE SOIL AT THE ROSTOV-ON-DON ZOO

ABSTRACT

A comparative study has been conducted on the ecological and biological parameters of the soil at the Rostov-on-Don Zoo. The objects of the research were the parts of the zoo with various conditions: the cages with different animals (hyenas, emus, cranes, peacocks and other birds, zebras, deer, camels and mountain sheep). Moreover, the influence of the recreational impact, caused by the visitors of the park, on the soil landscape has also been examined. The control part of the zoo for drawing the comparison was the relatively intact part of the park in the territory of the zoo. The held examinations have shown significant differences in various properties of the soil in the examined area. The physical properties of the soil from different parts of the zoo differed the most significantly. The density and the structural properties of the soil at the animal cages were changed to the highest degree. The structure of the soil was mostly disturbed in the cages with large animals: zebras, deer and camels. The biological indication using the free living nitrogen-fixing bacteria of the Azotobacter genus and the radish seeds Raphanus sativus allowed determining the degree of soil degradation in the cages in comparison with the soil of the control part of the zoo. The minimal quantity of the bacteria was found in the soil in the zebras’ cage; the reduced amount was also found in the blue sheep’s and the hyenas’ cage. The amount of organic carbon was reduced in the soil of the zebras’ and the sheep’ cages due to the artificial addition of the sand to the soil to improve its hydrophysical qualities.

Keywords: bioindication, biological activity, chernozem