ECOLOGY-RELATED MICROBIOLOGICAL AND BIOCHEMICAL PARAMETERS IN ASSESSING SOILS EXPOSED TO ANTHROPOGENIC POLLUTION

摘要

Soil is the foundation of the entire biosphere, and the most important complex interface for the global transformation and interchange of matter and energy. Also, only a healthy, that is, biologically active soil warrants the sufficient production of food for the growing human population. Yet, for decades soils have increasingly been subject to pollution and other adverse side effects of different human activities which negatively affect soil organisms, and especially microorganisms, which play a key role in ecologically important biogeochemical processes. Under stress conditions caused, for example, by a long-term dissemination of chemical pollutants, the development and biochemical activities of soil microorganisms undergo several alterations. To prevent negative ecological consequences, microbiologically related parameters should be involved in the indication of soil quality. In order to determine some reliable indicators, an international project was established and performed for 3 years in which scientists from the Czech Republic, Hungary, Russia, Slovak Republic, and Germany were participating. All participating teams applied a number of standardized methods for selected microbiological and biochemical soil parameters in their laboratories. Soil samples from both unaffected, and differently polluted soils were repeatedly analyzed. After evaluation of more than 20 individual parameters it was concluded that nitrogen-fixing bacteria, total microbial biomass, soil respiration (CO2 release), enzymatic activity (dehydrogenase), and in part also the humification activity of soil microorganisms could be used as quite sensitive indicators of soil quality. However, seasonal oscillations in the values of the individual parameters occurred, and should be appropriately respected in a comparative evaluation of results achieved. In further research, critical limits of the most prospective parameters should be recognized with respect to individual soil types and different soil uses.