| Scope and method of study. The objectives were (1) to evaluate impact of chronic flooding with heavy metal contaminations on soil biota in a river floodplain continuum; and (2) to assess microbial responses to soil redox states. Soils were collected from four sites at each of two locations along Tisza River in Hungary. Each soil profile was divided into three redox horizons: oxic, intermittent, and anoxic. Microbial communities were evaluated by microbial biomass carbon and nitrogen contents, dehydrogenase activity, and culturable bacterial populations. Depth- and redox-related variation in microbial community structure was evaluated using a 16S rRNA-based approach and fatty acids methyl esters (FAME) analysis.; Findings and conclusions. Results from this study indicated that nutrient and oxygen availability regulated microbial distribution along a soil profile. Oxygen and carbon limitation reduced bacterial diversity and distribution evenness in the environment. (Abstract shortened by UMI.)... |
