Pyrosequencing Analysis of Bacterial and Fungal Diversity in Reclaimed Lands in a Mining Region.

Mining activities cause drastic disturbances to the terrestrial ecosystems affecting the landscape, various organisms and soil quality. Several studies have focused on above ground diversity in different ecological systems. Data related to belowground diversity is limited. The main objective of the present study was to determine the effects of mining on plant population diversity, genetic variation, soil respiration, and the abundance and composition of soil microbiota, an essential aspect of soil health in disturbed and undisturbed sites in the Greater Sudbury Region. Results from population diversity analyses revealed that plant species diversity and abundance were lower in sites close to the smelters. The mean Shannon index value was significantly higher in reference sites compared to the metal-contaminated sites. Tree species richness was 4.67, 5.33, and 7.67 for eroded/disturbed (metal-contaminated), stable upland (metal-contaminated) and reference (metal–uncontaminated) sites, respectively. Molecular analysis of the three targeted hardwood species (Betula papyrifera, Quercus rubra, and Acer rubrum) detected no significant differences in genetic variation among plant populations from metal contaminated and reference sites. Phospholipid fatty acid (PLFA) analysis revealed that total microbial biomass, fungal and bacterial abundance were significantly lower in metal-contaminated sites compared to reference sites. This trend was also observed in the comparative soil respiration analysis Overall, results showed that soil microbial community biomass, respiration and fungal abundance significantly increased with greater plant diversity as did carbon and nitrogen concentrations. The ratios between fungi and bacteria and among other PLFA measures were extremely low suggesting that the targeted region is still under environmental stress. The current study indicates that population diversity and species richness has an effect on soil microbial community and ecosystem processes. Metagenomic analysis will be discussed.