A key component for microbial ecology is the study how microorganisms become distributed in the environments. The transition of microbial communities from less disturbed to heavily disturbed soil ecosystems in the coastal plain of Georgia, USA was studied. Soils with different disturbance intensities including less disturbed forest soils, highly disturbed agricultural soils, and moderately disturbed transitional lands between forest and agricultural soils were selected at three different locations (Acacia Farm, Strickland Farm, and Honeydew Farm) of operational crop-producing farms in the coastal plain of Georgia, USA. Five soil samples from the three soil disturbance intensities at each of three locations were collected. Length Heterogeneity PCR (LH-PCR), the fragment analysis of operational taxonomic units (OTUs) based on bacterial 16S rRNA genes, fungal ITS-1, and animal 18S rRNA genes were performed for microbial diversity and community analyses.
Results/Conclusions
Soil fungal communities showed distinct grouping by soil disturbance intensities. Less disturbed forest soil displayed lower degrees of fungal community similarity than heavily disturbed agricultural soil due to a higher number of unique OTUs or less number of common species in forest soils compared to agricultural soils. Soil fungal and animal communities in highly disturbed crop soil included the highest amount of common OTUs, while less disturbed forest soils contained the least number of common OTUs. This trend was not observed in relatively small size soil bacterial communities, suggesting size of the organisms contributed to common OTUs observed in disturbed ecosystems at the studied sites. More unique or less common OTUs were observed for soil animals under different soil disturbance intensities, and grouping of soil animal communities by disturbance intensity was less distinct than grouping of bacteria or fungi. The size of microorganisms may determine their dispersal ability under different soil disturbance intensities at a local scale range.