Changes in soil microbial community structure in relation to plant succession and soil properties during 4000 years of pedogenesis

Soil bacterial and fungal community compositions have a significant influence on plant community structure and diversity because of their key role in nutrient cycles in the soil. Studies conducted on microbial diversity in relation to soil development could provide insight on how changes in microbial community structure influence ecosystem functions. Soil chronosequences are excellent systems for evaluating soil genesis, nutrient availability and biologically significant elements and their implications for ecosystem functioning. This study was conducted to assess the changes in soil bacterial and fungal communities associated with the dynamics of soil physico-chemical and vegetative characteristics along a sand chronosequence by using phospholipid fatty acid (PLFA) profiling. Soil samples were collected and analyzed from different successional stages in a soil chronosequence with ages ranging from 105 years to 4010 years. The results showed that soil microbial PLFAs changed significantly with increasing soil age. Bacterial PLFAs were higher in younger soils while the old soils had higher fungal PLFAs. Correlation analysis showed that plant community composition had the strongest correlation with soil microbial community structure, followed by soil pH. This could be attributed to a shift in nutrient concentration and quality of the litter inputs along the chronosequence. The results showed that there was a close relationship between plant succession and pH in shaping the soil microbial communities along the soil development gradient.