Effects of land utilization patterns on soil microbial communities in an acid red soil based on DNA and PLFA analyses

Disturbances such as cultivation, logging, and plantation occurred widely in acid red soil area of China, yet little is known about their effects on soil microbial community which is closely related to soil function. In this study, microbial community compositions were investigated in a red soil with different long-term land utilization patterns to understand the potential effects of cultivation and vegetation successions on relevant soil functions. Land utilization patterns include restoration, degradation (logging), cropland, and pine plantation. Both DNA- and phospholipid fatty acid (PLFA)-based methods were used to measure the abundance and community structure of microorganisms. In general, DNA- and PLFA-based methods showed similar results of microbial composition, but for some parameters, only one approach showed significant differences between different land utilization patterns. Land utilization patterns showed significant effects on abundance of total microbial community, bacteria, fungi, and actinomycetes which were all lowest in the cropland plot either by PLFA or DNA analyses. 17:0 cyclo/16:1 omega 7c and 19:0 cyclo/18:1 omega 7c which are possibly associated with environmental stresses also varied among different land utilization patterns. Both PLFA and T-RFLP analyses showed that each land utilization pattern possessed a specific microbial community structure. These results revealed significant effects of different land utilization patterns especially cultivation and logging on soil microbial communities and suggested that we should be cautious in utilizing red soils to sustain soil properties and functions. Combination of DNA- and PLFA-based methods is effective to provide precise results of microbial composition.