Effects Of Reclamation And Land Use Styles On Soil Microbial Community And Ammonia Oxidizing Microbes

Soil microbes play vital role in the ecological nutrition cycling, especially in carbon and nitrogen cycling. Soil microbial structure, diversity and corresponding relationships between functional microbes and ecosystems always attract researchers focus. Accompanied by fast developing modern biological technologies, people acquired more and more understandings about microbial structure and function in different ecosystems.Chongming Island is located at the estuary of Yangtze River. Because the relatively short and clear land use history and excellent homogeneous background of the soils on this island, researches designed by a chronosequence could be replaced by geographical scales. Microbial structure and function researches here could help us understand the effect of anthropogenic long-term land usage on microbes.This research focused on a chronosequence of 7 soil samples under 3 different land use styles. We adopted Phospholipid Fatty Acid (PLFA) fingerprints to investigate the soil microbial structures. Meanwhile, we also applied Real-time Quantitative PCR (q-PCR) to discuss the relative abundance of ammonia oxidizing bacteria (AOB) and archaea (AOA), which are responsible for a key step during the ammonia oxidizing processes.The results showed that after reclamation of beach sand, soil microbial biomass significantly reduced. Human long-term disturbances obviously influenced microbial structures during the dissimilation process between ecosystems. We also found that land use styles and reclamation ages significantly affected the expression of soil amoA genes. Meanwhile, AOA amoA gene predominated in almost all soil samples. This work would help us to understand the microbial structure differentiation trend under different land use styles and the importance of ammonia oxidizing microbes during the ammonia oxidizing processes.