Comparison of total organic carbon(TOC), total nitrogen(TN), total phosphorus(TP), soil microbial biomass carbon(MBC), nitrogen(MBN), phosphorus(MBP) and their stoichiometric ratios measuring from understory planting of Paris polyphylla and Panax japonicus rhizosphere soil with the data of the original forest soil will help us to understand the influence of different planting patterns between soil traits and soil microbial interaction and nutrient cycle characteristics. The results showed that the contents of TOC, TN and MBN were the highest in the rhizosphere soil of P. japonicus, while the highest values of TP, MBC and MBP were found in the rhizosphere soil of P. polyphylla. The changes of TOC∶TN, TOC∶TP, TN∶TP, MBC∶MBN, MBC∶MBP and MBN∶MBP of P. polyphylla and P. japonicus rhizosphere soil compared with the data of the original forest soil were 3.65 and 37.32%,-14.89 and 82.23%,-17.87 and 32.76%, 25.67 and-50.60%,-75.95 and-16.33% as well as-80.79 and 69.76%, respectively. TN and TP were significantly correlated with MBN and MBP respectively. Although, monoculture of P. polyphylla and P. japonicus changed soil nutrient level, it did not reach the state of nutrient deficiency. The demands for nitrogen and phosphorus between P. polyphylla and P. japonicus were quite different. According to their different habits, monoculture of P. polyphylla and P. japonicus could change the understory soil traits, resulting in allometric changes in part of soil nutrient stoichiometry and soil microbial stoichiometry, and then the disappearance of internal stability. The variations in the understory soil caused by P. polyphylla and P. japonicus is developing in completely different directions, whether this phenomenon indicates that the two species have less niche overlap needs further study.
Keywords: Panax japonicus; Paris polyphylla; cultivated understory; ecological stoichiometric ratios; homeostasis; nutrient; soil microbial biomass elements.