Positive effects of plant diversity on soil microbial biomass and activity are associated with more root biomass production

2017-11-15T15:08:09Z (GMT) by Xiao-Yan Wang Yuan Ge Jiang Wang
<p>This study aims to explore relationships between plant diversity and soil microbial function and the factors that mediate the relationships. Artificial plant communities (1, 2, 4 and 8 species) were established filled with natural and mine tailing soils, respectively. After 12 months, the plant species richness positively affected the soil microbial functional diversity in both soil environments but negatively affected microbial biomass and soil basal respiration in the natural soil. The root biomass positively correlated with the microbial biomass, cultural bacterial activity and soil basal respiration in both soil environments. Moreover, the <i>D<sub>i</sub></i> (deviations between observed performances and expected performances from the monoculture performance of each species of mixture) of microbial biomass, cultural bacterial activity and soil basal respiration positively correlated with the <i>D<sub>i</sub></i> of root biomass in both soil environments. Consistent with stress-gradient hypothesis, the <i>D<sub>mix</sub></i> (over-function index) of aboveground biomass positively correlated plant species richness in the mine tailing soil. Results suggest that the root biomass production is an important mechanism that affects the effects of plant diversity on soil microbial functions. Different responses of soil microbial function to increasing plant diversity may be due to root biomass production mediated by other factors.</p>