Abstract

The information on the rhizosphere microorganisms of Leymus chinensis (L. chinensis)was limited. To demonstrate the rhizosphere microbial dynamics and its relation to aboveground biomass and soil environment, the rhizosphere microbial numbers, biomass carbon, diversity index, aboveground biomass and soil temperature/moisture were measured and analyzed at different growth stages of L. chinensis. The results showed that the rhizosphere microbial numbers and biomass carbon were significantly related (P<0.05) among different growth stages based on one-way ANOVA analysis, showing single peak type in all growth stages with a maximum value at the fruiting stage. The rhizosphere effect was evident during active growing stages of L. chinensis. Regardless of other factors, aboveground biomass and soil temperature/moisture had significant effect (P<0.05) on the rhizosphere microbial numbers and biomass carbon based on correlation analysis. However, the results of stepwise regression equation suggested that the effect of aboveground biomass was dominated. The microbial community diversity index had no change (P>0.05) in all growth stages of L. chinensis based on one-way ANOVA and student’s t-test, and no significant effect of aboveground biomass and soil temperature/moisture was found based on correlation analysis (P>0.05). To sum it up, the rhizosphere microbial numbers and biomass carbon showed significant dynamics with growth stages of L. chinensis, and the change were related primarily by plant growth. Nevertheless, the microbial community was indefinitely stable in all growth stages of L. chinensis.

Key words: Leymus chinensis, rhizosphere microorganisms, aboveground biomass, soil temperature/moisture, dynamics, correlation