Utilization of carbon sources by soil bacteria in different plant functional groups in the Songnen Steppe

Biolog EcoPlates were used to analyse carbon source utilization by soil bacteria in different plant functional groups (Leymus chinensis, grass, legume, and forb) in the Songnen steppe. The results showed there were differences in carbon source utilization and bacterial metabolic activity among the four plant functional groups. Carbon source utilization of the soil bacteria community was the highest in the forb group, followed by grass and L. chinensis groups, and was lowest in the legume group. Carbohydrate and amino acids were used the most by soil bacteria in the four plants functional groups; however, phenolic acids and amines were poorly used in all plant functional groups. The Shannon-Wiener index, Pielou index, and the Gini index were the highest in the forb group and the lowest in the legume group. Redundancy analysis (RDA) showed that total N and organic matter were the major factors affecting carbon source utilization by soil bacteria in the forb and legume functional groups, and electrical conductivity, pH value, and moisture content were the major factors in the L. chinensis and grass groups.