Effects of Microbial Diversity on Soil Carbon Mineralization

Abstract

Soil microbial community plays an important role in ecosystem functions; however, little is known about the importance of microbial diversity to the ecosystems. In this study, serial dilution of soil suspension (10-1, 10-3, and 10-5) was performed and inoculated into the sterilized soils that form the broadleaf mixed forests in Pangquangou. The change in the carbon mineralization rate and the pattern of the carbon source utilization were studied by titration, Biolog Eco, and other experimental methods. The results show that after being incubated for six weeks, carbon mineralization rate, the cumulative amount of carbon mineralization, average well color development (AWCD), and diversity index (Shannon, McIntosh, and richness index) of D1 were significantly higher than those of the D5 treatment. The cumulative amount of carbon mineralization and AWCD was strongly and inversely correlated with richness. Principal component analysis and one-way ANOVA also indicated that the patterns of carbon source utilization of microbially diverse soil were different. Therefore, the loss of microbial diversity affects the carbon mineralization rate and the pattern of carbon source utilization, leading to functional changes in terrestrial ecosystems. In the management of forest soils, the effects of soil microbial diversity on ecosystem functions should be considered.