Abstract:

Microbial diversity plays important roles in improving local soil environment and ecological functions of biological soil crusts in desert ecosystems. In this study, high throughput sequencing of 16S rDNA was carried out to reveal the seasonal dynamics of bacterial diversity of algae crusts, moss crusts and their sublayer soils for four seasons during the evolution of biological soil crusts in the southeast Tengger Desert. The results showed that the bacterial richness of the sampled soils was significantly lower in summer than in the other three seasons. The main bacterial groups in the four soils were Proteobacteria, Actinobacteria, Chloroflexi, Acidobacteria and Cyanobacteria, of which Proteobacteria and Actinobacteria were the dominant groups. The relative abundance of Proteobacteria was significantly higher in summer than in spring, autumn and winter, and significantly higher in the biocrust samples than in the sublayers. The relative abundance of Actinobacteria was significantly higher in spring and summer than in autumn and winter, and significantly higher in sublayers of biocrusts than in biocrusts. The seasonal dynamics of bacterial diversity and relative abundance during the processes of biocrust succession indicate that it responds to changes in the local desert environment, which provides bacteria diversity data for understanding the ecological functions of biocrusts in the desert ecosystems.

Key words: biological soil crusts, seasonal dynamics, high throughput sequencing, bacterial diversity