Increasing biodiversity loss profoundly affects community structure and ecosystem functioning. Therefore, revealing the mechanisms associated with community assembly and co-occurrence network structure of microbes along plant species diversity gradients is very important for understanding biodiversity maintenance and community stability in response to plant diversity loss. Here, we examined soil fungal and bacterial communities in a Chinese subtropical tree species richness experiment (from 1 to 16 species), using amplicon sequencing targeting the internal transcribed spacer 2 and V4 hypervariable region of the rDNA, respectively.
The study found that tree species richness had no significant effect on the diversity of either fungi or bacteria. In addition to soil and spatial distance, tree species richness and composition had a significant effect on fungal community composition but not on bacterial community composition. In fungal rather than bacterial co-occurrence networks, the average degree, degree centralization and clustering coefficient significantly decreased, but the modularity significantly increased with increasing tree species richness. Fungal co-occurrence network structure was influenced by tree species richness and community composition as well as the soil carbon : nitrogen ratio, but the bacterial co-occurrence network structure was affected by soil pH and spatial distance. The findings highlight that plants play more important roles in shaping community assembly and interactions of fungi than of bacteria in the subtropical tree diversity experiment.
Figure 1 Non-metric multidimensional scaling (NMDS) ordination of the community composition (Bray-Curtis dissimilarity) of fungi and bacteria.
Figure 2 Architecture and features of the fungal and bacterial co-occurrence networks in different tree species richness classes.
Huiyun Gan, Xingchun Li, Yonglong Wang, Pengpeng Lü, Niuniu Ji, Hui Yao, Shan Li and Liangdong Guo
*. 2022. Plants play stronger effects on soil fungal than bacterial communities and co-occurrence network structures in a subtropical tree diversity experiment. Microbiology spectrum. e0013422. https://doi.org/10.1128/spectrum.00134-22.