4.3 Role of core microbiota in rhizosphere soil nutrient
cycling
Exploring core microbiota can enhance our understanding of the influence
of microbial community assembly and stability on rhizosphere soil
nutrient cycling (27) Therefore, in the present study, we identified the
core taxa in the rhizosphere microbial communities associated withR. pseudoacacia plantations. In the microbial network, a high
value represents a node and a central
position, while a low value indicates a peripheral position (12, 48). We
observed core taxa in rhizosphere microbial communities, which exhibited
high connectivity. The results indicate that the core microbiota had a
central ecological position in the rhizosphere microbial network.
High soil microbial diversity could promote multifunctionality, as
reported in other terrestrial ecosystems (11, 19, 31, 49). Jiao et al.
reported that core microbiota played a major role in the maintenance of
microbial interactions, community stability, and belowground
multinutrient cycling in agricultural fields across eastern China (25).
Our results indicated that the diversity of core taxa has a greater
impact on rhizosphere soil multinutrient cycling than the diversity of
non-core taxa, based on random forest module. Accordingly, we concluded
that the core microbiota participated in rhizosphere soil multinutrient
cycling, while maintaining rhizosphere microbial network complexity.
Multiple regression modeling and variance decomposition analysis
revealed the potential influences of core microbiota, at the class
level, on soil nutrient properties.
Some core taxa can participate in the maintenance of plant health and
plant production (20, 52), and such taxa play important roles in soil
multifunctionality maintenance through the promotion of nutrient
exchange and facilitation of resource availability in agroecosystems
(52). The core microbiota identified in the present study have been
reported in other environments. For example, Acidimicrobiia are
observed extensively in acidic wastewater, marine lakes, deserts, and
other environments with important ecological functions and potential
development values (18). Bacillus can degrade
Polyhydroxy-alkanoates and promote plant growth (9, 44). So, identifying
core microbiota facilitates the understanding of microbial responses to
environmental disturbance (46).