Figure captions
Fig. 1 The number of common and unique operational taxonomic
units (OTUs) of rhizosphere bacterial (A) and fungi (B) under R.
pseudoacacia plantations with different ages. RS15, RS25, RS35, and
RS45 indicate the 15-, 25-, 35-, and 45-year-old age groups,
respectively.
Fig. 2 Variation in bacterial (A, C) and fungal (B, D)
β-diversity in the rhizosphere soils of R. pseudoacaciaplantations at different ages, and the contribution of soil
environmental properties to microbial β-diversity based on random forest
analysis (E, F).
Fig. 3 Co-occurrence patterns of forest age-sensitive
operational taxonomic units (fsOTUs) in the rhizosphere microbiota. (A,
B) Co-occurrence networks of bacterial (left) and fungal (right) fsOTUs
showing significant correlations (r > 0.07, p <
0.001). (C, D) Cumulative relative abundances (as counts per million;
y-axis in ×1000) of bacterial (left) and fungal (right) fsOTUs in
different network modules. The cumulative relative abundances in RS15
(brownish red), RS25 (blue), RS35 (green), and RS45 (purple) samples
indicate the overall responses of forest age-sensitive modules to the
different forest ages. (E, F) Abundances of bacterial (left) and fungal
(right) fsOTUs following regression with rhizosphere soil multinutrient
cycling index in different modules.
Fig. 4 Identification of rhizosphere core microbiota (A, B) and
their contribution to soil multinutrient cycling index (C). Figures of
core bacteria are shown in the top panel and figures of core fungi are
in the bottom panel. Red color indicates core microbiota and blue color
indicates non-core (other) microbiota. Co-occurrence networks of core
and non-core microbiotas were constructed based on correlation analysis.
Network degrees of core bacteria and fungi were calculated.
Contributions of core and non-core microbial diversity to rhizosphere
soil multinutrient cycling were estimated based on random forest
analysis.
Fig. 5 Potential contributions of the core microbiota to
rhizosphere soil nutrient properties based on correlation and optimal
multiple regression model for major classes of the core bacteria and
fungi (A-B). Color gradient represents Spearman’s correlation
coefficients. Circle size represents the variable’s importance, i.e.,
proportion of explained variation calculated via multiple regression
modeling and variance decomposition analysis.