Table 1.
Plant diversity and soil geochemical properties in two forest types.
Table 2.
Numbers of soil microbial OTUs and composition in two forest types.
Figure 1.
Detrended correspondence analysis (DCA) of soil microbial community structure.
The DCA was analyzed based on the relative abundances of OTUs (A) and functional genes based on GeoChip 4.0 (B).
Figure 2.
Relationship between soil microbial phylogenetic diversity index and functional gene diversity index.
Figure 3.
The normalized gene relative signal intensity of the detected key gene categories involved in carbon degradation.
The signal intensities were the sum of detected individual gene for each functional gene, averaged among 4 soil samples. The complexity of carbon is presented in order from active to recalcitrant. All data are presented as mean ± standard error. Significant differences between two forest types are indicated above the bars. *, P<0.05, **, P<0.01.
Table 3.
The relationships between relative abundances of microbial functional genes involved in carbon and nitrogen cycling and soil carbon or nitrogen components and enzyme activity by Mantel-test.
Figure 4.
The normalized average signal intensity of detected key gene categories involved in the N cycling between SEC and MAT.
The signal intensities were the sum of all detected individual gene for each gene category, and then averaged among 4 samples. (A). N2 fixation, including nifH encoding nitrogenase; (B). Nitrification, including amoA encoding ammonia monooxygenase, hao for hydroxylamine oxidoreductase; (C). Denitrification, including narG for nitrate reductase, nirS for nitrite reductase, norB for nitric oxide reductase, and nosZ for nitrate reductase; (D). Dissimilatory N reduction to ammonium, including napA for nitrate reductase, and nrfA for c-type cytochrome nitrite reductase; (E). Ammonification, including gdh for glutamate dehydrogenase and ureC encoding urease; (F). Assimilatory N reduction, including nasA encoding nitrate reductase, niR, nirA and nirB encoding dissimilatory nitrite reductase. All data are presented as the mean±SE (error bars). **, P<0.01, *, P<0.05.
Table 4.
Mantel test and partial Mantel test between 16S rRNA OTUs and Geochip data with environmental properties.
Figure 5.
The Canonical correspondence analysis (CCA) and Variation partitioning analysis (VPA) between OTUs data and soil environmental variables.
The left was CCA between microbial OTUs data and soil environmental factors, and the right was the VPA. DBH, diameter at breast height of tree. Soil, including soil organic carbon, total nitrogen and pH, soil temperature (Temp) and plant diversity (Plant, including the Shannon index of trees and shrubs, diameter at breast height of trees), and their relationships. Each diagram represents the biological variation partitioned into the relative effects of each factor or a combination of factors, in which geometric areas were proportional to the percentages of explained variation.