Table 1.
General physical and chemical properties (n = 3, mean±SE)* of soil for each site.
Table 2.
Estimated number of observed OTUs (at 97% similarity), richness, diversity, and coverage (n = 3, mean±SE)* of soil for each site.
Figure 1.
Rarefaction analyses of samples.
Rarefaction curves of OTUs clustered at 97% sequence identity across different samples from reclamation sites of different ages (REC) and the undisturbed reference (UND). UND refers to site undisturbed, REC-1 to site reclaimed for 1 year, REC-8 to site reclaimed for 8 years, REC-15 to site reclaimed for 15years and REC-20 to site reclaimed for 20 years.
Figure 2.
Shannon Wiener curves of samples.
Shannon Wiener curves of OTUs clustered at 97% sequence identity across different samples from reclamation sites of different ages (REC) and the undisturbed reference (UND).
Figure 3.
Relative abundance of the dominant bacteria phyla in all sites combined (A) and in each site (B).
Relative abundances (>1%) are based on the proportional frequencies of those DNA sequences that could be classified at the phylum (proteobacterial class) level. Phylogenetic groups accounting for ≤1% of all classified sequences are summarized in the artificial group “Others”.
Figure 4.
Cluster tree (left) and PCA (right) analyses for soil bacterial communities from reclaimed sites (REC-1, REC-8, REC-15, REC-20) and undisturbed site (UND).
The hierarchical clustering analysis of bacterial communities based on Bray–Curtis distance calculated by OTUs at a distance of 3% for soil samples. The scale bar indicates an estimated change of 1%. Principal component analyses (PCA) of soil bacterial communities based on OTUs at a distance of 3%.
Figure 5.
Heatmap and accompanying cluster analyses (x-axis) of all samples based on Bray–Curtis distance indices calculated by OTUs at a distance of 3%.
Percentages below the map indicate the abundance of each OTU relative to all bacterial sequences in soils that were classified in each of the 5 sites. The relative abundance for each OTU in different sites is colored in shades of blue (low relative abundance) to green, yellow or brown (high relative abundance) as shown in the color key (bottom).
Figure 6.
MEGAN integrative taxonomic analysis of bacterial 16S rRNA data sets in multi samples form REC-1, REC-8, REC-15, REC-20 and UND.
Taxonomy analysis tree of all sample sites from 2842 OTUs based on an evolutionary distance of 0.03 (species level) and NCBI GenBank reference sequences.
Table 3.
Correlations among soil properties and microbiological diversity parameters.
Figure 7.
Redundancy analysis (RDA) of abundant phyla (proteobacterial classes) and selected soil edaphic properties such as SOM, total N, total P, and pH for individual samples from undisturbed and reclaimed sites along a chronosequence of reclamation.