Figure captions
Fig. 1. Sampling plots distributed within the study site -i.e. CK: control; r8: 8 years since reclamation; r11: 11 years since reclamation; r14: 14 years since reclamation; and r17: 17 years since reclamation. Figs. A, B and show the study site in Zoucheng, China. The D pictures is from the subsidence area in eastern China.
Fig. 2. Soil key attributes in the reclaimed (i.e. r8, r11, r14 and r17) and control (iCK) plots. Mean ± standard deviation (SD) (n = 15). Letters indicate significant differences among the 5 sites. A: SOM; B: soil pH value; C: soil EC value; D: soil AK content; E: soil OP content; F: soil TN content; G: soil URA activity; H: soil PPO activity; I: soil DHG activity; J: soil FDA activity. The values in the picture represent the significance of T-test; when the number < 0.05, it means significant; the value < 0.01: very significant; the value < 0.001: extremely significant.
Fig. 3. Taxonomic distributions of the most abundant (A) phylum and (B) genera levels of the SMCs found in the studied sites after reclamation (i.e. r8, r11, r14, r17) and control sites (CK).
Fig. 4. Molecular ecological networks (MENs) retrieved for the sampling plots subjected to land reclamation 8 (r8; A), 11 (r11; B), 14 (r14; C), and 17 (r17; D) years before sampling and control plot (CK; E). The nodes are plotted in circles of different sizes. The established nodes are portrayed in colors (i.e. purple, yellow, blue, green, ….). Each node corresponds to one microbial population of the most abundant phylum. The identified modules are labeled with numbers. A pink connector indicates a negative correlation, while a light-blue connector indicates a positive correlation between modules. Please, see online version for colors. CK: control; r8: eighth years after reclamation; r11: eleventh years after reclamation; r14: fourteenth years after reclamation; r17: seventeenth years after reclamation
Fig. 5. Z-P plot showing the keystone species (i.e. module hubs and connectors) in the different molecular ecological networks (MENs). Different symbols with special colors represent different networks as follows: green square for the CK network, red star for the r8 network, blue upward-facing triangles for the r11 network, magenta downward-facing triangles for the r14 network and cross cirle for the r17 network. The module hubs and connectors are labeled with phylogenetic affiliations (Acido-Acidobacteria, Actino- Actinobacteria, Bacteroi-Bacteroidetes, Chloro-Chloroflexi, Depen-Dependentiae, Elusi-Elusimicrobia Gemma-Gemmatimonadetes, Nitro-Nitrospirae, Patesci-Patescibacteria, Plancto-Planctomycetes, Proteo-Proteobacteria and Verru-Verrucomicrobia ). CK: control; r8: eighth years after reclamation; r11: eleventh years after reclamation; r14: fourteenth years after reclamation; r17: seventeenth years after reclamation.
Fig. 6. Correlation between the identified molecular ecological networks (MEN) modules and the key soil attributes for the five study plots: (A) r8; (B) r11; (C) r14 and (D) r17; (E) CK. CK: control; r8: eighth years after reclamation; r11: eleventh years after reclamation; r14: fourteenth years after reclamation; r17: seventeenth years after reclamation. * mean significant difference at 5% (p<0.05), ** mean significant difference at 1% (p<0.01), *** mean extremely significant difference at 1% (p<0.001).