Title: Rapid recovery of soil bacterial communities after wildfire in a Chinese boreal
forest
Authors: Xingjia Xiang1,3,+, Yu Shi1,3,+, Jian Yang2, Jianjian Kong2,3, Xiangui Lin1,
Huayong Zhang1, Jun Zeng1, Haiyan Chu1,*
1
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science,
Chinese Academy of Sciences, East Beijing Road 71, Nanjing 210008, China
2
State Key Laboratory of Forest and Soil Ecology, Institute of Applied Ecology,
Chinese Academy of Sciences, Wenhua Road 72, Shenyang 110164, China
3
University of the Chinese Academy of Sciences, Beijing 100049, China
+
The authors contributed equally to this work
*Corresponding author:
Haiyan Chu, Tel.: 86-25-86881356
E-mail: hychu@issas.ac.cn
1
Table S1: Summary of the main characteristics of sampling sites in the Greater
Khingan Mountains. The values in brackets represent the standard deviation of the
mean. Different letters represent significant differences from Tukey’s HSD
comparisons (P < 0.05). OL: one year after low intensity fire; OH: one year after high
intensity fire; EL: 11 years after low intensity fire; EH: 11 years after high intensity
fire. SM: soil moisture; TC: total carbon; TN: total nitrogen; C/N: carbon/nitrogen;
DOC: dissolved organic carbon; DON: dissolved organic nitrogen; MBC: microbial
biomass carbon; MBN: microbial biomass nitrogen.
Soil variables
control
OL
OH
EL
EH
Soil pH
4.1 (0.11)
4.8 (0.19)
4.6 (0.13)
4.4 (0.15)
TC (%)
a
a
a
a
TN (%)
C/N ratio
SM (%)
AP (mg/kg)
+
NH4 (mg/kg)
-
NO3 (mg/kg)
DOC (mg/kg)
DON (mg/kg)
MBC (mg/kg)
MBN (mg/kg)
Elevation (m)
b
a
8.9 (1.4)
a
8.9 (2.2)
a
0.38 (0.05)
a
6.9 (1.1)
a
0.45 (0.09)
b
23 (0.9)
20.3 (1.5)
29.4 (3.7)
c
a
34 (2.1)
0.51 (0.21)
11.4 (4.5)
ab
440 (118)
a
a
133 (37)
2993 (447)
a
532 (93)
b
885 (41)
566 (100)
b
199 (67)
ab
961 (48)
2
7.5 (2.5)
288 (24)
32 (2)c
1.1 (0.3)b
ab
352 (22)ab
404 (36)
a
72 (5)a
105 (22)
b
b
489 (70)
1210 (204)
b
112 (35)
1007 (52)
1048 (133)b
b
113 (19)b
ab
948 (39)ab
187 (61)
a
23.8 (1.2)b
ab
5.6 (1.7)
b
107 (20)
b
25.4 (1.6)
43 (7)
a
a
132 (25)
a
ab
bc
58 (8)
a
a
490 (40)
26.8 (2.8)
ab
64 (11)
b
68 (6)ab
80 (12)
ab
0.36 (0.04)a
22 (0.7)ab
ab
55 (6)
a
0.42 (0.06)
20 (1.2)
b
56 (6)
b
a
b
20 (1.2)
b
86 (12)
0.33 (0.04)
4.3 (0.16)ab
7.9 (0.8)a
8.2 (1.1)
a
b
19 (1.1)
a
ab
967 (51)
Table S2: Relative average abundances of phyla classified with RDPII taxonomy
across all soils and soils grouped into different treatments (values represent % of total
sequences). Asterisks indicate sequences classified to the domain Bacteria, but not to
a specific phylum. The “0.00” value means less than 0.01. OL: one year after low
intensity fire; OH: one year after high intensity fire; EL: 11 years after low intensity
fire; EH: 11 years after high intensity fire.
Taxon
Alphaproteobacteria
Actinobacteria
Acidobacteria
Bacteria*
Betaproteobacteria
Bacteroidetes
Gammaproteobacteria
Proteobacteria;Other
Planctomycetes
Chloroflexi
Deltaproteobacteria
Gemmatimonadetes
Firmicutes
AD3
Armatimonadetes
Verrucomicrobia
WPS-2
Cyanobacteria
Elusimicrobia
TM6
SC3
Crenarchaeota
Chlorobi
Nitrospirae
CCM11b
TM7
OP3
SC4
SM2F11
Thermi
SPAM
Chlamydiae
WS3
Euryarchaeota
OP11
NC10
BRC1
ALL
21.56
17.74
15.16
14.54
8.45
7.46
4.28
1.87
1.73
1.24
1.19
0.81
0.82
0.39
0.37
0.29
0.28
0.27
0.10
0.09
0.08
0.08
0.07
0.03
0.03
0.03
0.02
0.02
0.02
0.01
0.01
0.01
0.01
0.01
0.00
0.00
0.00
Control
25.40
17.76
19.48
15.71
4.62
3.87
4.61
1.70
1.90
0.90
1.33
0.62
0.46
0.26
0.16
0.17
0.16
0.09
0.08
0.08
0.08
0.09
0.07
0.01
0.02
0.01
0.02
0.01
0.01
0.01
0.01
0.01
0.01
0.00
0.00
0.00
0.00
OL
20.24
19.80
9.52
11.55
13.46
11.13
4.15
2.03
1.07
1.32
0.72
0.80
1.23
0.44
0.50
0.21
0.45
0.28
0.07
0.04
0.08
0.02
0.07
0.01
0.01
0.02
0.01
0.02
0.00
0.04
0.00
0.00
0.00
0.00
0.00
0.00
0.00
3
OH
21.38
16.33
11.22
11.76
13.01
12.08
4.39
2.12
1.25
0.76
0.94
0.73
0.95
0.38
0.70
0.30
0.31
0.24
0.05
0.09
0.07
0.02
0.05
0.01
0.00
0.02
0.02
0.02
0.02
0.03
0.00
0.00
0.00
0.00
0.00
0.00
0.00
EL
20.36
18.50
14.74
17.85
6.30
5.38
4.15
1.96
2.10
1.87
1.44
1.06
1.06
0.41
0.23
0.43
0.17
0.37
0.17
0.09
0.08
0.13
0.08
0.05
0.06
0.04
0.03
0.02
0.03
0.00
0.01
0.03
0.01
0.01
0.01
0.01
0.00
EH
20.40
16.30
20.86
15.84
4.83
4.83
4.07
1.56
2.33
1.37
1.54
0.83
0.40
0.45
0.24
0.34
0.32
0.35
0.13
0.13
0.09
0.13
0.09
0.07
0.06
0.04
0.03
0.03
0.04
0.00
0.04
0.02
0.02
0.02
0.00
0.00
0.00
Table S3: Differences of bacterial communities across the different groups examined
by the dissimilarity test of ANOSIM. Pearson correlations coefficients (r) are shown
with associated Bonferroni-corrected P-value. P < 0.05, significant convention. OYF:
1 year post fire; EYF: 11 years post fire.
Control-OYF
Control-EYF
OYF-EYF
r
0.53
0.02
0.49
4
P
0.001
0.549
0.001
Table S4: Correlations between the relative abundances of the dominant bacterial
phyla and soil characteristics and altitude by linear regression analyses. Pearson
correlations coefficients (r) are shown for each taxon with associated Bonferronicorrected P-value. SM: soil moisture; TC: total carbon; TN: total nitrogen; C/N ratio:
carbon/nitrogen ratio; AP: available phosphorus; DOC: dissolved organic carbon;
DON: dissolved organic nitrogen; MBC: microbial biomass carbon; MBN: microbial
biomass nitrogen.
r value
Alphaproteobacteria
pH
-0.419**
TC (%) TN (%) C/N ratio SM (%)
AP
(mg/kg)
DOC
(mg/kg)
DON
(mg/kg)
0.135
0.071
0.071
-0.086
-0.118
Actinobacteria
**
0.586
0.245
*
Acidobacteria
-0.574**
-0.064
Betaproteobacteria
**
0.303
-0.234
0.037
-0.240
NO3(mg/kg)
-0.092
MBN Elevation
(mg/kg)
(m)
0.380*
0.011
0.440**
-0.010
-0.248
0.252
0.144
0.133
0.199
0.207
0.311
0.490**
0.052
-0.251
-0.444**
-0.470**
0.231
0.049
-0.265*
0.243
**
0.392*
0.230
-0.409**
-0.113
0.016
-0.433**
0.198
-0.267*
0.197
0.029
-0.049
0.225*
**
*
-0.162
0.009
-0.635
-0.079
Bacteroidetes
-0.082
-0.012
-0.187
Gammaproteobacteria
-0.391**
-0.184
-0.212
-0.282*
0.058
Planctomycetes
-0.284*
0.026
-0.064
Chloroflexi
0.518**
-0.166
0.362**
0.129
0.463**
0.001
0.309*
-0.173
0.509**
0.245
0.201
-0.223
0.240
0.482
-0.135
0.152
-0.260*
0.021
0.208
-0.078
-0.184
0.328*
-0.230
0.114
0.128
-0.102
-0.424**
0.536**
0.195
0.154
0.026
-0.119
0.213*
0.095
-0.193
*: P < 0.05; **: P < 0.01, significant convention
5
*
MBC
(mg/kg)
-0.073
0.377
0.191
Deltaproteobacteria
NH4+
(mg/kg)
-0.118
-0.213
0.170
0.234
-0.007
0.103
0.407**
-0.393*
-0.178
-0.089
-0.169
-0.050
-0.289*
-0.333*
0.188
-0.071
0.102
Table S5: Pearson correlations (R) between bacterial diversity (Faith’s PD, OTUs) and
soil and site characteristics by linear regression analyses. SM: soil moisture; TC: total
carbon; TN: total nitrogen; C/N ratio: carbon/nitrogen ratio; AP: available phosphorus;
DOC: dissolved organic carbon; DON: dissolved organic nitrogen; MBC: microbial
biomass carbon; MBN: microbial biomass nitrogen.
Soil variables
pH
r value
OTUs
PD
*
0.298 *
0.197
TC (%)
0.322
0.228
TN (%)
0.248
0.174
C/N ratio
0.126
0.107
SM (%)
0.247
0.204
AP (mg/kg)
0.121
0.104
NH4+ (mg/kg)
0.126
-0.139
NO3- (mg/kg)
0.021
-0.040
DOC (mg/kg)
0.270 *
0.257 *
DON (mg/kg)
0.026
-0.049
MBC (mg/kg)
0.194
0.136
MBN (mg/kg)
0.054
0.011
Elevation (m)
-0.268 *
-0.220
*: P < 0.05, significant convention
6
Figure S1: Relative abundances of the dominant bacterial phyla in soils. Relative
abundances are based on the proportional frequencies of DNA sequences that could be
classified at the phylum level. OL: one year after low intensity fire; OH: one year
after high intensity fire; EL: 11 years after low intensity fire; EH: 11 years after high
intensity fire.
7
Figure S2: OTUs that exhibited significant changes in abundance at one year after low
intensity fire. Significance was determined using response ratio methods at a 95% CI
(confidence interval).
8
Figure S3: Canonical correspondence analysis (CCA) of the bacterial communities
was completed in the vegan package of R v.2.8.1 project. SM: soil moisture; TN: total
nitrogen; C/N ratio: carbon/nitrogen ratio.
9
Figure S4: The relationships between relative abundances of dominant bacterial
groups and soil pH. Linear regressions were used to test the correlation between the
taxa’s relative abundances and pH. P < 0.05, significant convention.
10