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Journal of Arid Land  2020, Vol. 12 Issue (3): 473-494    DOI: 10.1007/s40333-020-0011-z     CSTR: 32276.14.s40333-020-0011-z
Research article     
Effect of vegetation on soil bacteria and their potential functions for ecological restoration in the Hulun Buir Sandy Land, China
YAN Ru1, FENG Wei1,2,*()
1 Yanchi Research Station, School of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China
2 Engineering Research Center of Forestry Ecological Engineering of the Ministry of Education, Beijing Forestry University,Beijing 100083, China
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Abstract  

To date, much of research on revegetation has focused on soil microorganisms due to their contributions in the formation of soil and soil remediation process. However, little is known about the soil bacteria and their functions respond to the diverse vegetational types in the process of vegetation restoration. Effects of dominated vegetation, i.e., Artemisia halodendron Turcz Ex Bess, Caragana microphylla Lam., Hedysarum fruticosum Pall. and Pinus sylvestris L. on bacterial community structures and their potential functions in the Hulun Buir Sandy Land, China were determined using high-throughput 16S rRNA gene sequencing and phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) in 2015. Although the dominant phyla of soil bacterial community among different types of vegetation, including Proteobacteria, Actinobacteria, Acidobacteria, Bacteroidetes and Firmicutes, were similar, the relative abundance of these dominant groups significantly differed, indicating that different types of vegetation might result in variations in the composition of soil bacterial community. In addition, functional genes of bacterial populations were similar among different types of vegetation, whereas its relative abundance was significantly differed. Most carbon fixation genes showed a high relative abundance in P. sylvestris, vs. recalcitrant carbon decomposition genes in A. halodendron, suggesting the variations in carbon cycling potential of different types of vegetation. Abundance of assimilatory nitrate reduction genes was the highest in P. sylvestris, vs. dissimilatory nitrate reduction and nitrate reductase genes in A. halodendron, indicating higher nitrogen gasification loss and lower nitrogen utilization gene functions in A. halodendron. The structures and functional genes of soil bacterial community showed marked sensitivities to different plant species, presenting the potentials for regulating soil carbon and nitrogen cycling.



Key wordsbacterial taxonomic composition      functional gene      vegetational type      soil carbon and nitrogen      16S rRNA     
Received: 06 September 2019      Published: 10 May 2020
Corresponding Authors:
About author: *Corresponding author: FENG Wei (E-mail: weifeng@bjfu.edu.cn)
Cite this article:

YAN Ru, FENG Wei. Effect of vegetation on soil bacteria and their potential functions for ecological restoration in the Hulun Buir Sandy Land, China. Journal of Arid Land, 2020, 12(3): 473-494.

URL:

http://jal.xjegi.com/10.1007/s40333-020-0011-z     OR     http://jal.xjegi.com/Y2020/V12/I3/473

Dominant plant species Vegetation coverage (%) Mean height (m) Mean canopy area (m2) Main associated plant species
Artemisia halodendron 60 0.63 0.80 Cleistogenes; Saussurea salsa;
Agropyron cristatum
Caragana microphylla 85 1.30 4.41 Setaria viridis; Agropyron cristatum; Cleistogenes squarrosa
Hedysarum fruticosum 90 1.40 6.19 Cleistogenes squarrosa; Setaria viridis; Agropyron cristatum
Pinus sylvestris 70 5.00 7.84 Saussurea salsa; Artemisia frigida; Carex spp.
Table 1 Basic information of the sampled vegetation
Variable Two way ANOVAs One way ANOVA
Vegetation Patch type Vegetation×Patch type AH CM HF PS
F P F P F P
Soil property
SOC 7.00 0.003 15.05 0.001 2.25 0.122 1.47b 1.32b 1.97ab 2.37a
TN 6.37 0.005 7.04 0.017 1.66 0.216 0.06b 0.13a 0.13a 0.13a
HN 9.63 0.001 2.38 0.142 1.50 0.252 7.93b 13.91a 15.59a 14.86a
TP 1.99 0.157 0.03 0.866 0.94 0.446 91.60 81.64 86.86 67.72
AP 2.46 0.100 1.99 0.178 0.10 0.961 4.22 4.68 4.88 6.02
SWC 1.96 0.161 0.02 0.881 0.69 0.571 0.03 0.02 0.03 0.01
EC 1.81 0.187 3.65 0.074 0.81 0.508 29.22 31.59 23.50 24.44
pH 7.25 0.003 0.25 0.625 1.86 0.177 7.20a 6.86ab 6.66b 6.71b
Soil bacterial diversity
Shannon 9.07 0.001 4.21 0.057 0.84 0.491 7.68b 7.91b 7.88b 8.24a
Chao1 5.78 0.007 1.49 0.240 0.69 0.570 14,042.00b 18,893.00ab 17,517.00ab 21,574.00a
Table 2 ANOVA results of soil property and bacterial diversity under different types of vegetation and patch types
Index SOC TN TP AP HN SWC pH EC
Shannon 0.5365** 0.5336** -0.5365** 0.5044** 0.5997** -0.4652* -0.3197 0.1587
Chao1 0.4374* 0.5653** -0.3530 0.4043 0.4410* -0.3652 -0.3071 0.0752
Table 3 Spearman correlation coefficient between soil bacterial alpha diversity (Shannon index and Chao1) and environmental variable
Fig. 1 Non-metric multidimensional scaling (NMDS) ordination based on Bray-Curtis distance showing soil bacterial beta diversity under different vegetation and patch types. AH, Artemisia halodendron; CM, Caragana microphylla; HF, Hedysarum fruticosum; PS, Pinus sylvestris; Be, beneath plant mid-canopy; In, plant interspace.
Vegetation pairing r P
AH-CM 0.5741 0.003
AH-HF 0.7185 0.001
AH-PS 1.0000 0.002
CM-HF -0.0852 0.752
CM-PS 0.4953 0.006
HF-PS 0.3722 0.005
Table 4 Significance test on the effects of different types of vegetation pairings on the soil bacterial community structure as detected by the analysis of similarities (ANOSIM)
Fig. 2 Bacteria taxonomic classification at the phyla and genus levels. The inner circle is the dominant phyla (relative abundance>1%), and the outer circle is the dominant genus (relative abundance>1%). The same colour represents a phylum, and the lowercase letters in each colour represent a certain genus in the phylum. Each quarter represents a plant species. PS, Pinus sylvestris; AH, Artemisia halodendron; CM, Caragana microphylla; HF, Hedysarum fruticosum.
Fig. 3 Heat map indicating difference in the relative abundance of specific genes among four types of vegetation. AH, Artemisia halodendron; CM, Caragana microphylla; HF, Hedysarum fruticosum; PS, Pinus sylvestris; Be, beneath plant mid-canopy; In, plant interspace. * represents the significant difference between beneath plant mid-canopy and plant interspace at P<0.05 level.
Fig. 4 Relationships of soil variable with bacterial community structure (a) and functional gene (b). Variation partitioning analyses of soil variable and vegetational type on functional gene (c) and bacterial composition (d). SOC, soil organic carbon; TN, total nitrogen; HN, hydrolytic nitrogen; TP, total phosphorus; AP, available phosphorus; SWC, soil water content; EC, electrical conductivity. AH, Artemisia halodendron; CM, Caragana microphylla; HF, Hedysarum fruticosum; PS, Pinus sylvestris. The environmental variables are divided into groups of soil (SOC, TN, TP, AP, HN, SWC, EC, pH and bacterial diversity) and vegetation. The numbers present percentage (%) of variation explained by the factors.
Index Bacterial community structure Index Functional gene
r P r P
Bdiv 0.3628 0.001 Bdiv 0.3624 0.001
TP 0.3101 0.002 TP 0.2341 0.006
HN 0.289 0.004 HN 0.3198 0.006
TN 0.2581 0.006 TN 0.2587 0.006
SWC 0.2065 0.009 SWC 0.2099 0.008
SOC 0.1658 0.034 SOC 0.1041 0.081
AP 0.1484 0.055 AP 0.0101 0.418
pH 0.1298 0.096 pH 0.2179 0.014
EC 0.0370 0.284 EC 0.0574 0.215
Bdiv+TP 0.4626 0.001 Bdiv+HN 0.4235 0.001
Bdiv+TP+HN 0.5024 0.001 Bdiv+HN+TN 0.4011 0.001
Bdiv+TP+HN+TN 0.4595 0.001 Bdiv+HN+TP 0.4396 0.001
Bdiv+TP+HN+SWC 0.4944 0.001 Bdiv+HN+TP+pH 0.4744 0.001
Bdiv+TP+HN+SOC 0.4815 0.001 Bdiv+HN+TP+pH+SWC 0.4844 0.001
Bdiv+TP+HN+AP 0.5037 0.001 Bdiv+HN+TP+pH+SWC+EC 0.4732 0.001
Bdiv+TP+HN+AP+pH 0.4694 0.001 Bdiv+HN+TP+pH+SWC+AP 0.4511 0.001
Bdiv+TP+HN+AP+EC 0.4772 0.001
Table 5 Correlations of environmental variable with bacterial community structure and functional gene
Table S1 ANOVA results of relative abundance of soil bacreria under different types of vegetation and patch types
Table S2 ANOVA results of relative abundance of soil functional genes under different types of vegetation and patch types
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