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Citation: Zhang, N.; Chen, K.; Wang,
X.; Ji, W.; Yang, Z.; Wang, X.; Li, J.
Response Mechanism of cbbM Carbon
Sequestration Microbial Community
Characteristics in Different Wetland
Types in Qinghai Lake. Biology 2024,
13, 333. https://doi.org/10.3390/
biology13050333
Academic Editors: Pabulo H.
Rampelotto and Juan Carlos
Gutiérrez
Received: 21 April 2024
Revised: 8 May 2024
Accepted: 9 May 2024
Published: 10 May 2024
Copyright: © 2024 by the authors.
Licensee MDPI, Basel, Switzerland.
This article is an open access article
distributed under the terms and
conditions of the Creative Commons
Attribution (CC BY) license (https://
creativecommons.org/licenses/by/
4.0/).
biology
Article
Response Mechanism of cbbM Carbon Sequestration Microbial
Community Characteristics in Different Wetland Types in
Qinghai Lake
Ni Zhang 1,2,3 , Kelong Chen 1,2,3,*, Xinye Wang 1,2,3, Wei Ji 1,2,3, Ziwei Yang 1,2,3, Xia Wang 1,2,3 and Junmin Li 4
1Qinghai Province Key Laboratory of Physical Geography and Environmental Process, College of
Geographical Science, Qinghai Normal University, Xining 810008, China; zhangni0224@163.com (N.Z.);
202047341016@stu.qhnu.edu.cn (X.W.); jiwei100500@163.com (W.J.); 15756789182@163.com (Z.Y.);
wx_813113@163.com (X.W.)
2Key Laboratory of Tibetan Plateau Land Surface Processes and Ecological Conservation (Ministry of
Education), Qinghai Normal University, Xining 810008, China
3National Positioning Observation and Research Station of Qinghai Lake Wetland Ecosystem in Qinghai,
National Forestry and Grassland Administration, Haibei 812300, China
4School of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo 255000,
China; lijunmin@163.com
*Correspondence: ckl7813@163.com; Tel.: +86-139-0971-7813
Simple Summary: In this paper, the differences in carbon sequestration microbial communities
in different wetland types and their main influencing factors were investigated. It was found that
the alpha diversity of cbbM carbon-sequestering microorganisms was consistent with the change
trend in the total carbon content. Acidithiobacillus was used as a biomarker in lakeside wetlands,
and Thiothrix and Thiodictyon were used as biomarkers in marsh wetlands. The diversity of cbbM
carbon-fixing microorganisms was primarily influenced by the total nitrogen content, while the
community structure was significantly affected by the soil total carbon content. The increase in
soil temperature and humidity was conducive to the carbon-sequestering process of Thiomicrospira,
Thiomonas,Polaromonas and Acidithiobacillus. The changes in wetland types seriously affected the
characteristics of cbbM carbon sequestration in microbial communities, and a warm and humid
climate may be conducive to wetland carbon sequestration.
Abstract: Carbon-sequestering microorganisms play an important role in the carbon cycle of wetland
ecosystems. However, the response mechanism of carbon-sequestering microbial communities to
wetland type changes and their relationship with soil carbon remain unclear. To explore these differ-
ences and identify the main influencing factors, this study selected marsh wetlands, river wetlands
and lakeside wetlands around Qinghai Lake as research subjects. High-throughput sequencing
was employed to analyze the functional gene cbbM of carbon-sequestering microorganisms. The
results revealed that the alpha diversity of cbbM carbon-sequestering microorganisms mirrored
the trend in total carbon content, with the highest diversity observed in marsh wetlands and the
lowest in lakeside wetlands. The dominant bacterial phylum was Proteobacteria, with prevalent
genera including Thiothrix,Acidithiobacillus, and Thiodictyon.Acidithiobacillus served as a biomarker
in lakeside wetlands, while two other genera were indicative of marsh wetlands. The hierarchical
partitioning analysis indicated that the diversity of cbbM carbon-fixing microorganisms was pri-
marily influenced by the total nitrogen content, while the community structure was significantly
affected by the soil total carbon content. Moreover, an increased soil temperature and humidity
were found to favor the carbon fixation processes of Thiomicrospira,Thiomonas,Polaromonas, and
Acidithiobacillus. In summary, changes in wetland types seriously affected the characteristics of cbbM
carbon sequestration in microbial communities, and a warm and humid climate may be conducive to
wetland carbon sequestration.
Biology 2024,13, 333. https://doi.org/10.3390/biology13050333 https://www.mdpi.com/journal/biology
Biology 2024,13, 333 2 of 13
Keywords: Qinghai–Tibet Plateau; climate change; carbon cycle; carbon sequestration microorganisms;
carbon fixation
1. Introduction
Soil is the largest terrestrial carbon reservoir, storing far more carbon than plants
and the atmosphere [
1
,
2
]. Wetland soil carbon storage accounts for 1/3 of the total soil
carbon storage on land and has great potential for regulating atmospheric carbon dioxide
concentrations and mitigating climate change [
3
,
4
]. Therefore, wetlands are extremely
important in the regulation of the global carbon balance of terrestrial ecosystems [
5
–
7
].
Maintaining a high carbon storage in wetland ecosystems also plays an important role in
mitigating climate warming caused by increasing carbon dioxide (CO
2
) concentrations [
8
,
9
].
However, climate change also affects the ability of wetlands to sequester carbon [
10
,
11
]. In
the foreseeable future, global temperatures will continue to rise [
12
], and the frequency and
intensity of biogeochemical cycles will further increase [
13
]. These changes may exacerbate
land degradation processes, have strong impacts on ecosystem functions and biological
interactions [
14
,
15
], and they may even significantly affect the carbon sequestration capacity
of wetlands. Previous studies have shown that different wetland types can lead to changes
in vegetation types and further lead to changes in the size of the organic carbon pool and its
chemical composition [
16
–
18
]. Currently, published carbon sequestration rates for various
wetlands range from 0.02 to 6 Mg SOC ha
−1
-year
−1
, and this difference is also closely
related to the wetland type [
19
]. Therefore, it is necessary to study the carbon fixation
mechanism of different wetland types.
As the “engine” of the biogeochemical cycle, microorganisms usually drive the carbon
cycle of wetland soil through catabolism and anabolism [
2
,
20
]. Carbon sequestration microor-
ganisms are critical to the conservation and restoration of the carbon sequestration potential
of wetland soils and soil functions, and they act by absorbing carbon dioxide and converting
atmospheric CO
2
into organic carbon [
21
]. Carbon sequestration microbial groups fix CO
2
through six main pathways [
22
–
24
]. The Calvin cycle is the most important CO
2
fixation
pathway for carbon sequestration microorganisms, and the key enzyme involved in this
cycle is 1,5-diphosphate ribulose carboxylase/oxygenase (RubisCO) [
25
]. Two functional
genes, cbbL and cbbM, are highly conserved and encode large subunits of RubisCO forms I
and II, respectively, and they are commonly used as biomarkers to measure carbon seques-
tration in the environment [
26
]. However, Liu et al. [
27
] investigated the controlling factors
and driving microorganisms of dark carbon fixation in intertidal sediments and found that
cbbM-carrying bacteria were more responsible for carbon sequestration in ecosystems than
cbbL-carrying bacteria were, confirming the importance of cbbM functional genes.
With an average elevation of more than 4000 m, the Qinghai–Tibet Plateau has the
largest area of alpine wetlands in the world [
28
], and was also the first region affected
by climate change in China [
29
]. Global climate change has had a significant impact on
the carbon cycle of the Qinghai–Tibet Plateau ecosystem [
30
]. Recent studies found that
climate warming will cause changes in various hydrological processes in the Qinghai–Tibet
Plateau water system, which may adversely affect its ecological structure, function and
resilience [
31
,
32
]. Therefore, in this study, the Qinghai Lake Basin in the northeastern
Qinghai–Tibet Plateau was selected as the research area, and the riverhead wetlands, lake-
side wetlands and swamp wetlands in the Qinghai Lake Basin were selected as research
objects. High-throughput sequencing technology was used to determine the microflora
of cbbM functional genes, and the biogeochemical properties of the soil were also deter-
mined. The objectives of this study were to (1) study the response patterns of cbbM carbon
sequestration microbial communities to different wetland types; (2) evaluate the effects of
soil properties driven by different wetland types on cbbM carbon sequestration microbial
communities; and (3) analyze the interaction between cbbM carbon sequestration microor-
ganisms and environmental factors in different wetland types in the Qinghai Lake Basin.
Biology 2024,13, 333 3 of 13
The results can not only provide basic data for the quantitative study of the carbon cycle
and transformation in the Qinghai Lake Basin but also provide a reference and guidance
for the study of the mechanism of carbon sources and sinks in alpine wetlands.
2. Materials and Methods
2.1. Overview of the Study Area
Wayan Mountain, situated between 37
◦
43
′
and 37
◦
46
′
N and 100
◦
01
′
and 100
◦
05
′
E, is
a characteristic riverhead wetland. It boasts an elevation ranging from 3720 to 3850 m, an
annual mean temperature of
−
3.31
◦
C, and an average annual precipitation of 420.37 mm.
The vegetation here is primarily dominated by Kobresia humilis (C. A. Mey. ex Trautv.) Serg.
Xiaobo Lake, on the other hand, is a year-round flooded swamp wetland with coordinates
of 36
◦
41
′
to 36
◦
42
′
N and 100
◦
46
′
to 100
◦
47
′
E. It has an average elevation of 3228 m, an
annual mean temperature ranging from
−
0.8 to 1.1
◦
C, and an average annual precipitation
of 324.5 to 412.8 mm. The wetland’s flora is primarily composed of Kobresia humilis (C. A.
Mey. ex Trautv.) Serg and Blysmus sinocompressus Tang et Wang. Bird Island, located between
36
◦
57
′
and 37
◦
04
′
N and 99
◦
44
′
and 99
◦
54
′
E, is a typical lakeside wetland. It has an
elevation of 3194 to 3226 m, an average annual temperature of
−
0.7
◦
C, and an average
annual precipitation of 322.7 mm. The dominant species found in this wetland type are
Allium przewalskianum Regel,Astragalus adsurgens Pall, and Poa annua L [33].
2.2. Soil Sample Collection
In June 2020, during the early stage of plant growth, soil samples were collected. Each
plot was 1 m
×
1 m in size, and a five-point sampling method was used to collect soil from
the 0–10 cm surface layer using a soil auger with a diameter of 4.5 cm. The samples were
named according to the experimental station name as Wck (Wayan Mountain), Bck (Xiaobo
Lake), and Nck (Bird Island). Five replicates were collected at each sampling site, resulting
in a total of 15 soil samples. These samples were mixed and sieved through a 2 mm mesh
sieve. Some soil samples were preserved in liquid nitrogen tanks for soil DNA extraction,
while the remaining samples were stored in ice bags for rapid transportation back to the
laboratory for further analysis.
2.3. Determination of Soil Physical and Chemical Properties
A TDR-300 (produced by Spectrum Technologies in Plainfield, IL, USA) is utilized to
monitor soil moisture levels within a 0–10 cm depth. Meanwhile, the LI-8100 instrument
(manufactured by LI-COR in Lincoln, NE, USA) measured the soil temperature within the
same depth range. For pH measurements, a pH meter (model FE20-FiveEasy pH, from Mettler
Toledo in Gießen, Germany) was employed after mixing the soil with water at a ratio of 1:2.5.
To determine total carbon (TC) and total nitrogen (TN) content, an Elemental Analysis System
(Vario EL III, Elemental Analysis System GmbH, Langenselbold, Germany) was used [34].
2.4. DNA Extraction and Illumina MiSeq Sequencing
Soil microbial DNA was extracted from 0.5 g of fresh soil using a PowerSoil DNA Isolation
Kit (Mio-bio, Carlsbad, CA, USA). Standard fixed carbon microbial amplification primers,
namely the forward primer (5
′
-TTCTGGCTGGGBGGHGAYTTYATYAARAAYGACGA-3
′
)
and the reverse primer (5
′
-CCGTGRCCRGCVCGRTGGTARTG-3
′
), were used to amplify
the cbbM gene fragment [
35
]. The Illumina MiSeq sequencing platform was utilized to
sequence the PCR products obtained. DNA extraction, quantification, and PCR procedures
were carried out following previously established and validated protocols [
35
]. This
approach ensured the accuracy and reproducibility of the sequencing results.
2.5. Statistical Analysis
Functional groups of microorganisms were predicted by FAPROTAX [
36
]. Using R
software (version 4.1.2), the p-value was calculated and plots were generated, referencing
specific R packages and functions from paper [34].
Biology 2024,13, 333 4 of 13
3. Results
3.1. Community Diversity of cbbM Carbon Sequestration Microorganisms in Different Wetland Types
The sequencing results indicated that the partial dilution curve did not reach saturation
(Figure 1a); it rather approached saturation, suggesting a comprehensive representation
of the diversity of carbon-sequestering bacterial communities containing cbbM genes.
Additionally, based on the calculation of Good’s coverage index (ranging from 0.9749 to
0.9826), higher coverage indices of the samples corresponded to smaller proportions of
undetected species. According to Illumina MiSeq analysis, at a 3% sequence difference level
clustering, the number of operational taxonomic units (OTUs) of cbbM carbon-sequestering
microorganisms in Qinghai Lake wetlands was 9930 (Figure 1b). The OTU counts of
marsh wetlands, lakefront wetlands and riverhead wetlands varied from 7812 to 8202,
with unique OTUs of 687, 405, and 720, respectively. Notably, the alpha diversity varied
among the different wetland types (Figure 1c). While the species richness and evenness
indices of riverhead wetlands fell between those of marsh and lakeside wetlands, with no
statistically significant differences, marsh wetlands exhibited significantly higher species
richness and evenness indices compared to lakeside wetlands, highlighting a notable
disparity between them. As shown in Figure 1d, a PCA based on the OTU levels illustrated
distinct differences among samples from the three wetland types. Generally, lakeside
wetlands exhibited minimal soil heterogeneity and similar community compositions of
carbon-sequestering microorganisms. Conversely, river source wetlands displayed the
greatest soil heterogeneity, with slightly larger differences in carbon sequestration microbial
community composition among samples.
Biology 2024, 13, 333 4 of 14
2.5. Statistical Analysis
Functional groups of microorganisms were predicted by FAPROTAX [36]. Using R
software (version 4.1.2), the p-value was calculated and plots were generated, referencing
specific R packages and functions from paper [34].
3. Results
3.1. Community Diversity of cbbM Carbon Sequestration Microorganisms in Different
Wetland Types
The sequencing results indicated that the partial dilution curve did not reach satura-
tion (Figure 1a); it rather approached saturation, suggesting a comprehensive representa-
tion of the diversity of carbon-sequestering bacterial communities containing cbbM genes.
Additionally, based on the calculation of Good’s coverage index (ranging from 0.9749 to
0.9826), higher coverage indices of the samples corresponded to smaller proportions of
undetected species. According to Illumina MiSeq analysis, at a 3% sequence difference
level clustering, the number of operational taxonomic units (OTUs) of cbbM carbon-se-
questering microorganisms in Qinghai Lake wetlands was 9930 (Figure 1b). The OTU
counts of marsh wetlands, lakefront wetlands and riverhead wetlands varied from 7812
to 8202, with unique OTUs of 687, 405, and 720, respectively. Notably, the alpha diversity
varied among the different wetland types (Figure 1c). While the species richness and even-
ness indices of riverhead wetlands fell between those of marsh and lakeside wetlands,
with no statistically significant differences, marsh wetlands exhibited significantly higher
species richness and evenness indices compared to lakeside wetlands, highlighting a no-
table disparity between them. As shown in Figure 1d, a PCA based on the OTU levels
illustrated distinct differences among samples from the three wetland types. Generally,
lakeside wetlands exhibited minimal soil heterogeneity and similar community composi-
tions of carbon-sequestering microorganisms. Conversely, river source wetlands dis-
played the greatest soil heterogeneity, with slightly larger differences in carbon seques-
tration microbial community composition among samples.
Figure 1. Illumina sequencing results and carbon sequestration microbial community diversity: (a)
sample dilution curve; (b) OTU distribution map; (c) cbbM microbial alpha diversity index; (d)
cbbM microbial principal component analysis. NS indicates p > 0.05, and ** indicates p < 0.01.
Figure 1. Illumina sequencing results and carbon sequestration microbial community diversity:
(a) sample dilution curve; (b) OTU distribution map; (c) cbbM microbial alpha diversity index;
(d) cbbM microbial principal component analysis. NS indicates p> 0.05, and ** indicates p< 0.01.
3.2. Composition of cbbM Carbon Sequestration Microbial Communities in Different Wetland Types
At the phylum level, proteobacteria emerged as the dominant bacterial group in the
wetland soil of Qinghai Lake, constituting a relative abundance exceeding 99.9%. Un-
classified genera accounted for 23.09% to 30.32% of bacterial relative abundance. Twelve
Biology 2024,13, 333 5 of 13
genera-level bacteria with relative abundances greater than 1% in the Qinghai Lake wet-
land were selected to construct a histogram of relative abundance percentages (Figure 2).
Thiothrix,Acidithiobacillus and Thiodictyon were the most abundant, all belonging to Pro-
teobacteria, with average relative abundances of 17.18%, 17.75% and 12.01%, respectively.
ANOVA analysis revealed that nine genera-level microflora (relative abundance > 1%) were
significantly influenced by wetland type (Figure 3). Distinct biomarkers were identified for
different wetland types. Acidithiobacillus,Ectothiorhodospira,Polaromonas,Thiomicrospira and
Thiomonas exhibited the highest relative abundances in lakeside wetlands. Dechloromonas
and Rhodoferax were most abundant in river source wetlands, while Thiodictyon and Thio-
thrix dominated in swamp wetlands.
Biology 2024, 13, 333 5 of 14
3.2. Composition of cbbM Carbon Sequestration Microbial Communities in Different
Wetland Types
At the phylum level, proteobacteria emerged as the dominant bacterial group in the
wetland soil of Qinghai Lake, constituting a relative abundance exceeding 99.9%. Unclas-
sified genera accounted for 23.09% to 30.32% of bacterial relative abundance. Twelve gen-
era-level bacteria with relative abundances greater than 1% in the Qinghai Lake wetland
were selected to construct a histogram of relative abundance percentages (Figure 2). Thio-
thrix, Acidithiobacillus and Thiodictyon were the most abundant, all belonging to Proteobac-
teria, with average relative abundances of 17.18%, 17.75% and 12.01%, respectively.
ANOVA analysis revealed that nine genera-level microflora (relative abundance > 1%)
were significantly influenced by wetland type (Figure 3). Distinct biomarkers were iden-
tified for different wetland types. Acidithiobacillus, Ectothiorhodospira, Polaromonas, Thiomi-
crospira and Thiomonas exhibited the highest relative abundances in lakeside wetlands.
Dechloromonas and Rhodoferax were most abundant in river source wetlands, while Thiodic-
tyon and Thiothrix dominated in swamp wetlands.
Figure 2. Community composition of cbbM carbon sequestration microorganisms in Qinghai Lake
wetlands.
Figure 3. Genera-level difference of microflora of three wetland types in Qinghai Lake. abc indicates
significance, the same leer indicates no significant difference between groups (p > 0.05), and differ-
ent leers indicate a significant difference between groups (p < 0.05).
Figure 2. Community composition of cbbM carbon sequestration microorganisms in Qinghai
Lake wetlands.
Biology 2024, 13, 333 5 of 14
3.2. Composition of cbbM Carbon Sequestration Microbial Communities in Different
Wetland Types
At the phylum level, proteobacteria emerged as the dominant bacterial group in the
wetland soil of Qinghai Lake, constituting a relative abundance exceeding 99.9%. Unclas-
sified genera accounted for 23.09% to 30.32% of bacterial relative abundance. Twelve gen-
era-level bacteria with relative abundances greater than 1% in the Qinghai Lake wetland
were selected to construct a histogram of relative abundance percentages (Figure 2). Thio-
thrix, Acidithiobacillus and Thiodictyon were the most abundant, all belonging to Proteobac-
teria, with average relative abundances of 17.18%, 17.75% and 12.01%, respectively.
ANOVA analysis revealed that nine genera-level microflora (relative abundance > 1%)
were significantly influenced by wetland type (Figure 3). Distinct biomarkers were iden-
tified for different wetland types. Acidithiobacillus, Ectothiorhodospira, Polaromonas, Thiomi-
crospira and Thiomonas exhibited the highest relative abundances in lakeside wetlands.
Dechloromonas and Rhodoferax were most abundant in river source wetlands, while Thiodic-
tyon and Thiothrix dominated in swamp wetlands.
Figure 2. Community composition of cbbM carbon sequestration microorganisms in Qinghai Lake
wetlands.
Figure 3. Genera-level difference of microflora of three wetland types in Qinghai Lake. abc indicates
significance, the same leer indicates no significant difference between groups (p > 0.05), and differ-
ent leers indicate a significant difference between groups (p < 0.05).
Figure 3. Genera-level difference of microflora of three wetland types in Qinghai Lake. abc indicates
significance, the same letter indicates no significant difference between groups (p> 0.05), and different
letters indicate a significant difference between groups (p< 0.05).
Biology 2024,13, 333 6 of 13
3.3. Functional Groups of cbbM Carbon Sequestration Microbial Community in Qinghai Lake Wetlands
The FAPROTAX function annotation results of the carbon sequestration microbial
community in Qinghai Lake wetlands (Figure 4) revealed that the ecological functions of
the community could be categorized into 25 functional groups (with relative abundances
exceeding 1%). Among the microbial functions associated with cbbM (Top 10), the predom-
inant ones included dark_oxidation_of_odor_compounds (12.49%), phototrophy (8.71%),
anoxygenic_photoautotrophy (7.13%), photoautotrophy (7.13%), anoxygen_photoautotrophy_
S_oxidizing (7.13%), dark_oxidation (6.72%), dark_sulfide_oxidation (6.33%), dark_iron_
oxidation (5.96%), chemoheterotrophy (4.53%), and aerobic_chemoheterotrophy (4.52%).
The relative abundance of each was closely related to wetland type. The corresponding
microflora were reversed through the nine main functional groups of the C cycle (Figure 5),
and it was found that cbbM carbon sequestration microorganisms in the Qinghai Lake
wetland were in 30 genus-level microflora of four phyla, of which 25 genus-level microflora
belonged to Proteobacteria. The predominant functional groups among most bacteria were
phototrophs and photoautotrophs, while some bacteria also exhibited chemoheterotrophs
and aerobic chemoheterotrophs as primary functional groups.
Biology 2024, 13, 333 6 of 14
3.3. Functional Groups of cbbM Carbon Sequestration Microbial Community in
Qinghai Lake Wetlands
The FAPROTAX function annotation results of the carbon sequestration microbial
community in Qinghai Lake wetlands (Figure 4) revealed that the ecological functions of
the community could be categorized into 25 functional groups (with relative abundances
exceeding 1%). Among the microbial functions associated with cbbM (Top 10), the pre-
dominant ones included dark_oxidation_of_odor_compounds (12.49%), phototrophy
(8.71%), anoxygenic_photoautotrophy (7.13%), photoautotrophy (7.13%), anoxygen_pho-
toautotrophy_S_oxidizing (7.13%), dark_oxidation (6.72%), dark_sulfide_oxidation
(6.33%), dark_iron_oxidation (5.96%), chemoheterotrophy (4.53%), and aerobic_chemo-
heterotrophy (4.52%). The relative abundance of each was closely related to wetland type.
The corresponding microflora were reversed through the nine main functional groups of
the C cycle (Figure 5), and it was found that cbbM carbon sequestration microorganisms
in the Qinghai Lake wetland were in 30 genus-level microflora of four phyla, of which 25
genus-level microflora belonged to Proteobacteria. The predominant functional groups
among most bacteria were phototrophs and photoautotrophs, while some bacteria also
exhibited chemoheterotrophs and aerobic chemoheterotrophs as primary functional
groups.
Figure 4. Main functional groups of cbbM carbon sequestration microorganisms in the Qinghai Lake
wetlands.
Figure 4. Main functional groups of cbbM carbon sequestration microorganisms in the Qinghai
Lake wetlands.
3.4. Correlations between the cbbM Carbon Sequestration Microbial Community and Soil
Environmental Factors in the Qinghai Lake Wetlands
The physical and chemical factors of the soil were significantly influenced by wetland
types, displaying notable spatial variations (p< 0.05) (Figure 6a). Regarding physical
factors, lakeside wetlands exhibited significantly higher temperatures and humidity levels
compared to marsh and riverhead wetlands. Although the soil moisture of the riverhead
wetland was higher than that of the marsh wetland, the soil temperature of the riverhead
wetlands was lower than that of the marsh wetlands. The pH values of the Qinghai Lake
wetlands followed a similar trend to soil temperature variations, while total carbon and
nitrogen contents were lowest in lakeside wetlands. Additionally, marsh wetlands dis-
played a higher total carbon content than river source wetlands, with the trend reversed
Biology 2024,13, 333 7 of 13
for total nitrogen content. Positive correlations were observed between soil temperature
and moisture, as well as between soil total carbon and nitrogen contents (p< 0.05). How-
ever, no significant correlations were found between pH and total carbon content or soil
moisture
(p> 0.05)
, while other physical and chemical factors exhibited significant negative
correlations (p< 0.05) (Figure 6b). At the phylum level, soil environmental factors did not
significantly influence the community of carbon-fixing microorganisms (p> 0.05). However,
at the genus level, microbial communities were closely correlated with soil temperature
and total carbon and nitrogen content (p< 0.05) (Figure 6b). A redundancy analysis of
the top 10 carbon sequestration microflora and soil environmental factors revealed that
different environmental factors had varying impacts on different microorganisms. The pH
exhibited minimal impact on carbon sequestration microbial communities. Further correla-
tion analyses demonstrated significant positive correlations between pH and Thiomicrospira
and Thiomonas, and significant negative correlation with Thiodictyon. Soil temperature and
humidity showed positive correlations with Thiomicrospira, Thiomonas,Polaromonas, and
Acidithiobacillus, while total carbon and nitrogen exhibited negative correlations with these
microflora. Moreover, the total carbon content displayed significant positive correlations
with Dechloromonas and Rhodoferax, potentially important markers of cbbM carbon se-
questration in Qinghai Lake wetlands. Hierarchical partitioning analysis indicated that the
wetland type, total carbon, and humidity explained the majority of variation in the commu-
nity structure of cbbM carbon-fixing microorganisms in Qinghai Lake wetlands (Figure 7).
The total carbon emerged as the most significant environmental factor, interacting with
other factors to influence the assembly of wetland carbon-fixing microbial communities
(Figure 7). While the alpha diversity of carbon-fixing microorganisms exhibited a less
pronounced response to wetland type, it was primarily influenced by soil physicochemical
properties, with total nitrogen being the primary driver, while temperature also played an
important role (Figure 8).
Biology 2024, 13, 333 7 of 14
Figure 5. The main functional groups of the C cycle and the corresponding generic level microflora
in the Qinghai Lake wetlands.
3.4. Correlations between the cbbM Carbon Sequestration Microbial Community and Soil
Environmental Factors in the Qinghai Lake Wetlands
The physical and chemical factors of the soil were significantly influenced by wetland
types, displaying notable spatial variations (p < 0.05) (Figure 6a). Regarding physical fac-
tors, lakeside wetlands exhibited significantly higher temperatures and humidity levels
compared to marsh and riverhead wetlands. Although the soil moisture of the riverhead
wetland was higher than that of the marsh wetland, the soil temperature of the riverhead
wetlands was lower than that of the marsh wetlands. The pH values of the Qinghai Lake
wetlands followed a similar trend to soil temperature variations, while total carbon and
nitrogen contents were lowest in lakeside wetlands. Additionally, marsh wetlands dis-
played a higher total carbon content than river source wetlands, with the trend reversed
for total nitrogen content. Positive correlations were observed between soil temperature
and moisture, as well as between soil total carbon and nitrogen contents (p < 0.05). How-
ever, no significant correlations were found between pH and total carbon content or soil
moisture (p > 0.05), while other physical and chemical factors exhibited significant nega-
tive correlations (p < 0.05) (Figure 6b). At the phylum level, soil environmental factors did
not significantly influence the community of carbon-fixing microorganisms (p > 0.05).
However, at the genus level, microbial communities were closely correlated with soil tem-
perature and total carbon and nitrogen content (p < 0.05) (Figure 6b). A redundancy anal-
ysis of the top 10 carbon sequestration microflora and soil environmental factors revealed
that different environmental factors had varying impacts on different microorganisms.
The pH exhibited minimal impact on carbon sequestration microbial communities. Fur-
ther correlation analyses demonstrated significant positive correlations between pH and
Thiomicrospira and Thiomonas, and significant negative correlation with Thiodictyon. Soil
temperature and humidity showed positive correlations with Thiomicrospira, Thiomonas,
Polaromonas, and Acidithiobacillus, while total carbon and nitrogen exhibited negative cor-
relations with these microflora. Moreover, the total carbon content displayed significant
positive correlations with Dechloromonas and Rhodoferax, potentially important markers
of cbbM carbon sequestration in Qinghai Lake wetlands. Hierarchical partitioning analy-
sis indicated that the wetland type, total carbon, and humidity explained the majority of
Figure 5. The main functional groups of the C cycle and the corresponding generic level microflora in
the Qinghai Lake wetlands.
Biology 2024,13, 333 8 of 13
Biology 2024, 13, 333 8 of 14
variation in the community structure of cbbM carbon-fixing microorganisms in Qinghai
Lake wetlands (Figure 7). The total carbon emerged as the most significant environmental
factor, interacting with other factors to influence the assembly of wetland carbon-fixing
microbial communities (Figure 7). While the alpha diversity of carbon-fixing microorgan-
isms exhibited a less pronounced response to wetland type, it was primarily influenced
by soil physicochemical properties, with total nitrogen being the primary driver, while
temperature also played an important role (Figure 8).
Figure 6. Correlation between soil environmental factors and carbon-sequestering microorganisms
in the Qinghai Lake wetlands: (a) changes in physicochemical factors in different types of wetlands;
(b) correlation network diagram between carbon-sequestering microbial community characteristics
and environmental factors; (c) redundancy analysis of environmental factors and genus-level mi-
croflora (Top 10); (d) heatmap of correlation between environmental factors and genus-level micro-
flora (Top 10). abc indicates significance, the same leer indicates no significant difference between
groups (p > 0.05), and different leers indicate a significant difference between groups (p < 0.05); *
indicates p < 0.05, ** indicates p < 0.01, *** indicates p < 0.001.
Figure 6. Correlation between soil environmental factors and carbon-sequestering microorganisms in
the Qinghai Lake wetlands: (a) changes in physicochemical factors in different types of wetlands;
(b) correlation network diagram between carbon-sequestering microbial community characteris-
tics and environmental factors; (c) redundancy analysis of environmental factors and genus-level
microflora (Top 10); (d) heatmap of correlation between environmental factors and genus-level mi-
croflora (Top 10). abc indicates significance, the same letter indicates no significant difference between
groups (p> 0.05), and different letters indicate a significant difference between groups (p< 0.05);
* indicates p< 0.05, ** indicates p< 0.01, *** indicates p< 0.001.
Biology 2024, 13, 333 9 of 14
Figure 7. Hierarchical segmentation analysis of influencing factors of community structure.
Figure 8. Hierarchical segmentation analysis of influencing factors of Alpha diversity.
4. Discussion
4.1. Effects of Wetland Type Changes on cbbM Carbon Sequestration Microbial
Community Diversity
Richness and diversity serve as two crucial indicators of carbon sequestration micro-
bial community characteristics, and they are significantly influenced by the heterogeneity
of wetland types [37]. The richness and diversity of cbbM carbon sequestration microbial
communities in the Qinghai Lake wetlands responded to changes in wetland types to a
certain extent. The richness and diversity indices of the microbial community in marsh
wetlands were significantly higher than those in lakeside wetlands. However, the differ-
ence between river source wetlands and the other two types of wetlands was not as
Figure 7. Hierarchical segmentation analysis of influencing factors of community structure.
Biology 2024,13, 333 9 of 13
Biology 2024, 13, 333 9 of 14
Figure 7. Hierarchical segmentation analysis of influencing factors of community structure.
Figure 8. Hierarchical segmentation analysis of influencing factors of Alpha diversity.
4. Discussion
4.1. Effects of Wetland Type Changes on cbbM Carbon Sequestration Microbial
Community Diversity
Richness and diversity serve as two crucial indicators of carbon sequestration micro-
bial community characteristics, and they are significantly influenced by the heterogeneity
of wetland types [37]. The richness and diversity of cbbM carbon sequestration microbial
communities in the Qinghai Lake wetlands responded to changes in wetland types to a
certain extent. The richness and diversity indices of the microbial community in marsh
wetlands were significantly higher than those in lakeside wetlands. However, the differ-
ence between river source wetlands and the other two types of wetlands was not as
Figure 8. Hierarchical segmentation analysis of influencing factors of Alpha diversity.
4. Discussion
4.1. Effects of Wetland Type Changes on cbbM Carbon Sequestration Microbial Community Diversity
Richness and diversity serve as two crucial indicators of carbon sequestration micro-
bial community characteristics, and they are significantly influenced by the heterogeneity
of wetland types [
37
]. The richness and diversity of cbbM carbon sequestration microbial
communities in the Qinghai Lake wetlands responded to changes in wetland types to a
certain extent. The richness and diversity indices of the microbial community in marsh
wetlands were significantly higher than those in lakeside wetlands. However, the dif-
ference between river source wetlands and the other two types of wetlands was not as
pronounced, possibly due to the high carbon and nitrogen contents in marsh wetlands,
which promote the activity of carbon-sequestering microorganisms [
38
,
39
]. The carbon
and nitrogen contents of lakeside wetlands were also significantly lower than those of
marsh wetlands, further supporting this view. Previous studies have indicated that the
diversity of carbon sequestration microbial communities on the Qinghai–Tibet Plateau is
closely related to environmental factors. Soil moisture and pH are generally regarded as
key factors determining soil microbial diversity [
40
,
41
]. For instance, Hu [
42
] demonstrated
a significant correlation between microbial diversity and variations in soil moisture, with
the latter also exerting a notable influence on soil nutrient variations. Wang [
43
] conducted
a study examining the influence of environmental factors on microbial communities, re-
vealing that pH impacts these communities by modulating carbon and nitrogen content.
Additionally, Wang [
44
] investigated the factors affecting the carbon sequestration microbial
community under changes in precipitation on the Tibetan Plateau and found that the soil
temperature, humidity, and pH were the most important factors influencing the diversity of
the carbon sequestration microbial community. In Wang’s [
45
] research on the influencing
factors of carbon sequestration microbial communities in the Tibetan Plateau, changes in
total nitrogen content significantly affected carbon sequestration microorganisms. This
study also identified the total nitrogen content as the most influential factor on the alpha
diversity of carbon-fixing microbial communities in the Qinghai Lake wetlands, with the
soil temperature also playing a significant role. The significant differences in total nitrogen
content and temperature between lakeside wetlands and marsh wetlands also provide
Biology 2024,13, 333 10 of 13
support for these findings. However, their correlation with pH and humidity was relatively
weak, possibly due to small spatial scales and consistent land use practices [46,47].
4.2. Effects of Wetland Type Changes on cbbM Carbon Sequestration Microbial Community Structure
Proteobacteria were the dominant bacteria in the carbon sequestration microbial com-
munities of the three types of wetlands in Qinghai Lake, consistent with the research
findings of Wang et al. [
48
] on carbon sequestration microorganisms in karst wetlands.
Similarly, Gao et al. [
49
] investigated the community characteristics of carbon sequestration
microorganisms on the northern Tibetan Plateau and reached similar conclusions. However,
numerous studies have shown that the community composition of cbbM carbon sequestra-
tion microorganisms in wetland ecosystems is different at the genus level. Wang et al. [
48
]
investigated the abundance and diversity of carbon sequestration bacterial communities in
karst wetland soil ecosystems. The dominant bacterial genera of cbbM carbon-sequestering
microorganisms were Ferriphaselus,Halothiobacillus,Rhodopseudomona,Sinorhizobium and
Sulphitalea. Yousuf et al. [
50
] compared cbbM carbon-sequestering microbial communities
in saline soil and farmland soil and found that Rhodopseudomonas and Thiobacillus were the
dominant bacterial genera in farmland soil. In this study, the dominant bacterial genera of
cbbM carbon sequestration microorganisms in the Qinghai Lake wetlands were Thiothrix,
Acidithiobacillus and Thiodictyon, which differed from previous studies. Yang et al. [
51
]
investigated the dynamics of soil organic carbon and nitrogen in coastal wetlands in eastern
China after Spartamina alterniflora invasion and found that the coastal salt marsh wetlands
were in a local state of hypoxia, and this unique environment produced a unique domi-
nant genus of carbon fixation microorganisms. Therefore, the differences in the dominant
bacterial genera of carbon-sequestering microorganisms in wetland ecosystems are closely
related to changes in the microenvironment. A correlation analysis between carbon-fixing
microorganisms and soil physicochemical factors in Qinghai Lake wetlands indicated that
the community structure of carbon-fixing microorganisms was primarily influenced by the
soil total carbon content. Wang et al. [
48
] also found that changes in soil carbon components
are the main factors influencing the structure of wetland soil carbon-fixing microbial com-
munities, which is consistent with the results of this study. In addition, soil temperature
and humidity were positively correlated with Thiomicrospira,Thiomonas,Polaromonas and
Acidithiobacillus, while total carbon and nitrogen were negatively correlated with these
four microbial communities, indicating that a higher soil temperature and humidity might
be more conducive to the carbon sequestration process of these microbial communities.
The dominant species of bacteria in the Qinghai Lake wetlands were significantly affected
by the wetland types, and the relative abundance of Acidithiobacillus in lakeside wetlands
was the highest, which may be due to the higher temperature in lakeside wetlands and the
thermophilic characteristics of the bacteria [
52
]. The relative abundances of Thiodictyon and
Thiothrix were the highest in swamp wetlands, which may be related to the high carbon
content in this wetland type.
5. Conclusions
This study compared the characteristics of cbbM carbon sequestration microbial com-
munities and their correlation with soil environmental factors in three types of wetlands in
Qinghai Lake. The alpha diversity of the carbon sequestration microbial community was
significantly different between marsh wetlands and lakeside wetlands, with the highest
diversity in marsh wetlands, followed by riverhead wetlands and then lakeside wetlands.
The dominant species composition of cbbM carbon-sequestering microorganisms in the
three wetland types was similar, with Proteobacteria as the dominant bacterial group at
the phylum level and Thiothrix,Acidithiobacillus and Thiodictyon as the dominant bacterial
groups at the genus level. However, Acidithiobacillus had the highest relative abundance in
lakeside wetlands, while Thiothrix and Thiodictyon had the highest relative abundance in
marsh wetlands. Total nitrogen was the most significant influencing factor on the alpha
diversity of soil carbon-fixing bacterial communities in Qinghai Lake wetlands, with the
Biology 2024,13, 333 11 of 13
soil total carbon content being the primary soil physicochemical factor affecting community
structure. The changes in wetland types result in variations in soil microenvironments and
environmental factors. Marsh wetlands are more conducive to the carbon sequestration
process in wetland ecosystems. This study provides a scientific basis and reference for soil
carbon sequestration and ecological protection of alpine wetland ecosystems.
Author Contributions: Conceptualization, N.Z., K.C. and X.W. (Xinye Wang); Data curation, W.J.,
X.W. (Xia Wang) and J.L.; Investigation, X.W. (Xinye Wang), W.J. and Z.Y.; Software, Z.Y., X.W.
(Xia Wang) and J.L.; Writing—original draft, N.Z.; Writing—review and editing, N.Z. and K.C. All
authors have read and agreed to the published version of the manuscript.
Funding: This research was funded by the Second Comprehensive Scientific Expedition to the Qinghai–
Tibet Plateau (2019QZKK0405), the Qinghai Province key research and development and transforma-
tion plan (2022-QY-204), and the Qinghai Province science and technology plan (2023-ZJ-905T).
Institutional Review Board Statement: Not applicable.
Informed Consent Statement: Not applicable.
Data Availability Statement: Raw data have been uploaded to NCBI, and Its BioProject is PR-
JNA1006296.
Conflicts of Interest: We declare that we have no financial and personal relationships with other
people or organizations that could inappropriately influence our work.
References
1. Jobbagy, E.G.; Jackson, R.B. The vertical distribution of soil organic carbon and its relation to climate and vegetation. Ecol. Appl.
2000,10, 423–436. [CrossRef]
2.
Lange, M.; Eisenhauer, N.; Sierra, C.A.; Bessler, H.; Engels, C.; Griffiths, R.I.; Mellado-Vázquez, P.G.; Malik, A.A.; Roy, J.; Scheu, S.;
et al. Plant diversity increases soil microbial activity and soil carbon storage. Nat. Commun. 2015,6, 6707. [CrossRef]
3.
Sheehan, L.; Sherwood, E.T.; Moyer, R.P.; Radabaugh, K.R.; Simpson, S. Blue carbon: An additional driver for restoring and
preserving ecological services of coastal wetlands in Tampa Bay (Florida, USA). Wetlands 2019,39, 1317–1328. [CrossRef]
4.
Asanopoulos, C.; Baldock, J.; Macdonald, L.; Cavagnaro, T. Quantifying blue carbon and nitrogen stocks in surface soils of
temperate coastal wetlands. Soil Res. 2021,59, 619–629. [CrossRef]
5. Lehmann, J. A handful of carbon. Nature 2007,447, 143–144. [CrossRef] [PubMed]
6.
Kirwan, M.; Blum, L.K. Enhanced decomposition offsets enhanced productivity and soil carbon accumulation in coastal wetlands
responding to climate change. Biogeosci. Discuss. 2011,8, 707–722. [CrossRef]
7.
Cao, Q.; Wang, R.; Zhang, H.; Ge, X.; Liu, J. Distribution of organic carbon in the sediments of Xinxue river and the Xinxue river
constructed wetland, China. PLoS ONE 2015,10, e0134713. [CrossRef] [PubMed]
8.
Bridgham, S.D.; Megonigal, J.P.; Keller, J.K.; Bliss, N.B.; Trettin, C. The carbon balance of North American wetlands. Wetlands
2006,26, 889–916. [CrossRef]
9. Song, C.C. Advance in research on carbon cycling in wetlands. Sci. Geogr. Sin. 2003,23, 622–628. [CrossRef]
10.
Bianchi, T.S.; Allison, M.A.; Zhao, J.; Li, X.; Comeaux, R.S.; Feagin, R.A.; Kulawardhana, R.W. Historical reconstruction of
mangrove expansion in the Gulf of Mexico: Linking climate change with carbon sequestration in coastal wetlands. Estuar. Coast.
Shelf Sci. 2013,119, 7–16. [CrossRef]
11.
Saintilan, N.; Rogers, K.; Kelleway, J.; Ens, E.; Sloane, D. Climate change impacts on the coastal wetlands of Australia. Wetlands
2019,39, 1145–1154. [CrossRef]
12. IPCC. Special Report: Global Warming of 1.5 ◦C; Cambridge University Press: Cambridge, UK, 2018.
13.
IPCC. Climate Change 2021: The Physical Science Basis. Contribution of Working Group to the Fourth Assessment Report of the
Intergovernmental Panel on Climate Change; Cambridge University Press: Cambridge, UK, 2021.
14.
Bardgett, R.D.; Freeman, C.; Ostle, N.J. Microbial contributions to climate change through carbon cycle feedbacks. ISME J. 2008,2,
805–814. [CrossRef]
15.
IPCC. Central and South America: Impacts, Adaptation, and Vulnerability Contribution of Working Group II to the Sixth Assessment
Report of the Intergovernmental Panel on Climate Change; Cambridge University Press: Cambridge, UK, 2022.
16.
Fu, X.; Shao, M.; Wei, X.; Horton, R. Soil organic carbon and total nitrogen as affected by vegetation types in Northern Loess
plateau of China. Geoderma 2010,155, 31–35. [CrossRef]
17. Albaladejo, J.; Ortiz, R.; Garcia-Franco, N.; Navarro, A.R.; Almagro, M.; Pintado, J.G.; Martinez-Mena, M. Land use and climate
change impacts on soil organic carbon stocks in semi-arid Spain. J. Soils Sediments 2013,13, 265–277. [CrossRef]
18.
Cheng, M.; Xiang, Y.; Xue, Z.; An, S.; Darboux, F. Soil aggregation and intra-aggregate carbon fractions in relation to vegetation
succession on the Loess plateau, China. Catena 2015,124, 77–84. [CrossRef]
Biology 2024,13, 333 12 of 13
19.
Craft, C.; Vymazal, J.; Kröpfelová, L. Carbon sequestration and nutrient accumulation in floodplain and depressional wetlands.
Ecol. Eng. 2018,114, 137–145. [CrossRef]
20.
Liang, C.; Schimel, J.P.; Jastrow, J.D. The importance of anabolism in microbial control over soil carbon storage. Nat. Microbiol.
2017,2, 17105. [CrossRef]
21.
Lynn, T.M.; Ge, T.; Yuan, H.; Wei, X.; Wu, X.; Xiao, K.; Kumaresan, D.; Yu, S.S.; Wu, J.; Whiteley, A.S. Soil carbon-fixation rates and
associated bacterial diversity and abundance in three natural ecosystems. Microb. Ecol. 2017,73, 645–657. [CrossRef] [PubMed]
22.
Claassens, N.J.; Sousa, D.Z.; Dos Santos, V.A.; De Vos, W.M.; Van Der Oost, J. Harnessing the power of microbial autotrophy. Nat.
Rev. Microbiol. 2016,14, 692–706. [CrossRef]
23.
Liu, Z.; Sun, Y.; Zhang, Y.; Feng, W.; Lai, Z.; Fa, K.; Qin, S. Metagenomic and 13C tracing evidence for autotrophic atmospheric
carbon absorption in a semiarid desert. Soil Biol. Biochem. 2018,125, 156–166. [CrossRef]
24.
Rubin-Blum, M.; Dubilier, N.; Kleiner, M. Genetic evidence for two carbon fixation pathways (the calvin-benson-bassham cycle
and the reverse tricarboxylic acid cycle) in symbiotic and free-living bacteria. mSphere 2019,4, e00394-18. [CrossRef] [PubMed]
25.
Hügler, M.; Sievert, S.M. Beyond the calvin cycle: Autotrophic carbon fixation in the ocean. Ann. Rev. Mar. Sci. 2011,3, 261–289.
[CrossRef] [PubMed]
26.
Emerson, J.B.; Thomas, B.C.; Alvarez, W.; Banfield, J.F. Metagenomic analysis of a high carbon dioxide subsurface microbial
community populated by chemolithoautotrophs and bacteria and archaea from candidate phyla. Environ. Microbiol. 2016,18,
1686–1703. [CrossRef] [PubMed]
27.
Liu, B.; Hou, L.; Zheng, Y.; Zhang, Z.; Tang, X.; Mao, T.; Du, J.; Bi, Q.; Dong, H.; Yin, G.; et al. Dark carbon fixation in intertidal
sediments: Controlling factors and driving microorganisms. Water Res. 2022,216, 118381. [CrossRef] [PubMed]
28.
Bai, R.; Xi, D.; He, J.Z.; Hu, H.W.; Fang, Y.T.; Zhang, L.M. Activity, abundance and community structure of anammox bacteria
along depth profiles in three different paddy soils. Soil Biol. Biochem. 2015,91, 212–221. [CrossRef]
29.
Pan, B.T.; Li, J.J. Qinghai-Tibetan Plateau: A Driver and Amplifier of the Global Climatic Change—III. The effects of the uplift of
Qinghai-Tibetan Plateau on Climatic Changes. J. Lanzhou Univ. (Nat. Sci.) 1996,32, 108–115.
30.
Chen, H.; Zhu, Q.; Peng, C.; Wu, N.; Wang, Y.; Fang, X.; Gao, Y.; Zhu, D.; Yang, G.; Tian, J.; et al. The impacts of climate change
and human activities on biogeochemical cycles on the Qinghai-Tibetan Plateau. Glob. Chang. Biol. 2013,19, 2940–2955. [CrossRef]
[PubMed]
31.
McLauchlan, K.K.; Williams, J.J.; Craine, J.M.; Jeffers, E.S. Changes in global nitrogen cycling during the holocene epoch. Nature
2013,495, 352–355. [CrossRef]
32.
O’Beirne, M.D.; Werne, J.P.; Hecky, R.E.; Johnson, T.C.; Katsev, S.; Reavie, E.D. Anthropogenic climate change has altered primary
productivity in lake superior. Nat. Commun. 2017,8, 15713. [CrossRef]
33.
Zhang, N.; Bao, H.; Zuo, D.Z.; Cui, B.L.; Chen, K.L. Community characteristics of methanogenic bacteria in different types of
alpine wetlands around Qinghai Lake. J. Appl. Environ. Biol. 2022,28, 283–289. [CrossRef]
34.
Zhang, N.; Chen, K.; Wang, S.; Qi, D.; Zhou, Z.; Xie, C.; Liu, X. Dynamic Response of the cbbL Carbon Sequestration Microbial
Community to Wetland Type in Qinghai Lake. Biology 2023,12, 1503. [CrossRef]
35.
Liu, J.F.; Mbadinga, S.M.; Sun, X.B.; Yang, G.C.; Yang, S.Z.; Gu, J.D.; Mu, B.Z. Microbial communities responsible for fixation of
CO
2
revealed by using mcrA, cbbM, cbbL, fthfs, fefe-hydrogenase genes as molecular biomarkers in petroleum reservoirs of
different temperatures. Int. Biodeterior. Biodegrad. 2016,114, 164–175. [CrossRef]
36.
Liang, S.; Deng, J.; Jiang, Y.; Wu, S.; Zhou, Y.; Zhu, W. Functional Distribution of Bacterial Community under Different Land Use
Patterns Based on FaProTax Function Prediction. Pol. J. Environ. Stud. 2020,29, 1245–1261. [CrossRef] [PubMed]
37.
Ma, S.; Fang, J.; Liu, J.; Yang, X.; Lyu, T.; Wang, L.; Zhou, S.; Dou, H.; Zhang, H. Differences in sediment carbon-fixation rate and
associated bacterial communities in four wetland types in Hulun lake basin. Catena 2022,213, 106167. [CrossRef]
38.
Xiang, X.; Gibbons, S.M.; Li, H.; Shen, H.; Fang, J.; Chu, H. Shrub encroachment is associated with changes in soil bacterial
community composition in a temperate grassland ecosystem. Plant Soil 2018,425, 539–551. [CrossRef]
39.
Liao, Q.; Liu, H.; Lu, C.; Liu, J.; Waigi, M.G.; Ling, W. Root exudates enhance the PAH degradation and degrading gene abundance
in soils. Sci. Total Environ. 2021,764, 144436. [CrossRef] [PubMed]
40.
Zhang, H.; Fu, G. Responses of plant, soil bacterial and fungal communities to grazing vary with pasture seasons and grassland
types, northern Tibet. Land Degrad. Dev. 2021,32, 1821–1832. [CrossRef]
41.
Yang, Y.; Cheng, H.; Gao, H.; An, S. Response and driving factors of soil microbial diversity related to global nitrogen addition.
Land Degrad. Dev. 2020,31, 190–204. [CrossRef]
42.
Hu, Y.; Wang, S.; Niu, B.; Chen, Q.; Wang, J.; Zhao, J.; Luo, T.; Zhang, G. Effect of increasing precipitation and warming on
microbial community in Tibetan alpine steppe. Environ. Res. 2020,189, 109917. [CrossRef]
43.
Wang, X.; Ren, Y.; Yu, Z.; Shen, G.; Cheng, H.; Tao, S. Effects of environmental factors on the distribution of microbial communities
across soils and lake sediments in the Hoh Xil Nature Reserve of the Qinghai-Tibetan Plateau. Sci. Total Environ. 2022,838, 156148.
[CrossRef]
44.
Wang, Z. Diversity of Carbon Sequestration Microbial Communities in Meadow Soil of Qinghai-Tibet Plateau and Its Influencing
Factors. Master ’s Thesis, China University of Geosciences, Wuhan, China, 2019.
45.
Wang, B.C. Study on Carbon Sequestration Microbial Community Structure, Carbon Sequestration Function and Environmental
Influencing Factors in Lake Sediments of Northern Tibetan Plateau. Master’s Thesis, China University of Geosciences, Wuhan,
China, 2019.
Biology 2024,13, 333 13 of 13
46.
Lauber, C.L.; Ramirez, K.S.; Aanderud, Z.; Lennon, J.; Fierer, N. Temporal variability in soil microbial communities across land-use
types. ISME J. 2013,7, 1641–1650. [CrossRef]
47.
Yuan, H.; Ge, T.; Chen, C.; O’Donnell, A.G.; Wu, J. Significant role for microbial autotrophy in the sequestration of soil carbon.
Appl. Environ. Microbiol. 2012,78, 2328–2336. [CrossRef] [PubMed]
48.
Wang, X.; Li, W.; Xiao, Y.; Cheng, A.; Shen, T.; Zhu, M.; Yu, L.J. Abundance and diversity of carbon-fixing bacterial communities
in karst wetland soil ecosystems. Catena 2021,204, 105418. [CrossRef]
49.
Gao, J.; Said, M.; Yue, L.; Yongtao, H.; Dorji, T.; Zhang, X. Changes in CO
2
-fixing microbial community characteristics with
elevation and season in alpine meadow soils on the Northern Tibetan plateau. Acta Ecol. Sin. 2018,38, 3816–3824. [CrossRef]
50.
Yousuf, B.; Kumar, R.; Mishra, A.; Jha, B. Unravelling the carbon and sulphur metabolism in coastal soil ecosystems using
comparative cultivation-independent genome-level characterisation of microbial communities. PLoS ONE 2014,9, e107025.
[CrossRef]
51.
Yang, W.; Zhao, H.; Leng, X.; Cheng, X.; An, S. Soil organic carbon and nitrogen dynamics following Spartina alterniflora invasion
in a coastal wetland of Eastern China. Catena 2017,156, 281–289. [CrossRef]
52.
Schippers, A. Microorganisms involved in bioleaching and nucleic acid-based molecular methods for their identification and
quantification. In Microbial Processing of Metal Sulfides; Donati, E., Sand, W., Eds.; Springer: Heidelberg, NY, USA, 2007. [CrossRef]
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