Soil Microbial Community Characteristics Research Articles

Nitrogen application increases the productivity of perennial alpine cultivated grassland by improving soil physicochemical properties and microbial community characteristics

Nitrogen application increases the productivity of perennial alpine cultivated grassland by improving soil physicochemical properties and microbial community characteristics

Soil Microbial Community Characteristics and Their Effect on Tea Quality under Different Fertilization Treatments in Two Tea Plantations.

Fertilization is an essential aspect of tea plantation management that supports a sustainable tea production and drastically influences soil microbial communities. However, few research studies have focused on the differences of microbial communities and the variation in tea quality in response to different fertilization treatments. In this work, the soil fertility, tea quality, and soil microbial communities were investigated in two domestic tea plantations following the application of chemical and organic fertilizers. We determined the content of mineral elements in the soil, including nitrogen, phosphorus, and potassium, and found that the supplementation of chemical fertilizer directly increased the content of mineral elements. However, the application of organic fertilizer significantly improved the accumulation of tea polyphenols and reduced the content of caffeine. Furthermore, amplicon sequencing results showed that the different ways of applying fertilizer have limited effect on the alpha diversity of the microbial community in the soil while the beta diversity was remarkably influenced. This work also suggests that the bacterial community structure and abundance were also relatively constant while the fungal community structure and abundance were dramatically influenced; for example, Chaetomiaceae at the family level, Hypocreaceae at the order level, Trichoderma at the genus level, and Fusarium oxysporum at the species level were predominantly enriched in the tea plantation applying organic fertilizer. Moreover, the bacterial and fungal biomarkers were also analyzed and it was found that Proteobacteria and Gammaproteobacteria (bacteria) and Tremellomycetes (fungi) were potentially characterized as biomarkers in the plantation under organic fertilization. These results provide a valuable basis for the application of organic fertilizer to improve the soil of tea plantations in the future.

Aggregate composition directly affects the characteristics of soil microbial and nematode communities in a chronosequence of Chinese fir plantations

Aggregate composition directly affects the characteristics of soil microbial and nematode communities in a chronosequence of Chinese fir plantations

Soil Nutrient, Enzyme Activity, and Microbial Community Characteristics of E. urophylla × E. grandis Plantations in a Chronosequence

The effects of continuous Eucalyptus cropping on soil properties and microbial characteristics and the specific factors influencing tree species growth remain elusive. In this study, three Eucalyptus stands of three different ages were selected, and soil nutrients, microbial biomass, enzyme activity, microbial community composition, and diversity were quantified for each. The findings indicated a significant decline in soil pH, soil cation exchange, soil organic matter, and available phosphorus content with the plantation age. Simultaneously, there was an observed increase in soil alkaline hydrolyzed nitrogen content. In addition, urease and acid phosphatase activities did not show a significant difference with age. In spite of this, catalase activity exhibited a decline corresponding to the advancement in plantation age. The carbon and nitrogen content of the soil microbial biomass increased with the progression of Eucalyptus planting time. The high-throughput sequencing data demonstrated a reduction in microbial diversity in Eucalyptus soils as the planting age increased. Interestingly, the microbial community structure exhibited minimal alterations, and did not exhibit a predominantly oligotrophic state overall. In conclusion, the study results showed that short-term successive Eucalyptus cropping exerts a significant negative impact on the soil system.

Vertical differentiation drives the changes in the main microflora and metabolites of carbon and nitrogen cycling in the early freeze-thaw period in the Qinghai Lake Basin.

Global climate change has altered the frequency of soil freeze-thaw cycles, but the response of soil microorganisms to different elevation gradients during the early freeze-thaw period remains unclear. So far, the influence of the altitudinal gradient on the microbial community and metabolic characteristics in the early freeze-thaw period of the Qinghai Lake Basin remains unclear. To this end, we collected soil at different elevations in the early freeze-thaw period of the Qinghai Lake Basin and investigated the influence of the elevation gradient on soil microbial community characteristics and soil metabolic processes as well as the corresponding environmental driving mechanism by high-throughput sequencing and LC-MS (Liquid Chromatograph-Mass Spectrometer) nontargeted metabolite determination. The results showed that Proteobacteria were the dominant microflora in the Qinghai Lake Basin. The dominant phyla associated with carbon and nitrogen are Proteobacteria and Firmicutes, both of which are significantly affected by elevation. The soil physicochemical factors jointly affected the soil microbial communities and metabolism. Total phosphorus nitrate nitrogen and pH were the main driving factors of the microbial community, and metabolites were sensitive to changes in chemical factors. In short, the microbial community structure and function, soil physicochemical factors and soil metabolic processes were significantly affected by the altitudinal gradient in the early freeze-thaw period, while the microbial community diversity showed no significant response to the altitudinal gradient. Additionally, a high potassium content in the soil may promote the growth and reproduction of bacteria associated with carbon and nitrogen cycling, as well as the production of metabolites.

The potential of soil microbial communities to transform deoxynivalenol in agricultural soils-a soil microcosm study.

Infestation of cereal fields with toxigenic Fusarium species is identified as an environmental source for the mycotoxin deoxynivalenol (DON). During rain events, DON may be washed off from infested plants and enter the soil, where microbial transformation may occur. Although some studies showed DON transformation potential of soil microbial communities in liquid soil extracts, these findings can not be transferred to environmental conditions. Accordingly, microbial transformation of DON in soil has to be investigated under realistic conditions, e.g., microcosms mimicking field situations. In this study, we investigated the potential of soil microbial communities to transform DON in six different agricultural soils at two levels (0.5 and 5 µg g-1). The dissipation and the formation of transformation products were investigated in a period of 35 days and compared to a sterilized control. In addition, we measured soil respiration and applied the phospholipid-derived fatty acid (PLFA) analysis to assess whether soil microbial community characteristics are related to the microbial transformation potential. Dissipation of DON in non-sterilized soils was fast (50% dissipation within 0.6-3.7 days) compared to the sterile control where almost no dissipation was observed. Thus, dissipation was mainly attributed to microbial transformation. We verified that small amounts of DON are transformed to 3-keto-deoxynivalenol (3-keto-DON) and 3-epi-deoxynivalenol (3-epi-DON), which were not detectable after 16-day incubation, indicating further transformation processes. There was a trend towards faster transformation in soils with active and large microbial communities and low fungi-to-bacteria ratio.

Coupling and decoupling of soil carbon and nutrients cycles at different salinity levels in a mangrove wetland: Insights from CUE and enzymatic stoichiometry

Soil carbon (C), nitrogen (N), and phosphorus (P) cycling, in conjunction with microbial metabolism, varies significantly with salinity in coastal areas. However, microbial metabolism limitation on salinity levels has received limited attention. Based on soil microbial carbon use efficiency and enzymatic stoichiometry, microbial nutrient limitation characteristics of soil microbial communities in different salinity levels (4.45 mS·cm−1 - 17.25 mS·cm−1) in a subtropical mangrove wetland were investigated. Compared to low-salinity levels, the activity of soil C-acquiring enzyme activities, enzymatic C:N ratios and enzymatic C:P ratios decreased with medium salinity levels and high salinity levels. Soil microbial metabolism was primarily constrained by C and N at different salinity levels. Boosted regression tree analysis revealed that abiotic factors had the greatest influence on C and N limitation of microbial metabolism at different salinity levels. This study underscores the significance of salinity in microbial metabolic processes and enhances our understanding of how future salinity changes induced by rising sea levels will affect soil carbon and nutrient cycling in coastal wetlands.

Variations in Soil Organic Carbon Fractions and Microbial Community in Rice Fields under an Integrated Cropping System

Combining rice cultivation and aquaculture into an integrated cropping system is a management approach that enhances the sustainability of rice fields. However, how soil characteristics influence soil microbial community characteristics following implementation of such an integrated system, particularly in the waterlogged paddies of the Pearl River Delta, is poorly understood. An integrated cropping system (rice–fish–duck integrated cropping system, RFD) and a rice–pepper rotation system (RPS) were compared using a conventional rice cropping system (CRS) as a reference. We used phospholipid-derived fatty acid (PLFA) analysis to assess soil microbial community structure and function and measured soil nutrient content and organic carbon fractions. Our results indicated that the soil nutrient content, organic carbon fractions, and C-hydrolyzing activities differed among the cropping systems. The RFD resulted in higher microbial PLFA concentrations and a lower ratio of Gram-positive to Gram-negative bacteria than CRS. Additionally, the integrated system reduced microbial nutrient stress by increasing soil pH. Further analysis revealed that active soil organic carbon significantly affected the soil microbial community. Thus, the RFD integrated cropping systems that alter the combined actions of pH and active organic carbon fractions can be used to improve soil microbial communities.

The Impact and Determinants of Mountainous Topographical Factors on Soil Microbial Community Characteristics.

Soil bacterial and fungal community communities play significant ecological functions in mountain ecosystems. However, it is not clear how topographic factors and soil physicochemical properties influence changes in microbial community structure and diversity. This study aims to investigate how altitude and slope orientation affect soil physicochemical properties, soil microbial communities, and their contributing factors. The assessment was conducted using Illumina MiSeq sequencing in various altitude gradients and on slopes with different aspects (shady slopes and sunny slopes) in the subalpine meadow of Dongling Mountain, Beijing. Topographical factors had a significant effect on soil physicochemical properties: the primary factors determining the structure of microbial communities are total potassium (TK), ammonium nitrogen (NH4+-N), and soil organic carbon (SOC). There was no significant change in the diversity of the bacterial community, whereas the diversity of the fungal community displayed a single-peaked trend. The effect of slope orientation on microbial communities was not as significant as the effect of elevation on them. The number of bacterial communities with significant differences showed a unimodal trend, while the number of fungal communities showed a decreasing trend. The co-occurrence network of fungal communities exhibits greater intricacy than that of bacterial communities, and bacterial communities are more complex in soils with sunny slopes compared to soils with shady slopes, and the opposite is true for fungal communities. The identification of the main factors that control soil microbial diversity and composition in this study, provided the groundwork for investigating the soil microbial response and adaptation to environmental changes in subalpine meadows.

Potentilla parvifolia strongly influenced soil microbial community and environmental effect along an altitudinal gradient in central Qilian Mountains in western China.

The Qilian Mountains (QLMs) form an important ecological security barrier in western China and a priority area for biodiversity conservation. Potentilla parvifolia is a widespread species in the mid-high altitudes of the QLMs and has continuously migrated to higher altitudes in recent years. Understanding the effects of P. parvifolia on microbial community characteristics is important for exploring future changes in soil biogeochemical processes in the QLMs. This study found that P. parvifolia has profound effects on the community structure and ecological functions of soil microorganisms. The stability and complexity of the root zone microbial co-occurrence network were significantly higher than those of bare soils. There was a distinct altitudinal gradient in the effect of P. parvifolia on soil microbial community characteristics. At an elevation of 3204 m, P. parvifolia promoted the accumulation of carbon, nitrogen, and phosphorus and increased sucrase activity and soil C/N while significantly improving the community richness index of fungi (p < .05) compared with that of bacteria and the relative abundance of Ascomycota. The alpha diversity of fungi in the root zone soil of P. parvifolia was also significantly increased at 3550 m altitude. Furthermore, the community similarity distance matrix of fungi showed an evident separation at 3204 m. However, at an altitude of 3750 m, P. parvifolia mainly affected the bacterial community. Potentilla parvifolia increased the bacterial community richness. This is in agreement with the findings based on the functional prediction that P. parvifolia favors the growth and enrichment of denitrifying communities at 3550 and 3750 m. The results provide a scientific basis for predicting the evolutionary trends of the effects of P. parvifolia on soil microbial communities and functions and have important implications for ecological governance in the QLMs.

High intensity perturbations induce an abrupt shift in soil microbial state

Soil microbial communities play a pivotal role in regulating ecosystem functioning. But they are increasingly being shaped by human-induced environmental change, including intense “pulse” perturbations, such as droughts, which are predicted to increase in frequency and intensity with climate change. While it is known that soil microbial communities are sensitive to such perturbations and that effects can be long-lasting, it remains untested whether there is a threshold in the intensity and frequency of perturbations that can trigger abrupt and persistent transitions in the taxonomic and functional characteristics of soil microbial communities. Here we demonstrate experimentally that intense pulses of drought equivalent to a 30-year drought event (<15% WHC) induce a major shift in the soil microbial community characterised by significantly altered bacterial and fungal community structures of reduced complexity and functionality. Moreover, the characteristics of this transformed microbial community persisted after returning soil to its previous moisture status. As a result, we found that drought had a strong legacy effect on bacterial community function, inducing an enhanced growth rate following subsequent drought. Abrupt transitions are widely documented in aquatic and terrestrial plant communities in response to human-induced perturbations. Our findings demonstrate that such transitions also occur in soil microbial communities in response to high intensity pulse perturbations, with potentially deleterious consequences for soil health.

Characteristics of rhizosphere and bulk soil microbial community of Chinese cabbage (Brassica campestris) grown in Karst area.

Understanding the rhizosphere soil microbial community and its relationship with the bulk soil microbial community is critical for maintaining soil health and fertility and improving crop yields in Karst regions. The microbial communities in the rhizosphere and bulk soils of a Chinese cabbage (Brassica campestris) plantation in a Karst region, as well as their relationships with soil nutrients, were examined in this study using high-throughput sequencing technologies of 16S and ITS amplicons. The aim was to provide theoretical insights into the healthy cultivation of Chinese cabbage in a Karst area. The findings revealed that the rhizosphere soil showed higher contents of organic matter (OM), alkaline hydrolyzable nitrogen (AN), available phosphorus (AP), total phosphorus (TP), available potassium (AK), total potassium (TK), total nitrogen (TN), catalase (CA), urease (UR), sucrase (SU), and phosphatase (PHO), in comparison with bulk soil, while the pH value showed the opposite trend. The diversity of bacterial and fungal communities in the bulk soil was higher than that in the rhizosphere soil, and their compositions differed between the two types of soil. In the rhizosphere soil, Proteobacteria, Acidobacteriota, Actinobacteriota, and Bacteroidota were the dominant bacterial phyla, while Olpidiomycota, Ascomycota, Mortierellomycota, and Basidiomycota were the predominant fungal phyla. In contrast, the bulk soil was characterized by bacterial dominance of Proteobacteria, Acidobacteriota, Chloroflexi, and Actinobacteriota and fungal dominance of Ascomycota, Olpidiomycota, Mortierellomycota, and Basidiomycota. The fungal network was simpler than the bacterial network, and both networks exhibited less complexity in the rhizosphere soil compared with the bulk soil. Moreover, the rhizosphere soil harbored a higher proportion of beneficial Rhizobiales. The rhizosphere soil network was less complicated than the network in bulk soil by building a bacterial-fungal co-occurrence network. Furthermore, a network of relationships between soil properties and network keystone taxa revealed that the rhizosphere soil keystone taxa were more strongly correlated with soil properties than those in the bulk soil; despite its lower complexity, the rhizosphere soil contains a higher abundance of bacteria which are beneficial for cabbage growth compared with the bulk soil.

Phytoremediation Effect and Soil Microbial Community Characteristics of Jiulong Iron Tailings Area, Jiangxi

The aim of this paper was to explore the remediation effect and mechanism of Wetland pine (Pinus elliottii), Chinese fir (Cunninghamia lanceolata (Lamb.) Hook), and Alder (Alnus cremastogyne Burkill) on heavy metal contaminated soil in the iron tailings of Jiulong Iron Tailings Area. At the same time, the specificity of plant rhizosphere and non-rhizosphere soil microbial community structure and ecological function were analyzed based on macrogenomic sequencing. The results showed that the dominant microbial genera in J1 (control) was Acidobacteria, followed by Proteobacteria and Actinobacteria. The microbial genera with the highest percentage of relative abundance in J2, J3, J4, J5, and J6 (J2, Wetland Pine rhizosphere; J3, Wetland Pine non-rhizosphere; J4, Chinese fir rhizosphere; J5, Alder rhizosphere; J6, Alder non-rhizosphere) were Proteobacteria, followed by Acidobacteria, and Actinobacteria. It was found that Proteobacteria promoted heavy metal solubilization, activated heavy metals, and converted their forms to improve plant uptake of heavy metals. This proves that the microorganisms of Proteobacteria are the key microbial genera in the study of regional heavy metal remediation. The antibiotic resistance genes (ARGs) in microorganisms can respond to the inducement of heavy metals. Here, we investigated the relationship between the abundance of soil microorganisms ARGs and heavy metal pollution in Jiulong Iron Tailings Area. There are significant differences in the quantity and category of ARGs in the rhizosphere and non-rhizosphere soil samples of the three tree species. The results of this study provide the foundation for the theory and practice of remediation of heavy metal contamination in soils of iron tailing areas in Jiulong Iron Tailings Area in similar stand conditions.

The response of soil respiration to land‐use change depends on soil microbial community being regulated by edaphic factors in the Loess Plateau, China

AbstractLand‐use change has significant influences on soil respiration (Rs) in terrestrial ecosystems. Soil microbes play critical roles in soil carbon cycling. Nevertheless, the specific mechanism of how changes in soil microbial properties are linked to the variation of Rs rate during land‐use change still remains poorly understood, especially in the Loess Plateau, China. Here, the characteristics of Rs rate and soil microbial community following the land‐use change from farmland to plantation/grassland were analyzed via an automated soil CO2 flux system and high‐throughput 16S rDNA gene sequencing. The afforestation altered soil microbial diversity and community composition, which was mainly explained by soil pH, temperature, organic matter, nitrate, alkali‐hydrolyzed nitrogen, and available phosphorus. The biomarkers of Bacteroidetes, Firmicutes, and Thaumarchaeota were found in farmland soil at the phylum level. The afforestation also significantly decreased Rs rate, which was closely related to Shannon's index, Simpson's index, and some microbial taxa, such as Bacteroidetes, Firmicutes, Nitrospirae, and Acidobacteria. Bacteroidetes, and Firmicutes were particularly expected to be important drivers of high Rs rate in farmland soil. Moreover, the microbial interaction was probably also an important factor affecting Rs rate. Our results indicate that the response of Rs to land‐use change depends on soil microbial community being regulated by soil physicochemical properties in the Loess Plateau, China.

Dynamic characteristics of soil heavy metals and microbial communities under moss cover at different successional stages in a manganese mining area.

The mining and smelting of manganese ores and the accumulation of slag not only pollute the environment and increase the threat to biodiversity, but also adversely affect the health of human and other organisms. Therefore, it's important to study the restoration of manganese mining area. Since mosses play an irreplaceable role in the ecological restoration of mine sites, this study is carried out in a slag heap area that has been in continuous operation for about 50years, and spatial variation is used instead of temporal variation to study the diversity of moss plants, the characteristics of soil heavy metal changes under moss cover, and the characteristics of bacterial communities in manganese mine sites at different time scales. A total of 20 moss taxa from 8 genera and 5 families are recorded, the dominant families are Bryaceae (50%) and Pottiaceae (25%), with the development of succession, the alpha-diversity index of mosses increases with the development of succession. The study area has a relatively high level of heavy metal contamination, the heavy metals Mn, V, Cu and Ni are significantly affected by succession in the Manganese mining area, and the soil heavy metal content generally shows a decreasing trend with the development of succession. Actinobacteriota, Proteobacteria, Chloroflexi Acidobacteriota and Gemmatimonadota are the dominant soil bacterial phyla in manganese mining areas (relative abundance > 10%), the composition of soil bacteria at different successional stages at the phylum level was the same, but the abundance of each bacterial community differed. The soil bacterial community in the manganese mining area is significantly affected by soil heavy metals.

Soil microbial community characteristics and the influencing factors at different elevations on the eastern slope of Helan Mountain, Northwest China.

As an important bridge connecting aboveground communities and belowground biological processes, soil microorganisms play an important role in regulating belowground ecological processes. The altitudinal changes and driving factors of soil microbial community in mountain ecosystem in arid region are still unclear. We measured soil physicochemical properties at seven altitudes in the range of 1300-2800 m in Helan Mountains, and investigated the understory community composition, soil physicochemical properties, and soil microbial community. The driving factor for soil microbial community was explored by variance partitioning analysis and redundancy analysis. The results showed that the total amount of soil microorganisms and bacterial biomass first increased and then decreased with the increases of altitude, fungi, actinomyces, arbuscular mycorrhizal fungi, Gram-positive bacteria, and Gram-negative bacteria groups showed a gradual increase. The variation of fungal-to-bacterial ratio (F/B) along the altitude showed that the cumulative ability of soil bacteria was stronger than that of fungi at low altitudes, while the pattern is opposite at high altitudes. The ratio of Gram-positive bacteria to Gram-negative bacteria (GP/GN) showed an overall decreasing trend with the increases of altitude, indicating that soil bacteria and organic carbon availability changed from "oligotrophic" to "eutrophication" and from "low" to "high" transition as the altitude increased. Vegetation properties, soil physical and chemical properties jointly accounted for 95.7% of the variation in soil microbial community. Soil organic carbon (SOC), soil water content (SWC), and total nitrogen (TN) were significantly correlated with soil microbial community composition. Our results revealed the distribution pattern and driving factors of soil microbial communities at different elevations on the eastern slope of Helan Mountain, which would provide theoretical basis and data support for further understanding the interaction between plant-soil-microorganisms in arid areas.

Arsenic pollution from human activities drives changes in soil microbial community characteristics.

Soil arsenic (As) pollution not only decreases plant productivity but also soil quality, in turn hampering sustainable agricultural development. Despite the negative effects of As contamination on rice yield and quality being reported widely, the responses of microbial communities and co-occurrence networks in paddy soil to As pollution have not been explored. Here, based on high-throughput sequencing technologies, we investigated bacterial abundance and diversity in paddy soils with different levels of As contamination, and constructed associated microbial co-occurrence networks. As pollution reduced soil bacterial diversity significantly (p < 0.001). In addition, bioavailable As concentrations were negatively correlated with Actinobacteria and Acidobacteria relative abundance (p < 0.05). Conversely, As pollution had a positive relationship with Chloroflexi, Betaproteobacteria, and Bacteroidetes relative abundance (p < 0.05). Firmicutes relative abundance decreased with an increase in total As concentration. The ecological clusters and key groups in bacterial co-occurrence networks exhibited distinct trends with an increase in As pollution. Notably, Acidobacteria play an important role in maintaining microbial networks in As contaminated soils. Overall, we provide empirical evidence that As contamination influences soil microbial community structure, posing a threat to soil ecosystem health and sustainable agriculture.

Variations in soil microbial community structure and extracellular enzymatic activities along a forest-wetland ecotone in high-latitude permafrost regions.

Permafrost degradation by global warming is expected to alter the hydrological processes, which results in changes in vegetation species composition and gives rise to community succession. Ecotones are sensitive transition areas between ecosystem boundaries, attract particular interest due to their ecological importance and prompt responses to the environmental variables. However, the characteristics of soil microbial communities and extracellular enzymes along the forest-wetland ecotone in high-latitude permafrost region remain poorly understood. In this study, we evaluated the variations of soil bacterial and fungal community structures and soil extracellular enzymatic activities of 0-10 cm and 10-20 cm soil layers in five different wetland types along environmental gradients, including Larix gmelinii swamp (LY), Betula platyphylla swamp (BH), Alnus sibirica var. hirsute swamp (MCY), thicket swamp (GC), and tussock swamp (CC). The relative abundances of some dominant bacterial (Actinobacteria and Verrucomicrobia) and fungal (Ascomycota and Basidiomycota) phyla differed significantly among different wetlands, while bacterial and fungal alpha diversity was not strongly affected by soil depth. PCoA results showed that vegetation type, rather than soil depth explained more variation of soil microbial community structure. β-glucosidase and β-N-acetylglucosaminidase activities were significantly lower in GC and CC than in LY, BH, and MCY, while acid phosphatase activity was significantly higher in BH and GC than LY and CC. Altogether, the data suggest that soil moisture content (SMC) was the most important environmental factor contributing to the bacterial and fungal communities, while extracellular enzymatic activities were closely related to soil total organic carbon (TOC), nitrate nitrogen () and total phosphorus (TP).

Effects of the Transformation from Natural Alpine Grassland to Mixed Artificial Grassland on the Characteristics of Soil Microbial Community

This study aimed to analyze the effects of the transformation from natural alpine grassland (NAG) to mixed artificial grassland (MAG) on the characteristics of soil microbial community. We used Illumina Miseq high-throughput sequencing technology to investigate the soil microbial community of natural grassland and mixed artificial grassland. The results showed that plant diversity and the content of soil organic matter decreased significantly from NAG to MAG. In total, 29 and 11 phyla bacteria and fungi were detected, respectively. Compared with that in NAG, the Shannon indexes of the bacterial community increased significantly in MAG (from 9.51 to 9.89), whereas these differences were not significant between the NAG and MAG fungal community. The structure and composition of the soil microbial community showed significant differences between NAG and MAG. In addition, Mantel test results suggested that soil total organic matter, total nitrogen, and soil moisture were significantly correlated with variations in the bacterial community, and soil total organic matter and soil moisture were significantly correlated with variations in fungal community. The results of linear discriminant analysis (LEfSe) indicated that Atribacteria and Ascomycota microorganisms could be considered as the indicator groups for NAG, whereas Gemmata and Trichocomaceae microorganisms could be considered as the indicator groups for MAG. Tax4Fun2 results showed that the transition from NAG to MAG affected the utilization of different carbon sources by bacteria.

Characteristics of Soil Microbial Community in Different Habitats in the Process of Ecological Restoration of Haifeng Wetland in Guangdong

Soil microorganisms can respond to changes in wetland ecosystem quality and functional evolution sensitively. To explore the changes and response mechanisms of soil microorganisms under ecological restoration measures, the characteristics of the soil microbial community and their influencing factors were analyzed using high-throughput sequencing technology in four different habitats (revegetation area, native vegetation area, tidal creek, and tidal flat) during the ecological restoration process in Haifeng wetland in Guangdong. The results showed that:soil physicochemical properties of the four different habitats were significantly different; the contents of TC, TN, TOC, and TK in the tidal creek were significantly higher than those in the other habitats; and the contents of TC, TN, and TP in the revegetation restoration area were significantly higher than those in the tidal flat. The EC values in the tidal creeks and tidal flat were significantly higher than those in the revegetation area and the native vegetation area. The diversity index and abundance of soil bacteria in the tidal creek were the highest, and those in the vegetation restoration area were significantly higher than those in the bare flat. The archaea in the tidal creek were significantly more complex than those in the other three habitats, and the fungal community diversity index and abundance in the native vegetation area were significantly higher than those in the other areas, which had the most complex community structure. TN and TC were the main factors affecting the bacterial community, whereas TN and EC were the main factors affecting the archaea community, and pH, TN, and TP were the key factors affecting the fungal community. In conclusion, the planting of vegetation on the tidal flat increased the diversity and richness of the soil microbial community during the process of ecological restoration, indicating that it has resulted in positive feedback on ecological restoration so far. The results of this study can provide a theoretical basis for the selection of ecological restoration strategies for the tidal flat.