Soil Bacterial Communities and Diversity in Alpine Grasslands on the Tibetan Plateau Based on 16S rRNA Gene Sequencing

The Tibetan Plateau, widely known as the world’s “Third Pole,” has gained extensive attention due to its susceptibility to climate change. Alpine grasslands are the dominant ecosystem on the Tibetan Plateau, albeit little is known about the microbial community and diversity among different alpine grassland types. Here, soil bacterial composition and diversity in the upper soils of five alpine grassland ecosystems, alpine meadow (AM), alpine steppe (AS), alpine meadow steppe (AMS), alpine desert (AD), and alpine desert steppe (ADS), were investigated based on the 16S rRNA gene sequencing technology. Actinobacteria (46.12%) and Proteobacteria (29.67%) were the two dominant soil bacteria at the phylum level in alpine grasslands. There were significant differences in the relative abundance at the genus level among the five different grassland types, especially for the Rubrobacter, Solirubrobacter, Pseudonocardia, Gaiella, Haliangium, and Geodermatophilus. Six alpha diversity indices were calculated based on the operational taxonomic units (OTUs), including Good’s coverage index, phylogenetic diversity (PD) whole tree index, Chao1 index, observed species index, Shannon index, and Simpson index. The Good’s coverage index value was around 0.97 for all the grassland types in the study area, meaning the soil bacteria samplings sequenced sufficiently. No statistically significant difference was shown in other diversity indices’ value, indicating the similar richness and evenness of soil bacteria in these alpine grasslands. The beta diversity, represented by Bray–Curtis dissimilarity and the non-metric multidimensional scaling (NMDS), showed that OTUs were clustered within alpine grasslands, indicating a clear separation of soil bacterial communities. In addition, soil organic matter (SOM), total nitrogen (TN), total phosphorus (TP), pH, and soil water content (SWC) were closely related to the variations in soil bacterial compositions. These results indicated that soil bacterial taxonomic compositions were similar, while soil bacterial community structures were different among the five alpine grassland types. The environmental conditions, including SOM, TN, TP, pH, and SWC, might influence the soil bacterial communities on the Tibetan Plateau.

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Interactive effects of elevation and land use on soil bacterial communities in the Tibetan Plateau

Pedosphere ◽

10.1016/s1002-0160(19)60836-2 ◽

2020 ◽

Vol 30 (6) ◽

pp. 817-831

Author(s):

Yuanyuan YANG ◽

Yin ZHOU ◽

Zhou SHI ◽

Raphael A. VISCARRA ROSSEL ◽

Zongzheng LIANG ◽

...

Keyword(s):

Land Use ◽

Tibetan Plateau ◽

Bacterial Communities ◽

Interactive Effects ◽

The Tibetan Plateau ◽

Soil Bacterial Communities ◽

Soil Bacterial

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Carbon fluxes and environmental controls across different alpine grassland types on the Tibetan Plateau

Agricultural and Forest Meteorology ◽

10.1016/j.agrformet.2021.108694 ◽

2021 ◽

Vol 311 ◽

pp. 108694

Author(s):

Yuyang Wang ◽

Jingfeng Xiao ◽

Yaoming Ma ◽

Yiqi Luo ◽

Zeyong Hu ◽

...

Keyword(s):

Tibetan Plateau ◽

Carbon Fluxes ◽

Alpine Grassland ◽

The Tibetan Plateau ◽

Environmental Controls ◽

Grassland Types

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Urbanization and Carpobrotus edulis invasion alter the diversity and composition of soil bacterial communities in coastal areas

FEMS Microbiology Ecology ◽

10.1093/femsec/fiaa106 ◽

2020 ◽

Vol 96 (7) ◽

Author(s):

Ana Novoa ◽

Jan-Hendrik Keet ◽

Yaiza Lechuga-Lago ◽

Petr Pyšek ◽

Johannes J Le Roux

Keyword(s):

Community Composition ◽

Bacterial Communities ◽

Soil Bacteria ◽

Coastal Dunes ◽

Coastal Dune ◽

Western Coast ◽

Carpobrotus Edulis ◽

Soil Bacterial Communities ◽

Soil Bacterial ◽

The Impact

ABSTRACT Coastal dunes are ecosystems of high conservation value that are strongly impacted by human disturbances and biological invasions in many parts of the world. Here, we assessed how urbanization and Carpobrotus edulis invasion affect soil bacterial communities on the north-western coast of Spain, by comparing the diversity, structure and composition of soil bacterial communities in invaded and uninvaded soils from urban and natural coastal dune areas. Our results suggest that coastal dune bacterial communities contain large numbers of rare taxa, mainly belonging to the phyla Actinobacteria and Proteobacteria. We found that the presence of the invasive C. edulis increased the diversity of soil bacteria and changed community composition, while urbanization only influenced bacterial community composition. Furthermore, the effects of invasion on community composition were conditional on urbanization. These results were contrary to predictions, as both C. edulis invasion and urbanization have been shown to affect soil abiotic conditions of the studied coastal dunes in a similar manner, and therefore were expected to have similar effects on soil bacterial communities. Our results suggest that other factors (e.g. pollution) might be influencing the impact of urbanization on soil bacterial communities, preventing an increase in the diversity of soil bacteria in urban areas.

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Impact of Maize–Mushroom Intercropping on the Soil Bacterial Community Composition in Northeast China

Agronomy ◽

10.3390/agronomy10101526 ◽

2020 ◽

Vol 10 (10) ◽

pp. 1526

Author(s):

Xiaoqin Yang ◽

Yang Wang ◽

Luying Sun ◽

Xiaoning Qi ◽

Fengbin Song ◽

...

Keyword(s):

Bacterial Communities ◽

Northeast China ◽

Management Practice ◽

Bacterial Community Composition ◽

Soil Microbial Communities ◽

Chemical Properties ◽

Crop Productivity ◽

Rrna Gene ◽

Soil Bacterial Communities ◽

Soil Bacterial

Conservative agricultural practices have been adopted to improve soil quality and maintain crop productivity. An efficient intercropping of maize with mushroom has been developed in Northeast China. The objective of this study was to evaluate and compare the effects of planting patterns on the diversity and structure of the soil bacterial communities at a 0–20 cm depth in the black soil zone of Northeast China. The experiment consisted of monoculture of maize and mushroom, and intercropping in a split-plot arrangement. The characteristics of soil microbial communities were performed by 16S rRNA gene amplicom sequencing. The results showed that intercropping increased soil bacterial richness and diversity compared with maize monoculture. The relative abundances of Acidobacteria, Chloroflexi, Saccharibacteria and Planctomycetes were significantly higher, whereas Proteobacteria and Firmicutes were lower in intercropping than maize monoculture. Redundancy analysis suggested that pH, NO3−-N and NH4+-N contents had a notable effect on the structure of the bacterial communities. Moreover, intercropping significantly increased the relative abundance of carbohydrate metabolism pathway functional groups. Overall, these findings demonstrated that intercropping of maize with mushroom strongly impacts the physical and chemical properties of soil as well as the diversity and structure of the soil bacterial communities, suggesting this is a sustainable agricultural management practice in Northeast China.

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Temporal variation in soil bacterial communities can be confounded with spatial variation

FEMS Microbiology Ecology ◽

10.1093/femsec/fiaa192 ◽

2020 ◽

Vol 96 (12) ◽

Author(s):

Syrie M Hermans ◽

Hannah L Buckley ◽

Fiona Curran-Cournane ◽

Matthew Taylor ◽

Gavin Lear

Keyword(s):

Temporal Variation ◽

Bacterial Communities ◽

Amplicon Sequencing ◽

Spatial Distance ◽

Rrna Gene ◽

Soil Bacterial Communities ◽

Causal Processes ◽

Fundamental Understanding ◽

Soil Bacterial ◽

Indigenous Forest

ABSTRACT Investigating temporal variation in soil bacterial communities advances our fundamental understanding of the causal processes driving biological variation, and how the composition of these important ecosystem members may change into the future. Despite this, temporal variation in soil bacteria remains understudied, and the effects of spatial heterogeneity in bacterial communities on the detection of temporal changes is largely unknown. Using 16S rRNA gene amplicon sequencing, we evaluated temporal patterns in soil bacterial communities from indigenous forest and human-impacted sites sampled repeatedly over a 5-year period. Temporal variation appeared to be greater when fewer spatial samples per site were analysed, as well as in human-impacted compared to indigenous sites (P < 0.01 for both). The biggest portion of variation in bacterial community richness and composition was explained by soil physicochemical variables (13–24%) rather than spatial distance or sampling time (<1%). These results highlight the importance of adequate spatiotemporal replication when sampling soil communities for environmental monitoring, and the importance of conducting temporal research across a wide variety of land uses. This will ensure we have a true understanding of how bacterial communities change over space and time; the work presented here provides important considerations for how such research should be designed.

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Impact of Logging and Forest Conversion to Oil Palm Plantations on Soil Bacterial Communities in Borneo

Applied and Environmental Microbiology ◽

10.1128/aem.02541-13 ◽

2013 ◽

Vol 79 (23) ◽

pp. 7290-7297 ◽

Cited By ~ 72

Author(s):

Larisa Lee-Cruz ◽

David P. Edwards ◽

Binu M. Tripathi ◽

Jonathan M. Adams

Keyword(s):

Forest Soil ◽

Oil Palm ◽

Bacterial Communities ◽

Soil Bacteria ◽

Forest Conversion ◽

Soil Bacterial Communities ◽

Oil Palm Plantation ◽

Β Diversity ◽

Logged Forest ◽

Soil Bacterial

ABSTRACTTropical forests are being rapidly altered by logging and cleared for agriculture. Understanding the effects of these land use changes on soil bacteria, which constitute a large proportion of total biodiversity and perform important ecosystem functions, is a major conservation frontier. Here we studied the effects of logging history and forest conversion to oil palm plantations in Sabah, Borneo, on the soil bacterial community. We used paired-end Illumina sequencing of the 16S rRNA gene, V3 region, to compare the bacterial communities in primary, once-logged, and twice-logged forest and land converted to oil palm plantations. Bacteria were grouped into operational taxonomic units (OTUs) at the 97% similarity level, and OTU richness and local-scale α-diversity showed no difference between the various forest types and oil palm plantations. Focusing on the turnover of bacteria across space, true β-diversity was higher in oil palm plantation soil than in forest soil, whereas community dissimilarity-based metrics of β-diversity were only marginally different between habitats, suggesting that at large scales, oil palm plantation soil could have higher overall γ-diversity than forest soil, driven by a slightly more heterogeneous community across space. Clearance of primary and logged forest for oil palm plantations did, however, significantly impact the composition of soil bacterial communities, reflecting in part the loss of some forest bacteria, whereas primary and logged forests did not differ in composition. Overall, our results suggest that the soil bacteria of tropical forest are to some extent resilient or resistant to logging but that the impacts of forest conversion to oil palm plantations are more severe.

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Field-Scale Transplantation Experiment To Investigate Structures of Soil Bacterial Communities at Pioneering Sites

Applied and Environmental Microbiology ◽

10.1128/aem.05778-11 ◽

2011 ◽

Vol 77 (23) ◽

pp. 8241-8248 ◽

Cited By ~ 30

Author(s):

Anna Lazzaro ◽

Andreas Gauer ◽

Josef Zeyer

Keyword(s):

Bacterial Community ◽

Environmental Conditions ◽

Bacterial Communities ◽

Seasonal Pattern ◽

Dry Weight ◽

Rrna Gene ◽

Soil Bacterial Communities ◽

Reciprocal Transplantation ◽

Temperature And Precipitation ◽

Soil Bacterial

ABSTRACTStudies on the effect of environmental conditions on plants and microorganisms are a central issue in ecology, and they require an adequate experimental setup. A strategy often applied in geobotanical studies is based on the reciprocal transplantation of plant species at different sites. We adopted a similar approach as a field-based tool to investigate the relationships of soil bacterial communities with the environment. Soil samples from two different (calcareous and siliceous) unvegetated glacier forefields were reciprocally transplanted and incubated for 15 months between 2009 and 2010. Controls containing local soils were included. The sites were characterized over time in terms of geographical (bedrock, exposition, sunlight, temperature, and precipitation) and physicochemical (texture, water content, soluble and nutrients) features. The incubating local (“home”) and transplanted (“away”) soils were monitored for changes in extractable nutrients and in the bacterial community structure, defined through terminal restriction fragment length polymorphism (T-RFLP) of the 16S rRNA gene. Concentrations of soluble ions in most samples were more significantly affected by seasons than by the transplantation. For example, NO3−showed a seasonal pattern, increasing from 1 to 3 μg NO3−(g soil dry weight)−1after the melting of snow but decreasing to <1 μg NO3−(g soil dry weight)−1in autumn. Seasons, and in particular strong precipitation events occurring in the summer of 2010 (200 to 300 mm of rain monthly), were also related to changes of bacterial community structures. Our results show the suitability of this approach to compare responses of bacterial communities to different environmental conditions directly in the field.

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High throughput sequencing-based analysis of the soil bacterial community structure and functions of Tamarix shrubs in the lower reaches of the Tarim River

PeerJ ◽

10.7717/peerj.12105 ◽

2021 ◽

Vol 9 ◽

pp. e12105

Author(s):

Fangnan Xiao ◽

Yuanyuan Li ◽

Guifang Li ◽

Yaling He ◽

Xinhua Lv ◽

...

Keyword(s):

Bacterial Community ◽

Bacterial Communities ◽

Metabolic Pathways ◽

Soil Bacteria ◽

High Throughput Sequencing ◽

Soil Bacterial Community ◽

Tarim River ◽

Soil Bacterial Communities ◽

Soil Bacterial ◽

And Function

Tamarix is a dominant species in the Tarim River Basin, the longest inland river in China. Tamarix plays an important role in the ecological restoration of this region. In this study, to investigate the soil bacterial community diversity in Tamarix shrubs, we collected soil samples from the inside and edge of the canopy and the edge of nebkhas and non-nebkhas Tamarix shrubs located near the Yingsu section in the lower reaches of Tarim River. High throughput sequencing technology was employed to discern the composition and function of soil bacterial communities in nebkhas and non-nebkhas Tamarix shrubs. Besides, the physicochemical properties of soil and the spatial distribution characteristics of soil bacteria and their correlation were analyzed. The outcomes of this analysis demonstrated that different parts of Tamarix shrubs had significantly different effects on soil pH, total K (TK), available K (AK), ammonium N (NH4+), and available P (AP) values (P < 0.05), but not on soil moisture (SWC), total salt (TDS), electrical conductivity (EC), organic matter (OM), total N (TN), total P (TP), and nitrate N (NO3−) values. The soil bacterial communities identified in Tamarix shrubs were categorized into two kingdoms, 71 phyla, 161 classes, 345 orders, 473 families, and 702 genera. Halobacterota, unidentified bacteria, and Proteobacteria were found to be dominant phyla. The correlation between the soil physicochemical factors and soil bacterial community was analyzed, and as per the outcomes OM, AK, AP, EC, and NH4+ were found to primarily affect the structure of the soil bacterial community. SWC, TK and pH were positively correlated with each other, but negatively correlated with other soil factors. At the phyla level, a significantly positive correlation was observed between the Halobacterota and AP, OM as well as Bacteroidota and AK (P < 0.01), but a significantly negative correlation was observed between the Chloroflexi and AK, EC (P < 0.01). The PICRUSt software was employed to predict the functional genes. A total of 6,195 KEGG ortholog genes were obtained. The function of soil bacteria was annotated, and six metabolic pathways in level 1, 41 metabolic pathways in level 2, and 307 metabolic pathways in level 3 were enriched, among which the functional gene related to metabolism, genetic information processing, and environmental information processing was found to have the dominant advantage. The results showed that the nebkhas and canopy of Tamarix shrubs had a certain enrichment effect on soil nutrients content, and bacterial abundance and significant effects on the structure and function of the soil bacterial community.

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Potential effects of temperature levels on soil bacterial community structure

E3S Web of Conferences ◽

10.1051/e3sconf/202129201008 ◽

2021 ◽

Vol 292 ◽

pp. 01008

Author(s):

Jing Fang ◽

Shuli Wei ◽

Gongfu Shi ◽

Yuchen Cheng ◽

Xiangqian Zhang ◽

...

Keyword(s):

Bacterial Communities ◽

Soil Bacteria ◽

Soil Microorganisms ◽

Temperature Gradients ◽

Control Treatment ◽

Effect Of Temperature ◽

Main Reaction ◽

Soil Bacterial Communities ◽

Infrared Temperature Measurement ◽

Soil Bacterial

Soil microorganisms play a crucial role in the response to global warming in terrestrial ecosystems. Soils with higher microbial diversity have more ecological functions, higher resistance to environmental stress and higher crop production capacity. At present, the research on the effect of temperature change on soil microorganisms mostly adopts the methods of outdoor infrared temperature measurement or exchange and transplantation of soil with different temperature zones. Here, we investigate how temperature gradients potentially affect soil bacterial communities to change. For this reason, we used indoor precise temperature control treatment and combined high-throughput sequencing with bioinformatics to systematically analyze the diversity and species composition of soil bacteria under different temperature gradients, and to clarify the variation trend and interaction relationships of different species with temperature gradients. The results showed that temperature significantly affected the Alpha diversity of soil bacterial communities (P<0.05).Soil bacteria has different sensitivity and adaptability to temperature. In the range of 0-40℃, insensitive bacteria includes Proteobacteria, Gemmatimonadetes and Chloroflexi. Sensitive bacteria includes Sphingomonas, Ellin6055 and norank_f_67-14. The main reaction types of two bacteria showed four trends: ① Proteobacteria and Sphingomonas showed an “arch” variation; ② Gemmatimonadetes and Chloroflexi showed “inverted arch”. ③ Norank_f_67-14 showed an “inverted S type” change; ④ Ellin6055 shows a” parabolic ” shape. In different classification levels such as phylum and genus, the higher the classification level is, the higher degree it is weakened by temperature on, and the lower the classification level is, the stronger effect temperature has on it. In short, when temperature changes, soil bacteria can respond positively or negatively according to their ability to adapt to temperature, and accordingly form certain regular changes.

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