scholarly journals Predicting spatial patterns of soil bacteria under current and future environmental conditions

2021 ◽  
Author(s):  
Heidi K. Mod ◽  
Aline Buri ◽  
Erika Yashiro ◽  
Nicolas Guex ◽  
Lucie Malard ◽  
...  
Keyword(s):  
Bacterial Communities ◽  
Soil Bacteria ◽  
Environmental Changes ◽  
Climatic Factors ◽  
Species Distribution Modelling ◽  
Community Change ◽  
Abundance Distribution ◽  
Mountain Area ◽  
Soil Bacterial ◽  
Ecosystem Changes

AbstractSoil bacteria are largely missing from future biodiversity assessments hindering comprehensive forecasts of ecosystem changes. Soil bacterial communities are expected to be more strongly driven by pH and less by other edaphic and climatic factors. Thus, alkalinisation or acidification along with climate change may influence soil bacteria, with subsequent influences for example on nutrient cycling and vegetation. Future forecasts of soil bacteria are therefore needed. We applied species distribution modelling (SDM) to quantify the roles of environmental factors in governing spatial abundance distribution of soil bacterial OTUs and to predict how future changes in these factors may change bacterial communities in a temperate mountain area. Models indicated that factors related to soil (especially pH), climate and/or topography explain and predict part of the abundance distribution of most OTUs. This supports the expectations that microorganisms have specific environmental requirements (i.e., niches/envelopes) and that they should accordingly respond to environmental changes. Our predictions indicate a stronger role of pH over other predictors (e.g. climate) in governing distributions of bacteria, yet the predicted future changes in bacteria communities are smaller than their current variation across space. The extent of bacterial community change predictions varies as a function of elevation, but in general, deviations from neutral soil pH are expected to decrease abundances and diversity of bacteria. Our findings highlight the need to account for edaphic changes, along with climate changes, in future forecasts of soil bacteria.

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

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.

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

2013 ◽  
Vol 79 (23) ◽  
pp. 7290-7297 ◽  
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.

scholarly journals Diversity of dominant soil bacteria increases with warming velocity at the global scale

2020 ◽  
Author(s):  
Yoshiaki Kanzaki ◽  
Kazuhiro Takemoto
Keyword(s):  
Bacterial Diversity ◽  
Soil Bacteria ◽  
Environmental Changes ◽  
Global Climate ◽  
Aridity Index ◽  
Global Scale ◽  
Soil Bacterial Diversity ◽  
Dominant Soil ◽  
Global Soil ◽  
Soil Bacterial

AbstractUnderstanding global soil bacterial diversity is important because of the key roles soil bacteria play in the global ecosystem. Given the effects of environmental changes (e.g., climate change and human effect) on the diversity of animals and plants, effects on soil bacterial diversity are expected; however, they have been poorly evaluated to date. Thus, in this study, we focused on the soil dominant bacteria because of their global importance and investigated the effects of warming velocity and human activities on their diversity. Using a global dataset of bacteria, we performed spatial analysis to evaluate the effects, while statistically controlling for the potential confounding effects of current climate and geographic parameters with global climate and geographic data. It was demonstrated that the diversity of the dominant soil bacteria was influenced globally by warming velocity (showing significant increases) in addition to aridity index (dryness) and pH. The effects of warming velocity were particularly significant in forests and grasslands. An effect from human activity was also observed, but it was secondary to warming velocity. These findings provide robust evidence, and advance our understanding of the effects of environmental changes (particularly global warming) on soil bacterial diversity at the global scale.

scholarly journals Diversity of Dominant Soil Bacteria Increases with Warming Velocity at The Global Scale

Diversity ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 120
Author(s):  
Yoshiaki Kanzaki ◽  
Kazuhiro Takemoto
Keyword(s):  
Bacterial Diversity ◽  
Human Activities ◽  
Soil Bacteria ◽  
Environmental Changes ◽  
Global Climate ◽  
Aridity Index ◽  
Global Scale ◽  
Soil Bacterial Diversity ◽  
Dominant Soil ◽  
Soil Bacterial

Understanding global soil bacterial diversity is important because of its role in maintaining a healthy global ecosystem. Given the effects of environmental changes (e.g., warming and human impact) on the diversity of animals and plants, effects on soil bacterial diversity are expected; however, they have been poorly evaluated at the global scale to date. Thus, in this study, we focused on the dominant soil bacteria, which are likely critical drivers of key soil processes worldwide, and investigated the effects of warming velocity and human activities on their diversity. Using a global dataset of bacteria, we performed spatial analysis to evaluate the effects of warming velocity and human activities, while statistically controlling for the potentially confounding effects of current climate and geographic parameters with global climate and geographic data. We demonstrated that the diversity of the dominant soil bacteria was influenced globally, not only by the aridity index (dryness) and pH but also by warming velocity from the Last Glacial Maximum (21,000 years ago) to the present, showing significant increases. The increase in bacterial diversity with warming velocity was particularly significant in forests and grasslands. An effect of human activity was also observed, but it was secondary to warming velocity. These findings provide robust evidence and advance our understanding of the effects of environmental changes (particularly global warming) on soil bacterial diversity at the global scale.

scholarly journals 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 ◽  
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.

scholarly journals Forensic DNA Profiling of Bacterial Communities in Soil

2021 ◽  
Author(s):  
◽  
Rachel Parkinson
Keyword(s):  
Bacterial Community ◽  
Bacterial Communities ◽  
Community Change ◽  
Soil Samples ◽  
Dna Profiling ◽  
The Body ◽  
Soil Bacterial Community ◽  
Preliminary Evaluation ◽  
Soil Bacterial ◽  
Pmi Estimation

<p>Soil is frequently encountered as trace evidence in forensic science case-work, but because of the limitations of current analytical techniques, this evidence is rarely utilised. A technique has been developed that allows comparisons of soil samples to be made, based on molecular analysis of the bacterial communities living in the soil. This project assesses the practicality of using this technique, known as 16S rDNA T-RFLP community profiling, for forensic soil analysis, by refining the basic methodology and performing a preliminary evaluation of its reproducibility and utility. Initial difficulties associated with generating profiles from soil samples have been overcome through methodology improvement, and the technique has been found to be effective for generating simple, visual profiles that clearly demonstrate differences between soil samples. Soil bacterial community DNA profiling is likely to be a powerful yet simple forensic tool, providing the ability to routinely use soil as associative evidence. The potential for using the same technology to develop a time since death or post mortem interval (PMI) estimation tool was also investigated. This study monitored the changes in the soil bacterial community beneath decomposing human cadavers and pig carcasses and showed that community change is dynamic and progressive. These changes are caused by fluctuations in specific bacterial species populations that are able to utilise organic breakdown products released from the body over time. Release of the body’s natural microflora into the underlying soil may also contribute to an altered bacterial community. This project has demonstrated that the soil microbial community clearly changes over the course of decomposition, and potential exists for development of a PMI estimation tool based on soil bacterial community succession.</p>

scholarly journals Urbanization-induced environmental changes strongly affect wetland soil bacterial community composition and diversity

2021 ◽  
Author(s):  
Xinyu Yi ◽  
Chen Ning ◽  
Shuailong Feng ◽  
Haiqiang Gao ◽  
Jianlun Zhao ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Bacterial Communities ◽  
Environmental Changes ◽  
Bacterial Community Composition ◽  
Soil Microbial Communities ◽  
Environmental Drivers ◽  
Wetland Soil ◽  
Rrna Gene ◽  
Soil Microbial ◽  
Soil Bacterial

Abstract Soil microbial communities potentially serve as indicators for their responses to changes in various ecosystems at scales from a region to the globe. However, changes in wetland soil bacterial communities and how they are related to urbanization intensities remains poorly understood. Here, we collected sixty soil samples along urbanization intensity gradients from twenty wetlands. We measured a range of environmental factors and characterized bacterial communities structure using 16S rRNA gene amplicon sequencing that targeted the V4-V5 region. Our results revealed the dominant soil microbial phyla included Proteobacteria (39.3%), Acidobacteria (21.4%) and Chloroflexi (12.3%) in the wetlands, and showed a significant divergence of composition in intensive urbanization area (UI_4) than other places. A critical "threshold" exists in the soil bacterial diversity, demonstrating different patterns: a gradual increase in the areas of low-to-intermediate disturbances but a significant decrease in highly urbanized areas where metabolic functions were significantly strong. Additionally, soil pH, total phosphorus (TP), available phosphorus (AP ) and ammonia nitrogen (NH4+-N) made a significant contribution to variations in bacterial communities, explaining 49.6%, 35.1%, 26.2% and 30.7% of the total variance, respectively. pH and NH4+-N were identified as the main environmental drivers to determine bacterial community structure and diversity in the urban wetlands. Our results highlight collective changes in multiple environmental variables induced by urbanization rather than by the proportion of impervious surface area (ISA), which were potentially attributed to the spatial heterogeneity along different urbanization gradients.

scholarly journals Potential effects of temperature levels on soil bacterial community structure

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.

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

2021 ◽  
Vol 9 ◽  
Author(s):  
Hongmao Jiang ◽  
Youchao Chen ◽  
Yang Hu ◽  
Ziwei Wang ◽  
Xuyang Lu
Keyword(s):  
Tibetan Plateau ◽  
Bacterial Communities ◽  
Soil Bacteria ◽  
Alpine Grassland ◽  
Rrna Gene ◽  
The Tibetan Plateau ◽  
Alpine Grasslands ◽  
Soil Bacterial Communities ◽  
Soil Bacterial ◽  
Grassland Types

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.

scholarly journals Assessing the Effects of β-Triketone Herbicides on the Soil Bacterial and hppd Communities: A Lab-to-Field Experiment

2021 ◽  
Vol 11 ◽  
Author(s):  
Clémence Thiour-Mauprivez ◽  
Marion Devers-Lamrani ◽  
David Bru ◽  
Jérémie Béguet ◽  
Aymé Spor ◽  
...  
Keyword(s):  
Field Experiment ◽  
Bacterial Communities ◽  
Soil Bacteria ◽  
Plant Protection ◽  
Plant Protection Products ◽  
Transient Effects ◽  
Soil Bacterial ◽  
Living Organisms ◽  
Over Time ◽  
Triketone Herbicides

Maize cultivators often use β-triketone herbicides to prevent the growth of weeds in their fields. These herbicides target the 4-HPPD enzyme of dicotyledons. This enzyme, encoded by the hppd gene, is widespread among all living organisms including soil bacteria, which are considered as “non-target organisms” by the legislation. Within the framework of the pesticide registration process, the ecotoxicological impact of herbicides on soil microorganisms is solely based on carbon and nitrogen mineralization tests. In this study, we used more extensive approaches to assess with a lab-to-field experiment the risk of β-triketone on the abundance and the diversity of both total and hppd soil bacterial communities. Soil microcosms were exposed, under lab conditions, to 1× or 10× the recommended dose of sulcotrione or its commercial product, Decano®. Whatever the treatment applied, sulcotrione was fully dissipated from soil after 42 days post-treatment. The abundance and the diversity of both the total and the hppd bacterial communities were not affected by the herbicide treatments all along the experiment. Same measurements were led in real agronomical conditions, on three different fields located in the same area cropped with maize: one not exposed to any plant protection products, another one exposed to a series of plant protection products (PPPs) comprising mesotrione, and a last one exposed to different PPPs including mesotrione and tembotrione, two β-triketones. In this latter, the abundance of the hppd community varied over time. The diversity of the total and the hppd communities evolved over time independently from the treatment received. Only slight but significant transient effects on the abundance of the hppd community in one of the tested soil were observed. Our results showed that tested β-triketones have no visible impact toward both total and hppd soil bacteria communities.

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