scholarly journals Are recently deglaciated areas at both poles colonised by the same bacteria?

2021 ◽  
Vol 368 (3) ◽  
Author(s):  
Álvaro del Moral ◽  
Isaac Garrido-Benavent ◽  
Jorge Durán ◽  
Jan R Lehmann ◽  
Alexandra Rodríguez ◽  
...  

ABSTRACT Polar glacier forefields offer an unprecedented framework for studying community assembly processes in regions that are geographically and climatically isolated. Through amplicon sequence variant (ASV) inference, we compared the composition and structure of soil bacterial communities from glacier forefields in Iceland and Antarctica to assess overlap between communities and the impact of established cryptogamic covers on the uniqueness of their taxa. These pioneer microbial communities were found to share only 8% of ASVs and each taxonomic group's contribution to the shared ASV data subset was heterogeneous and independent of their relative abundance. Although the presence of ASVs specific to one glacier forefield and/or different cryptogam cover values confirms the existence of habitat specialist bacteria, our data show that the influence of cryptogams on the edaphic bacterial community structure also varied also depending on the taxonomic group. Hence, the establishment of distinct cryptogamic covers is probably not the only factor driving the uniqueness of bacterial communities at both poles. The structure of bacterial communities colonising deglaciated areas seems also conditioned by lineage-specific limitations in their dispersal capacity and/or their establishment and persistence in these isolated and hostile regions.

2009 ◽  
Vol 75 (15) ◽  
pp. 5111-5120 ◽  
Author(s):  
Christian L. Lauber ◽  
Micah Hamady ◽  
Rob Knight ◽  
Noah Fierer

ABSTRACT Soils harbor enormously diverse bacterial populations, and soil bacterial communities can vary greatly in composition across space. However, our understanding of the specific changes in soil bacterial community structure that occur across larger spatial scales is limited because most previous work has focused on either surveying a relatively small number of soils in detail or analyzing a larger number of soils with techniques that provide little detail about the phylogenetic structure of the bacterial communities. Here we used a bar-coded pyrosequencing technique to characterize bacterial communities in 88 soils from across North and South America, obtaining an average of 1,501 sequences per soil. We found that overall bacterial community composition, as measured by pairwise UniFrac distances, was significantly correlated with differences in soil pH (r = 0.79), largely driven by changes in the relative abundances of Acidobacteria, Actinobacteria, and Bacteroidetes across the range of soil pHs. In addition, soil pH explains a significant portion of the variability associated with observed changes in the phylogenetic structure within each dominant lineage. The overall phylogenetic diversity of the bacterial communities was also correlated with soil pH (R2 = 0.50), with peak diversity in soils with near-neutral pHs. Together, these results suggest that the structure of soil bacterial communities is predictable, to some degree, across larger spatial scales, and the effect of soil pH on bacterial community composition is evident at even relatively coarse levels of taxonomic resolution.


Author(s):  
Xiaoli Zhou ◽  
Jingang Liang ◽  
Ying Luan ◽  
Xinyuan Song ◽  
Zhengguang Zhang

Returning straw to the soil is an effective way to improve the soil quality. As genetically modified (GM) crops experience expanded growing scales, returning straw to the soil could also be necessary. However, the impact of GM crop straws on soil safety remains unclear. The environment (including soil types, humidity and temperature) can result in a significant difference in the diversity of soil bacterial communities. Here, we compared the impacts of the straw from Bt maize IE09S034 (IE) and near-isogenic non-Bt maize Zong31 (CK) on soil bacterial community and microbial metabolic activity in three different environments. Sampling was carried out following 6–10 months of decomposition (May, June, July, and August) in three localities in Chinese cities (Changchun, Jinan, and Beijing). Our results showed that Bt maize residues posed no direct impact on soil bacterial communities in contrast to the environment and decomposed time. The microbial functional diversity and metabolic activity showed no significant difference between IE and CK. The results could be a reference for further assessing the effect of Bt maize residues on the soil that promotes the commercialisation of Bt maize IE09S034.


2020 ◽  
Vol 96 (7) ◽  
Author(s):  
Ana Novoa ◽  
Jan-Hendrik Keet ◽  
Yaiza Lechuga-Lago ◽  
Petr Pyšek ◽  
Johannes J Le Roux

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.


2016 ◽  
Vol 52 (8) ◽  
pp. 1121-1134 ◽  
Author(s):  
Luigi Chessa ◽  
Sven Jechalke ◽  
Guo-Chun Ding ◽  
Alba Pusino ◽  
Nicoletta Pasqualina Mangia ◽  
...  

SOIL ◽  
2016 ◽  
Vol 2 (3) ◽  
pp. 459-474 ◽  
Author(s):  
Michael P. Ricketts ◽  
Rachel S. Poretsky ◽  
Jeffrey M. Welker ◽  
Miquel A. Gonzalez-Meler

Abstract. Soil microbial communities play a central role in the cycling of carbon (C) in Arctic tundra ecosystems, which contain a large portion of the global C pool. Climate change predictions for Arctic regions include increased temperature and precipitation (i.e. more snow), resulting in increased winter soil insulation, increased soil temperature and moisture, and shifting plant community composition. We utilized an 18-year snow fence study site designed to examine the effects of increased winter precipitation on Arctic tundra soil bacterial communities within the context of expected ecosystem response to climate change. Soil was collected from three pre-established treatment zones representing varying degrees of snow accumulation, where deep snow  ∼ 100 % and intermediate snow  ∼ 50 % increased snowpack relative to the control, and low snow ∼ 25 % decreased snowpack relative to the control. Soil physical properties (temperature, moisture, active layer thaw depth) were measured, and samples were analysed for C concentration, nitrogen (N) concentration, and pH. Soil microbial community DNA was extracted and the 16S rRNA gene was sequenced to reveal phylogenetic community differences between samples and determine how soil bacterial communities might respond (structurally and functionally) to changes in winter precipitation and soil chemistry. We analysed relative abundance changes of the six most abundant phyla (ranging from 82 to 96 % of total detected phyla per sample) and found four (Acidobacteria, Actinobacteria, Verrucomicrobia, and Chloroflexi) responded to deepened snow. All six phyla correlated with at least one of the soil chemical properties (% C, % N, C : N, pH); however, a single predictor was not identified, suggesting that each bacterial phylum responds differently to soil characteristics. Overall, bacterial community structure (beta diversity) was found to be associated with snow accumulation treatment and all soil chemical properties. Bacterial functional potential was inferred using ancestral state reconstruction to approximate functional gene abundance, revealing a decreased abundance of genes required for soil organic matter (SOM) decomposition in the organic layers of the deep snow accumulation zones. These results suggest that predicted climate change scenarios may result in altered soil bacterial community structure and function, and indicate a reduction in decomposition potential, alleviated temperature limitations on extracellular enzymatic efficiency, or both. The fate of stored C in Arctic soils ultimately depends on the balance between these mechanisms.


2019 ◽  
Author(s):  
Lucie A Malard ◽  
Muhammad Zohaib Anwar ◽  
Carsten S Jacobsen ◽  
David A Pearce

AbstractThe considerable microbial diversity of soils, their variety and key role in biogeochemical cycling has led to growing interest in their global distribution and the impact that environmental change might have at the regional level. In the broadest study of Arctic soil bacterial communities to date, we used high-throughput DNA sequencing to investigate the bacterial diversity from 200 independent Arctic soil samples from 43 sites. We quantified the impact of spatial and environmental factors on bacterial community structure using variation partitioning analysis, illustrating a non-random distribution across the region. pH was confirmed as the key environmental driver structuring Arctic soil bacterial communities, while total organic carbon, moisture and conductivity were shown to have little effect. Specialist taxa were more abundant in acidic and alkaline soils while generalist taxa were more abundant in acidoneutral soils. Of 48,147 bacterial taxa, a core microbiome composed of only 13 taxa that were ubiquitously distributed and present within 95% of samples was identified, illustrating the high potential for endemism in the region. Overall, our results demonstrate the importance of spatial and edaphic factors on the structure of Arctic soil bacterial communities.


2018 ◽  
Vol 64 (3) ◽  
pp. 167-181 ◽  
Author(s):  
Lei Yang ◽  
Lanlan Tan ◽  
Fenghua Zhang ◽  
William Jeffrey Gale ◽  
Zhibo Cheng ◽  
...  

Salinized land in the China’s Xinjiang Region is being reclaimed for continuous cotton production. The specific objectives of this field study were (i) to compare bacterial composition and diversity in unfarmed (i.e., unreclaimed) and continuously (5, 10, 15, and 20 years) cropped soils and (ii) to explore correlations between soil properties and the bacterial communities identified by Illumina MiSeq sequencing. The results showed that bacterial species richness and diversity increased for 10–15 years and then declined when salinized land was reclaimed for cotton production. Proteobacteria and Firmicutes were the dominant phyla in unfarmed soil. Continuous cropping reduced the abundance of Firmicutes but increased that of Chloroflexi, Acidobacteria, and Actinobacteria. Cluster analyses showed that the greatest similarities in bacterial communities were between the 5- and 10-year treatments and between the 15- and 20-year treatments. Soil pH, electrical conductivity, alkali-hydrolyzable N, and available P were significantly correlated with bacterial community distribution. Overall, cotton production improved soil physicochemical properties and altered the structure and composition of soil bacterial communities compared with unfarmed soil. These positive effects began to decrease after 10–15 years of continuous cotton production.


Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1017
Author(s):  
Zhiping Liu ◽  
Wenyan Xie ◽  
Zhenxing Yang ◽  
Xuefang Huang ◽  
Huaiping Zhou

The application of organic fertilizer affects soil microbes and enzyme activities. In this study, we explored the effects of various long-term different fertilization treatments (manure, M; chemical fertilizer, NP; manure + chemical fertilizer, MNP; and no fertilizer, CK) on bacterial community structure and soil sucrase, urease, and alkaline phosphatase activities in Shaping, Hequ, China. High-throughput sequencing was used to amplify the third to the fourth hypervariable region of the 16S ribosomal RNA for analysis of the bacterial community structure. Enzyme activities were determined by colorimetry. Soil treated with MNP had the highest bacterial Abundance-based Coverage Estimator index and enzyme activities. The principal coordinates analysis results showed significant differences among the various fertilization treatments (p < 0.001). Proteobacteria, Actinobacteria, Acidobacteria, Gemmatimonadetes, and Chloroflexi were consistently dominant in all soil samples. The redundancy analysis and Monte Carlo permutation tests showed that the soil bacterial communities were significantly correlated with alkali-hydrolyzable nitrogen, organic matter, urease, and alkaline phosphatase. Our results reveal the fundamentally different effects that organic and inorganic fertilizers have on soil bacterial communities and their functions.


2015 ◽  
Vol 81 (17) ◽  
pp. 6070-6077 ◽  
Author(s):  
Junpeng Rui ◽  
Jiabao Li ◽  
Shiping Wang ◽  
Jiaxing An ◽  
Wen-tso Liu ◽  
...  

ABSTRACTThe soil microbial community plays an important role in terrestrial carbon and nitrogen cycling. However, microbial responses to climate warming or cooling remain poorly understood, limiting our ability to predict the consequences of future climate changes. To address this issue, it is critical to identify microbes sensitive to climate change and key driving factors shifting microbial communities. In this study, alpine soil transplant experiments were conducted downward or upward along an elevation gradient between 3,200 and 3,800 m in the Qinghai-Tibet plateau to simulate climate warming or cooling. After a 2-year soil transplant experiment, soil bacterial communities were analyzed by pyrosequencing of 16S rRNA gene amplicons. The results showed that the transplanted soil bacterial communities became more similar to those in their destination sites and more different from those in their “home” sites. Warming led to increases in the relative abundances inAlphaproteobacteria,Gammaproteobacteria, andActinobacteriaand decreases inAcidobacteria,Betaproteobacteria, andDeltaproteobacteria, while cooling had opposite effects on bacterial communities (symmetric response). Soil temperature and plant biomass contributed significantly to shaping the bacterial community structure. Overall, climate warming or cooling shifted the soil bacterial community structure mainly through species sorting, and such a shift might correlate to important biogeochemical processes such as greenhouse gas emissions. This study provides new insights into our understanding of soil bacterial community responses to climate warming and cooling.


Sign in / Sign up

Export Citation Format

Share Document