scholarly journals Bacterial and fungal communities experience rapid succession during the first year following a wildfire in a California chaparral.

2021 ◽  
Author(s):  
M. Fabiola Pulido-Chavez ◽  
James W. J. Randolph ◽  
Cassandra Zalman ◽  
Loralee Larios ◽  
Peter M. Homyak ◽  
...  
Keyword(s):  
Fungal Biomass ◽  
Secondary Succession ◽  
Soil Microbial Communities ◽  
Bacterial Biomass ◽  
Illumina Miseq ◽  
High Temporal Resolution ◽  
Rapid Succession ◽  
Time Points ◽  
Soil Microbial ◽  
Successional Stages

The rise in wildfire frequency in the western United States has increased interest in secondary succession. However, despite the role of soil microbial communities in plant regeneration and establishment, microbial secondary succession is poorly understood owing to a lack of measurements immediately post-fire and at high temporal resolution. To fill this knowledge gap, we collected soils at 2 and 3 weeks and 1, 2, 3, 4, 6, 9, and 12 months after a chaparral wildfire in Southern California. We assessed bacterial and fungal biomass with qPCR of 16S and 18S and richness and composition with Illumina MiSeq sequencing of the 16S and ITS2 amplicons. We found that fire severely reduced bacterial biomass by 47% and richness by 46%, but the impacts were stronger for fungi, with biomass decreasing by 86% and richness by 68%. These declines persisted for the entire post-fire year, but bacterial biomass and richness oscillated in response to precipitation, whereas fungal biomass and richness did not. Fungi and bacteria experienced rapid succession, with 5-6 compositional turnover periods. As with plants, fast-growing surviving microbes drove successional dynamics. For bacteria, succession was driven by the phyla Firmicutes and Proteobacteria, with the Proteobacteria Massilia dominating all successional time points, and the Firmicutes (Domibacillus and Paenibacillus) dominating early- to mid-successional stages (1-4.5 months), while the Proteobacteria Noviherbaspirillum dominated late successional stages (4.5-1 year). For fungi, succession was driven by the phyla Ascomycota, but ectomycorrhizal basidiomycetes, and the heat-resistant yeast, Geminibasidium were present in the early successional stages (1 month). However, pyrophilous filamentous Ascomycetes Pyronema, Penicillium, and Aspergillus, dominated all post-fire time points. While wildfires vastly decrease bacterial and fungal biomass and richness, similar to plants, pyrophilous bacteria and fungi increase in abundance and experience rapid succession and compositional turnover in the first post-fire year, with potential implications for post-fire chaparral regeneration

Alleviating Continuous Monocropping Obstacle in Melon: Biological Elimination of Phenolic Acid

2020 ◽  
Author(s):  
Huiqin Xie ◽  
Yongli Ku ◽  
Xiangna Yang ◽  
Le Cao ◽  
Xueli Mei ◽  
...  
Keyword(s):  
Microbial Community ◽  
Microbial Communities ◽  
Phenolic Acids ◽  
Fruit Quality ◽  
High Performance ◽  
Soil Microbial Communities ◽  
Illumina Miseq ◽  
Continuous Cropping ◽  
Soil Microbial

Abstract Background: Melon (Cucumis melo L.) is one of the most important fruit crops grown in China. However, the yield and quality of melon have significantly declined under continuous cropping. Phenolic acids are believed to be associated with the continuous monocropping obstacle (CMO) and can influence plant microbe interactions. Coumaric acid (CA) is one of the major phenolic acids found in melon root exudates. The objectives of this study were to estimate the elimination of CA by the soil bacterium K3 as well as its effects on mitigating melon CMO. CA degradation was investigated by monitoring the CA retained in the growth medium using high performance liquid chromatography (HPLC). The effects of CA and K3 on rhizosphere soil microbial communities were investigated by the spread plate method and Illumina MiSeq sequencing. Furthermore, the effects of CA and K3 on melon seedling growth were measured under potted conditions. The changes in soil enzymes and fruit quality under K3 amendment were examined in a greenhouse experiment. Result:The results suggest that the addition of CA had the same result as the CMO, such as deterioration of the microbial community and slower growth of melon plants. HPLC and microbial analysis showed that K3 had a pronounced ability to decompose CA and could improve the soil microbial community environment. Soil inoculation with K3 agent could significantly improve the fruit quality of melon.Conclusion: Our results show that the effects of K3 in the soil are reflected by changes in populations and diversity of soil microbes and suggest that deterioration of microbial communities in soil might be associated with the growth constraint of melon in continuous monoculture systems.

scholarly journals Distinct effects of short-term reconstructed topsoil on soya bean and corn rhizosphere bacterial abundance and communities in Chinese Mollisol

2019 ◽  
Vol 6 (1) ◽  
pp. 181054
Author(s):  
Zhenhua Yu ◽  
Jian Jin ◽  
Yansheng Li ◽  
Yue Yang ◽  
Yue Zhao ◽  
...  
Keyword(s):  
Nutrient Cycling ◽  
Microbial Communities ◽  
Bacterial Communities ◽  
Bacterial Abundance ◽  
Soil Microbial Communities ◽  
Illumina Miseq ◽  
Crop Productivity ◽  
Soya Bean ◽  
Soil Microbial ◽  
Topsoil Layer

Eroded black soils (classified as Mollisols) lead to a thinner topsoil layer, reduced organic carbon storage and declined crop productivity. Understanding the changes in soil microbial communities owing to soil erosion is of vital importance as soil microbial communities are sensitive indicators of soil condition and are essential in soil nutrient cycling. This study used the reconstructed facility with 10, 20 and 30 cm topsoil thickness under no-till soya bean–corn rotation in black soil region of Northeast China. Illumina MiSeq sequencing targeting 16S rRNA, q PCR and soil respiration measurement were performed to assess the changes in soya bean and corn rhizosphere bacterial communities, as well as their abundance and activities due to the topsoil thickness. The results showed that soil bacterial communities from both soya bean and corn were more sensitive to topsoil removal than to soil biogeochemical characteristics. Topsoil depths significantly influenced both soya bean and corn bacterial communities, while they only significantly influenced the bacterial abundance and respiration in corn. We also found that the topsoil depths significantly induced the changes in phyla and genera from both soya bean and corn rhizosphere bacterial community, which aid further understandings on how topsoil layer influences the global nutrient cycling of Mollisols by influencing the change in microbial communities.

Effects of land use, short-term drought and warming on microbial responses to drying and rewetting

2021 ◽  
Author(s):  
Ainara Leizeaga ◽  
Lettice Hicks ◽  
Albert Brangarí ◽  
Carla Cruz-Paredes ◽  
Menale Wondie ◽  
...  
Keyword(s):  
Land Use ◽  
Microbial Communities ◽  
Soil Microbial Communities ◽  
High Temporal Resolution ◽  
Northern Ethiopia ◽  
Land Uses ◽  
Soil Microbial ◽  
Drying And Rewetting ◽  
Microbial Responses ◽  
Simulated Drought

<p>Climate change predicts an increase in temperature and an intensification of the hydrological cycles resulting in more extreme drought and rainfall events. When dry soils experience a rainfall event, there is a big CO<sub>2</sub> release from soil to the atmosphere which is regulated by soil microorganisms. In the present study, we set out to investigate how drought and warming affects the soil microbial responses to drying and rewetting (DRW); and how those responses are affected by differences in land use. Previous work has shown that exposure DRW cycles in the laboratory and in the field can induce faster recovery (more ‘resilient’) of the microbial responses after a DRW cycle. In addition, a history of drought has been suggested to result in microbial communities with higher carbon use efficiency (CUE) during DRW in a wet heathland in Northern Europe and in semi-arid grasslands in Texas. We wanted to extend these observations to subtropical environments.</p><p> </p><p>With the aim of simulating drought and warming, rain shelters and open top chambers (OTC) were installed in Northern Ethiopia in 2 contrasting land-uses (a degraded cropland and a pristine forest) for 1.5 years. Soils were then sampled and exposed to a DRW cycle in the laboratory. Microbial growth and respiration responses were followed with high temporal resolution over 3 weeks, as well as, changes in microbial community structure.  </p><p> </p><p>Microbial functions universally showed a resilient response after a DRW cycle, with bacterial growth and fungal growth increasing immediately upon rewetting linked with the expected respiration response. The field treatments and land-use differences, therefore, did not have an effect on the resilience of soil microbial communities to DRW cycles. There were differences between the two main decomposer groups: fungi were more resilient than bacteria, as they showed a faster recovery rate. Microbial CUE upon rewetting responded differently in the different field treatments and land-uses. CUE was generally higher in croplands than in forests. Besides, while simulated drought reduced CUE, simulated drought increased CUE. These differences might be explained by either (i) the selection or more efficient microbial communities due to a higher exposure to DRW events or (ii) differences in resource availability (i.e. plant input).  </p>

scholarly journals Heterotrophic microbial communities use ancient carbon following glacial retreat

2007 ◽  
Vol 3 (5) ◽  
pp. 487-490 ◽  
Author(s):  
Richard D Bardgett ◽  
Andreas Richter ◽  
Roland Bol ◽  
Mark H Garnett ◽  
Rupert Bäumler ◽  
...  
Keyword(s):  
Organic Matter ◽  
Microbial Community ◽  
Microbial Communities ◽  
Microbial Community Composition ◽  
Soil Microbial Communities ◽  
Community Change ◽  
Plant Production ◽  
Soil Microbial ◽  
Initial Stage ◽  
Successional Stages

When glaciers retreat they expose barren substrates that become colonized by organisms, beginning the process of primary succession. Recent studies reveal that heterotrophic microbial communities occur in newly exposed glacial substrates before autotrophic succession begins. This raises questions about how heterotrophic microbial communities function in the absence of carbon inputs from autotrophs. We measured patterns of soil organic matter development and changes in microbial community composition and carbon use along a 150-year chronosequence of a retreating glacier in the Austrian Alps. We found that soil microbial communities of recently deglaciated terrain differed markedly from those of later successional stages, being of lower biomass and higher abundance of bacteria relative to fungi. Moreover, we found that these initial microbial communities used ancient and recalcitrant carbon as an energy source, along with modern carbon. Only after more than 50 years of organic matter accumulation did the soil microbial community change to one supported primarily by modern carbon, most likely from recent plant production. Our findings suggest the existence of an initial stage of heterotrophic microbial community development that precedes autotrophic community assembly and is sustained, in part, by ancient carbon.

Trends in soil microbial communities during secondary succession

2017 ◽  
Vol 115 ◽  
pp. 92-99 ◽  
Author(s):  
Zhenghu Zhou ◽  
Chuankuan Wang ◽  
Lifen Jiang ◽  
Yiqi Luo
Keyword(s):  
Microbial Communities ◽  
Secondary Succession ◽  
Soil Microbial Communities ◽  
Soil Microbial

scholarly journals Changes in Bacterial and Fungal Community of Soil under Treatment of Pesticides

Agronomy ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 124
Author(s):  
Rostislav Streletskii ◽  
Angelika Astaykina ◽  
George Krasnov ◽  
Victor Gorbatov
Keyword(s):  
Fungal Community ◽  
Large Scale ◽  
High Throughput Sequencing ◽  
Soil Microbial Communities ◽  
Illumina Miseq ◽  
Soil Microbiome ◽  
Soil Microbial ◽  
Large Scale Assessment ◽  
Integral Methods ◽  
State Registration

Experiments were carried out in soil microcosms with the treatment of pesticide formulations—imidacloprid, benomyl, and metribuzin in single and tenfold application rates. For additional stimulation of microorganisms, a starch–mineral mixture was added to some variants. For all samples, high-throughput sequencing on the Illumina MiSeq platform of the V4 (16S rRNA) and ITS1 (18S rRNA) fragments was carried out. As a result, it was possible to establish the characteristic changes in the structure of the soil fungal and bacterial communities under pesticides application. The application of pesticides was accompanied by dramatic shifts in alfa-diversity of the fungal community. The phylum Basidiomycota was likely to be involved in the degradation of pesticides. The changes in the relative abundance of the genera Terrabacter, Kitasatospora, Streptomyces, Sphingomonas, Apiotrichum, Solicoccozyma, Gamsia, and Humicola can be proposed as an indicator of pesticide contamination. It is suggested to use these markers for large-scale assessment of the effect of pesticides on soil microbial communities instead of classical integral methods, including within the framework of state registration of pesticides. It is also recommended to research the effect of pesticides on the soil microbiome during artificially initiated successions using the additional source of carbon.

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