scholarly journals Landscape Position Influences Microbial Composition and Function via Redistribution of Soil Water across a Watershed

2015 ◽  
Vol 81 (24) ◽  
pp. 8457-8468 ◽  
Author(s):  
Zhe Du ◽  
Diego A. Riveros-Iregui ◽  
Ryan T. Jones ◽  
Timothy R. McDermott ◽  
John E. Dore ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Water Content ◽  
Soil Water ◽  
Environmental Conditions ◽  
Soil Microbial Communities ◽  
Subalpine Forest ◽  
Rrna Gene ◽  
Type I ◽  
Microbial Composition ◽  
Soil Microbial

ABSTRACTSubalpine forest ecosystems influence global carbon cycling. However, little is known about the compositions of their soil microbial communities and how these may vary with soil environmental conditions. The goal of this study was to characterize the soil microbial communities in a subalpine forest watershed in central Montana (Stringer Creek Watershed within the Tenderfoot Creek Experimental Forest) and to investigate their relationships with environmental conditions and soil carbonaceous gases. As assessed by tagged Illumina sequencing of the 16S rRNA gene, community composition and structure differed significantly among three landscape positions: high upland zones (HUZ), low upland zones (LUZ), and riparian zones (RZ). Soil depth effects on phylogenetic diversity and β-diversity varied across landscape positions, being more evident in RZ than in HUZ. Mantel tests revealed significant correlations between microbial community assembly patterns and the soil environmental factors tested (water content, temperature, oxygen, and pH) and soil carbonaceous gases (carbon dioxide concentration and efflux and methane concentration). With one exception, methanogens were detected only in RZ soils. In contrast, methanotrophs were detected in all three landscape positions. Type I methanotrophs dominated RZ soils, while type II methanotrophs dominated LUZ and HUZ soils. The relative abundances of methanotroph populations correlated positively with soil water content (R= 0.72,P< 0.001) and negatively with soil oxygen (R= −0.53,P= 0.008). Our results suggest the coherence of soil microbial communities within and differences in communities between landscape positions in a subalpine forested watershed that reflect historical and contemporary environmental conditions.

Bushfire impacts on a threatened swamp ecosystem: responses of the soil microbial communities and restoration

2021 ◽  
Author(s):  
Nathali Machado de Lima ◽  
Alexandria Thomsen ◽  
Mark Ooi ◽  
Miriam Muñoz-Rojas
Keyword(s):  
Microbial Communities ◽  
Longwall Mining ◽  
Soil Microbial Communities ◽  
Environmental Indicators ◽  
Fire Season ◽  
Rrna Gene ◽  
Microbial Composition ◽  
Drought Period ◽  
Soil Microbial ◽  
The Impact

&lt;p&gt;Australia faced the most extreme and prolonged fire season in 2019-2020, resulting in tragic habitat loss for many threatened species and the destruction of many ecological communities. &amp;#160;Newnes Plateau Shrub Swamps are peatlands located in the upper Blue Mountains region of New South Wales, Australia. These ecosystems perform many important ecological functions while absorbing and filtering water and releasing it slowly back to the environment. Their functions are related to the control of peak flow events, water purification and the harboring of many threatened plant and animal species. Despite their ecological importance, the area has been intensively degraded through longwall mining processes, resulting in the lowering and loss of water tables in the area. In December 2019 these impacts were compounded by an intense prolonged drought period and extensive wildfire. While the effects of these combined factors on the vegetation have been analysed and revealed remarkable negative impacts in the swamps under mining pressures, the effects on the soil microbial communities and related soil functions have not yet been studied. To investigate both drivers (fire and mining activities), we selected three mined swamps and three unmined swamps to assess their soil microbial composition and diversity through Next Generation Sequencing, and to characterise the soil chemical composition. At each site, we collected samples considering three treatments, one in the swamp valley fill and two at two different heights of the swamp valley margin, focusing on the soil close to specific groups of plants (e.g. sedges and shrubs). For each site and treatment, three soil samples (~ 10 m from each other) of 10x10 cm and ~ 3 to 5 cm of depth were collected using a trowel. We aim to build 16S rRNA gene libraries and co-relate them with the soil chemical variables, to assess the impact on these microbial communities and their possible use as environmental indicators and basis for future applied initiatives in conservation and restoration.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;

scholarly journals Associations between human impacts and forest soil microbial communities

Elem Sci Anth ◽  
2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Yongjian Chen ◽  
Jialiang Kuang ◽  
Pandeng Wang ◽  
Wensheng Shu ◽  
Albert Barberán
Keyword(s):  
Microbial Communities ◽  
Forest Soil ◽  
Human Activity ◽  
Eastern China ◽  
Soil Microbial Communities ◽  
Nitrifying Bacteria ◽  
Rrna Gene ◽  
Internal Transcribed Spacer Region ◽  
Soil Microbial ◽  
Soil Variables

We are living in a new epoch—the Anthropocene, in which human activity is reshaping global biodiversity at an unprecedented rate. Increasing efforts are being made toward a better understanding of the associations between human activity and the geographic patterns in plant and animal communities. However, similar efforts are rarely applied to microbial communities. Here, we collected 472 forest soil samples across eastern China, and the bacterial and fungal communities in those samples were determined by high-throughput sequencing of 16S rRNA gene and internal transcribed spacer region, respectively. By compiling human impact variables as well as climate and soil variables, our goal was to elucidate the association between microbial richness and human activity when climate and soil variables are taken into account. We found that soil microbial richness was associated with human activity. Specifically, human population density was positively associated with the richness of bacteria, nitrifying bacteria and fungal plant pathogens, but it was negatively associated with the richness of cellulolytic bacteria and ectomycorrhizal fungi. Together, these results suggest that the associations between geographic variations of soil microbial richness and human activity still persist when climate and soil variables are taken into account and that these associations vary among different microbial taxonomic and functional groups.

scholarly journals Soil Heating at High Temperatures and Different Water Content: Effects on the Soil Microorganisms

Geosciences ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 355
Author(s):  
Ana Barreiro ◽  
Alba Lombao ◽  
Angela Martín ◽  
Javier Cancelo-González ◽  
Tarsy Carballas ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Water Content ◽  
Thermal Shock ◽  
Soil Microbial Communities ◽  
Initial Water Content ◽  
Initial Water ◽  
Soil Heating ◽  
Soil Microbial ◽  
Induced Changes ◽  
The Impact

Soil properties determining the thermal transmissivity, the heat duration and temperatures reached during soil heating are key factors driving the fire-induced changes in soil microbial communities. The aim of the present study is to analyze, under laboratory conditions, the impact of the thermal shock (infrared lamps reaching temperatures of 100 °C, 200 °C and 400 °C) and moisture level (0%, 25% and 50% per soil volume) on the microbial properties of three soil mixtures from different sites. The results demonstrated that the initial water content was a determinant factor in the response of the microbial communities to soil heating treatments. Measures of fire impact included intensity and severity (temperature, duration), using the degree-hours method. Heating temperatures produced varying thermal shock and impacts on biomass, bacterial activity and microbial community structure.

scholarly journals Vertebrate Decomposition Is Accelerated by Soil Microbes

2014 ◽  
Vol 80 (16) ◽  
pp. 4920-4929 ◽  
Author(s):  
Christian L. Lauber ◽  
Jessica L. Metcalf ◽  
Kyle Keepers ◽  
Gail Ackermann ◽  
David O. Carter ◽  
...  
Keyword(s):  
Microbial Community ◽  
Microbial Communities ◽  
Soil Microbes ◽  
Soil Microbial Communities ◽  
Natural Phenomenon ◽  
Rrna Gene ◽  
Data Set ◽  
Soil Microbial ◽  
Decomposer Community ◽  
Carrion Decomposition

ABSTRACTCarrion decomposition is an ecologically important natural phenomenon influenced by a complex set of factors, including temperature, moisture, and the activity of microorganisms, invertebrates, and scavengers. The role of soil microbes as decomposers in this process is essential but not well understood and represents a knowledge gap in carrion ecology. To better define the role and sources of microbes in carrion decomposition, lab-reared mice were decomposed on either (i) soil with an intact microbial community or (ii) soil that was sterilized. We characterized the microbial community (16S rRNA gene for bacteria and archaea, and the 18S rRNA gene for fungi and microbial eukaryotes) for three body sites along with the underlying soil (i.e., gravesoils) at time intervals coinciding with visible changes in carrion morphology. Our results indicate that mice placed on soil with intact microbial communities reach advanced stages of decomposition 2 to 3 times faster than those placed on sterile soil. Microbial communities associated with skin and gravesoils of carrion in stages of active and advanced decay were significantly different between soil types (sterile versus untreated), suggesting that substrates on which carrion decompose may partially determine the microbial decomposer community. However, the source of the decomposer community (soil- versus carcass-associated microbes) was not clear in our data set, suggesting that greater sequencing depth needs to be employed to identify the origin of the decomposer communities in carrion decomposition. Overall, our data show that soil microbial communities have a significant impact on the rate at which carrion decomposes and have important implications for understanding carrion ecology.

scholarly journals Effects of Wildfire and Harvest Disturbances on Forest Soil Bacterial Communities

2007 ◽  
Vol 74 (1) ◽  
pp. 216-224 ◽  
Author(s):  
Nancy R. Smith ◽  
Barbara E. Kishchuk ◽  
William W. Mohn
Keyword(s):  
Microbial Biomass ◽  
Microbial Communities ◽  
Community Composition ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Microbial Biomass Carbon ◽  
Bacterial Community Composition ◽  
Soil Microbial Communities ◽  
Rrna Gene ◽  
Microbial Biomass Nitrogen ◽  
Soil Microbial

ABSTRACT Wildfires and harvesting are important disturbances to forest ecosystems, but their effects on soil microbial communities are not well characterized and have not previously been compared directly. This study was conducted at sites with similar soil, climatic, and other properties in a spruce-dominated boreal forest near Chisholm, Alberta, Canada. Soil microbial communities were assessed following four treatments: control, harvest, burn, and burn plus timber salvage (burn-salvage). Burn treatments were at sites affected by a large wildfire in May 2001, and the communities were sampled 1 year after the fire. Microbial biomass carbon decreased 18%, 74%, and 53% in the harvest, burn, and burn-salvage treatments, respectively. Microbial biomass nitrogen decreased 25% in the harvest treatment, but increased in the burn treatments, probably because of microbial assimilation of the increased amounts of available NH4 + and NO3 − due to burning. Bacterial community composition was analyzed by nonparametric ordination of molecular fingerprint data of 119 samples from both ribosomal intergenic spacer analysis (RISA) and rRNA gene denaturing gradient gel electrophoresis. On the basis of multiresponse permutation procedures, community composition was significantly different among all treatments, with the greatest differences between the two burned treatments versus the two unburned treatments. The sequencing of DNA bands from RISA fingerprints revealed distinct distributions of bacterial divisions among the treatments. Gamma- and Alphaproteobacteria were highly characteristic of the unburned treatments, while Betaproteobacteria and members of Bacillus were highly characteristic of the burned treatments. Wildfire had distinct and more pronounced effects on the soil microbial community than did harvesting.

scholarly journals How the Soil Microbial Communities and Activities Respond to Long-Term Heavy Metal Contamination in Electroplating Contaminated Site

2021 ◽  
Vol 9 (2) ◽  
pp. 362 ◽  
Author(s):  
Wen-Jing Gong ◽  
Zi-Fan Niu ◽  
Xing-Run Wang ◽  
He-Ping Zhao
Keyword(s):  
Heavy Metal ◽  
Microbial Communities ◽  
Metal Contamination ◽  
Heavy Metal Contamination ◽  
Soil Microbial Communities ◽  
Contaminated Site ◽  
Rrna Gene ◽  
Soil Microbial ◽  
Cu And Zn

The effects of long-term heavy metal contamination on the soil biological processes and soil microbial communities were investigated in a typical electroplating site in Zhangjiakou, China. It was found that the soil of the electroplating plant at Zhangjiakou were heavily polluted by Cr, Cr (VI), Ni, Cu, and Zn, with concentrations ranged from 112.8 to 9727.2, 0 to 1083.3, 15.6 to 58.4, 10.8 to 510.0 and 69.6 to 631.6 mg/kg, respectively. Soil urease and phosphatase activities were significantly inhibited by the heavy metal contamination, while the microbial biomass carbon content and the bacterial community richness were much lower compared to noncontaminated samples, suggesting that the long-term heavy metal contamination had a severe negative effect on soil microorganisms. Differently, soil dehydrogenase was promoted in the presence of Chromate compared to noncontaminated samples. This might be due to the enrichment of Sphingomonadaceae, which have been proven to be able to secrete dehydrogenase. The high-throughput sequencing of the 16S rRNA gene documented that Proteobacteria, Actinobacteria, and Chloroflexi were the dominant bacterial phyla in the contaminated soil. The Spearman correlation analysis showed the Methylobacillus, Muribaculaceae, and Sphingomonadaceae were able to tolerate high concentrations of Cr, Cr (VI), Cu, and Zn, indicating their potential in soil remediation.

scholarly journals The Impacts of Different Green Manure on Soil Microbial Communities and Crop Health

2016 ◽  
Author(s):  
Hongwu Yang ◽  
Jiaojiao Niu ◽  
Jiemeng Tao ◽  
Yabing Gu ◽  
Chao Zhang ◽  
...  
Keyword(s):  
Soil Properties ◽  
Microbial Communities ◽  
Soil Nutrients ◽  
Green Manure ◽  
Soil Microbial Communities ◽  
Disease Rate ◽  
Rrna Gene ◽  
Soil Microbial ◽  
Tobacco Disease ◽  
Crop Health

Green manure could improve soil nutrients and crop production, playing a significant role in sustainable agriculture. However, the impacts of green manure on crop health and the roles soil microbial communities play in the process haven&rsquo;t been clarified clearly yet. In this study, we investigated soil microbial community composition and structure in four tobacco farmlands, which were treated with different green manure (control, ryegrass, pea and rape), using 16S rRNA gene amplicons sequencing. Results showed that green manure had significant impacts on soil properties, microbial communities and tobacco health. First, soil total C, N and Ca content increased significantly in groups treated with green manure than control. Second, soil community diversity was significantly higher in groups treated with green manure. Third, green manure especially ryegrass, decreased tobacco disease (bacterial wilt) rate dramatically, and the process might be mediated by soil microbial communities. On the one hand, several microbial populations were found to be potentially disease inducible or suppressive. For example, the abundances of Dokdonella and Rhodanobacter were positively correlated to tobacco disease rate, while Acidobacteira_Gp4 and Gp6 had negative correlations with tobacco disease. On the other hand, soil microbial communities were shaped by soil properties (e.g., pH, C and N content). In conclusion, our research showed that green manure could increase soil nutrients directly, and further improve tobacco health mediated by soil microorganisms, which may shed light on revealing interactions among soil properties, microorganisms and plants.

scholarly journals Long-Term Drought and Warming Alter Soil Bacterial and Fungal Communities in an Upland Heathland

Ecosystems ◽  
2021 ◽  
Author(s):  
Fiona M. Seaton ◽  
Sabine Reinsch ◽  
Tim Goodall ◽  
Nicola White ◽  
Davey L. Jones ◽  
...  
Keyword(s):  
Climate Change ◽  
Microbial Communities ◽  
Soil Microbial Communities ◽  
Fungal Communities ◽  
Its2 Region ◽  
Rrna Gene ◽  
Summer Drought ◽  
Soil Microbial ◽  
Soil Bacterial

AbstractThe response of soil microbial communities to a changing climate will impact global biogeochemical cycles, potentially leading to positive and negative feedbacks. However, our understanding of how soil microbial communities respond to climate change and the implications of these changes for future soil function is limited. Here, we assess the response of soil bacterial and fungal communities to long-term experimental climate change in a heathland organo-mineral soil. We analysed microbial communities using Illumina sequencing of the 16S rRNA gene and ITS2 region at two depths, from plots undergoing 4 and 18 years of in situ summer drought or warming. We also assessed the colonisation of Calluna vulgaris roots by ericoid and dark septate endophytic (DSE) fungi using microscopy after 16 years of climate treatment. We found significant changes in both the bacterial and fungal communities in response to drought and warming, likely mediated by changes in soil pH and electrical conductivity. Changes in the microbial communities were more pronounced after a longer period of climate manipulation. Additionally, the subsoil communities of the long-term warmed plots became similar to the topsoil. Ericoid mycorrhizal colonisation decreased with depth while DSEs increased; however, these trends with depth were removed by warming. We largely ascribe the observed changes in microbial communities to shifts in plant cover and subsequent feedback on soil physicochemical properties, especially pH. Our results demonstrate the importance of considering changes in soil microbial responses to climate change across different soil depths and after extended periods of time.

Diversity of Soil Microbial Communities under Different Soil Salinity Levels Analyzing by PLFA

2014 ◽  
Vol 955-959 ◽  
pp. 314-320 ◽  
Author(s):  
Xin Li ◽  
Yan Jiao ◽  
Ming De Yang
Keyword(s):  
Microbial Communities ◽  
Soil Salinity ◽  
Saline Soil ◽  
Phospholipid Fatty Acid ◽  
Soil Microbial Communities ◽  
Microbial Composition ◽  
Soil Microbial ◽  
Salinity Levels ◽  
Salinized Soil ◽  
Soil Microbial Composition

Under different soil salinity levels, diversity of soil microbial communities from Hetao irrigated land of Inner Mongolia was studied by phospholipid fatty acid (PLFA) analysis. The study found that PLFAs biomass in saline soil was significantly lower than those of strongly salinized soil and slight salinized soil. Microbes was bacteria-based from these soil. The bacterial PLFA loading in saline soil is significantly less than those of strongly salinized soil and slight salinized soil . Cluster analysis showed that changes had obviously taken place on soil microbial composition and quantity under different soil salinity levels.About 76.89% of variation in PLFA patterns explained by PC1(the first  principal components),and 17:1, 16:0, 18:1w9c, 18:1w9t, 18:2, 18:3w3c, 12:0 were strongly negatively correlated with PC1.However,soil salinity and pH were positively correlated with PC1.We conclude that soil salinity has  a profound affect on the microbial community structure.

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