scholarly journals Airborne microbial biodiversity and seasonality in Northern and Southern Sweden

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8424 ◽  
Author(s):  
Edvin Karlsson ◽  
Anna-Mia Johansson ◽  
Jon Ahlinder ◽  
Moa J. Lundkvist ◽  
Navinder J. Singh ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Community Composition ◽  
Bacterial Community Composition ◽  
Geographic Location ◽  
Time Factors ◽  
Ground Level ◽  
Fungal Communities ◽  
The Arctic ◽  
Fungal Community Composition ◽  
Local Climate

Microorganisms are essential constituents of ecosystems. To improve our understanding of how various factors shape microbial diversity and composition in nature it is important to study how microorganisms vary in space and time. Factors shaping microbial communities in ground level air have been surveyed in a limited number of studies, indicating that geographic location, season and local climate influence the microbial communities. However, few have surveyed more than one location, at high latitude or continuously over more than a year. We surveyed the airborne microbial communities over two full consecutive years in Kiruna, in the Arctic boreal zone, and Ljungbyhed, in the Southern nemoral zone of Sweden, by using a unique collection of archived air filters. We mapped both geographic and seasonal differences in bacterial and fungal communities and evaluated environmental factors that may contribute to these differences and found that location, season and weather influence the airborne communities. Location had stronger influence on the bacterial community composition compared to season, while location and season had equal influence on the fungal community composition. However, the airborne bacterial and fungal diversity showed overall the same trend over the seasons, regardless of location, with a peak during the warmer parts of the year, except for the fungal seasonal trend in Ljungbyhed, which fluctuated more within season. Interestingly, the diversity and evenness of the airborne communities were generally lower in Ljungbyhed. In addition, both bacterial and fungal communities varied significantly within and between locations, where orders like Rhizobiales, Rhodospirillales and Agaricales dominated in Kiruna, whereas Bacillales, Clostridiales and Sordariales dominated in Ljungbyhed. These differences are a likely reflection of the landscape surrounding the sampling sites where the landscape in Ljungbyhed is more homogenous and predominantly characterized by artificial and agricultural surroundings. Our results further indicate that local landscape, as well as seasonal variation, shapes microbial communities in air.

scholarly journals Tundra Type Drives Distinct Trajectories of Functional and Taxonomic Composition of Arctic Fungal Communities in Response to Climate Change – Results From Long-Term Experimental Summer Warming and Increased Snow Depth

2021 ◽  
Vol 12 ◽  
Author(s):  
József Geml ◽  
Luis N. Morgado ◽  
Tatiana A. Semenova-Nelsen
Keyword(s):  
Climate Change ◽  
Community Composition ◽  
Fungal Community ◽  
Snow Depth ◽  
Fungal Communities ◽  
The Arctic ◽  
Fungal Community Composition ◽  
Summer Warming ◽  
Edaphic Variables

The arctic tundra is undergoing climate-driven changes and there are serious concerns related to the future of arctic biodiversity and altered ecological processes under possible climate change scenarios. Arctic land surface temperatures and precipitation are predicted to increase further, likely causing major transformation in terrestrial ecosystems. As a response to increasing temperatures, shifts in vegetation and soil fungal communities have already been observed. Little is known, however, how long-term experimental warming coupled with increased snow depth influence the trajectories of soil fungal communities in different tundra types. We compared edaphic variables and fungal community composition in experimental plots simulating the expected increase in summer warming and winter snow depth, based on DNA metabarcoding data. Fungal communities in the sampled dry and moist acidic tundra communities differed greatly, with tundra type explaining ca. one-third of compositional variation. Furthermore, dry and moist tundra appear to have different trajectories in response to climate change. Specifically, while both warming and increased snow depth had significant effects on fungal community composition and edaphic variables in dry tundra, the effect of increased snow was greater. However, in moist tundra, fungal communities mainly were affected by summer warming, while increased snow depth had a smaller effect and only on some functional groups. In dry tundra, microorganisms generally are limited by moisture in the summer and extremely low temperatures in winter, which is in agreement with the stronger effect of increased snow depth relative to warming. On the contrary, moist tundra soils generally are saturated with water, remain cold year-round and show relatively small seasonal fluctuations in temperature. The greater observed effect of warming on fungi in moist tundra may be explained by the narrower temperature optimum compared to those in dry tundra.

scholarly journals Diversity patterns and drivers of soil microbial communities in urban and suburban park soils of Shanghai, China

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11231
Author(s):  
Weiwei Zhang ◽  
Jigang Han ◽  
Haibing Wu ◽  
Qicheng Zhong ◽  
Wen Liu ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Community Composition ◽  
Urban Areas ◽  
Bacterial Community Composition ◽  
Soil Microbial Communities ◽  
Rapid Expansion ◽  
Fungal Communities ◽  
Urban Park ◽  
Fungal Abundance ◽  
Significant Difference

Background The rapid expansion of urbanization leads to significant losses of soil ecological functions. Microbes directly participate in key soil processes and play crucial roles in maintaining soil functions. However, we still have a limited understanding of underlying mechanisms shaping microbial communities and the interactions among microbial taxa in park soils. Methods In this study, the community variations of bacteria and fungi in urban and suburban park soils were investigated in Shanghai, China. Real-time PCR and high-throughput Illumina sequencing were used to examine the microbial abundance and community composition, respectively. Results The results showed that soil molecular biomass and fungal abundance in urban park soils were significantly higher than those in suburban park soils, while no significant difference was observed in the bacterial abundance between urban and suburban park soils. The alpha diversity of soil microbes in urban and suburban park soils was similar to each other, except for Chao1 index of fungal communities. The results of similarity analysis (ANOSIM) revealed remarkable differences in the composition of bacterial and fungal communities between urban and suburban park soils. Specifically, park soils in urban areas were enriched with the phyla Methylomirabilota and Verrucomicrobiota, while the relative abundance of Gemmatimonadota was higher in suburban park soils. Moreover, the fungal class Eurotiomycetes was also enriched in urban park soils. Compared with suburban park soils, nodes and average paths of the bacterial and fungal networks were higher in urban park soils, but the number of module hubs and connectors of the bacterial networks and negative interactions among bacterial taxa were lower. Compared with suburban park soils, Acidobacteriota bacterium and Mortierellomycota fungus played more important roles in the ecological networks of urban park soils. Soil available zinc (Zn), available nitrogen (N), pH, and total potassium (K) significantly affected fungal community composition in park soils in Shanghai. Soil available Zn was also the most important factor affecting the bacterial community composition in this study. Conclusion There were significant differences in the soil molecular biomass, fungal abundance, and the community composition and co-occurrence relations of both soil bacterial and fungal communities between urban and suburban park soils. Soil available Zn played an important part in shaping the structures of both the bacterial and fungal communities in park soils in Shanghai.

scholarly journals Bacteria Respond Stronger Than Fungi Across a Steep Wood Ash-Driven pH Gradient

2021 ◽  
Vol 4 ◽  
Author(s):  
Carla Cruz-Paredes ◽  
Toke Bang-Andreasen ◽  
Søren Christensen ◽  
Flemming Ekelund ◽  
Tobias G. Frøslev ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Community Composition ◽  
Fungal Community ◽  
Environmental Parameters ◽  
Wood Ash ◽  
Ph Gradient ◽  
Fungal Communities ◽  
Ph Effects ◽  
Fungal Community Composition ◽  
Plantation Forests

Soil pH is probably the most important variable explaining bacterial richness and community composition locally as well as globally. In contrast, pH effects on fungi appear to be less pronounced, but also less studied. Here we analyze the community responses of bacteria and fungi in parallel over a local extreme pH gradient ranging from 4 to 8. We established the pH gradient by applying strongly alkaline wood ash in dosages of 0, 3, 9, 15, 30, and 90 t ha–1 to replicated plots in a Picea abies plantation and assessed bacterial and fungal community composition using high throughput amplicon sequencing 1 year after ash application. At the same time, the experiment investigated if returning wood ash to plantation forests pose any immediate threats for the microbial communities. Among the measured environmental parameters, pH was by far the major driver of the microbial communities, however, bacterial and fungal communities responded differently to the pH increment. Whereas both bacterial and fungal communities showed directional changes correlated with the wood ash-induced increase in pH, the bacterial community displayed large changes at wood ash dosages of 9 and 15 t ha–1 while only higher dosages (>30 t ha–1) significantly changed the fungal community. The results confirm that fungi are less sensitive to pH changes than bacteria but also that fertilizing plantation forests with wood ash, viewed through the lens of microbial community changes, is a safe management at standard dosages (typically 3 t ha–1).

Do fungi and bacteria respond similar across a steep local pH gradient?

2021 ◽  
Author(s):  
Rasmus Kjoller ◽  
Carla Cruz-Paredes
Keyword(s):  
Community Composition ◽  
Soil Ph ◽  
Wood Ash ◽  
Ph Gradient ◽  
Fungal Communities ◽  
Ph Effects ◽  
Fungal Community Composition ◽  
Ph Gradients ◽  
Field Samples ◽  
Bacterial Richness

<p>Soil pH is consistently recorded as the single most important variable explaining bacterial richness and community composition locally as globally. Bacterial richness responds to soil pH in a bell-shaped pattern, highest in soils with near-neutral pH, while lower diversity is found in soil with pH >8 and <4.5. Also, community turnover is strongly determined by pH for bacteria. In contrast, pH effects on fungi is apparently less pronounced though also much less studied compared to bacteria. Still, pH appears to be a significant determinant for fungal communities but typically not the most important. Rarely are bacterial and fungal communities co-analyzed from the same field samples taken across pH gradients. Here we analyze the community responses of fungi and bacteria in parallel over an extreme pH gradient ranging from pH 4 to 8 established by applying strongly alkaline wood ash to replicated plots in a Picea abies plantation. Bacterial and fungal community composition were assessed by amplicon-based meta-barcoding. Bacterial richness were not significantly affected by pH, while fungal richness and a-diversity were stimulated with higher pH. We found that both, bacterial and fungal communities increasingly deviated from the untreated plots with increasing amount of wood ash though fungal communities were more resistant to changes than bacterial. Soil NH<sub>4</sub>, NO<sub>3</sub> and pH significantly correlated with the NMDS pattern for both bacterial and fungal communities. In the presentation we will discuss resistance versus sensitivity of different fungal functional guilds towards higher pH as well as the underlying factors explaining the community changes.</p>

scholarly journals Microbial Communities Show Parallels at Sites with Distinct Litter and Soil Characteristics

2011 ◽  
Vol 77 (21) ◽  
pp. 7560-7567 ◽  
Author(s):  
Marketa Sagova-Mareckova ◽  
Marek Omelka ◽  
Ladislav Cermak ◽  
Zdenek Kamenik ◽  
Jana Olsovska ◽  
...  
Keyword(s):  
Microbial Community ◽  
Microbial Communities ◽  
Community Composition ◽  
Soil Ph ◽  
Soil Chemistry ◽  
High Performance ◽  
Bacterial Community Composition ◽  
Microbial Community Composition ◽  
Carbon Sources ◽  
Soil Extracts

ABSTRACTPlant and microbial community composition in connection with soil chemistry determines soil nutrient cycling. The study aimed at demonstrating links between plant and microbial communities and soil chemistry occurring among and within four sites: two pine forests with contrasting soil pH and two grasslands of dissimilar soil chemistry and vegetation. Soil was characterized by C and N content, particle size, and profiles of low-molecular-weight compounds determined by high-performance liquid chromatography (HPLC) of soil extracts. Bacterial and actinobacterial community composition was assessed by terminal restriction fragment length polymorphism (T-RFLP) and cloning followed by sequencing. Abundances of bacteria, fungi, and actinobacteria were determined by quantitative PCR. In addition, a pool of secondary metabolites was estimated byermresistance genes coding for rRNA methyltransferases. The sites were characterized by a stable proportion of C/N within each site, while on a larger scale, the grasslands had a significantly lower C/N ratio than the forests. A Spearman's test showed that soil pH was correlated with bacterial community composition not only among sites but also within each site. Bacterial, actinobacterial, and fungal abundances were related to carbon sources while T-RFLP-assessed microbial community composition was correlated with the chemical environment represented by HPLC profiles. Actinobacteria community composition was the only studied microbial characteristic correlated to all measured factors. It was concluded that the microbial communities of our sites were influenced primarily not only by soil abiotic characteristics but also by dominant litter quality, particularly, by percentage of recalcitrant compounds.

scholarly journals Limited Effects of Variable-Retention Harvesting on Fungal Communities Decomposing Fine Roots in Coastal Temperate Rainforests

2017 ◽  
Vol 84 (3) ◽  
Author(s):  
Timothy J. Philpott ◽  
Jason S. Barker ◽  
Cindy E. Prescott ◽  
Sue J. Grayston
Keyword(s):  
Community Composition ◽  
Fungal Community ◽  
Fine Roots ◽  
Fine Root ◽  
Plant Litter ◽  
Fungal Communities ◽  
Decomposition Rates ◽  
Fungal Community Composition ◽  
Variable Retention ◽  
Variable Retention Harvesting

ABSTRACT Fine root litter is the principal source of carbon stored in forest soils and a dominant source of carbon for fungal decomposers. Differences in decomposer capacity between fungal species may be important determinants of fine-root decomposition rates. Variable-retention harvesting (VRH) provides refuge for ectomycorrhizal fungi, but its influence on fine-root decomposers is unknown, as are the effects of functional shifts in these fungal communities on carbon cycling. We compared fungal communities decomposing fine roots (in litter bags) under VRH, clear-cut, and uncut stands at two sites (6 and 13 years postharvest) and two decay stages (43 days and 1 year after burial) in Douglas fir forests in coastal British Columbia, Canada. Fungal species and guilds were identified from decomposed fine roots using high-throughput sequencing. Variable retention had short-term effects on β-diversity; harvest treatment modified the fungal community composition at the 6-year-postharvest site, but not at the 13-year-postharvest site. Ericoid and ectomycorrhizal guilds were not more abundant under VRH, but stand age significantly structured species composition. Guild composition varied by decay stage, with ruderal species later replaced by saprotrophs and ectomycorrhizae. Ectomycorrhizal abundance on decomposing fine roots may partially explain why fine roots typically decompose more slowly than surface litter. Our results indicate that stand age structures fine-root decomposers but that decay stage is more important in structuring the fungal community than shifts caused by harvesting. The rapid postharvest recovery of fungal communities decomposing fine roots suggests resiliency within this community, at least in these young regenerating stands in coastal British Columbia. IMPORTANCE Globally, fine roots are a dominant source of carbon in forest soils, yet the fungi that decompose this material and that drive the sequestration or respiration of this carbon remain largely uncharacterized. Fungi vary in their capacity to decompose plant litter, suggesting that fungal community composition is an important determinant of decomposition rates. Variable-retention harvesting is a forestry practice that modifies fungal communities by providing refuge for ectomycorrhizal fungi. We evaluated the effects of variable retention and clear-cut harvesting on fungal communities decomposing fine roots at two sites (6 and 13 years postharvest), at two decay stages (43 days and 1 year), and in uncut stands in temperate rainforests. Harvesting impacts on fungal community composition were detected only after 6 years after harvest. We suggest that fungal community composition may be an important factor that reduces fine-root decomposition rates relative to those of above-ground plant litter, which has important consequences for forest carbon cycling.

scholarly journals Application of Methods for Identifying Broiler Chicken Gut Bacterial Species Linked with Increased Energy Metabolism

2007 ◽  
Vol 74 (3) ◽  
pp. 783-791 ◽  
Author(s):  
Valeria A. Torok ◽  
Kathy Ophel-Keller ◽  
Maylene Loo ◽  
Robert J. Hughes
Keyword(s):  
Microbial Community ◽  
Microbial Communities ◽  
Community Composition ◽  
Bacterial Species ◽  
Bacterial Community Composition ◽  
Microbial Community Composition ◽  
Metabolizable Energy ◽  
Principal Coordinates ◽  
Improved Performance ◽  
Gut Microbial Community

ABSTRACT A high-throughput microbial profiling tool based on terminal restriction fragment length polymorphism was developed to monitor the poultry gut microbiota in response to dietary manipulations. Gut microbial communities from the duodena, jejuna, ilea, and ceca of 48 birds fed either a barley control diet or barley diet supplemented with exogenous enzymes for degrading nonstarch polysaccharide were characterized by using multivariate statistical methods. Analysis of samples showed that gut microbial communities varied significantly among gut sections, except between the duodenum and jejunum. Significant diet-associated differences in gut microbial communities were detected within the ileum and cecum only. The dissimilarity in bacterial community composition between diets was 73 and 66% within the ileum and cecum, respectively. Operational taxonomic units, representing bacterial species or taxonomically related groups, contributing to diet-associated differences were identified. Several bacterial species contributed to differences between diet-related gut microbial community composition, with no individual bacterial species contributing more than 1 to 5% of the total. Using canonical analysis of principal coordinates biplots, we correlated differences in gut microbial community composition within the ileum and cecum to improved performance, as measured by apparent metabolizable energy. This is the first report that directly links differences in the composition of the gut microbial community with improved performance, which implies that the presence of specific beneficial and/or absence of specific detrimental bacterial species may contribute to the improved performance in these birds.

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 Landscape-level DNA metabarcoding study in the Pannonian forests reveals differential effects of slope aspect on taxonomic and functional groups of fungi

2018 ◽  
Author(s):  
József Geml
Keyword(s):  
Functional Groups ◽  
Community Composition ◽  
Fungal Community ◽  
Environmental Conditions ◽  
Community Dynamics ◽  
Fungal Communities ◽  
Slope Aspect ◽  
Fungal Community Composition ◽  
Dna Metabarcoding ◽  
Landscape Level

AbstractIn temperate regions, slope aspect is one of the most influential drivers of environmental conditions at landscape level. The effect of aspect on vegetation has been well studied, but virtually nothing is known about how fungal communities are shaped by aspect-driven environmental conditions. I carried out DNA metabarcoding of fungi from soil samples taken in a selected study area of Pannonian forests to compare richness and community composition of taxonomic and functional groups of fungi between slopes of predominantly southerly vs. northerly aspect and to assess the influence of selected environmental variables on fungal community composition. The deep sequence data presented here (i.e. 980 766 quality-filtered sequences) indicate that both niche (environmental filtering) and neutral (stochastic) processes shape fungal community composition at landscape level. Fungal community composition correlated strongly with aspect, with many fungi showing preference for either south-facing or north-facing slopes. Several taxonomic and functional groups showed significant differences in richness between north-and south-facing slopes and strong compositional differences were observed in all functional groups. The effect of aspect on fungal communities likely is mediated through contrasting mesoclimatic conditions, that in turn influence edaphic processes as well as vegetation. Finally, the data presented here provide an unprecedented insight into the diversity and landscape-level community dynamics of fungi in the Pannonian forests.

scholarly journals Response of Microbial Communities on Culturing Plates of Post-settlement Sea Cucumbers to Seawater Acidification and Warming

2021 ◽  
Vol 8 ◽  
Author(s):  
Hongxia Zhang ◽  
Mingshan Song ◽  
Lili Wang ◽  
Anguo Zhang ◽  
Xiaolong Yang ◽  
...  
Keyword(s):  
Microbial Community ◽  
Microbial Communities ◽  
Community Composition ◽  
Apostichopus Japonicus ◽  
Bacterial Community Composition ◽  
Early Period ◽  
Control Group ◽  
Microbial Composition ◽  
Seawater Acidification ◽  
Corrugated Plates

Seawater acidification and warming have been found to affect the early life of many marine organisms, but their effects on the microbial community in the environment related to the early development stage of aquaculture species have been rarely investigated. To understand how seawater acidification and warming impact the microbial community in aquaculture systems, we designed four microcosms to monitor and characterize the microbial composition on the corrugated plates in the Apostichopus japonicus culture tanks during its post-settlement stage. High-throughput 16S rRNA sequencing revealed that the bacterial community composition varied significantly in different periods of incubation. The bacterial diversity and community composition were obviously changed by seawater acidification and warming in the early period and then tended to revert to the level of the control group. Acidification significantly increased the relative abundance of dominant families Rhodobacteraceae and Flavobacteriaceae in the early period, suggesting that microbiota could increase the abundance of predominant taxa to adapt to increased CO2 concentration and reconstruct a stable community structure. No interaction effect of both factors was observed in the combined group. Results reveal that the microbial communities on the corrugated plates in A. japonicus culture tank were affected in the early period of incubation, and could then acclimatize to the increased CO2 and temperature. This study provides new insights into the variation and adaptation responses of the microbiota in aquaculture systems to seawater acidification and warming.

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