scholarly journals Invertebrate-induced priority effects and secondary metabolites control fungal community composition in dead wood

2021 ◽  
Author(s):  
Lisa Lunde ◽  
Rannveig Jacobsen ◽  
Havard Kauserud ◽  
Lynne Boddy ◽  
Line Nybakken ◽  
...  

During decomposition of organic matter, microbial communities may follow different successional trajectories depending on the initial environment and colonizers. The timing and order of the assembly history can lead to divergent communities through priority effects. We explored how assembly history and resource quality affected fungal dead wood communities and decomposition, 1.5 and 4.5 years after tree felling. Additionally, we investigated the effect of invertebrate exclusion during the first two summers. For aspen (Populus tremula) logs, we measured initial resource quality of bark and wood, and surveyed the fungal communities by DNA metabarcoding at different time points during succession. We found that a gradient in fungal community composition was related to resource quality and discuss how this may reflect tolerance-dominance trade-offs in fungal life history strategies. As with previous studies, the initial amount of bark tannins was negatively correlated with wood decomposition rate over 4.5 years. The initial fungal community explained variation in community composition after 1.5, but not 4.5 years, of succession. Although the assembly history of initial colonizers may cause alternate trajectories in successional communities, our results indicate that the communities may easily converge with the arrival of secondary colonizers. We also identified a strong invertebrate-induced priority effect of fungal communities, even after 4.5 years of succession, thereby adding crucial knowledge to the importance of invertebrates in affecting fungal community development. By measuring and manipulating aspects of assembly history and resource quality that have rarely been studied, we expand our understanding of the complexity of fungal community dynamics.

2018 ◽  
Author(s):  
József Geml

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.


2017 ◽  
Vol 84 (3) ◽  
Author(s):  
Timothy J. Philpott ◽  
Jason S. Barker ◽  
Cindy E. Prescott ◽  
Sue J. Grayston

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.


Author(s):  
Kaire Loit ◽  
Liina Soonvald ◽  
Alar Astover ◽  
Eve Runno-Paurson ◽  
Maarja Öpik ◽  
...  

The rhizosphere fungal community can play an important role in determining plant growth and health. In this study, using high-throughput sequencing, we investigated the fungal diversity and community composition in the roots and rhizosphere soil of 21 potato (Solanum tuberosum L.) cultivars. The samples were collected at three different sampling points. Furthermore, we assessed the differences in both diversity and composition of pathogen and saprotroph communities. In soil and roots, the fungal richness and relative abundance of pathogens and saprotrophs were mainly affected by sampling time. However, root fungal communities were also significantly affected by cultivar. The most substantial effect of cultivar was on root pathogen diversity. Moreover, the occurrence of most pathogens strongly varied among cultivars. Soil fungal community composition was primarily determined by sampling time; whereas in roots, the primary determinant was cultivar. Our results demonstrate changes in fungal communities over the potato growing season, as well as highlight the importance of potato cultivar on root fungal communities, and emphasise their importance in plant breeding.


2020 ◽  
Author(s):  
Tahliyah S. Mims ◽  
Qusai Al Abdullah ◽  
Justin D. Stewart ◽  
Sydney P. Watts ◽  
Catrina T. White ◽  
...  

ABSTRACTObjectiveAs an active interface between the host and their diet, the gut bacteriome influences host metabolic adaptation. However, the contribution of gut fungi to host metabolic outcomes is not yet understood. Therefore, we aimed to determine if host metabolic response to an ultra-processed diet reflects gut fungal community composition.DesignWe compared jejunal fungi and bacteria from 72 healthy mice with the same genetic background but different starting mycobiomes before and after 8 weeks on an ultra-processed or standardized diet using 16S and internal transcribed spacer region 2 ribosomal RNA sequencing. We measured host body composition using magnetic resonance imaging, examined changes in metabolically active host tissues and quantified serum metabolic biomarkers.ResultsGut fungal communities are highly variable between mice, differing by vendor, age and sex. After exposure to an ultra-processed diet for 8 weeks, persistent differences in fungal community composition strongly associate with differential deposition of body mass in male mice compared to mice on standardized diet. Fat deposition in the liver, genomic adaptation of metabolically active tissues and serum metabolic biomarkers are correlated with alterations in fungal diversity and community composition. Variation in fungi from the genera Thermomyces and Saccharomyces most strongly associate with increased weight gain.ConclusionsIn the gut of healthy mice, host-microbe metabolic interactions strongly reflect variability in fungal communities. Our results confirm the importance of luminal fungal communities to host metabolic adaptation to dietary exposure. Gut fungal communities may represent a therapeutic target for the prevention and treatment of metabolic disease.Graphical AbstractIn BriefWhat is already known about this subject?Gut bacterial communities have evolved to influence the metabolic outcomes of the host in mammals. Evidence from across the lifespan suggests that differences in composition of these communities is associated with energy consumption. However, gut microbial communities, while often equated to bacteria, are diverse, multi-kingdom ecologies and limited information is available for the role of other kingdoms of life, such as fungi.What are the new findings?Gut fungal communities, collectively termed the mycobiome, are less diverse and abundant than bacterial communities in the gastrointestinal tract. This study identifies the considerable influence of the environment and dietary exposure on the composition of jejunal fungal communities in healthy mice with the same genetic background. After exposure to processed diet, differences in fungal community composition in male mice were strongly correlated with persistent differences body composition and markers of metabolic tone.How might it impact on clinical practice in the foreseeable future?These results verify that the baseline metabolic tone of health mice strongly reflects the ecological complexity of the gastrointestinal mycobiome. Variation in the composition of gut fungal communities is likely an underappreciated source of experimental and clinical variability in metabolic studies. Gastrointestinal fungi are likely a target for prevention and treatment of metabolic disease.


2021 ◽  
Vol 12 ◽  
Author(s):  
József Geml ◽  
Luis N. Morgado ◽  
Tatiana A. Semenova-Nelsen

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.


2020 ◽  
Vol 96 (12) ◽  
Author(s):  
An Bui ◽  
Devyn Orr ◽  
Michelle Lepori-Bui ◽  
Kelli Konicek ◽  
Hillary S Young ◽  
...  

ABSTRACT A large part of ecosystem function in woodland systems depends on soil fungal communities. However, global climate change has the potential to fundamentally alter these communities as fungal species are filtered with changing environmental conditions. In this study, we examined the potential effects of climate on host-associated (i.e. tree-associated) soil fungal communities at climatically distinct sites in the Tehachapi Mountains in California, where more arid conditions represent likely regional climate futures. We found that soil fungal community composition changes strongly across sites, with species richness and diversity being highest at the most arid site. However, host association may buffer the effects of climate on community composition, as host-associated fungal communities are more similar to each other across climatically distinct sites than the whole fungal community. Lastly, an examination of functional traits for ectomycorrhizal fungi, a well-studied guild of fungal mutualist species, showed that stress-tolerant traits were more abundant at arid sites than mesic sites, providing a mechanistic understanding of these community patterns. Taken together, our results indicate that fungal community composition will likely shift with future climate change but that host association may buffer these effects, with shifts in functional traits having implications for future ecosystem function.


Author(s):  
Tânia F. L. Vicente ◽  
Micael F. M. Gonçalves ◽  
Cláudio Brandão ◽  
Cátia Fidalgo ◽  
Artur Alves

Fungal communities associated with macroalgae remain largely unexplored. To characterize algicolous fungal communities using culture dependent methods, macroalgae were collected from different sampling sites in the Ria de Aveiro estuary, Portugal. From a collection of 486 isolates that were obtained, 213 representative isolates were selected through microsatellite-primed PCR (MSP-PCR) fingerprinting analysis. The collection yielded 33 different genera, which were identified using the ITS region of the rDNA. The results revealed that the most abundant taxa in all collections were Acremonium-like species: Alternaria, Cladosporium, Leptobacillium and Penicillium. The fungal community composition varied with macroalgae species. Through multilocus phylogenetic analyses based on ITS, tub2, tef1-α and actA sequences, in addition to detailed morphological data, we propose Cladosporium rubrum sp. nov. (type strain=CMG 28=MUM 19.39) and Hypoxylon aveirense sp. nov. (type strain=CMG 29=MUM 19.40) as novel species.


2020 ◽  
Vol 63 (1) ◽  
Author(s):  
Zaihua He ◽  
Qiang Li ◽  
Xiaoyi Zeng ◽  
Kai Tian ◽  
Xiangshi Kong ◽  
...  

Abstract Peat, as a heterogeneous mixture of decaying plant debris and microbial residues, has been widely used in many fields. However, little research focused on the impact of peat addition on food waste composting. To fill this gap, a composting experiment of food waste mixed with five varying percent peat 0, 5, 10, 15, and 20% (w/w, dry weight) was designed to investigate the effect of different dosages of peat on nitrogen conservation, physiochemical parameters, and fungal community dynamics during composting. The results showed that adding peat elevated the peak temperature of composting, lowered final pH, reduced ammonia emissions and increased the final total nitrogen content. Compared to control, adding 5, 10, 15, and 20% peat decreased ammonia emissions by 1.91, 10.79, 23.73, and 18.26%, respectively, during 42 days of composting. Moreover, peat addition increased fungal community diversity especially during maturation phase. The most two abundant phyla were Basidiomycota and Ascomycota in all treatments throughout the composting process. At the end of composting, in treatments with adding 10 and 15% peat, the richest fungi were Scedosporium spp. and Coprinopsis spp., respectively. Simultaneously, canonical correlation analyses showed that pH, moisture content, and seed germination index had significant association with fungal community composition. The study also showed that fungal community and nitrogen conservation had no direct obvious relation during composting. Overall, the results suggest that the addition of peat could efficiently enhance nitrogen conservation through reduction of ammonia emissions and 15% peat addition is the optimal formula for food waste composting.


2021 ◽  
Vol 9 (11) ◽  
pp. 2280
Author(s):  
Xueying Wang ◽  
Guixiang Li ◽  
Yuxin Zhang ◽  
Keming Ma

The treeline is a sensitive region of the terrestrial ecosystem responding to climate change. However, studies on the composition and formation mechanisms of soil fungal communities across the treeline are still lacking. In this study, we investigated the patterns of soil fungal community composition and interactions among functional guilds above and below the treeline using Illumina high-throughput sequencing and ecological network analysis. The results showed that there were significant differences in the soil environment and soil fungal community composition between the two ecosystems above and below the treeline. At the local scale of this study, geographic distance and environmental factors affected the composition of the soil fungal community. Soil temperature was an important environmental predictor of soil fungal community composition. Species in soil fungal communities in the subalpine meadow were more closely related to each other compared to those in the montane forest. Furthermore, the soil fungal community in montane forest was more stable. Our findings contribute to a better understanding of how mountain ecological functions respond to global climate change.


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