29600493 OR Drivers of microbial community structure in forest soils Dotaz Zobrazit nápovědu
Forests are essential biomes for global biogeochemical cycles, and belowground microorganisms have a key role in providing relevant ecosystem services. To predict the effects of environmental changes on these ecosystem services requires a comprehensive understanding of how biotic and abiotic factors drive the composition of microbial communities in soil. However, microorganisms are not homogeneously distributed in complex environments such as soil, with different features affecting microbes at different extent depending on the niche they occupy. Indeed, this spatial heterogeneity hampers the extrapolation of microbial diversity study results from particular habitats to the ecosystem level, even if the resolution of the more recent studies has increased significantly after the standardization of high-throughput sequencing techniques. The present work intends to give a comprehensive view of the knowledge accumulated until date defining the more important drivers determining the structure of forest soil microbial communities from fine to continental scales.
- MeSH
- Bacteria MeSH
- ekosystém * MeSH
- lesy * MeSH
- mikrobiota fyziologie MeSH
- půda chemie MeSH
- půdní mikrobiologie * MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Understanding the ecology of coniferous forests is very important because these environments represent globally largest carbon sinks. Metatranscriptomics, microbial community and enzyme analyses were combined to describe the detailed role of microbial taxa in the functioning of the Picea abies-dominated coniferous forest soil in two contrasting seasons. These seasons were the summer, representing the peak of plant photosynthetic activity, and late winter, after an extended period with no photosynthate input. The results show that microbial communities were characterized by a high activity of fungi especially in litter where their contribution to microbial transcription was over 50%. Differences in abundance between summer and winter were recorded for 26-33% of bacterial genera and < 15% of fungal genera, but the transcript profiles of fungi, archaea and most bacterial phyla were significantly different among seasons. Further, the seasonal differences were larger in soil than in litter. Most importantly, fungal contribution to total microbial transcription in soil decreased from 33% in summer to 16% in winter. In particular, the activity of the abundant ectomycorrhizal fungi was reduced in winter, which indicates that plant photosynthetic production was likely one of the major drivers of changes in the functioning of microbial communities in this coniferous forest.
- MeSH
- Archaea klasifikace genetika MeSH
- Bacteria klasifikace genetika MeSH
- borovicovité mikrobiologie MeSH
- ekosystém MeSH
- fotosyntéza MeSH
- genetická transkripce genetika MeSH
- houby klasifikace genetika MeSH
- lesy MeSH
- messenger RNA biosyntéza genetika MeSH
- mikrobiota genetika MeSH
- mykorhiza MeSH
- půda MeSH
- půdní mikrobiologie * MeSH
- roční období MeSH
- stanovení celkové genové exprese MeSH
- stromy mikrobiologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Dead wood represents an important pool of organic matter in forests and is one of the sources of soil formation. It has been shown to harbour diverse communities of bacteria, but their roles in this habitat are still poorly understood. Here, we describe the bacterial communities in the dead wood of Abies alba, Picea abies and Fagus sylvatica in a temperate natural forest in Central Europe. An analysis of environmental factors showed that decomposing time along with pH and water content was the strongest drivers of community composition. Bacterial biomass positively correlated with N content and increased with decomposition along with the concurrent decrease in the fungal/bacterial biomass ratio. Rhizobiales and Acidobacteriales were abundant bacterial orders throughout the whole decay process, but many bacterial taxa were specific either for young (<15 years) or old dead wood. During early decomposition, bacterial genera able to fix N2 and to use simple C1 compounds (e.g. Yersinia and Methylomonas) were frequent, while wood in advanced decay was rich in taxa typical of forest soils (e.g. Bradyrhizobium and Rhodoplanes). Although the bacterial contribution to dead wood turnover remains unclear, the community composition appears to reflect the changing conditions of the substrate and suggests broad metabolic capacities of its members.
- MeSH
- Bacteria klasifikace genetika izolace a purifikace MeSH
- biodiverzita MeSH
- biomasa MeSH
- buk (rod) mikrobiologie MeSH
- dřevo mikrobiologie MeSH
- ekosystém MeSH
- houby klasifikace genetika izolace a purifikace MeSH
- jedle mikrobiologie MeSH
- lesy MeSH
- mikrobiota genetika MeSH
- půda chemie MeSH
- půdní mikrobiologie MeSH
- smrk mikrobiologie MeSH
- stromy mikrobiologie MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Evropa MeSH
Studies on testate amoeba species distribution at small scales (i.e., single peatland sites) are rare and mostly focus on bogs or mineral-poor Sphagnum fens, leaving spatial patterns within mineral-rich fens completely unexplored. In this study, two mineral-rich fen sites of contrasting groundwater chemistry and moss layer composition were selected for the analysis of testate amoeba compositional variance within a single site. At each study site, samples from 20 randomly chosen moss-dominated plots were collected with several environmental variables being measured at each sampling spot. We also distinguished between empty shells and living individuals to evaluate the effect of empty shell inclusion on recorded species distribution. At the heterogeneous-rich Sphagnum-fen, a clear composition turnover in testate amoebae between Sphagnum-dominated and brown moss-dominated samples was closely related to water pH, temperature and redox potential. We also found notable species composition variance within the homogeneous calcareous fen, yet it was not as high as for the former site and the likely drivers of community assembly remained unidentified. The exclusion of empty shells provided more accurate data on species distribution as well as their relationship with some environmental variables, particularly moisture. Small-scale variability in species composition of communities seems to be a worthwhile aspect in testate amoeba research and should be considered in future sampling strategies along with a possible empty shell bias for more precise understanding of testate amoeba ecology and paleoecology.
- MeSH
- Bryophyta růst a vývoj MeSH
- Lobosea klasifikace fyziologie MeSH
- mikrobiota * MeSH
- mokřady MeSH
- půda chemie MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
Marine-to-terrestrial transition represents one of the most fundamental shifts in microbial life. Understanding the distribution and drivers of soil microbial communities across coastal ecosystems is critical given the roles of microbes in soil biogeochemistry and their multifaceted influence on landscape succession. Here, we studied the fungal community dynamics in a well-established salt marsh chronosequence that spans over a century of ecosystem development. We focussed on providing high-resolution assessments of community composition, diversity and ecophysiological shifts that yielded patterns of ecological succession through soil formation. Notably, despite containing 10- to 100-fold lower fungal internal transcribed spacer abundances, early-successional sites revealed fungal richnesses comparable to those of more mature soils. These newly formed sites also exhibited significant temporal variations in β-diversity that may be attributed to the highly dynamic nature of the system imposed by the tidal regime. The fungal community compositions and ecophysiological assignments changed substantially along the successional gradient, revealing a clear signature of ecological replacement and gradually transforming the environment from a marine into a terrestrial system. Moreover, distance-based linear modelling revealed soil physical structure and organic matter to be the best predictors of the shifts in fungal β-diversity along the chronosequence. Taken together, our study lays the basis for a better understanding of the spatiotemporally determined fungal community dynamics in salt marshes and highlights their ecophysiological traits and adaptation in an evolving ecosystem.
