The soil carbon/nitrogen ratio and moisture affect microbial community structures in alkaline permafrost-affected soils with different vegetation types on the Tibetan plateau

et al. 2017

Sci Rep

103

Similar land-use types usually have similar soil properties, and, most likely, similar microbial communities. Here, we assessed whether land-use types or soil chemical properties are the primary drivers of soil microbial community composition, and how changes in one part of the ecosystem affect another. We applied Ion Torrent sequencing to the bacterial and fungal communities of five different land-use (vegetation) types in the Loess Plateau of China. We found that the overall trend of soil quality was natural forest > plantation > bare land. Dominant bacterial phyla consisted of Proteobacteria (42.35%), Actinobacteria (15.61%), Acidobacteria (13.32%), Bacteroidetes (8.43%), and Gemmatimonadetes (6.0%). The dominant fungi phyla were Ascomycota (40.39%), Basidiomycota (38.01%), and Zygomycota (16.86%). The results of Canonical Correspondence Analysis (CCA) and Redundancy Analysis (RDA) based on land-use types displayed groups according to the land-use types. Furthermore, the bacterial communities were mainly organized by soil organic carbon (SOC). The fungal communities were mainly related to available phosphorus (P). The results suggested that the changes of land use type generated changes in soil chemical properties, controlling the composition of microbial community in the semiarid Loess Plateau region. The microbial community could be an indicator for soil quality with respect to ecological restoration.

Section: Discussionmentioning

confidence: 52%

Land-use types and soil chemical properties influence soil microbial communities in the semiarid Loess Plateau region in China

Tian

Taniguchi

et al. 2017

Sci Rep

103

“…Additionally beyond moisture conditions, soil C:N ratio also showed a strong influence on the soil archaeal community composition in the Tibetan soils. The importance of C:N ratio for bacterial community has been well documented in other studies elsewhere45641. In a recent study, C:N ratio was found to be the best predictor for both surface and subsurface bacterial community distribution in western Tibetan Plateau soils7.…”

Section: Discussionmentioning

confidence: 53%

“…Recently, widespread and rapid degradation of permafrost has been occurring due to climate warming, and these changes may significantly alter soil moisture content and soil nutrient availability44, and may possibly release of massive amounts of carbon into the atmosphere41. The substantial soil carbon reservoir on the Tibetan Plateau45 may become labile due to thawing permafrost and accelerated microbial metabolism4647.…”

Section: Resultsmentioning

confidence: 99%

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The biogeography of soil archaeal communities on the eastern Tibetan Plateau

Adams

et al. 2016

Sci Rep

The biogeographical distribution of soil bacterial communities has been widely investigated. However, there has been little study of the biogeography of soil archaeal communities on a regional scale. Here, using high-throughput sequencing, we characterized the archaeal communities of 94 soil samples across the eastern Tibetan Plateau. Thaumarchaeota was the predominant archael phylum in all the soils, and Halobacteria was dominant only in dry soils. Archaeal community composition was significantly correlated with soil moisture content and C:N ratio, and archaeal phylotype richness was negatively correlated with soil moisture content (r = −0.47, P < 0.01). Spatial distance, a potential measure of the legacy effect of evolutionary and dispersal factors, was less important than measured environmental factors in determining the broad scale archaeal community pattern. These results indicate that soil moisture and C:N ratio are the key factors structuring soil archaeal communities on the eastern Tibetan Plateau. Our findings suggest that archaeal communities have adjusted their distributions rapidly enough to reach range equilibrium in relation to past environmental changes e.g. in water availability and soil nutrient status. This responsiveness may allow better prediction of future responses of soil archaea to environmental change in these sensitive ecosystems.

“…The influence of vegetation type on soil bacterial communities is better characterized in other ecosystems, such as the Tibetan Plateau, where a combination of phospholipid fatty acid analysis, community-level physiological profiles, and pyrosequencing has been employed (32)(33)(34). In particular, the pyrosequencing profiles of rRNA genes indicated that both bacterial and fungal communities clearly differed in three plateau habitats.…”

mentioning

confidence: 99%

Vegetation-Associated Impacts on Arctic Tundra Bacterial and Microeukaryotic Communities

Xiang

Shen

et al. 2015

Appl Environ Microbiol

The Arctic is experiencing rapid vegetation changes, such as shrub and tree line expansion, due to climate warming, as well as increased wetland variability due to hydrological changes associated with permafrost thawing. These changes are of global concern because changes in vegetation may increase tundra soil biogeochemical processes that would significantly enhance atmospheric CO 2 concentrations. Predicting the latter will at least partly depend on knowing the structure, functional activities, and distributions of soil microbes among the vegetation types across Arctic landscapes. Here we investigated the bacterial and microeukaryotic community structures in soils from the four principal low Arctic tundra vegetation types: wet sedge, birch hummock, tall birch, and dry heath. Sequencing of rRNA gene fragments indicated that the wet sedge and tall birch communities differed significantly from each other and from those associated with the other two dominant vegetation types. Distinct microbial communities were associated with soil pH, ammonium concentration, carbon/nitrogen (C/N) ratio, and moisture content. In soils with similar moisture contents and pHs (excluding wet sedge), bacterial, fungal, and total eukaryotic communities were correlated with the ammonium concentration, dissolved organic nitrogen (DON) content, and C/N ratio. Operational taxonomic unit (OTU) richness, Faith's phylogenetic diversity, and the Shannon species-level index (H=) were generally lower in the tall birch soil than in soil from the other vegetation types, with pH being strongly correlated with bacterial richness and Faith's phylogenetic diversity. Together, these results suggest that Arctic soil feedback responses to climate change will be vegetation specific not just because of distinctive substrates and environmental characteristics but also, potentially, because of inherent differences in microbial community structure.T he rate of increase in Arctic surface air temperatures has been twice as rapid as the average global rate (ϳ0.10°C per decade) (1, 2) over the last few decades (3); this augmented warming has impacted Arctic species and ecosystems (4). Arctic shrub cover and density have increased, the tree line has migrated in some places, and the distribution of wetland vegetation is changing in association with permafrost thawing (5, 6). Because plants supply organic matter to soils and impact belowground soil microbial communities (7,8), changes in soil vegetation cover could result in substantial bacterial, fungal, and metazoan community composition changes (9-12). These changes could alter overall biogeochemical functioning, such as the release of carbon via soil decomposition, in these ecosystems (13), which would be expected to further exacerbate climate change. A better understanding of the vegetation-associated soil microbial structures could facilitate predictions of the effects of climate change on tundra ecosystems and determine if Arctic soil feedback responses to climate change are vegetation specific.Bacterial conso...