Article

The phylogenetic composition and structure of soil microbial communities shifts in response to elevated carbon dioxide

Institute for Environmental Genomics, Department of Botany and Microbiology, University of Oklahoma, Norman, OK 73019, USA.
The ISME Journal (Impact Factor: 9.27). 07/2011; 6(2):259-72. DOI: 10.1038/ismej.2011.99
Source: PubMed

ABSTRACT One of the major factors associated with global change is the ever-increasing concentration of atmospheric CO(2). Although the stimulating effects of elevated CO(2) (eCO(2)) on plant growth and primary productivity have been established, its impacts on the diversity and function of soil microbial communities are poorly understood. In this study, phylogenetic microarrays (PhyloChip) were used to comprehensively survey the richness, composition and structure of soil microbial communities in a grassland experiment subjected to two CO(2) conditions (ambient, 368 p.p.m., versus elevated, 560 p.p.m.) for 10 years. The richness based on the detected number of operational taxonomic units (OTUs) significantly decreased under eCO(2). PhyloChip detected 2269 OTUs derived from 45 phyla (including two from Archaea), 55 classes, 99 orders, 164 families and 190 subfamilies. Also, the signal intensity of five phyla (Crenarchaeota, Chloroflexi, OP10, OP9/JS1, Verrucomicrobia) significantly decreased at eCO(2), and such significant effects of eCO(2) on microbial composition were also observed at the class or lower taxonomic levels for most abundant phyla, such as Proteobacteria, Firmicutes, Actinobacteria, Bacteroidetes and Acidobacteria, suggesting a shift in microbial community composition at eCO(2). Additionally, statistical analyses showed that the overall taxonomic structure of soil microbial communities was altered at eCO(2). Mantel tests indicated that such changes in species richness, composition and structure of soil microbial communities were closely correlated with soil and plant properties. This study provides insights into our understanding of shifts in the richness, composition and structure of soil microbial communities under eCO(2) and environmental factors shaping the microbial community structure.

Download full-text

Full-text

Available from: Zhili He, Jul 06, 2015
0 Followers
 · 
164 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Carbon dioxide is an increasing greenhouse gas; its capture and sequestration seems a promising alternative to mitigate global warming, providing all physical, chemical and biological aspects of subsurface gas sequestration are understood. Possible leaks may change soil balance, impacting ecosystems and, consequently, human and animal health. Few data are available on the effects of augmented CO2 concentrations in soil and studies are required to define the role of biological systems and response mechanisms, and to identify CO2 bioindicators for post-injection monitoring. This study was conducted with soil from the Atlantic forest zone, in two scales: unstructured soil batch experiments, in aerobic and CO2 atmosphere, and column microcosms with unstructured and structured soil under CO2 percolation. Microbial metabolic profiles, protein synthesis and degradation activity, soils moisture, available carbon and pH were assessed. In all assays, microbial activity tended to drop with prolonged exposure to CO2. In batch and structured soils, augmented activity, biomass, species richness, besides altered metabolic profiles, all seemed linked to increased CO2. In unstructured column soil a slower pace of response was explained by low initial activity. No significant change in soil moisture was detected and stable pH indicated absence of carbonate precipitation. In conclusion, augmented CO2 changes microbiota composition, enhancing the activity of favoured anaerobic species, which could change ecosystem functions.
    International Journal of Greenhouse Gas Control 01/2015; 32. DOI:10.1016/j.ijggc.2014.11.009 · 3.82 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Land degradation deteriorates biological productivity and affects environmental, social, and economic sustainability, particularly so in the semi-arid region of Northeast Brazil. Although some studies exist reporting gross measures of soil microbial parameters and processes, limited information is available on how land degradation and restoration strategies influence the diversity and composition of soil microbial communities. In this study we compare the structure and diversity of bacterial communities in degraded and restored lands in Northeast Brazil and determine the soil biological and chemical properties influencing bacterial communities. We found that land degradation decreased the diversity of soil bacteria as indicated by both reduced operational taxonomic unit (OTU) richness and Shannon index. Soils under native vegetation and restoration had significantly higher bacterial richness and diversity than degraded soils. Redundancy analysis revealed that low soil bacterial diversity correlated with a high respiratory quotient, indicating stressed microbial communities. By contrast, soil bacterial communities in restored land positively correlated with high soil P levels. Importantly, however, we found significant differences in the soil bacterial community composition under native vegetation and in restored land, which may indicate differences in their functioning despite equal levels of bacterial diversity.
    Antonie van Leeuwenhoek 08/2014; 106(5). DOI:10.1007/s10482-014-0258-5 · 2.14 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: High altitude alpine meadows are experiencing considerably greater than average increases in soil surface temperature, potentially as a result of ongoing climate change. The effects of warming on plant productivity and soil edaphic variables have been established previously, but the influence of warming on soil microbial community structure has not been well characterized. Here, the impact of 15 months of soil warming (both +1 and +2 ˚C) on bacterial community structure was examined in a field experiment on a Tibetan Plateau alpine meadow using bar-coded pyrosequencing. Warming significantly changed (P < 0.05) the structure of the soil bacterial community, but the alpha diversity was not dramatically affected. Changes in the abundance of the Actinobacteria and Alphaproteobacteria were found to contribute the most to differences between ambient and artificially warmed conditions. A variance partitioning analysis showed that warming directly explained 7.15% variation in bacterial community structure, while warming-induced changes in soil edaphic and plant phenotypic properties indirectly accounted for 28.3% and 20.6% of the community variance, respectively. Interestingly, certain taxa showed an inconsistent response to the two warming treatments, e.g., Deltaproteobacteria showed a decreased relative abundance at +1 ˚C, but a return to ambient control relative abundance at +2 ˚C. This suggests complex microbial dynamics that could result from conditional dependencies between bacterial taxa. This article is protected by copyright. All rights reserved.
    FEMS Microbiology Ecology 01/2014; 89(2). DOI:10.1111/1574-6941.12289 · 3.88 Impact Factor