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Distinct soil bacterial communities along a small-scale elevational gradient in alpine tundra.

Shen C, Ni Y, Liang W, Wang J, Chu H - Front Microbiol (2015)

Bottom Line: Bacterial communities were more phylogenetically clustered than expected by chance at all elevations based on the standardized effect size of MNTD metric.Taken together, this is the first time that a significant bacterial diversity pattern has been observed across a small-scale elevational gradient.Our results indicated that soil carbon and nitrogen contents were the critical environmental factors affecting bacterial elevational distribution in Changbai Mountain tundra.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing China ; University of Chinese Academy of Sciences, Beijing China.

ABSTRACT
The elevational diversity pattern for microorganisms has received great attention recently but is still understudied, and phylogenetic relatedness is rarely studied for microbial elevational distributions. Using a bar-coded pyrosequencing technique, we examined the biodiversity patterns for soil bacterial communities of tundra ecosystem along 2000-2500 m elevations on Changbai Mountain in China. Bacterial taxonomic richness displayed a linear decreasing trend with increasing elevation. Phylogenetic diversity and mean nearest taxon distance (MNTD) exhibited a unimodal pattern with elevation. Bacterial communities were more phylogenetically clustered than expected by chance at all elevations based on the standardized effect size of MNTD metric. The bacterial communities differed dramatically among elevations, and the community composition was significantly correlated with soil total carbon (TC), total nitrogen, C:N ratio, and dissolved organic carbon. Multiple ordinary least squares regression analysis showed that the observed biodiversity patterns strongly correlated with soil TC and C:N ratio. Taken together, this is the first time that a significant bacterial diversity pattern has been observed across a small-scale elevational gradient. Our results indicated that soil carbon and nitrogen contents were the critical environmental factors affecting bacterial elevational distribution in Changbai Mountain tundra. This suggested that ecological niche-based environmental filtering processes related to soil carbon and nitrogen contents could play a dominant role in structuring bacterial communities along the elevational gradient.

No MeSH data available.


Related in: MedlinePlus

(A) Relative abundances of the dominant bacterial phyla in soils separated according to elevation categories. Relative abundances are based on the proportional frequencies of those DNA sequences that could be classified at the phylum level. (This figure is based on the information provided in Supplementary Table S4.) (B) Canonical correspondence analysis (CCA) of the bacterial communities with symbols coded by elevation category.
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Figure 2: (A) Relative abundances of the dominant bacterial phyla in soils separated according to elevation categories. Relative abundances are based on the proportional frequencies of those DNA sequences that could be classified at the phylum level. (This figure is based on the information provided in Supplementary Table S4.) (B) Canonical correspondence analysis (CCA) of the bacterial communities with symbols coded by elevation category.

Mentions: In total, we obtained 257,229 quality sequences for all soil samples, which ranged from 4931 to 20477 sequences per sample with an average length of approximately 400 bp (Supplementary Table S3). A total of 11961 unique OTUs were identified and were assigned to more than 39 bacterial phyla. Among the identified groups, Alphaproteobacteria (26%) were the most abundant across the six elevation gradient soils and Acidobacteria were the second most abundant phylum, accounting for 17% of all sequences (Figure 2A, Supplementary Table S4). Testing by ANOSIM revealed that OTU-based taxonomic community composition differed significantly among elevations. However, the difference in community composition between 2000 and 2100 m, 2100 and 2200 m, 2200 and 2300 m was not significant (Table 1). PCoA of the pairwise UniFrac distances for the bacterial communities in each sample indicated that bacterial phylogenetic structure tended to be relatively similar among samples within the same elevation and distinctly different among the different elevations (Supplementary Figure S1).


Distinct soil bacterial communities along a small-scale elevational gradient in alpine tundra.

Shen C, Ni Y, Liang W, Wang J, Chu H - Front Microbiol (2015)

(A) Relative abundances of the dominant bacterial phyla in soils separated according to elevation categories. Relative abundances are based on the proportional frequencies of those DNA sequences that could be classified at the phylum level. (This figure is based on the information provided in Supplementary Table S4.) (B) Canonical correspondence analysis (CCA) of the bacterial communities with symbols coded by elevation category.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4493907&req=5

Figure 2: (A) Relative abundances of the dominant bacterial phyla in soils separated according to elevation categories. Relative abundances are based on the proportional frequencies of those DNA sequences that could be classified at the phylum level. (This figure is based on the information provided in Supplementary Table S4.) (B) Canonical correspondence analysis (CCA) of the bacterial communities with symbols coded by elevation category.
Mentions: In total, we obtained 257,229 quality sequences for all soil samples, which ranged from 4931 to 20477 sequences per sample with an average length of approximately 400 bp (Supplementary Table S3). A total of 11961 unique OTUs were identified and were assigned to more than 39 bacterial phyla. Among the identified groups, Alphaproteobacteria (26%) were the most abundant across the six elevation gradient soils and Acidobacteria were the second most abundant phylum, accounting for 17% of all sequences (Figure 2A, Supplementary Table S4). Testing by ANOSIM revealed that OTU-based taxonomic community composition differed significantly among elevations. However, the difference in community composition between 2000 and 2100 m, 2100 and 2200 m, 2200 and 2300 m was not significant (Table 1). PCoA of the pairwise UniFrac distances for the bacterial communities in each sample indicated that bacterial phylogenetic structure tended to be relatively similar among samples within the same elevation and distinctly different among the different elevations (Supplementary Figure S1).

Bottom Line: Bacterial communities were more phylogenetically clustered than expected by chance at all elevations based on the standardized effect size of MNTD metric.Taken together, this is the first time that a significant bacterial diversity pattern has been observed across a small-scale elevational gradient.Our results indicated that soil carbon and nitrogen contents were the critical environmental factors affecting bacterial elevational distribution in Changbai Mountain tundra.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing China ; University of Chinese Academy of Sciences, Beijing China.

ABSTRACT
The elevational diversity pattern for microorganisms has received great attention recently but is still understudied, and phylogenetic relatedness is rarely studied for microbial elevational distributions. Using a bar-coded pyrosequencing technique, we examined the biodiversity patterns for soil bacterial communities of tundra ecosystem along 2000-2500 m elevations on Changbai Mountain in China. Bacterial taxonomic richness displayed a linear decreasing trend with increasing elevation. Phylogenetic diversity and mean nearest taxon distance (MNTD) exhibited a unimodal pattern with elevation. Bacterial communities were more phylogenetically clustered than expected by chance at all elevations based on the standardized effect size of MNTD metric. The bacterial communities differed dramatically among elevations, and the community composition was significantly correlated with soil total carbon (TC), total nitrogen, C:N ratio, and dissolved organic carbon. Multiple ordinary least squares regression analysis showed that the observed biodiversity patterns strongly correlated with soil TC and C:N ratio. Taken together, this is the first time that a significant bacterial diversity pattern has been observed across a small-scale elevational gradient. Our results indicated that soil carbon and nitrogen contents were the critical environmental factors affecting bacterial elevational distribution in Changbai Mountain tundra. This suggested that ecological niche-based environmental filtering processes related to soil carbon and nitrogen contents could play a dominant role in structuring bacterial communities along the elevational gradient.

No MeSH data available.


Related in: MedlinePlus