Geographic distance and pH drive bacterial distribution in alkaline lake sediments across Tibetan Plateau
Article first published online: 7 JUN 2012
© 2012 Society for Applied Microbiology and Blackwell Publishing Ltd
Special Issue: Microbial Communities - Structure, Behaviour, Evolution
Volume 14, Issue 9, pages 2457–2466, September 2012
How to Cite
Xiong, J., Liu, Y., Lin, X., Zhang, H., Zeng, J., Hou, J., Yang, Y., Yao, T., Knight, R. and Chu, H. (2012), Geographic distance and pH drive bacterial distribution in alkaline lake sediments across Tibetan Plateau. Environmental Microbiology, 14: 2457–2466. doi: 10.1111/j.1462-2920.2012.02799.x
- Issue published online: 4 SEP 2012
- Article first published online: 7 JUN 2012
- Received 3 March, 2012; revised 10 May, 2012; accepted 15 May, 2012.
Continent-scale biogeography has been extensively studied in soils and marine systems, but little is known about biogeographical patterns in non-marine sediments. We used barcode pyrosequencing to quantify the effects of local geochemical properties and geographic distance for bacterial community structure and membership, using sediment samples from 15 lakes on the Tibetan Plateau (4–1670 km apart). Bacterial communities were surprisingly diverse, and distinct from soil communities. Four of 26 phyla detected were dominant: Proteobacteria, Bacteroidetes, Firmicutes and Actinobacteria, albeit 20.2% of sequences were unclassified at the phylum level. As previously observed in acidic soil, pH was the dominant factor influencing alkaline sediment community structure, phylotype richness and phylogenetic diversity. In contrast, archaeal communities were less affected by pH. More geographically distant sites had more dissimilar communities (r = 0.443, P = 0.030). Variance partitioning analysis showed that geographic distance (historical contingencies) contributed more to bacterial community variation (12.2%) than any other factor, although the environmental factors explained more variance when combined (28.9%). Together, our results show that pH is the best predictor of bacterial community structure in alkaline sediments, and confirm that both geographic distance and chemical factors govern bacterial biogeography in lake sediments.