Effects of drought on the archaeal community in soil of the Zoige wetlands of the Qinghai–Tibetan plateau

Drought is likely to affect wetlands, including wetland soil microorganisms that drive soil biogeochemical cycling. Frequent drought could reduce the ability of wetlands to serve as sinks for global carbon or could eventually turn them into sources of atmospheric carbon in general and methane in particular. However, the response of microbial communities involved in methane production to drought remains unclear. The current study characterized archaeal communities of an alpine wetland in 2006, which was a drought year, and in 2007, which was not a drought year. A total of 12 soil samples (two years × two plant communities × three samples per plant community) were collected under two plant communities (dominated by Carex muliensis or Eleocharis valleculosa) at the Zoige wetlands on the Qinghai-Tibetan Plateau. Archaeal community size and structure were determined by qPCR and terminal restriction fragment length polymorphismanalysis of the 16S rRNA gene fragment, respectively. Methanosaeta, Methanomicrobiales, Methanobacteriales, uncultured Rice Cluster-II, and uncultured Crenarchaeota were detected. Ordination analysis indicated that archaeal community composition was strongly related to vegetation type and drought. The archaeal community was 10-times smaller in the drought year than in the non-drought year. The results indicated that drought may influence both archaeal community size and structure.