The biogeographic pattern of microbial communities inhabiting terrestrial mud volcanoes across the Eurasian continent

[摘要] Terrestrial mud volcanoes (MVs) represent the surfaceexpression of conduits tapping fluid and gas reservoirs in the deepsubsurface. Such plumbing channels provide a direct, effective means toextract deep microbial communities fueled by geologically produced gases andfluids. The drivers accounting for the diversity and composition of theseMV microbial communities, which are distributed over a wide geographic range, remainelusive. This study characterized the variation in microbial communities in15 terrestrial MVs across a distance of ∼  10 000 km on theEurasian continent to test the validity of distance control andphysiochemical factors in explaining biogeographic patterns. Our analysesyielded diverse community compositions with a total of 28 928 ampliconsequence variances (ASVs) taxonomically assigned to 73 phyla. While no truecosmopolitan member was found, ∼  85 % of ASVs were confinedwithin a single MV. Community variance between MVs appeared to be higher andmore stochastically controlled than within MVs, generating a slope of thedistance–decay relationship exceeding those for marine seeps and MVs as well asseawater columns. For comparison, physiochemical parameters explained 12 %of community variance, with the chloride concentration being the mostinfluential factor. Overall, the apparent lack of fluid exchange rendersterrestrial MVs a patchy habitat, with microbiomes diverging stochasticallywith distance and consisting of dispersal-limited colonists that are highlyadapted to the local environmental context.

[学科分类] 大气科学