The elevational patterns of diversity for plants and animals have been well established over the past century. However, it is unclear whether there is a general elevational distribution pattern for microbes. Changbai Mountain is one of few well conserved natural ecosystems on the earth, where the vegetation vertical distribution is known as a miniature of vegetation horizontal zonality from temperate to frigid zones in the Eurasian continent.

With sampling assistance from many colleagues, Dr. Haiyan Chu’s group present a comprehensive analysis of soil bacterial community composition and diversity along six elevations representing six typical vegetation types from forest to alpine tundra soils using a bar-coded pyrosequencing technique. The bacterial communities differed dramatically along elevations (vegetation types), and the community composition was significantly correlated with soil pH, carbon/nitrogen ratio (C/N), moisture or total organic carbon (TOC), respectively. Phylogenetic diversity was positively correlated with soil pH, while phylotype richness was positively correlated with soil pH, total nitrogen, and negatively correlated with C/N ratio. Our results emphasize that pH is a better predictor of soil bacterial elevational distribution and also suggest that vegetation types may indirectly affect soil bacterial elevational distribution through altering soil C and N status. To the best of our knowledge, this is the first study to reveal that pH is also a key factor in driving the elevational distribution of bacterial communities. As pH has been widely recognized as a primary driver for soil bacterial horizontal distribution, together these results suggest that, in both horizontal and elevational, pH could be a universal factor determining soil bacterial spatial distribution.

 

The relationship between soil pH and bacterial OTUs phylotype richness (A) and phylogenetic diversity (B)                                                                Canonical correspondence analysis (CCA) of the bacterial communities with symbols coded by                                                                 elevation category