Data from : Soil pH determines bacterial distribution and assembly processes in natural mountain forests of eastern China

Aim: There have been numerous studies of forest-soil microbial
biogeography, but an integrated view of edaphic factors, plant, climatic
factors, and geographic distance in determining the variation of bacterial
community and assembly processes remains unclear at large spatial scales.
Here, we analyzed the factors affecting the biogeographic pattern and
assembly processes of soil bacterial communities under 58 tree species in
five natural mountain forests. Location: Eastern China. Major taxa
studied: Bacterial communities. Methods: Hierarchical partitioning
analysis and distance decay models were performed to evaluate the relative
contributions of plant phylogeny, environmental, and spatial variables to
the composition of bacterial communities. We applied the Nearest Taxon
Index (NTI), β-Nearest Taxon Index (βNTI), and the modified Raup-Crick
metric to reveal the mechanisms of bacterial assembly processes. Results:
We found that plant phylogeny accounted for a significant, but minor,
fraction (0.7%) of the variation in composition of bacterial communities.
In contrast, soil pH was the primary determinant of bacterial diversity
and community composition, independently explaining 68.6% and 69.9% of the
variation, respectively. Based on the NTI analysis, bacterial community
assembly was more phylogenetically clustered with increasing soil pH.
Variable selection was the predominant process explaining bacterial
community assembly when differences in soil pH were ≥ 0.83, whereas
homogenizing dispersal dominated when differences in soil pH were <
0.83. However, there was no significant relationship between plant
phylogenetic distance and βNTI. Main conclusions: Our findings provide
strong evidence that soil pH predominantly determines bacterial
distribution and mediates the relative impact of stochasticity and
determinism in soil bacterial community assembly. This suggests that
climate-change associated forest soil acidification could have a dramatic
impact on soil bacterial diversity, composition, and function.