Title |
Assembly mechanisms of soil bacterial communities in subalpine coniferous forests on the Loess Plateau, China |
Author |
Pengyu Zhao1, Jinxian Liu1, Tong Jia1, Zhengming Luo1, Cui Li2, and Baofeng Chai1* |
Address |
1Institute of Loess Plateau, Shanxi University, Taiyuan 030006, P. R. China, 2Faculty of Environment Economics, Shanxi University of Finance and Economics, Taiyuan 030006, P. R. China |
Bibliography |
Journal of Microbiology, 57(6),461–469, 2019,
|
DOI |
10.1007/s12275-019-8373-7
|
Key Words |
bacterial community, assembly mechanisms, ecological
groups, niche breadth |
Abstract |
Microbial community assembly is affected by trade-offs between
deterministic and stochastic processes. However, the
mechanisms underlying the relative influences of the two
processes remain elusive. This knowledge gap limits our ability
to understand the effects of community assembly processes
on microbial community structures and functions. To better
understand community assembly mechanisms, the community
dynamics of bacterial ecological groups were investigated
based on niche breadths in 23 soil plots from subalpine coniferous
forests on the Loess Plateau in Shanxi, China. Here,
the overall community was divided into the ecological groups
that corresponded to habitat generalists, ‘other taxa’ and specialists.
Redundancy analysis based on Bray-Curtis distances
(db-RDA) and multiple regression tree (MRT) analysis indicated
that soil organic carbon (SOC) was a general descriptor
that encompassed the environmental gradients by which the
communities responded to, because it can explain more significant
variations in community diversity patterns. The three
ecological groups exhibited different niche optima and degrees
of specialization (i.e., niche breadths) along the SOC
gradient, suggesting the presence of a gradient in tolerance
for environmental heterogeneity. The inferred community
assembly processes varied along the SOC gradient, wherein
a transition was observed from homogenizing dispersal to
variable selection that reflects increasing deterministic processes.
Moreover, the ecological groups were inferred to perform
different community functions that varied with community
composition, structure. In conclusion, these results
contribute to our understanding of the trade-offs between
community assembly mechanisms and the responses of community
structure and function to environmental gradients. |