Journal Article

Stochasticity, succession, and environmental perturbations in a fluidic ecosystem

Zhili He, Ye Deng, Kai Xue, Adam P. Arkin, Jizhong Zhou, Joy D. Van Nostrand, Liyou Wu, Terry C. Hazen, James M. Tiedje, Ping Zhang, David A. Stahl, Yuting Liang, Yunfeng Yang

2014

Overview

Unraveling the drivers of community structure and succession in response to environmental change is a central goal in ecology. Although the mechanisms shaping community structure have been intensively examined, those controlling ecological succession remain elusive. To understand the relative importance of stochastic and deterministic processes in mediating microbial community succession, a unique framework composed of four different cases was developed for fluidic and nonfluidic ecosystems. The framework was then tested for one fluidic ecosystem: a groundwater system perturbed by adding emulsified vegetable oil (EVO) for uranium immobilization. Our results revealed that groundwater microbial community diverged substantially away from the initial community after EVO amendment and eventually converged to a new community state, which was closely clustered with its initial state. However, their composition and structure were significantly different from each other. Null model analysis indicated that both deterministic and stochastic processes played important roles in controlling the assembly and succession of the groundwater microbial community, but their relative importance was time dependent. Additionally, consistent with the proposed conceptual framework but contradictory to conventional wisdom, the community succession responding to EVO amendment was primarily controlled by stochastic rather than deterministic processes. During the middle phase of the succession, the roles of stochastic processes in controlling community composition increased substantially, ranging from 81.3% to 92.0%. Finally, there are limited successional studies available to support different cases in the conceptual framework, but further well-replicated explicit time-series experiments are needed to understand the relative importance of deterministic and stochastic processes in controlling community succession.

• Publisher: National Academy of Sciences,National Acad Sciences
• Subject: Biological Sciences / community assembly / Community composition / Community structure / disturbances / Ecological succession / Ecosystem / Ecosystems / Environmental changes / ENVIRONMENTAL SCIENCES / GeoChip / Groundwater / Groundwater - microbiology / metagenomics / microbial communities / Microbiota - drug effects / Microbiota - genetics / Models, Biological / Plant Oils - pharmacology / PNAS Plus / Population Dynamics / remediation / Species Specificity / Stochastic models / Stochastic Processes / Time Factors / Time series / time series analysis / Uranium / vegetable oil / Vegetable oils / Water Microbiology