Disentangling mechanisms that mediate the balance between stochastic and deterministic processes in microbial succession
Disentangling mechanisms that mediate the balance between stochastic and deterministic processes in microbial succession
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DOI：
10.1073/pnas.1414261112
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发表时间：
2015-03-17
影响因子：
11.1
通讯作者：
Salles, Joana Falcao
中科院分区：
文献类型：
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作者：
Dini-Andreote, Francisco;Stegen, James C.;Salles, Joana Falcao
生态演替和随机与确定性过程之间的平衡是微生物生态学中的两个主要主题，但这些概念领域大多是相互独立的。在这里，我们提供了一个框架，整合社区组装过程中的变化与微生物的主要继承，以更好地了解机制的随机/确定性的平衡。综合以前的工作，我们设计了一个概念模型，生态系统的发展与生态组装过程中的变化相关的替代假设。概念模型假设进行了测试，耦合时空数据的土壤细菌群落与环境条件的盐沼时序跨越105年的演替。演替阶段内的分析表明，社区组成最初由随机性，但随着演替的进行，有一个逐步增加的确定性选择与增加钠浓度。群落演替阶段之间的周转分析，这提供了一个更大的时空尺度相对于内阶段分析揭示，土壤有机质浓度的变化是主要的预测类型和相对影响的决定性。总之，这些结果表明规模依赖性的机制选择。为了更好地理解这些模式的机制，我们开发了一个生态模拟模型，揭示了选择性环境的变化如何导致随机/确定性平衡的变化。最后，我们提出了一个扩展的和实验可测试的概念模型集成生态组装过程与初级和次级演替。该框架为未来的实验提供了先验假设，从而促进了系统的方法来理解整个生态系统中微生物群落的组装和演替。
Ecological succession and the balance between stochastic and deterministic processes are two major themes within microbial ecology, but these conceptual domains have mostly developed independent of each other. Here we provide a framework that integrates shifts in community assembly processes with microbial primary succession to better understand mechanisms governing the stochastic/deterministic balance. Synthesizing previous work, we devised a conceptual model that links ecosystem development to alternative hypotheses related to shifts in ecological assembly processes. Conceptual model hypotheses were tested by coupling spatiotemporal data on soil bacterial communities with environmental conditions in a salt marsh chronosequence spanning 105 years of succession. Analyses within successional stages showed community composition to be initially governed by stochasticity, but as succession proceeded, there was a progressive increase in deterministic selection correlated with increasing sodium concentration. Analyses of community turnover among successional stages-which provide a larger spatiotemporal scale relative to within stage analyses-revealed that changes in the concentration of soil organic matter were the main predictor of the type and relative influence of determinism. Taken together, these results suggest scale-dependency in the mechanisms underlying selection. To better understand mechanisms governing these patterns, we developed an ecological simulation model that revealed how changes in selective environments cause shifts in the stochastic/deterministic balance. Finally, we propose an extended-and experimentally testable-conceptual model integrating ecological assembly processes with primary and secondary succession. This framework provides a priori hypotheses for future experiments, thereby facilitating a systematic approach to understand assembly and succession in microbial communities across ecosystems.