Despite the growing number of investigations on microbial succession during the last decade, most of our knowledge on primary succession of bacteria in natural environments comes from conceptual models and/or studies of chronosequences. Successional patterns of litter-degrading bacteria remain poorly documented, especially in undisturbed environments. Here we conducted an experiment with tank bromeliads as natural freshwater microcosms to assess major trends in bacterial succession on two leaf-litter species incubated with or without animal exclusion. We used amplicon sequencing and a co-occurrence network to assess changes in bacterial community structure according to treatments. Alpha-diversity and community complexity displayed the same trends regardless of the treatments, highlighting that primary succession of detrital-bacteria is subject to resource limitation and biological interactions, much like macro-organisms. Shifts in bacterial assemblages along the succession were characterized by an increase in uncharacterized taxa and potential N-fixing bacteria, the latter being involved in positive co-occurrence between taxa. These findings support the hypothesis of interdependence between taxa as a significant niche-based process shaping bacterial communities during the advanced stage of succession.

中文翻译：

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在凤梨科生态系统中，资源的可获得性驱动叶片凋落物分解过程中的细菌演替

尽管在过去十年中有关微生物演替的研究越来越多，但我们对自然环境中细菌的主要演替的大多数知识还是来自概念模型和/或时间序列研究。降解垃圾的细菌的连续模式仍然鲜有记载，特别是在不受干扰的环境中。在这里，我们进行了罐头凤梨科动物作为天然淡水缩影的实验，以评估在有或没有动物排斥的情况下培养的两种凋落物上细菌演替的主要趋势。我们使用了扩增子测序和共现网络，以根据治疗方法评估细菌群落结构的变化。无论采取何种处理方式，阿尔法多样性和社区复杂性都呈现出相同的趋势，强调碎屑细菌的主要继承受到资源的限制和生物学相互作用的影响，就像大微生物一样。沿演替过程中细菌组合的变化特征是未表征的分类单元和潜在的N固定细菌的增加，后者与分类单元之间的阳性共存有关。这些发现支持了分类单元之间的相互依赖性这一假设，认为分类单元是在演替后期形成细菌群落的一个重要的基于生态位的过程。