This article reviews some ecological concepts common to all kinds of ecosystems, describes the characteristics of microbial mats, and focuses on the description of the Ebro Delta microbial mats, to assess whether they fit the concept of a minimal ecosystem. First, microorganisms as components of ecosystems are considered, and some features of microbial life, including ubiquity, size and metabolism, genetic versatility, and strategies to overcome unfavorable conditions, are discussed. Models for ecosystems, regardless of their size, have the same basic components; tropical forests, multilayered planktonic microbial communities, and benthic microbial mats are analogous ecosystems at different scales. The structure – in terms of populations and communities – and ecophysiology of microbial mats are also discussed. The linear distribution of microbial populations along steep gradients of light and hydrogen sulfide allows for the simultaneous presence of different microbial populations. Defining the minimal ecosystem requirements necessary for the survival and proliferation of organisms is crucial in the search for extraterrestrial life and for establishing ecosystems beyond the Earth.

中文翻译：

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微生物垫和寻找最小的生态系统。

本文回顾了各种生态系统共有的一些生态概念，描述了微生物垫的特征，并重点介绍了埃布罗三角洲微生物垫，以评估它们是否适合于最小生态系统的概念。首先，将微生物视为生态系统的组成部分，并讨论了微生物生活的一些特征，包括普遍存在，大小和代谢，遗传多样性和克服不利条件的策略。生态系统的模型，不论其大小如何，都具有相同的基本组成部分；热带森林，多层浮游微生物群落和底栖微生物垫是不同规模的类似生态系统。还讨论了结构（就人口和社区而言）以及微生物垫的生态生理学。沿着光和硫化氢的陡峭梯度，微生物种群的线性分布允许同时存在不同的微生物种群。定义生物生存和繁殖所必需的最低生态系统要求，对于寻找地球外生命和建立地球以外的生态系统至关重要。