Abstract Microbial mats were the dominant habitat type in shallow marine environments between the Palaeoarchean and Phanerozoic. Many of these (termed ‘microbialites’) calcified as they grew but such lithified mats are rare along modern coasts for reasons such as unsuitable water chemistry, destructive metazoan influences and competition with other reef-builders such as corals or macroalgae. Nonetheless, extant microbialites occur in unique coastal ecosystems such as the Exuma Cays, Bahamas or Lake Clifton and Hamelin Pool, Australia, where limitations such as calcium carbonate availability or destructive bioturbation are diminished. Along the coast of South Africa, extensive distributions of living microbialites (including layered stromatolites) have been discovered and described since the early 2000s. Unlike the Bahamian and Australian ecosystems, the South African microbialites form exclusively in the supratidal coastal zone at the convergence of emergent groundwater seepage. Similar systems were documented subsequently in southwestern Australia, Northern Ireland and the Scottish Hebrides, as recently as 2018, revealing that supratidal microbialites have a global distribution. This review uses the best-studied formations to contextualise formative drivers and processes of these supratidal ecosystems and highlight their geological, ecological and societal relevance. Dynamic interchanges between salinity states both exclude many destructive metazoans and competitors and provides optimal nutrient conditions for benthic microbial and microalgal growth. The outflowing groundwater seeps are alkaline and rich in calcium carbonate, which reflects local catchment geological processes. These habitats support a diverse microbial community dominated by Cyanobacteria as well as some metazoan species previously unknown to science, or unknown for the region. Several taxa (from invertebrates to fish) utilise this environment as refugia. Supratidal microbialites are important coastal features because of the organisms they support and the ecological processes that they facilitate, such as habitat connectivity. Culturally and socially, the value of these habitats is increasingly being appreciated, for example as traditional freshwater supply points or as an unrealised geotourism opportunity. This review also frames new information about threats, opportunities for future research and conservation trajectories for these unique geobiological habitats.

中文翻译：

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由地下水供给的现代潮上微生物岩的功能驱动因素、价值和轨迹

摘要 微生物垫是古太古代和显生宙之间浅海环境中的主要生境类型。其中许多（称为“微生物岩”）随着它们的生长而钙化，但由于不合适的水化学、破坏性后生动物影响以及与珊瑚或大型藻类等其他造礁生物的竞争等原因，现代海岸很少见这种石化垫。尽管如此，现存的微生物岩存在于独特的沿海生态系统中，例如巴哈马的 Exuma Cays 或澳大利亚的克利夫顿湖和 Hamelin Pool，在那里碳酸钙可用性或破坏性生物扰动等限制减少。沿着南非海岸，自 2000 年代初以来，已经发现并描述了广泛分布的活微生物岩（包括层状叠层石）。与巴哈马和澳大利亚的生态系统不同，南非微生物群完全形成于地下水渗流汇合处的潮上带沿海地区。随后在澳大利亚西南部、北爱尔兰和苏格兰赫布里底群岛记录了类似的系统，最近在 2018 年，揭示了潮上微生物岩具有全球分布。本综述使用研究最充分的地层将这些潮上生态系统的形成驱动因素和过程置于背景下，并强调它们的地质、生态和社会相关性。盐度状态之间的动态交换既排除了许多破坏性的后生动物和竞争者，也为底栖微生物和微藻的生长提供了最佳的营养条件。流出的地下水渗出液呈碱性，富含碳酸钙，反映了当地的流域地质过程。这些栖息地支持着以蓝藻以及一些以前科学未知或该地区未知的后生动物物种为主的多样化微生物群落。几个分类群（从无脊椎动物到鱼类）利用这种环境作为避难所。潮上微生物岩是重要的沿海特征，因为它们支持生物体以及它们促进的生态过程，例如栖息地连通性。在文化和社会方面，这些栖息地的价值越来越受到重视，例如作为传统的淡水供应点或未实现的地质旅游机会。该评论还构建了有关威胁、未来研究机会和这些独特的地球生物栖息地的保护轨迹的新信息。这些栖息地支持着以蓝藻以及一些以前科学未知或该地区未知的后生动物物种为主的多样化微生物群落。几个分类群（从无脊椎动物到鱼类）利用这种环境作为避难所。潮上微生物岩是重要的沿海特征，因为它们支持生物体以及它们促进的生态过程，例如栖息地连通性。在文化和社会方面，这些栖息地的价值越来越受到重视，例如作为传统的淡水供应点或未实现的地质旅游机会。该评论还构建了有关威胁、未来研究机会和这些独特的地球生物栖息地的保护轨迹的新信息。这些栖息地支持着以蓝藻以及一些以前科学未知或该地区未知的后生动物物种为主的多样化微生物群落。几个分类群（从无脊椎动物到鱼类）利用这种环境作为避难所。潮上微生物岩是重要的沿海特征，因为它们支持生物体以及它们促进的生态过程，例如栖息地连通性。在文化和社会方面，这些栖息地的价值越来越受到重视，例如作为传统的淡水供应点或未实现的地质旅游机会。该评论还构建了有关威胁、未来研究机会和这些独特的地球生物栖息地的保护轨迹的新信息。