The soils of the McMurdo Dry Valleys (MDV) of Antarctica are established models for understanding fundamental processes in soil ecosystem functioning (e.g. ecological tipping points, community structuring and nutrient cycling) because the extreme physical environment drastically reduces biodiversity and ecological complexity. Understanding the functioning of MDV soils requires in‐depth knowledge of the diversity of MDV soil species. Protists, which contribute significantly to soil ecosystem functioning worldwide, remain poorly characterized in the MDV. To better assess the diversity of MDV protists, we performed shotgun metagenomics on 18 sites representing a variety of landscape features and edaphic variables. Our results show MDV soil protists are diverse at both the genus (155 of 281 eukaryote genera) and family (120) levels, but comprise only 6% of eukaryotic reads. Protists are structured by moisture, total N and distance from the local coast and possess limited richness in arid (< 5% moisture) and at high elevation sites, known drivers of communities in the MDV. High relative diversity and broad distribution of protists in our study promotes these organisms as key members of MDV soil microbiomes and the MDV as a useful system for understanding the contribution of soil protists to the structure of soil microbiomes.

中文翻译：

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弹枪宏基因组学揭示了南极土壤生态系统模型中多种多样的原生生物。

建立南极麦克默多干旱谷（MDV）的土壤是建立模型，用于了解土壤生态系统功能的基本过程（例如生态临界点，群落结构和养分循环），因为极端的物理环境会大大降低生物多样性和生态复杂性。要了解MDV土壤的功能，需要深入了解MDV土壤物种的多样性。在全球范围内，对原生生态系统的功能做出巨大贡献的原生生物，其特征仍然很差。为了更好地评估MDV原生生物的多样性，我们在18个地点进行了shot弹枪宏基因组学研究，这些地点代表了各种景观特征和深层变量。我们的结果表明，MDV土壤原生生物在属（281个真核生物属中的155个）和家族（120个）水平上都不同，但仅占真核生物读物的6％。原生生物由水分，总氮和与当地海岸的距离构成，在干旱地区（水分<5％）和高海拔地区（MDV中已知的社区驱动力）拥有有限的丰富度。在我们的研究中，原生生物的高度相对多样性和广泛分布促进了这些生物成为MDV土壤微生物群落的关键成员，而MDV则成为理解土壤原生生物对土壤微生物群落结构的有用系统。