Biological soil crusts (biocrusts) accommodate diverse communities of phototrophic and heterotrophic microorganisms. Heterotrophic protists have critical roles in the microbial food webs of soils, with Cercozoa and Endomyxa often being dominant groups. Still, the diversity, community composition, and functions of Cercozoa and Endomyxa in biocrusts have been little explored. In this study, using a high-throughput sequencing method with taxon-specific barcoded primers, we studied cercozoan and endomyxan communities in biocrusts from two unique habitats (subarctic grassland and temperate dunes). The communities differed strongly, with the grassland and dunes being dominated by Sarcomonadea (69%) and Thecofilosea (43%), respectively. Endomyxa and Phytomyxea were the minor components in dunes. Sandonidae, Allapsidae, and Rhogostomidae were the most abundant taxa in both habitats. In terms of functionality, up to 69% of the grassland community was constituted by bacterivorous Cercozoa. In contrast, cercozoan and endomyxan communities in dunes consisted of 31% bacterivores, 25% omnivores, and 20% eukaryvores. Facultative and obligate eukaryvores mostly belonged to the families Rhogostomidae, Fiscullidae, Euglyphidae, Leptophryidae, and Cercomonadidae, most of which are known to feed mainly on algae. Biocrust edaphic parameters such as pH, total organic carbon, nitrogen, and phosphorus did not have any significant influence on shaping cercozoan communities within each habitat, which confirms previous results from dunes.

中文翻译：

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来自生物土壤结皮的异养原生生物（Cercozoa和Endomyxa）的分类和功能多样性

生物土壤结皮（生物结皮）容纳了光养和异养微生物的各种群落。异养原生生物在土壤微生物食物网中起着关键作用，其中Cercozoa和Endomyxa通常是优势群体。但是，在生物结壳中，Cercozoa和Endomyxa的多样性，群落组成和功能还很少被探索。在这项研究中，使用高通量测序方法和分类群特有的条形码引物，我们研究了来自两个独特生境（南北草原和温带沙丘）的生物壳中的头尾类动物和内生粉菌群落。群落之间的差异很大，草地和沙丘分别以肉瘤（69％）和and科（43％）为主。沙丘内生霉菌和腐霉菌是次要成分。Sandonidae，Allapsidae，两种生境中，Rhogostomidae和Rhogostomidae是最丰富的分类单元。就功能而言，高达69％的草原群落是由细菌化的角尾藻构成的。相比之下，沙丘中的天牛座和内生线虫群落由31％的噬菌体，25％的杂食动物和20％的真核生物组成。兼性和专性的真核生物主要属于Rhogostomidae，Fiscullidae，Euglyphidae，Leptophryidae和Cercomonadidae科，其中大多数已知主要以藻类为食。pH值，总有机碳，氮和磷等生物结壳的前生参数对每个生境内的尾生动物群落的形成没有任何显着影响，这证实了沙丘的先前结果。相比之下，沙丘中的天牛座和内虫座群落由31％的噬菌体，25％的杂食动物和20％的真核生物组成。兼性和专性的真核生物主要属于Rhogostomidae，Fiscullidae，Euglyphidae，Leptophryidae和Cercomonadidae科，其中大多数已知主要以藻类为食。pH值，总有机碳，氮和磷等生物结壳的前生参数对每个生境内的尾生动物群落的形成没有任何显着影响，这证实了沙丘的先前结果。相比之下，沙丘中的天牛座和内生线虫群落由31％的噬菌体，25％的杂食动物和20％的真核生物组成。兼性和专性的真核生物主要属于Rhogostomidae，Fiscullidae，Euglyphidae，Leptophryidae和Cercomonadidae科，其中大多数已知主要以藻类为食。pH值，总有机碳，氮和磷等生物结壳的前生参数对每个生境内的尾生动物群落的形成没有任何显着影响，这证实了沙丘的先前结果。