University of Zagreb, Faculty of Science, Department of Biology, Rooseveltov trg 6, HR-10000 Zagreb, Croatia.
University of Zagreb, Faculty of Science, Department of Biology, Rooseveltov trg 6, HR-10000 Zagreb, Croatia.
Sci Total Environ. 2022 Jul 10;829:154536. doi: 10.1016/j.scitotenv.2022.154536. Epub 2022 Mar 15.
Karst ecosystems play a unique role as exceptional natural habitats in sustaining biodiversity. This study focuses on diatoms, a diverse group of microeukaryotes in the periphytic community of a karstic river. In a multi-microhabitat study along the Krka River (Croatia), our goal was to obtain a detailed overview of diatom diversity and community structure using morphological and molecular approaches, and to assess the applicability of eDNA metabarcoding as a reliable tool for biomonitoring assessment. The results revealed a relatively low agreement in the diatom community composition between the two approaches, but also provided complementary information, with no differences in beta diversity detected between microhabitats. The SIMPER analysis underlined the importance of the molecular approach in identifying diatom community composition, due to errors in distinguishing between deposited diatom cells that occurred in the morphological analysis. In contrast, the morphological approach indicated a clear diatom community separation along the river with a strong location effect. Despite certain differences, both approaches provided a feasible assessment of the ecological status according to the relationship to environmental pressures, classifying the Krka River as High (morphological approach) or Good (molecular approach) throughout the most of its course. Moreover, diatom diversity based on both approaches provides a reliable dataset applicable in routine monitoring assessment and offers a deeper understanding of the presented ecological status. The incompleteness of a reference database presents one major drawback of the molecular approach, which needs further updating in order to improve routine diatom metabarcoding.
喀斯特生态系统作为维持生物多样性的特殊自然栖息地，具有独特的作用。本研究聚焦于硅藻，这是一种在喀斯特河流的周丛生物群中多样化的微型真核生物。在对克罗地亚的克尔卡河（Krka River）进行的多微生境研究中，我们的目标是使用形态学和分子方法，详细了解硅藻多样性和群落结构，并评估 eDNA 宏条形码作为生物监测评估可靠工具的适用性。研究结果表明，两种方法得到的硅藻群落组成之间的一致性相对较低，但也提供了互补信息，微生境之间未检测到β多样性的差异。SIMPER 分析强调了分子方法在识别硅藻群落组成方面的重要性，这是因为在形态学分析中存在区分沉积硅藻细胞的错误。相比之下，形态学方法表明，沿着河流存在明显的硅藻群落分离，位置效应很强。尽管存在某些差异，但这两种方法都根据与环境压力的关系对生态状况进行了可行的评估，将克尔卡河在其大部分河段归类为高（形态学方法）或良（分子方法）。此外，基于两种方法的硅藻多样性提供了一个可靠的数据集，适用于常规监测评估，并提供了对所呈现生态状况的更深入理解。分子方法的一个主要缺点是参考数据库不完整，需要进一步更新，以提高常规硅藻宏条形码的使用。
