Blanco S, Viso R, Borrego-Ramos M, López-Flores R, Mota-Echeandía D, Tierra M, Herrero J
Diatom Lab, University of León, La Serna St., 58, 24007, León, Spain.
Department of Agricultural and Environmental Natural Sciences, Technological College, University Institute for Research in Environmental Sciences of Aragon (IUCA), University of Zaragoza, Zaragoza, Spain.
Microb Ecol. 2025 Mar 17;88(1):16. doi: 10.1007/s00248-025-02514-3.
Benthic diatoms play a crucial role in aquatic ecosystems as indicators of environmental conditions and contributors to primary productivity. This study explores the ecology of benthic diatom assemblages in saline wetlands in NE Spain, focusing on the relationships between community parameters, species distributions, and environmental factors, particularly conductivity. Samples were collected from several wetlands representing a range of conductivity and trophic state. A total of 25 diatom taxa were identified, with assemblages dominated by halophilous species. Non-metric multidimensional scaling analysis revealed electrical conductivity (EC) as a primary factor shaping diatom communities, with nutrient levels as a secondary influence. Species exhibited varying responses to the EC gradient, with some showing overlapping niches and others clearly separated. The study found strong correlations between species abundance, occupancy, and their contribution to dissimilarity between sampling sites. More abundant and widespread species were key drivers of community structure and differentiation. Additionally, a significant relationship was observed between taxa occurrence and niche breadth, measured as EC tolerance. Species with broader tolerances tended to have higher occupancy rates, supporting ecological theories about generalist strategies in variable environments. Contrary to some previous research, rare taxa (3-5% in relative abundance) had a negligible effect on assemblage segregation among habitats. The findings suggest that both environmental filtering based on EC tolerance and species' inherent characteristics play important roles in shaping diatom community composition across these saline wetlands. This study contributes to our understanding of diatom ecology in saline habitats and highlights the importance of considering both local abundance and environmental tolerance in ecological studies of these communities. The insights gained can inform more accurate ecological models and improve our understanding of species distribution and community dynamics in saline aquatic ecosystems.
底栖硅藻在水生生态系统中起着至关重要的作用，它们是环境状况的指标，也是初级生产力的贡献者。本研究探讨了西班牙东北部盐沼中底栖硅藻群落的生态学，重点关注群落参数、物种分布与环境因素之间的关系，特别是电导率。样本采集自几个代表不同电导率和营养状态范围的湿地。共鉴定出25种硅藻分类单元，群落以嗜盐物种为主。非度量多维标度分析表明，电导率（EC）是塑造硅藻群落的主要因素，营养水平是次要影响因素。物种对EC梯度表现出不同的响应，一些物种表现出生态位重叠，而另一些则明显分离。研究发现物种丰度、占有率与其对采样点间差异的贡献之间存在强相关性。更丰富、分布更广的物种是群落结构和分化的关键驱动因素。此外，观察到分类单元的出现与以EC耐受性衡量的生态位宽度之间存在显著关系。耐受性更宽的物种往往占有率更高，这支持了关于多变环境中泛化策略的生态学理论。与之前的一些研究相反，稀有分类单元（相对丰度为3-5%）对不同生境间的群落分离影响可忽略不计。研究结果表明，基于EC耐受性的环境筛选和物种的固有特征在塑造这些盐沼中硅藻群落组成方面都起着重要作用。本研究有助于我们理解盐生境中的硅藻生态学，并强调在这些群落的生态学研究中考虑局部丰度和环境耐受性的重要性。所获得的见解可为更准确的生态模型提供信息，并增进我们对盐生水生生态系统中物种分布和群落动态的理解。
