Instituto de Investigaciones en Ciencias de La Tierra, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, México.
Applied Physics Centro de Investigación Científica y de Educación Superior de Ensenada, Baja California, México.
Environ Monit Assess. 2023 Mar 23;195(4):501. doi: 10.1007/s10661-023-11125-9.
The use of diatoms as indicators of water quality has been studied worldwide; however, the use of diatoms as indicators of thermic anomalies has received less attention. The objective of this study is not only to provide a record on algal communities, but also to investigate the relationship between the diversity in diatom species and the physicochemical conditions of water. Evaluating its temporal variability in a caldera with low permeability and cold acid hydrothermal anomalies. Diatom assemblages were identified at 11 sites. Species composition was compared between seasons (dry and wet) in different environments, as streams, ponds and pools within the caldera. The physicochemical and environmental differences are very specific, which allowed the diatom identification from geothermal and anthropogenic sources without finding mixtures. The results show that the main diatom flora of the Acoculco caldera consists of 15 dominant species. Sulphite-rich acidic hydrothermal waters are characterized by the presence of Eunotia exigua, Eunotia bilunaris, and Pinnularia brauniana. In non-hydrothermal streams, Planothidium, Achnanthidium, and Humidophila species are the most common taxa. Other diatoms from acidic environments were Frustulia saxonica, Surirella, and Stenopterobia. The assemblages are clearly different from those of alkaline environments. Epithemia, Planothidium, and Ulnaria are present in the streams and are not associated with thermalism. Ordination of diatom assemblages showed that pH, conductivity, and nutrient concentrations, some of which are influenced by anthropogenic activities, were the main factors influencing the distribution of diatom composition.
利用硅藻作为水质指标已经在全球范围内进行了研究；然而，利用硅藻作为热异常指标的研究却相对较少。本研究的目的不仅是提供藻类群落的记录，还研究硅藻物种多样性与水的理化条件之间的关系。评估其在低渗透性和冷酸热液异常的火山口中的时间变化。在 11 个地点鉴定了硅藻组合。比较了不同环境（溪流、池塘和火山口内的水池）中干湿季节的物种组成。理化和环境差异非常特殊，这使得能够从地热和人为来源识别硅藻，而不会发现混合物。结果表明，阿科库科火山口的主要硅藻植物群由 15 个优势种组成。富含亚硫酸盐的酸性热液水的特征是 Eunotia exigua、Eunotia bilunaris 和 Pinnularia brauniana 的存在。在非热液溪流中，Planothidium、Achnanthidium 和 Humidophila 是最常见的分类群。其他来自酸性环境的硅藻有 Frustulia saxonica、Surirella 和 stenopterobia。这些组合与碱性环境的组合明显不同。Epithemia、Planothidium 和 Ulnaria 存在于溪流中，与热异常无关。硅藻组合的排序表明，pH 值、电导率和营养浓度是影响硅藻组成分布的主要因素，其中一些因素受到人为活动的影响。
