Diversity and ecology of benthic diatoms in a mire with narrow pH gradient

Mires are specific freshwater habitats with great importance for global biodiversity. The present study investigated diatoms in different habitats of a Don Mocvar mire and their relationship with environmental parameters, as well as the use of diatom indicator values and the German Red List for conservation purposes. The study was conducted monthly from January to November 2012. Diatoms were sampled simultaneously with water for physical and chemical properties in three different habitats. A total of 50 diatom taxa were identified. Based on their relative abundance and diversity, habitat-related environmental factors shaped the diatom community when seasonal dynamics were less important. Multivariate analysis showed that chemical oxygen demand (COD) and conductivity were the most significant environmental variables describing diatom communities. The indicator values characterized the diatoms as a typical mire community and proved to be a reliable starting point for future monitoring and management. Diatom classification by German Red List revealed a dominance of species with priority for conservation, suggesting that the Don Mocvar should have conservation status. This study brings a better understanding of the response of diatoms to living in specific habitats and the basis for future studies on ecological characteristics of new or rare taxa.