ABSTRACT Temporary aquatic ecosystems are critical for biodiversity conservation, particularly in Mediterranean regions. Doñana National Park, in southern Spain, harbours a network of temporary ponds and marshes that support diverse microbial communities. Among them, ciliates play key ecological roles due to their taxonomic and functional diversity and sensitivity to environmental change. In this study, we investigated spatial and seasonal patterns of β‐diversity in ciliate communities, with emphasis on local contributions (LCBD), species contributions (SCBD) and functional traits. Samples were collected in spring and summer 2024, and taxonomic as well as functional approaches were applied. Results showed that spring connectivity promoted biotic homogenisation, while summer hydroperiod reduction enhanced community heterogeneity. Marshlands maintained higher richness and LCBD values, highlighting their role as biodiversity reservoirs under stressful summer conditions. Species such as Coleps hirtus and Cyclidium glaucoma emerged as key bioindicators, and smaller filter‐feeders and predators contributed disproportionately to β‐diversity. Environmental gradients, particularly pH, conductivity and chlorophyll, further shaped community differentiation. These findings highlight ciliates as sensitive indicators of environmental change and reinforce the importance of including protists in biodiversity conservation strategies.
Cochak et al. (2026) studied this question.