Key drivers influencing the colonization of periphytic ciliates and their functional role in hydrologically dynamic floodplain lake ecosystem

Abstract

We investigated the colonization process and community dynamics of periphytic ciliates in a floodplain lake. To elucidate the functional role of ciliates, we investigated variations in their functional traits during colonization. Our research revealed that ciliate colonization process differs significantly between spring and summer, mainly due to differences in water temperature and hydrological regime. The most pronounced influence of temperature-initiated differences was observed during the initial phase of colonization, during which faster colonization with different pioneer species, and more diverse and abundant ciliate community characterized the summer initial phase. Hydrological changes significantly affected periphytic communities during the intermediate and late phases, resulting in different patterns of the colonization process. Mitigation of suspended food particles during flooding periods led to a decrease in ciliate abundance and the dominance of mobile benthivore ciliates (raptorial and filter feeders), whilst during more stable periods of low water, sessile planktivores (filter feeders) that consume suspended particles, dominated. They are considered to be main representatives of periphytic ciliates in floodplain lakes, playing a significant role in the pelagic-benthic coupling. The results of the present study offer new insights into the ecology and functional role of periphytic ciliates in a floodplain ecosystems of temperate regions.