Flow Intermittence Drives the Benthic Algal Composition, Biodiversity and Diatom-Based Quality of Small Hilly Streams in the Pannonian Ecoregion, Hungary

Climate change is putting increasing pressure on flowing waters. Drastic water level fluctuations in rivers or drying up of small and medium-sized streams all contribute to the biodiversity crisis threatening freshwater ecosystems. Benthic diatoms are important elements biofilm streams. However, knowledge relationship between benthic flow intermittence incomplete, especially regions recently impacted by recurrent drying. Thus, we investigated diatom flora intermittent, hilly warm temperate region Europe (the Pannonian Ecoregion). Our hypotheses were addressed compositional changes, loss diatom-based ecological assessment. The results revealed clear intermittence-induced differences taxa trait composition diatoms. Altogether six species for dry phase three aquatic identified as indicative ones using indicator value analyses. In contrast regime induced changes assemblages, there was a seasonal overlap composition. During study period, did not result significant either at levels. Functional dispersion, however, reduced significantly summer. Overall, neither hydrological nor had effect quality indices, except Rott trophic index (TID index). TID values lower phases than ones. These suggested that has very complex influence It seems taxonomical functional redundancy can reduce negative impact short-time assemblages. As practical benefit, first support use indices assessment region.