Long-Term Changes of Species Composition and Functional Traits of Epiphytic Diatoms in the Szigetköz Region (Hungary) of the Danube River

Abstract

Here we report the results of our decades-long study on epiphytic communities from two tributary systems of the Szigetköz section of the Danube River. The main goal of the investigation was to detect changes in the epiphytic communities at structural (core species, changes in the relative abundance of common species) and functional (trait changes) levels as a result of the most important anthropogenic effects on Szigetköz, i.e., hydro-morphological modifications. We also examined the impact of rehabilitation on the tributary systems in terms of ecological potential. We discovered that mainly motile diatom species characterized the epiphyton due to reduced water volume were introduced into the tributary system after the diversion of the Danube. The ecosystem stabilized in the rehabilitated section, while the non-rehabilitated section showed a worsening tendency, mainly in the parapotamic branches. Our long-term data sets may provide a good basis for comparisons of different aquatic ecosystems, to define changes in the abundance of core species and in the structure of community in response to different anthropogenic pressures. It is fundamental to determine adaptive traits in assessing the impact of global warming stressors on biodiversity.

Benthic Diatom Composition in Coastal Zone of Black Sea, Sasyk Reservoir (Ukraine)

“…Sellaphora difficillima is a well-known diatom from waters with contrasting features-from low saline environments. The occurrence of S. difficillima and Mastogloia laterostrata, which are mixed in terms of environmental requirements, as well as Fallacia clepsidroides and Amphora inariensis proves the ectopic nature of the site 6 [13,14]. However, some tendencies of diatoms preference, with regard to salinity (Nitzschia filiformis var.…”