Poster Presentation Freshwater Sciences 2023

Contrasting patterns of native and alien species diversity along the Central European river corridors (#648)

Ivana Svitková 1 , Marek Svitok 2 3 , Tomáš Čejka 1 , Dobromil Galvánek 1 , Dušan Gömöry 2 , Erika Gömöryová 2 , Judita Kochjarová 2 , Dušan Senko 1 , Barbora Šingliarová 1 , Pavel Širka 2 , Katarína Skokanová 1 , Michal Slezák 4 , Stanislav Španiel 1 , Richard Hrivnák 1
  1. Institute of Botany, Plant Science and Biodiversity Centre, Slovak Academy of Sciences, Dúbravská cesta 9, SK-845 23, Bratislava, Slovakia
  2. Department of Biology and General Ecology, Faculty of Ecology and Environmental Sciences, Technical University in Zvolen, T. G. Masaryka 24, SK-960 01 , Zvolen, Slovakia
  3. Department of Ecosystem Biology, Faculty of Science, University of South Bohemia, Branišovská 1760, CZ-370 05, České Budějovice, Czech Republic
  4. Institute of Forest Ecology, Slovak Academy of Sciences, Ľ. Štúra 1774, SK-960 01, Zvolen, Slovakia

River corridors belong to the most important natural vectors for invasive species spreading into the landscape. Vegetation along streams and river banks is, therefore, under the strong influence of alien plants. The high susceptibility of riparian habitats to invasions is often attributed to the connectivity of water pathways allowing high propagule pressure of aliens, increased urbanization, or reduced competitiveness of native species due to frequent and severe disturbances. However, the processes behind plant invasions of riparian habitats are still not fully understood.

We have sampled riparian vegetation along three rivers with a similar length of about 65 km situated across the latitudinal gradient of the Western Carpathians. Plots of a 50 m2 area were placed in a checkerboard pattern along both sides of the river bank from the source to the river mouth. Altogether 60 plots (20 per river) were established. At each plot, we recorded vascular plants, bryophytes, molluscs, and hydro-morphological, landscape, spatial and soil characteristics.

We tested for differences in spatial patterns of native and alien species diversity along the river corridors using generalized additive models. Moreover, conditional random forests were employed to identify crucial environmental and anthropic factors driving species richness of native and alien species. We have revealed a similar trend in the native species richness, decreasing towards the mouth of all three rivers. The alien diversity showed an opposite pattern, but the trends were river-specific. Temperature played a more pronounced role in the diversity of alien species than native ones, which were rather driven by local land use (molluscs) or source-to-mouth river gradient (plants).

To conclude, the dispersal limitation and temperature constrain alien species distribution along river corridors, while a multitude of natural and anthropic influences drive native species diversity.

The study was supported by the Slovak Research and Development Agency under contract No. APVV-19-0134.