Multi-scale analysis of functional plankton diversity in floodplain wetlands: Effects of river regulation

GRISELDA CHAPARRO; INÉS O'FARRELL; THOMAS HEIN

SCIENCE OF THE TOTAL ENVIRONMENT

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2019 vol. 667 p. 338 - 347

0048-9697

Riverine floodplains are among the most diverse and dynamic ecosystems, but river regulation measures havealtered the natural hydrological regime threatening their ecological integrity. We compared spatial patterns ofphyto- and zooplankton functional diversity and of environmental heterogeneity between floodplain wetlandslocated in free-flowing and impounded stretches of the Danube River (Austria).We included two nested spatialscales (different habitats and water sections within wetland areas) and two contrasting hydrological conditions(post-flood, no flood). Environmental heterogeneity was lower in the wetland in the impounded stretch than inthe free-flowing ones. At post-flood conditions, increased alpha diversity of rotifers and microcrustaceans anddecreased beta diversity of phytoplankton and rotifers occurred in the impounded stretch as compared to thewetlands in free-flowing one. Beta diversity was higher between water sections than between habitats in freeflowingwetlands and similar across scales in the wetland in the impounded stretch. Regarding functional composition,the wetland in the impounded stretch hosted more homogeneous communities, as some ecologicaltraitswere nearly absent. Our results indicate that patterns of functional diversity in floodplainwetlands affectedby river regulation are altered, highlighting the major role of the gradient of lateral connectivity and dynamicwater level fluctuations as drivers for planktic diversity in river floodplains. This study contributeswith essentialknowledge to optimize restoration and diversity conservation measures in riverine ecosystems.