Distribution patterns of terrestrial and aquatic invertebrates influenced by different groyne forms along the River Elbe (Germany).
Kleinwächter, Meike; Eggers, T. O.; Henning, M.; Anlauf, A.; Hentschel, B.; Larink, O.
River regulation measures, such as groynes, severely alter hydro-morphological dynamics and subsequently habitat characteristics of riverbanks. In this study the influence of different groyne forms along the River Elbe on groyne field habitats was assessed using carabid beetle and macrozoobenthos assemblages prior to and after groyne adjustment. For analysis, 51 carabid species (n = 12,203), and 21 macrozoobenthos taxa (mean abundance 91.6 individuals. m-2) were assessed. Species of both groups were significantly correlated with soil texture and reacted sensitively to hydro-morphological changes. The ground beetle Bembidion velox and the dragonfly Gomphus flavipes serve as indicator species for riverbanks along the River Elbe. These autochthonous species are strongly adapted to sandy habitats and have become rare in German floodplains. Results show that modified groynes can increase hydro-morphological dynamics, and thus, provide suitable habitats for B. velox, G. flavipes and other characteristic species.