River bank stabilisation by bioengineering: potentials for ecological diversity

Abstract

Riverbanks hold a key position on functionality of floodplains as they constitute the gradual transition between aquatic and terrestrial ecosystems. However, due to technical constructions the majority of riverbanks in temperate regions are far from their ecological potential. This results in the loss of valuable habitats and biodiversity. The need for restoration is high but hardly compatible with economic interests. Bioengineering methods could help to increase the ecological potential of river banks. A comparative investigation on bioengineering bank protection techniques was conducted along two watercourses of different characters of navigation and hydrology (Rhine, Weser). We measured the response of four organism groups to different bioengineering methods. Our results indicate an ecological enhancement of riparian zones by re-establishing of valuable floodplain habitats. The number of terrestrial riparian species increased at both rivers. However, habitat quality for aquatic communities remained limited at due to insufficient extension of measures below mean water level.