Assessing the local effects of riparian restoration on urban streams

Riparian zones mediate chemical and biological exchanges between streams and the terrestrial environment. In urban systems, these zones are often heavily modified by removal of native vegetation and bank disruption. Management agencies have made considerable investments into restoring riparian vegetation through replanting. We investigated the potential for riparian plantings to restore invertebrate communities, bycomparing open and forested (replanted) reaches over winter within three urban streams in Melbourne, Australia. Clear differences in aquatic habitats, food resources and fauna were evident between reaches. Algal biomass on artificial substrates did not differ significantlybetween reaches. Open reaches had higher abundances of taxa reliant on autochthonous production as the primaryfood resources (e.g. gastropods, chironomids and oligochaetes), while forested reaches displayed a higher diversity of invertebrate taxa associated with allochthonous resources. We conclude that riparian plantings may have some positive effects on streams, even without broader catchment improvements in water quality and hydrology.