We investigated temporal effects of restoration on river morphology, on species and functional com-position of benthic invertebrates, floodplain vegetation and carabid beetles at three study sites in themountain river Lahn (Germany). We sampled restored and nearby non-restored sections 3–5 years and7–9 years after restoration. In the restored sections, instream microhabitat heterogeneity was higherdue to the increased presence of finer substrates, while cobbles and coarse gravel were still domi-nant. Instream habitat composition did not change between the two sampling events. Areas of restoredfloodplain were characterized by a more diverse habitat mosaic and by unvegetated bars, vegetatedislands and secondary channels. In restored sections, floodplain habitat heterogeneity was maintained7–9 years after restoration, but vegetated areas increased, while unvegetated bars and aquatic areasdecreased. The species composition of all studied groups was more variable over time in restored thannon-restored sections. In contrast to benthic invertebrates, the immigration rate of floodplain vegeta-tion and carabid beetle species was higher in restored sections. Assemblage composition of all threeorganism groups changed over time, with the highest change in carabid beetles and smallest in benthicinvertebrates. Restoration changed the abundances of functional response groups, mainly for carabid bee-tles, by supporting species that indicate increased hydrodynamics and early successional stages. Changesof functional response groups in non-restored and restored sections across time indicated decreasedhydrodynamics or hydrological connectivity for all organism groups. Although the response of organ-ism groups differed, our results support the conjecture that restored sections accumulate species andenhance the local species pool.
Januschke, K., S.C. Jähnig, A.W. Lorenz, D. Hering (2014) Mountain river restoration measures and their success(ion): effects on river morphology, local species pool, and functional composition of three organism groups. Ecological Indicators 38: 243–255.