 This study found that dam construction negatively impacts biodiversity in river and riparian ecosystems worldwide, specifically in subtropical river reservoir systems. Reservoir shorelines had lower plant species diversity and functional diversity than unregulated or lightly regulated riparian wetlands. Environmental factors such as elevation above water level, slope, landform type, substrate, disturbance, and cover were measured and found to significantly affect species and functional richness on reservoir shorelines, but not functional evenness and divergence. The findings suggest that reservoir shoreline wetlands formed by damming rivers can be a biodiversity cold spot in regulated rivers at the plot level, with topographic factors being important in determining plant diversity and vegetation establishment. This article was authored by Wanji Liu, Guihua Liu, Huiliu, and others.