Ecological Impacts of Altered Stream Hydrogeomorphic Characteristics Extend Beyond the Channel Boundary: Evidence From Urban Streams of Columbus, OH, United States

Urbanization in stream catchments can have strong effects on channel hydrogeomorphic features including dimensions, channel-floodplain connectivity, and flood regime. However, the consequences of alterations aquatic-terrestrial subsidy dynamics are largely unexplored. We examined associations among characteristics, emergent aquatic insect assemblages, density trophic riparian spiders family Tetragnathidae at 23 small urban reaches Columbus, OH (United States) Metropolitan Area. Naturally abundant stable isotopes 13 C 15 N were used to quantify relative contribution aquatically derived energy (i.e., nutritional pathways deriving from algae) tetragnathid their position. Bankfull discharge was negatively related both emergence rate richness. On average, relied for 36% nutrition, with greatest reliance found next channels wider flood-prone widths proportionally fewer insects Chironomidae. Mean 32% explained 44% variation energy. A positive relationship between δ provides additional evidence insects. position 2.85 positively associated sinuosity rate. Sinuosity also insects; as well richness; % Ephemeroptera, Plecoptera, Trichoptera (EPT); rate; implicating instream habitat-mediated shifts communities an indirect mechanistic link processes spiders. Our findings underscore that impacts cascade into terrestrial food webs. These results suggest monitoring restoration fluvial geomorphic form function (e.g., sinuosity, slope, hydrology) confer benefits ecosystems catchments.