Benthic insects in Swedish lake‐outlet streams: patterns in species richness and assemblage structure

摘要: SUMMARY 1. We studied how species richness of three hierarchical insect groups, namely all benthic, lotic and filtering taxa, were related to a number environmental variables in data set from fifteen Swedish lake outlets. 2. In partial least-squares analyses, we found that size-related factors (stream width, discharge) velocity-related (current velocity, substratum particle size) positively associated, productivity-related (chlorophyll a, seston energy, conductivity) negatively with the groups. 3. The weak negative relationship productivity largely negated theoretical predictions, whereas species-environment results corroborated earlier findings running water systems. 4. most important associated composition outlets included pH, area, discharge, channel width detritus. 5. Of filter feeders, blackflies (Diptera: Simuliidae) showed pH. 6. A nested subset analysis demonstrated species-poor sites did not have at more species-rich any groups.