Diversity Patterns and Assemblage Structure of Non-Biting Midges (Diptera: Chironomidae) in Urban Waterbodies

Urban waters are often neglected in biodiversity research; nonetheless, the number of aquatic microhabitats present in a city and the surrounding urban area is impressive. Twenty-two waterbodies in the Belgrade functional urban area (FUA) were investigated for faunistic and diversity patterns and to assess the effects of environmental factors on the differentiation of Chironomidae assemblages. A total of 66 chironomid taxa within four subfamilies was identified. Water quality at the studied sites, expressed by the water pollution index (WPI), varied significantly. K-means clustering gave four homogenous groups of chironomid assemblages, which showed clear preferences to specific habitat conditions and tolerance to anthropogenic pressures. These groups had high values of alpha and beta diversity components. The main component of beta diversity was species turnover. Waterbody type, water temperature, pH, nutrients and overall pollution were the most important factors influencing the distribution and composition of chironomid assemblages, which revealed clear preferences of each assemblage type to the category of waterbody type and tolerances to environmental pressures.

Automated summary

Urban waters are often overlooked in biodiversity research, but this study highlights the impressive number of aquatic microhabitats present in a city and its surrounding urban area. The research investigates the faunistic and diversity patterns of waterbodies in the Belgrade functional urban area and assesses the effects of environmental factors on Chironomidae assemblages. The study identifies clear preferences and tolerances of different chironomid assemblages to specific habitat conditions and anthropogenic pressures, with waterbody type, water quality, temperature, and pollution playing important roles in the distribution and composition of the assemblages.