Drivers of aquatic macroinvertebrate communities across European cities

Aquatic habitats in cities are increasingly being promoted to provide ecosystem services and adapt cities to climate change. These include protected and restored habitats, many of which as aquatic nature-based solutions (aquaNbS) focus on ponds and streams. Such habitats support diverse macroinvertebrate communities, for which knowledge gaps remain regarding their environmental drivers. We characterized macroinvertebrate composition in urban ponds and streams built as aquaNbS across four European cities under contrasting climatic conditions (Lisbon, Antwerp, Poznań, Helsinki). Further, we tested the influence of environmental factors as two types of variation, based on a geographical scale. Results have shown that variation between cities communities were mainly associated by climate and bottom material. At the variation within cities, communities were associated by the type of aquaNbS (pond vs. stream), followed by city specific drivers: water (temperature, oxygen, water residence time), aquaNbS (bottom material, depth) and vegetation (Normalized Vegetation Index) related variables. Results suggest that NbS planning can boost urban biodiversity by ensuring the presence of a wide range of habitats as in important factor for communities. Understanding the possible drivers of communities is critical to improve the functions and management of aquaNbS and should be considered when projecting or restoring them.