Green landscape and macrophyte cover influence macroinvertebrate taxonomic and functional feeding groups in urban waterbodies at multiple spatial scales

Urban waterbodies provide important services to humans and play a considerable role in biodiversity conservation. Yet, we still know very little about how urban pond ecosystems may respond to ongoing and future stresses operating at multiple spatial scales. Here we examined the littoral macroinvertebrates in 20 urban waterbodies as an indicator community to assess how local waterbody condition and urban land use affected their taxonomic and functional feeding group composition. Although macroinvertebrates were diverse (total richness of 60 family taxa ranging from 10 to 41), they were dominated by two major taxonomic groups, the Diptera Chironomidae (36%) and Annelida Oligochaeta (22%), which largely represent the dominant functional feeding group of the collector-gatherers (63%). Fuzzy clustering identified four different types of communities based on taxonomic and functional feeding groups. These reflected inversed gradients in the dominance of collector-gatherers versus ponds with higher abundances of herbivores (Gastropoda Pulmonata, Hemiptera, Trichoptera), collectors-filterers (Gastropoda Prosobranchia, Crustacea Ostracoda), predators (Odonata), and parasites (Nematoda, Hydracarina). Distance-based redundancy analysis identified macrophyte cover and green landscape (parks and buildings with green yards) within a 100-m radius as the best drivers to differentiate among the different waterbody clusters. Specifically, waterbodies characterized by high macrophyte cover and the presence of buildings with green yards within 100 m had the highest abundances and diversity. Our results illustrate the benefit of green spaces, beyond parks, up to 2000 m but especially within 100 m from ponds.