Urbanisation Restructures but Does Not Reduce Freshwater Pond Biodiversity

Aim Urbanisation is a dominant driver of landscape change leading to widespread displacement, degradation and fragmentation of habitat for native species and numerous studies have documented loss of biodiversity in response. However, most studies focus on a small range of taxa (e.g., vertebrates, plants), leaving many other groups poorly studied. Here we focus on a less well‐studied system, freshwater ponds, and on multiple taxonomic groups (amphibians, macroinvertebrates, microbes). We ask whether urbanisation effects are evident and whether they vary within and among groups. Location Thirty‐two freshwater ponds (median surface area 490 m 2 ) in the northeastern USA (New Haven County, Connecticut). Methods We surveyed amphibians and macroinvertebrates in each pond annually from 2019 to 2024. In 2024, we characterised microbial communities in 17 ponds. At each pond, we estimated ‘urbanicity’ (PCA of surrounding land cover, night time light levels, road density) and measured pond surface area, water depth, temperature, pH, conductivity, and canopy cover. Results We found mixed evidence for the impacts of urbanisation. Community composition of both amphibians and macroinvertebrates shifted with urbanicity, but there was minimal evidence that richness declined for either group. Most individual taxa had distributions unrelated to urbanicity, except wood frog larval density, which declined. Neither composition nor richness of microbes was associated with urbanicity, while diversity was positively associated. For all taxonomic groups, pH and temperature were the strongest predictors, with canopy cover also important for macroinvertebrates and some amphibians. Main Conclusions Across multiple taxa sampled in dozens of ponds and over several years, we found evidence that urbanicity is associated with community shifts, but generally not declines in richness or abundance. Ponds in developed contexts serve an important role in supporting native biodiversity. Continuing loss of urban ponds may be a greater threat than the conditions within or near them for many species.