Urban stormwater ponds can support dragonfly reproduction akin to natural ponds

Abstract

Stormwater ponds are constructed to receive urban runoff and regulate flooding of built areas. As a result, they can be more stressful habitats for aquatic organisms than natural ponds. Adult dragonflies are known to frequent stormwater management ponds in cities, but whether they successfully reproduce in these artificial systems is not clear. This study compared the reproductive potential of dragonflies in stormwater ponds across a temperate metropolitan area through weekly collections of exuviae at stormwater ponds and natural (reference) ponds. We hypothesized that stormwater ponds were poor habitats for dragonfly reproduction (in comparison to natural ponds) because of the typically negative effects of urbanization on wildlife. With respect to dragonfly reproduction, we therefore predicted: (1) lower breeding recruitment, (2) fewer habitat specialists, and (3) greater homogenization of breeding assemblages at stormwater ponds. However, we did not find a significant difference in the number of species and abundance of exuviae between stormwater and natural ponds. Stormwater ponds also supported similar numbers of habitat specialists as natural ponds. Furthermore, we did not find evidence of greater biotic homogenization across stormwater ponds as species composition was similar between both pond types. These results indicate that stormwater ponds can support the reproductive success of a diverse community of dragonflies.