To restore diverse and resilient communities, we must restore their required habitat. This is perhaps best exemplified in Ontario’s tallgrass prairie, one of the most endangered ecosystems in North America with less than 1% remaining of its original distribution. Effective restoration of this habitat requires monitoring the success of key taxonomic groups such as those providing pollination services. Pollinators are rarely incorporated into restoration goals and monitoring; as a result, little is known about how pollinators colonize sites following restoration and whether typical restoration practices attract diverse pollinator populations. This knowledge deficit is of particular concern both because native bee populations are declining and because changes in pollinator abundance and diversity could result in divergence from desired ecosystem restoration trajectories. To address this, we began an experiment to assess the pollinator community of three restored tallgrass prairie sites with the same management history restored in three different years: 2012, 2013, and 2014. Target organisms included Hymenoptera: Apiformes (bees), Syrphidae (hoverflies), and Lepidoptera (moths and butterflies). Twelve plots were established at each site, each consisting of one SpringStar® blue vane trap at vegetation level and three pan traps (white, yellow, and blue) arranged at ground level. For Lepidoptera sampling, netting surveys were conducted along two 200m transects per site. Sites were sampled for a 24h period once monthly during the growing season, June-September.
While total richness was similar at each site in the time series (50, 46, 47 from oldest to youngest), the distribution of families, genera, and individual species varied widely. Of 68 taxa recorded in the study, 35 were Apiformes, 23 were Lepidoptera, and 10 were Syrphids. Within the Apiformes and Syrphid groups, the overall tendency was toward an uneven distribution between the years since restoration and a greater abundance in younger sites. Conversely, Lepidoptera were most abundant and diverse in the oldest site. Of the 1,828 total pollinators collected, 41% were from the 2014 site, 30% from 2012, and 29% from 2013. The results of this study suggest that certain species benefit from the initial stages of tallgrass restoration characterized by the dominance of weedy plant species. This is by no means universal, however, as more species were found exclusively in the older sites. This and future research quantifying pollinator community establishment will inform our approach to restoration in the tallgrass prairie ecosystem and strengthen our ability to re-establish pollination services from diverse, resilient insect communities.