Sustaining ecosystem services through conservation of pollinator networks, invasive species removal and habitat restoration

Background/Question/Methods

Plants and pollinators are critical components of all terrestrial ecosystems, serving as the foundations for building biodiversity. The mutualistic relationships that result from plant-pollinator interactions are one of the most basic elements of healthy ecological networks. In the face of continued development pressure, pollinator conservation requires restoration of appropriate habitat. This adaptive management approach is being applied at the Wilds, a non-profit conservation center located on 3,700 hectares of reclaimed mine land in southeastern Ohio. Restoration efforts have focused on replacing invasive post-mining vegetation with native plant communities that provide food, shelter and high quality habitat for wildlife. Past prairie restoration projects have shown significant increases in local bee and butterfly populations, even within these highly altered landscapes. This present study compares butterfly community composition, species richness, and diversity in four distinct habitat types: a nine-year-old restored prairie, a one-year-old restored wetland complex, a one-year-old oak-pine savannah planting and a low diversity unit comprised of non-native cool season grasses. Multiple regressions were used to determine which environmental variables influenced butterfly species diversity and richness. Transects were monitored over the course of 21 weeks in accordance with the methodology used by The Ohio Lepidoptera Society Long-term Monitoring Program.

Results/Conclusions

Thirty species of butterflies were documented. Of these, three common species were most abundant: cabbage white (31%), eastern tailed blue (20%), and the pearl crescent (15%). When species richness and diversity were compared, the restored prairie and wetland were similar. Both had greater numbers of species and greater Shannon-Weiner diversity indices when compared to the savannah and the non-native grassland (P < 0.0001). A permutational multivariate analysis of variance resulted in significance differences in community composition (P = 0.005). A clustering analysis illustrated the formation of distinct communities in each of the habitat types; some overlap existed between both the prairie and the wetland, and the grassland and oak pine savannah. With regard to environmental predictors, butterfly species diversity and richness were best described by number of floral resources, relative humidity, and season. Of these, the number of floral resources was the strongest predictor (P = 0.0002, R² = 0.41). Habitat creation can serve as a biological refuge approach that sustains plant-pollinator interactions in a relatively short amount of time. Not only can restoration projects serve to mitigate damage to ecosystems, these strategies can help stimulate the return of basic ecosystem functionality through pollination services and increased resilience.