The effect of habitat restoration on plant-pollinator network structure through changes in floral richness

Pollinators and pollination services have become a prominent focus of research in the field of restoration and the management of natural lands as researchers and practitioners seek to understand how modifications of natural landscapes influence beneficial insects and the services they provide. We investigated the influence of distance from a remnant habitat and floral diversity on pollinator community composition and plant-pollinator network structure and stability at a restored strip mine in central Ohio. We found that increased distance from the remnant habitat was associated with decreased pollinator diversity regardless of floral diversity. Low floral diversity plots lacked uncommon pollinator species at greater distance from the remnant habitat but remained similar in overall composition. As a result, the plant-pollinator networks of low floral diversity plots far from the remnant habitat had lower connectedness, niche overlap, and network robustness. High diversity plots far from the remnant habitat, on the other hand, were comprised a significantly different pollinator community than plots of similar floral diversity close to the remnant habitat. Distant pollinator communities harbored proportionally more pollinators that acted as generalists. As a result, plant pollinator networks in these plots maintained a high level of network connectedness, pollinator niche overlap, and network robustness despite the experienced losses in pollinator diversity. Our study shows the importance of considering both the diversity of floral resources but also their distribution across a landscape when developing plans that promote the restoration of pollinator communities.