Human land use, including agriculture, is a leading contributor to declining biodiversity worldwide and can leave long-lasting legacies on ecosystems after cessation. One way to mitigate these impacts is through habitat restoration. However, little is known about how animal communities and plant-animal interactions respond to land use legacies and restoration. We investigated how experimental restoration through canopy thinning of remnant (no history of agriculture) and post-agricultural longleaf pine (Pinus palustris Mill.) woodlands (n=63 of each) affects pollinator communities and pollination function. To study pollinator communities, we collected bees using a combination of pan trapping and standardized netting transects. In order to measure pollination function, we conducted a sentinel plant experiment in which potted black mustard (Brassica nigra (L.) W.D.J. Koch) plants were placed out in a subset of our sites and either bagged to exclude pollinators or left open for pollinator access. Then we measured fruit and seed set of sentinel plants to compare pollination function among the restoration and land use history treatments.
Results/Conclusions
Bee abundance and richness were higher in sites which had been restored by canopy thinning, but were not affected by historical land use. Bee community composition was affected by restoration (p < 0.001) and was marginally affected by land use history (p = 0.06). Seed set (p < 0.001) and fruit set (p = 0.006) of sentinel plants was lower in bagged plants compared to open plants, indicating that the model system effectively measured pollination in our study. However, we found no differences in pollination based on restoration or land use history. These results indicate that although pollinator communities may show clear responses to restoration, this does not necessarily translate into differences in how effectively understory plants are pollinated after restoration. More broadly, our work illustrates that faunal communities may respond similarly to land-use legacies and restoration activities, compared to the more commonly studied plant communities.