Urbanization has a dramatic influence on biodiversity due to a replacement of native habitats by the built environment, landscaped areas, and gardens. Pollinators, such as bees and other insects, are receiving attention due to concern over their decline, and it is important to understand how urban environments influence their distribution and activity. In this study, we investigated the influence of different urban landscapes on the distribution and diversity of bees and other pollinators on the large metropolitan campus of the University of Central Florida. The project consisted of two parts. The first was to characterize the quality of landscape beds as pollinator habitat, by evaluating the areal coverage and pollinator quality of plant species in randomly selected landscape beds totaling approximately 10% of the total area of landscape beds on campus. Plant species were categorized on a scale of 1-5 of increasing pollinator habitat quality based on known characteristics of the species. The second phase of the project involved assessing pollinator activity, by monitoring flower visitation rates, and pollinator diversity on 5 different sampling dates from June through October, 2017, from three different landscape habitat types on campus: landscape beds, specialty gardens, and semi-natural woodland margins.
Results/Conclusions
Of the 75 total plant species observed in landscape beds the highest percentage of plants (45%) fell in the lowest category of pollinator habitat quality and only 7% of species were of the highest pollinator quality. The area coverages of the different categories were similar to the total species in each group, with the highest quality species covering the least area. Firebush (Hamelia patens), a native flowering shrub was the high quality pollinator plant that covered the greatest area in landscape beds. Flower visitation rates were much greater in the specialty and pollinator garden habitats than in flowering landscape beds. Average flower visitation rates for landscape beds, wild margins, and specialty gardens were 1.1 ± 1.5, 2.4 ± 3.4, and 8.2 ± 6.5, visits per m2 per minute. Pollinator gardens had the highest diversity of bees and wasps, among the three habitat types, but overall diversity in the developed landscape was much lower that the diversity observed in another study of pollinators occurring across three different habitat types in natural areas on campus.These results indicate that the campus landscape beds provide relatively poor resources for pollinators, and that pollinator abundance and diversity could be increased by incorporating more pollinator-friendly species in campus landscapes.