Benefits and limitations of isolated floral patches in a pollinator restoration project in Arizona

This study examined invertebrate floral visitor responses to floral richness, floral abundance, and distance between floral patches within a newly planted pollinator restoration habitat in an arid ecosystem in central Arizona, United States. We created a pollinator habitat experiment consisting of a large central garden (11-m diameter) surrounded by concentric rings of smaller habitat patches (1-m diameter), separated from one another by 1, 8, 13, and 21 m, respectively, and including four flowering species. We observed plant and visitor interactions via structured 10-minute flower visitation observations over a 3-month period. Key findings included: (1) each plant species interacted with a variety of flower visitors, but flower visitor groups differed only marginally among the plant species; (2) floral patches outside the central garden exhibited reduced quantities of floral structures; and (3) number of floral structures per patch, but not isolation of floral patches within the habitat, affected the number of visitors and visitor taxa richness. For practitioners and land managers looking to restore pollination systems in arid ecosystems with low establishment via seeding, the results of this study suggest that installing species-rich and florally abundant patches of flowering plant species within a habitat could efficiently support plant-pollinator interactions.