Assessment of Floral Nectar and Amino Acid Yield in Eight Landscape Trees for Enhanced Pollinator Food Resources in...

Urban environments pose challenges for pollinators due to habitat loss and limited floral resources. However, green infrastructure, particularly street and ornamental trees, can play a critical role in supporting urban pollinator communities. In this study, we evaluated nectar volume, sugar content, and amino acid composition across eight urban tree species commonly planted in South Korea. Using standardized productivity metrics at the flower, tree, and hectare scales, we compared their nutritional contributions. Our results revealed substantial interspecific differences in nectar quantity and composition. Tilia amurensis, Heptacodium miconioides, Aesculus turbinata, and Wisteria floribunda exhibited high nectar yields or amino acid productivity, whereas species such as Cornus kousa, though lower in nutritional yield, may offer complementary value due to their distinct flowering periods or other phenological traits. These findings underscore the importance of selecting tree species not only for aesthetic value but also for ecological function, providing an evidence-based approach to pollinator-friendly urban biodiversity planning and landscape management.