Effects of nectar secondary compounds on pollination of co-flowering species in a natural community

Abstract

Floral nectar provides crucial energy sources for diverse animals, many flowering species produce nectar to reward flower visitors, which provide pollination services for flowering plants. In addition to sugars and amino acids, the nectar of many plant species often contains secondary compounds such as alkaloids and phenolics, which are associated with plant defense against herbivores. The composition of nectar may influence an entire assemblage of local visitors and animal鄄 pollinated plants, but the basis for nectar resource selection is complex. Species co鄄existence and community assembly mechanisms depend on links between consumers and resources. A previous feeding trial showed that a sugar solution can motivate honey bees to use nectar containing plant defense chemicals (toxic nectar). Toxic鄄nectar plants are thus expected to be tightly linked with other non鄄toxic or less toxic floral resources for sharing pollinators, while general impacts of toxic nectar on plant communities have been little investigated. Most previous studies of the ecological and evolutionary significance of nectar secondary compounds have focused on the benefits to the plants that produce these compounds. For example, feeding experiments have shown that honey bees prefer to collect nectar containing secondary compounds.