PARENT SESSION
Oral Session #81: Pollination and Dispersal.
Presiding: T. Ricketts
Thursday, August 8. 9:00 AM to 11:30 AM. Grand Ballroom Central, Radisson.

How well do floral characteristics predict plant-pollinator interactions in a montane meadow community?

Alarcon, Ruben^*,1, ¹ University of California, Riverside, Riverside, CA

ABSTRACT- In recent years there has been renewed discussion of specialization in plant-pollinator interactions and the predictive value of pollinator syndrome characteristics. Floral characteristics are often interpreted as adaptations to specific pollinators or groups, such as bees or moths. However ecological studies often reveal that there is a great deal of generalization in plants and pollinators and that pollinators are not restricted to their purported "specialized" flowers. I surveyed plant-pollinator interactions in a montane meadow in the San Bernardino Mountains of Southern California, scoring the floral characteristics typically used to ascribe plants to syndromes for comparison with visitation profiles. I recorded nearly 1500 interactions between 37 angiosperm species and over 140 floral visitor species. Pollen loads were examined on 960 insects to determine if the visitors were potential pollinators or "robbers." The visitor community was dominated by a diverse group of Diptera and Hymenoptera. Most plants were generalists, being visited by a range of 1-60 visitor species, with an average of nearly 10. In addition, different taxonomic groups of visitors carried varying amounts of pollen, with Hymenoptera carrying the most. The flowering plants with the greatest diversity of visitors tended to possess small, open white flowers with accessible nectar. Visitation patterns and degree of specialization are further discussed in relation to floral characteristics.

KEY WORDS: generalization, plant -pollinator interactions, pollination syndromes, specialization