PARENT SESSION
Tuesday, August 8, 1:30-5:00 pm
COS 36 - Pollination ecology I
L-13, Lobby Level, Cook Convention Center
Presiders: S Travers and R Spigler

Pollination ecology in Everglades National Park, FL, US: community structure and plant-pollinator specificity.

Pascarella, John^{1, 2}, Waddington, Keith¹, ¹ University of Miami, Department of Biology, Coral Gables, FL² Valdosta State University, Department of Biology, Valdosta, GA

ABSTRACT- We conducted a regional, habitat, and microhabitat survey of the flower-visiting insect fauna of Everglades National Park (ENP), Florida, from 1995-1999 and recorded their interactions with flowering plants. We addressed the following questions: (1) How do the different regions, habitats, and microhabitats within ENP vary in relative abundance of major flower-visiting insect groups?; (2) How nested are pollinator webs and what is the level of specificity in plant-pollinator interactions?; (3) What floral and plant traits (shape, color, symmetry, geographic origin, and life form) are related to visitation by different insect groups? We sampled flower-visiting insects in three main regions of ENP (northern wetland, central pineland, and coastal mangroves) using observations, sweep nets, and timed walks of fixed length from 1995-1999. Over the five-year period, we recorded 7088 interactions between 220 insect taxa and 181 plant taxa. The majority of records were of bees (53%), followed by Lepidoptera (16%), flies (12%), beetles (11%), and wasps (8%). Relative abundance was similar across and within different habitats in the regions. Most insect groups, with the exception of the bees, were represented by a few common species and many rare species. Within all regions, habitats, and microhabitats, plant-insect interactions were significantly nested. Using just plants and insect taxa with greater than 10 records, we found a low level of specialization for both groups. For insects (N = 89), the mean number of plant species visited was 17.7 ± 13.1 (1 SD). For plants (N = 89), the mean number of visitor taxa was 18.9 ± 19.1. Twenty-six percent of plant species were visited by all five insect groups. Significant correlations were found in the percent species composition and percent visitation among insect groups. For example, visitation by bees was significantly negatively correlated with visitation by all other groups, suggesting that flowers that attracted bees were not similarly attractive to other insect groups. When grouped by flower shape or floral symmetry, plants did not differ significantly in the relative composition of insect visitors. However, when grouped by flower color, geographic origin, and life form, groups were significantly different in the composition of insect visitors.

Key words: plant-animal interactions, pollination ecology, insects