Arneson, Laura C , Tepedino, Vincent J. .
The unusual pollinator associations of Iliamna bakeri (Malvaceae), a rare, fire-following forb endemic to the Modoc plateau region (CA).
Iliamna bakeri (Malvaceae), declared a sensitive species in 1999 by the Forest Service and that states of California and Oregon, was at this time a little-known species. Preliminary studies and collections pointed to range-wide variability in pollinator associations, as plants in the northern periphery were visited haphazardly by generalist species (and were self-compatible) but one collection in the central range suggested a specialist bee association (Diadasia nitidifrons: Apidae). I surveyed nine sites in the central range of I. bakeri in northeastern California to investigate reproductive success variability and explore pollinator associations in more depth. I found reproductive success was highly variable among sites and the specialist bee association was consistent across all nine sites where I conducted systematic observations. Visitation rates to I. bakeri flowers were also highly variable, and I found a significant correlation between visitation rate by the specialist bee and the proportion fruits set per flower. I also discovered that plants in the central range were self-incompatible, in contrast to plants at the northern periphery. These results led me to a more systematic comparison of D. nitidifrons and generalist bee visitors in central-range sites in how their pollination behavior may affect I. bakeri success. I found several lines of evidence that specialist bees are in fact beneficial to I. bakeri, supporting the counter-intuitive notions that rare fire-followers can have specialist pollinators and that these bees are not necessarily pollen parasites on their host plants.
1 - Utah State University, Department of Forest, Range, and Wildlife Sciences, Logan, Utah, 84322-5230
2 - Utah State University, Department of Biology, College of Science, 5305 Old Main Hill, Logan, Utah, 84322-0305, United States
Presentation Type: Poster
Location: Special Event Center (Cliff Lodge)
Date: Tuesday, August 3rd, 2004
Time: 12:30 PM