Archbold Biological Station
Biennial Report 1995-1996

P.O. Box 2057 Lake Placid, Florida 33862 USA
863-465-2571 FAX: 863-699-1927

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Accomplishments 1995-96

• Completed 2 experiments examining the effects of crown loss, fertilization, and canopy cover on palmetto flowering responses.

• Surveyed the occurrences and host-association patterns of cynipid gall inducers throughout Florida.

* Published 3 papers reporting the effects of the reintroduction of fire to long unburned Florida scrub, scrubby flatwoods, and flatwoods, as well as details of the population demography of palmettos.

• Two papers are in press reporting changes to the taxonomy of cynipid gall inducing insects as well as completing a project examining the ecological interactions of these gallers and their host oaks.

Plant-Animal Interactions and Fire Ecology

Project Director: Warren G. Abrahamson, Bucknell University
Project Assistants: Chris Abrahamson, Jill Abrahamson, Karen Ball, Michelle Chipaloski, Robert Scrafford
Post-doctoral Associates: George Melika, Uzhgorod State University, Ukraine; Gyórgy Csóka, Hungarian Forest Research Institute, Hungary

Oak-Gall Inducer Studies. One of the most intriguing arthropod feeding habits is that of gall-inducing insects. Uniquely, gall inducers alter the development of plant tissue to gain nutrition and shelter. One of the most speciose families of gall-inducing insects is the Cynipidae (wasps) which commonly infests oaks worldwide, and the oaks of Florida scrub are no exception. Ongoing studies are examining cynipid gall-inducer taxonomic and ecological relationships. Ukrainian entomologist, George Melika, joined us at Archbold (during Abrahamson's sabbatic at Archbold in 1994–95) for 7 months and in 1995–96 he spent 10 months at Bucknell University. Currently 41 genera of cynipid gall inducers are recognized throughout North America. Our revision of this insect group will reduce this number to 28 genera. In addition, a number of species previously unknown to science will be described including several endemic to the Lake Wales Ridge and to Florida scrub. Jonathan Brown (Grinnell Coll.) is collaborating with us to produce a generic level phylogeny for these gall-inducing cynipids. Brown's DNA-based phylogenies are compared with phylogenies generated using morphological characters. A second collaborator, Gyórgy Csóka (Hungarian Forest Research Inst.) spent 6 weeks at Archbold in 1995 initiating an ongoing study of cynipid gall-inducer occurrence by habitat, oak species, and host-plant organs. Cynipid gall inducers are strongly host specific. No Florida cynipid that induces galls on members of the white-oak subgenus has been found to stimulate galls on members of the red-oak subgenus or vice versa. Furthermore, cynipid gall inducers recognize similarities among their host plants. For example, most gall inducers infesting the endemic Quercus inopina are found on its widespread progenitor Q. myrtifolia. The maximum richness of cynipids occurs on myrtle oak and the number of cynipids attacking oaks increases with time since fire and with tree size. Funding is from National Science Foundation, Bucknell's Burpee Endowment, a Smithsonian travel grant, and Archbold Biological Station.

Fire Response and Palmetto Demography Studies. Understanding the role of fire in altering the growth and reproductive patterns of the plant species composing fire-adapted ecosystems is critical to natural areas management and to the preservation of biodiversity. We are continuing our long-term studies exploring the reintroduction of fire to long-unburned plant communities and palmetto responses to fire. Our studies have shown that single-event fires in long-unburned stands do not restore populations of herbaceous endemics. Our work with palmettos shows that they quickly resprout; recently burned palmettos have elevated numbers of leaves and photosynthetic ability during the post-fire recovery period. The occurrence of flowering palmettos increases greatly after fire compared to preburn periods. Flower abundance depends on preburn biomass and light availability but not soil fertility level. This work is supported by Bucknell's Burpee Endowment and Archbold Biological Station.



blkball.gif (842 bytes)Lohrer, F.E . (Editor). 1998. Archbold Biological Station, Biennial Report 1995-1996. Archbold Biological Station, Lake Placid. 62 pp.
© Archbold Biological Station, 1998, October.
blkball.gif (842 bytes)Webmaster: Fred Lohrer.