PARENT SESSION
Poster Session 31: Rare, Threatened, and Endangered Species
Thursday, August 11, 5:00 PM - 6:30 PM, Exhibit Hall 220 A-E, Level 2, Palais des congrès de Montréal
Do Calamintha ashei's allelopathic properties affect other Florida scrub plants?
Calabrese, Laura*,1, Menges, Eric2, 1 University of New Mexico, Albuquerque, NM2 Archbold Biological Station, Lake Placid, FL
ABSTRACT- The effect of Calamintha ashei's allelopathy on the distribution of other Florida scrub species was evaluated in the field, in both intact scrub and degraded scrub. An experimental treatment involving the removal of C. ashei aboveground biomass and the application of activated carbon was carried out in order to remove the potential source of allelochemicals and to neutralize any remaining in the soil. It was expected that this treatment would result in an increase in species diversity due to the emergence of seedlings in the absence of C. ashei (as germination would have been suppressed in the presence of the allelopathic chemicals). There was a higher overall species richness in the absence of Calamintha ashei than in its presence. There was also higher herb/graminoid density and species richness in its absence. Only three species showed any specific patterns of association with C. ashei; Vaccinium myrsinites (negative), Serenoa repens (negative), and Sabal palmetto (positive). However, these associations are more likely a reflection of microhabitat preferences rather than allelopathic effects. The plant communities of intact and degraded scrub sites differed significantly in their species compositions. The densities of several species were greater in intact scrub (Selaginella arenicola, Vaccinium myrsinites, Lechea deckertii), while that of others was greater in degraded scrub (Rhynchelytrum repens, Opuntia humifusa, Mimosa quadrivalvis var. floridana, Polygonella robusta, and Smilax spp.). Lichen species diversity was also significantly higher in intact scrub than degraded scrub. The C. ashei removal treatment did not yield any significant increases in the germination of other species. Therefore, a field and/or laboratory study involving the direct application of leachate and the manipulation of water and other resources may be useful to determine whether Calamintha ashei is affecting other species via competition for resources or via the production of allelopathic chemicals.′′
Key words: Calamintha ashei, allelopathy, Florida scrub