PARENT SESSION
Oral Session # 65: Herbivory V: Deer, Geese, and Chemistry.
Presiding: K Bjorndal
Thursday, August 7. 8:00 AM to 11:30 AM, SITCC Meeting Room 103.
Deer florivory influences arthropod biodiversity in a southern brackish wetland.
Geddes, Neoma*,1, Mopper, Susan1, 1 University of Louisiana at Lafayette, Lafayette, LA, USA
ABSTRACT- Interactions between plants and herbivores are multifaceted. Herbivores can drastically alter the appearance of landscapes, and their overabundance not only affects primary production but can also have far-ranging effects on other trophic levels. Although herbivory has been a traditional research focus, florivory may alter community dynamics uniquely. Here, we report on an interaction between white-tailed deer (Odocoileus virginianus), blue flag iris (Iris hexagona), and arthropods associated with I. hexagona. Reproducing both sexually and clonally, I. hexagona is a native perennial wild flower that occurs throughout the southeastern Gulf Coast. Our study focused on the recently isolated I. hexagona populations that are found on Marsh Island, Louisiana. After establishing remote infrared camera systems at two Marsh Island sites, the organism responsible was determined conclusively to be white-tailed deer. First, we report on a field survey of the occurrence of complete florivory (entire flowers and immature seed capsules are browsed and seed production eliminated) at a total of ten I. hexagona populations located on Marsh Island, LA. Second, we present arthropod data collected from within and without experimental deer exclosures that were established to protect flowers from browsing. We discuss the implications of deer florivory on the more than forty-five arthropod species collected, among them native ants (Crematogaster sp. ) that are unique colonists of iris seed capsules. This research was supported by National Science Foundation grant DEB-0124901.
Key words: Iris hexagona, floral herbivory, white-tailed deer, Odocoileus virginianus