Document: MAR-3-48-34

Belowground overcompensation in response to floral predation in a clonal perennial.

TOBLER, M.*, P.A.VAN ZANDT and S.MOPPER

University of Louisiana at Lafayette, Lafayette, LA 70504, U.S.A. ¹

Abstract:
Numerous studies have focused on a plant's ability to compensate for lost tissue when attacked by herbivores. However, a majority of these studies have used annuals or biennials to examine aboveground vegetative and sexual reproductive biomass, seed set, and changes in architecture when apical meristimatic tissue is lost. In contrast, our research focuses on belowground compensation in a long-lived clonal perennial, which in the field is frequently exposed to high levels of vertebrate floral predation as well as salinity stress. We conducted a common garden experiment to examine the consequences of sexual reproductive loss and saline soil conditions on the compensatory ability of a native Louisiana iris (Iris hexagona). We found that when all flowers were removed from plants, belowground biomass increased 24% compared to plants with flowers. In addition, rhizome volume increased in all three clonal genotypes but rhizome number did not. Salinity negatively affected the belowground biomass of one clonal genotype, but there was no interaction between the salinity and flower removal treatments. These results were linked with field data from a salt marsh island iris population that show deer floral predation greater than 99 % for 10 isolated patches.

Keywords: clonal reproduction, compensation, overcompensation, plant-animal interactions, salinity stress

This abstract is being presented at: 3:30 PM in session:
PLANT-ANIMAL INTERACTIONS