PARENT SESSION
Poster Session 34: Herbivory
Thursday, August 11, 5:00 PM - 6:30 PM, Exhibit Hall 220 A-E, Level 2, Palais des congrès de Montréal

Resource allocation and sex-biased herbivory in Cecropia obtusifolia.

Palomino, Martha^*,, Dirzo, Rodolfo,

ABSTRACT- We compared resource allocation patterns and herbivory between male and female plants of the dioecious tree Cecropia obtusifolia. Our study found that plant gender affected resource allocation, which had important consequences for herbivory. We found that although male and female plants did not differ in total biomass allocated to reproduction, they did differ in the way in which the resources were allocated. Male plants produced more inflorescences, but with less biomass per unit influoresence, while female plants produced less infructescences, but with more biomass per unit infructescence. Male and females plants also differed in allocation to growth and defense, with males having higher growth rates but less chemical and structural defenses than females. As predicted by resource allocation theory, the variation we observed in growth, defense, and reproduction corresponded to differences in herbivore feeding preferences. Both in the field censuses of herbivory and in the foliage palatability bioassay, we consistently found that males were preferentially consumed over females. Our study adds to the existent evidence of sexual dimorphism in dioecious plants

Key words: sex-biased herbivory, resource allocation, Cecropia obtusifolia