HURRICANE CAUSES RESOURCE AND POLLINATION LIMITATION OF FRUIT SET IN A BIRD-POLLINATED SHRUB

Abstract

Hurricanes can strip leaves from plants and provide other stresses that can reduce resource availability for subsequent reproduction. In addition, hurricanes commonly reduce populations of bird pollinators. I measured both resource and pollination limitation of fruit set for Bahama Swamp-bush (Pavonia bahamensis) on San Salvador Island in the Bahamas before and after two seasons of hurricanes. Before the hurricanes in the winter flowering season in 1994–1995, fruit set of P. bahamensis was 100% for most shrubs. After a mild hurricane, in 1995–1996, fruit set was 48%. After the severe Hurricane Lili (Category 2) in 1996–1997, mean fruit set was only 11%. In both years after the hurricanes, lower fruit set reflected resource limitation. In 1996–1997 after Hurricane Lili, fruit set was severely reduced an additional 74% by pollination limitation. Pollination limitation was caused by declines of the two bird pollinators, Bananaquits and Bahama Woodstars. In 1994–1995, both species were frequent visitors to fl...