Document: HSI-3-45-1

Fate of fruits and seeds of Formosan sassafras.

YUAN, H.* and J.TSAI

National Taiwan Univ., Taipei, Taiwan ¹

Abstract:
Formosan Sassafras (Sassafras randaiense, Lauraceae), a rare tree species endemic to Taiwan, is patchily distributed from 900-2400 m above sea level. Its fruit, about 9 mm in diameter, is consumed by wildlife. We monitored the fate of the fruits and seeds of 9 trees growing at 2000 m above sea level on Chilan mountain, northern Taiwan. For 4 to 5 consecutive days each week, from Apr.-Sept. 1999, we counted the number of fruits on selected infructescences and recorded the numbers and types of fruit consumers by direct observation (diurnal) and with infrared cameras (nocturnal). Animals removed most sassafras fruits (88.1%), while 11.9% fell from the parent tree. The fruiting peak of each tree lasted about one week, and all 9 trees reached their fruiting peak from July 15-30. The percentage of fruit removed directly by mammals or birds was not significantly different for different trees. Fruits were removed by red-bellied squirrels (Callosciurus erythraeous) (18.31%), which were seed predators, and ten species of birds (69.75%) that were legitimate seed dispersers. Birds in the Timaliidae removed 61.8% of all sassafras fruits. The Formosan field mouse (Apodemus semotus), Formosan white-bellied rat (Niviventer culturatus) and Formosan black-bellied vole (Eothenomys melanogaster) consumed most of the fruits and seeds that fell to the ground, destroying the seeds.

Keywords: Formosan sassafras, fruits, seeds

This abstract is being presented at: 10:30 AM in session:
DISPERSAL