Document: TEN-3-69-32

Typhoon disturbance and dynamics of undercanopy light environments at a subtropical rain forest in Taiwan.

LIN, T.* ¹, S.P.HAMBURG ² and H.KING ³

National Changhua University of Education, Changhua, 500, Taiwan ¹
Taiwan Forestry Research Institute, Taipei, 100, Taiwan ²
Brown University, Providence, Rhode Island, 02912-1943, U.S.A. ³

Abstract:
Typhoon influenced subtropical forests remain untouched compared to hurricane influenced forests. We examined dynamics of undercanopy light environments at a subtropical rain forest in Taiwan. Light levels beneath the canopy (> 5% of that in the open) were substantially higher than that reported for many tropical and temperate forests. Defoliation associated with the frequent typhoons played a critical role on the dynamics of undercanopy light environments. Mean undercanopy light levels were 40% of that in the open after typhoon passage. Seedlings of canopy tree species did not occupy microsites with higher light levels than the random background light levels. Light did not seem to limit seedling distribution in the studied forest. Gaps in the studied forest tended to be small relative to many wind damaged forests. Light levels did not differ significantly between gaps and the frequently defoliated undercanopy. The forest probably does not depend on gaps for regeneration. Typhoon disturbance damaged individual trees but there was no sign of differential damages among tree species. Because typhoons occur very often, the forest is continuously disturbed and in recovery. Typhoons may act, therefore, like a stablizing force, keeping the forest in a dynamic equilibrium state.

Keywords: Typhoon, undercanoy light environment, gap, defoliation

This abstract is being presented at: 9:45 AM in session:
Oral Session #42: Disturbance Ecology: Effects of Storms.