Document: REB-3-69-6

Temporal dynamics of litter carbon and nutrients after hurricane disturbance in three tropical forests.

OSTERTAG, R.* ^1,2, F.N.SCATENA ² and W.L.SILVER ^1,2

University of California, Berkeley, CA, 94720, USA ¹
International Institute of Tropical Forestry, San Juan, PR, 00928, USA ²

Abstract:
While hurricane disturbances are known to cause large inputs of litter, transporting C and other nutrients to the forest floor and affecting seedling regeneration, little is known about the length of time these litter pulses affect forest ecosystems. We investigated these pulses in three tropical forests in Puerto Rico after the passage of Hurricane Georges by characterizing the initial litterfall and then harvesting litter from the forest floor monthly for one year. The three forest types (wet, moist, and palm-dominated) received different amounts of damage, and initial post-hurricane litter mass on the forest floor ranged from 1.5-2.5 times greater than pre-hurricane values. Green leaves deposited by the storm represented 5-26 % of the total input of mass but the N and P concentrations of these green leaves did not differ from brown leaf litter. Decay rates were exponential and were similar in the wet and moist forest, but slower in the palm-dominated forest. Nevertheless, at all sites forest floor mass returned to pre-disturbance levels within one year. The hurricane-added N was quickly lost as litter began to decay; P was retained in leaves and wood for approximately two months. Despite long-term damage to forest structure after hurricanes, the physical and biogeochemical effects of fine litter inputs appear to be short-lived, and may contribute to the resilience of these Puerto Rican forests.

Keywords: forest floor, hurricane damage, nutrient pulses, decomposition

This abstract is being presented at: 9:30 AM in session:
Oral Session #42: Disturbance Ecology: Effects of Storms.