PARENT SESSION
Organized Oral Session 4: Tropical cyclone disturbance and forest dynamics at multiple temporal scales: results from long-term studies in the new and old worlds
Organizer(s): T Lin, H King, and SP Hamburg
Monday, August 8, 8:00 AM - 11:30 AM, Meeting Room 511 B, Level 5, Palais des congrès de Montréal

Tropical cyclone disturbance and forest dynamics at multiple temporal scales: Results from long-term studies in the new and old worlds.

Vandermeer, John^*,1, ¹ Department of Ecology and Evolutionary Biology, Ann Arbor, MI, USA

ABSTRACT- The effect of catastrophic disturbance on forest structure was studied for ten years subsequent to the landfall of Hurricane Joan in 1988. Four sites within the damage area and one control site outside of the area were established in the early 1990s and positions and sizes (DBH and crown height) were measured annually. Results of the study are reported in the context of the debate between equilibrium versus non-equilibrium models of tropical forest dynamics. Four or five years after the disturbance two distinct canopies had developed; 1) a larger but diffuse canopy made up of the tress that had survived the hurricane standing and had begun resprouting high in their damaged crowns and 2) a "thinning canopy" of very densely packed crowns of small individual trees, resulting from the growth of surviving saplings and seedlings and trees that had sprouted near to the ground. Competitive thinning has begun to occur in this dense lower canopy. Since the disturbance, accumulation of species has been great, ranging from 134% to 208%. Mortality patterns in the thinning canopy suggest that trees are dying at random, with respect to species identity, and thus supports a non-niche-based model of forest regeneration.

Key words: hurricane Joan, tropical forest dynamics, thinning canopy, non-niche-based model