PARENT SESSION
Oral Session #44: Disturbance ecology of forests: Animals, wind, gaps, edges. Presiding: S. Archer.
Wednesday, August 8, 2001. 8:00 AM to 11:45 AM. Hall of Ideas G.
Predicting susceptibility to damage following hurricanes in a subtropical moist forest.
Ostertag, Rebecca1,2, Silver, Whendee 1,2, Lugo, Ariel2, 1 2
ABSTRACT- Hurricane winds can cause severe damage to tropical forest ecosystems, altering forest structure and resource availability, but the degree of tree damage is not evenly distributed across the landscape. We examined tree damage in long-term permanent plots in a subtropical moist forest in Puerto Rico following Hurricane Georges. These plots contained a mixture of native and non-native species. Severe damage included uprooted trees, snapped stems, or crowns with greater than 50 % loss. Hurricane induced mortality after 21 mo was 9.1 %, thirteen times higher than background mortality levels during non-hurricane periods. Species differed greatly in their mortality and damage patterns, but there was no relationship between damage and wood density or biogeographic origin. Rather, damage was correlated with mean annual increment, with faster growing species experiencing greater damage. Size (dbh, crown class) was also predictive of damage, with larger trees suffering more damage. Topography had no significant effect on damage patterns. A strong relationship was noted between previous hurricane damage and present structural damage. We suggest that resistance of trees to hurricane damage is therefore not only correlated with individual and species characteristics but also with past disturbance history, which suggests that in interpreting the effects of hurricanes on forest structure, individual storms cannot be treated as discrete, independent events.
KEY WORDS: hurricane damage, legacies, non-native species