Aridity and forest age mediate landscape scale patterns of tropical
forest resistance to cyclonic storms
Abstract
Ecological theory holds that tropical forest resistance to hurricanes
should increase with stand age and aridity. However, limited data beyond
a handful of long-term monitoring sites makes it hard to link resistance
to hurricanes with environmental gradients. We address this by using
trait data for 410 tree species, remote sensing metrics of canopy
structure, and 339 plots to assess whether forest age and aridity
mediate the impacts of two hurricanes in Puerto Rico. Hurricanes caused
a 45% and 21% decrease in forest canopy height and cover,
respectively, with a 25% increase in tree mortality. Old forest stands
in wetter regions as well as those with tall canopies dominated by low
wood density species were the most affected. Interestingly, high
resistance to hurricanes was related to enhanced drought tolerance.
These results highlight crucial complexity to include when forecasting
the fate of tropical forests to increasingly stronger hurricanes in a
changing climate.