Data from: Aridity and forest age mediate landscape scale patterns of tropical forest resistance to cyclonic storms

Cyclonic storms, or hurricanes, are expected to intensify as ocean heat
energy rises due to climate change. Ecological theory suggests that
tropical forest resistance to hurricanes should increase with forest age
and wood density. However, most data on hurricane effects on tropical
forests come from a limited number of well-studied long-term monitoring
sites, restricting our capacity to evaluate the resistance of tropical
forests to hurricanes across broad environmental gradients. In this study,
we assessed whether forest age and aridity mediate the effects of
hurricanes Irma and Maria in Puerto Rico, Vieques and Culebra islands. We
leveraged functional trait data for 410 tree species, remotely sensed
measurements of canopy height and cover, along with data on forest stand
characteristics of 180 out of 339 forest monitoring plots, each covering
an area of 0.067 ha. The plots represent a broad mean annual precipitation
(MAP) gradient from 701 to 4598 mm and a complex mosaic of forest age from
5 to around 85 years since deforestation. Hurricanes resulted in a 25%
increase in basal area mortality rates, a 45% decrease in canopy height,
and a 21% reduction in canopy cover. These effects intensified with forest
age, even after considering proximity to the hurricane path. The links
between forest age and hurricane disturbances were likely due the
prevalence of tall canopies. Tall forest canopies were strongly linked
with low community-weighted wood density (WD). These characteristics were
on average more common in moist and wet forests (MAP > 1250 mm).
Conversely, dry forests were dominated by short species with high wood
density (WD > 0.6 g cm-3) and did not show significant increases in
basal area mortality rates after the hurricanes. Synthesis: Our findings
show that in dry forests selection towards drought tolerant traits, such
as short stature and dense wood, enhances resistance to hurricanes.
However, forest age modulated responses to hurricanes, with older forests
being less resistant across the islands. This evidence highlights the
importance of considering the intricate links between ecological
succession and plant function when forecasting tropical forests responses
to increasingly strong hurricanes.