OOS 32-6 - An integrative model for understanding ecological and economic risk from hurricanes

Tropical storms such as hurricanes drive important ecological processes in forests including mortality, regeneration, carbon fluxes, and succession. Therefore, understanding hurricane regimes is critical for assessing the ecological impact of wind on various forest types. To date, hurricane regime studies focus on storm sizes and frequencies to deduce return periods generally, rather than distinguishing event probability across a range of wind intensities. Although minor hurricanes are more common, most hurricane research focuses on catastrophic events. However, it is unknown whether this research emphasis on catastrophic hurricane events is justified. Here, we present a classification of forest hurricane regimes for the eastern U.S. and Caribbean region and test the hypothesis that frequent minor hurricanes may cause more tree mortality than rare catastrophic hurricanes. By coupling meteorological and ecological models, we show that low-intensity hurricane winds may be responsible for most hurricane related mortality across the region and may play a larger role in shaping forests than previously realized. More generally, major insights on disturbance mortality patterns can be gleaned by examining disturbance occurrence and mortality profiles. We quantify major differences in forest hurricane disturbance regimes across the eastern U.S. and Caribbean and provide a framework for understanding the evolutionary and ecological role of wind disturbance in forests. Species traits related to windfirmness such as trunk strength, root adaptations, and crown properties may correspond to hurricane gradients. Quantitative characterization of forest hurricane regimes provides a critical first step for understanding the ecological and economic role of hurricane regimes in wind-prone forests.