Temporal Effects of Hurricanes on Fuel Loading and Regeneration
The frequency and severity of extreme weather events, including hurricanes, are expected to increase in response to global change. Concurrently, coastal southern US forests, will experience droughts that may facilitate a rise in the occurrence of wildfires. Wind damage can substantially alter fuel dynamics and forest structure in coastal forests by increasing their susceptibility to wildfire, especially during severe drought. To mitigate excessive fuel loading, managers commonly use salvage logging and prescribed fire, and time since disturbance may further reduce fuel loads through decomposition. To understand the effect of hurricanes on fuel loading, and the impact of time since disturbance and management action we compared fuel loads across four hurricanes: Hugo (1989), Opal (1995), Katrina (2005), and Ike (2008). Fuels and regeneration data were collected across five upland pine study sites located in South Carolina, Alabama, Mississippi, and Texas. Highly impacted stands (managed and/or unmanaged) were paired with an equal number of less impacted, control stands at each site. Fuels data were collected using Brown’s planar intercept method and tree regeneration was tallied by species. Fuel accumulations increased dramatically with disturbance but decreased and stabilized with time. With frequent prescribed fire, coarse woody debris decreased more rapidly than without fire. However, without prescribed fire, damaged stands had greater fuel loads than control stands, even after 24 years. Salvage logging reduced fuel loads across all fuel size classes. Although overstory mortality can provide growing space for regeneration of shade-intolerant species, effects from frequent prescribed fire override resource availability for recruitment. Presented by Lauren Pile, USDA Forest Service, at the 2018 SAF National Convention, Portland, OR.