Twenty year response of coastal plain forests from Hurricane Hugo in South Carolina, USA

Background/Question/Methods

In 1989, Hurricane Hugo inflicted catastrophic damage on approximately 1.8 million ha of forested land in South Carolina. This study’s purpose was to monitor species compositional shifts in several forest types following the disturbance from Hurricane Hugo. The immediate consequences of hurricane damage are well documented. However, there has been little research done on the long-term compositional and structural changes that may result from hurricane disturbance, especially in temperate forest ecosystems. Fifty plots were monitored within four study areas, receiving varying degrees of hurricane damage; Beidler Forest, Santee Experimental Forest, Hobcaw Barony, and Congaree National Park. Inventories included species density, damage class, and DBH. The objectives of this study were to 1) discover whether the coastal forests damaged by Hurricane Hugo are regaining pre-hurricane structure and composition; 2) compare the recovery speed of wetland forests, e.g. bottomland hardwood swamps and cypress tupelo swamps, to that of upland pine and hardwood forests; 3) To discover how the degree of hurricane wind damage can affect the timing and the pattern of forest recovery in the coastal plain.

Results/Conclusions

Over the 20-year study period, most sites have begun to regain pre-hurricane composition. We have examined the expected gradual increase in basal area following the disturbance. Sapling populations in most species increased dramatically and some of these populations have begun to thin. These results suggest that common southeastern species are resilient to hurricane wind damage. In several forest types, loblolly pine (not a predominant species at these sites) responded quickly and overtook some dominant species in basal area and tree/sapling abundance. In cypress-tupelo forests of Hobcaw Barony, the basal area of loblolly pine increased to nearly fifty times the initial level by 2013. Several other species that were not a major component of the tree strata (wax myrtle, green ash, water ash) showed a large increase in sapling population, taking advantage of the increase in site resources. Overall, recovery speed and species resilience was variable among forest types and study sites.