Print PageOn May 8, 2009 an intense wind and thunder storm, later classified as a ‘super derecho’ swept across parts of Kansas, Missouri and southern Illinois with estimated wind gusts of up to 150 km h-1. Intense windstorms can play a critical role in the stand dynamics of central hardwood forests, yet opportunities to study them are limited. In order to investigate the impacts of the super derecho, we sampled 54 forested plots (0.04 ha) located in the Shawnee National Forest in southern Illinois. The sampled plots are part of a long-term monitoring system and were situated across a gradient of topographic positions. Plots had been previously sampled one year prior to the storm event, and were subsequently resampled one year following the storm. Overstory trees (≥ 6.6 cm dbh) and saplings were tallied and recorded by species in each plot and used to compare changes in basal area and stem density following the storm.
Results/Conclusions
Storm related mortality ranged from 0-100% across all plots, which decreased total overstory basal area and stem density following the storm event (P< 0.001). Nearly all of the plots (96%) suffered some storm related damage. Across the landscape, tree communities were most closely related to slope position and elevation, and this relationship did not change post-storm. Prior to the storm, Quercus spp. dominated the landscape, but appeared to suffer the heaviest losses among all species, accounting for 62% and 37% of all reductions in basal area and stem density, respectively. Post-disturbance succession will most likely favor species that survived the storm, possibly altering the long term species composition of this area.
