Severe weather events are becoming more common, increasing the potential for damage and mortality in forests. Decision-makers at all levels need rapid yet reliable estimates of storm damage to inform disaster funding and to guide response efforts. With its expansive network of permanent plots, the Forest Inventory and Analysis (FIA) program is uniquely poised to be a reliable source of answers.

The Midwest Derecho of August 10-11, 2020, produced powerful straight-line winds and traveled 770 miles across Iowa and adjacent states. The storm damaged structures, crops, and trees and knocked out electrical power for approximately 1 million people. It was the most expensive thunderstorm-related event since 1980. Scientists with the Northern Research Station’s Forest Inventory and Analysis (FIA) program, in cooperation with the Iowa Department of Natural Resources, produced a rapid assessment of the windstorm’s impact on Iowa forest land. By combining data from the FIA plot network with a post-storm aerial survey, scientists estimated that 2.7 million trees were damaged or killed. Using FIA data allowed researchers to not only estimate the number of trees damaged and killed, but also estimate volume, species affected, and damage type (branch or bole), variables not readily observable in aerial surveys. This work laid the foundation for making rapid assessments and improving access to post-storm information. Future enhancements to methodology are planned.