U.S. Air Force Col. David Stanfield, 633rd Mission Support Group commander, presents a Certificate of Appreciation to Barbare Krumpon, Virginia Cooperative Extension volunteer, during an Arbor Day event at Joint Base Langley-Eustis, Va., April 21, 2017. Krumpon and two other volunteers surveyed every tree on Langley Air Force Base for three consecutive years and discovered there were more than 70 different tree species on the installation. (U.S. Air Force photo/Senior Airman Derek Seifert)