U.S. Air Force Col. John J. Allen Jr., 633rd Air Base Wing commander, and Col. David Chisenhall, 633rd Mission Support Group commander, pose for a picture with children from the Langley Child Development Center at Langley Air Force Base, Va., April 25, 2013. The tree planting ceremony was part of a week-long Earth Week celebration at Langley. (U.S. Air Force photo by Senior Airman Kayla Newman/Released)