The pilot provided a written statement to the Safety Board investigator. He reported that he departed from runway 25 during gusty wind conditions. At 800 feet above ground level, he turned the airplane onto the crosswind leg and the left wing went down. The pilot recovered the airplane, added full throttle, and the airplane continued to descend. The pilot pulled back on the yoke to make the airplane climb; however, the airplane continued to descend. The airplane impacted trees and sustained substantial damage. According to the nearest aviation weather reporting system that was located at the airport, winds were from 290 degrees at 16 knots, gusting to 21 knots. The Federal Aviation Administration inspector examined the airplane and found no mechanical anomalies that would have resulted in a loss of airplane control.