The private pilot and non-rated passenger were departing the airfield on runway 24. After becoming airborne they encountered several wind gusts which the pilot said "pushed the plane down and to the left." The float-equipped airplane caught one of the floats in the trees off the departure end of the runway and the airplane nosed over and impacted the ground. The pilot was not injured, the passenger received minor injuries, and the airplane sustained substantial damage to the fuselage frame forward of the cockpit. The pilot reported that the maximum gross weight for the airplane was 1,200 pounds and the weight at the time of the accident was 1,191 pounds. The pilot stated the winds were variable at ten knots with gusts to 15 knots. At 1152 Central Daylight Time (CDT), the reported winds at Springfield, MO (KSGF), 8 miles east of the accident site, were 060 degrees at 16 knots, gusting to 21 knots. Winds at KSGF at 1252 CDT were 090 degrees at 13 knots, gusting to 21 knots.