THE PILOT ATTEMPTED TO TAKE OFF ON A 2400 FEET GRASS RUNWAY WITH THE GRASS 3 TO 4 INCHES HIGH AND A SLIGHT UPHILL INCLINE. THE OUTSIDE AIR TEMPERATURE WAS 82 DEGREES F AND THE WINDS WERE 010 AT 7 KNOTS. THE PILOT TOOK OFF ON A HEADING OF 270 DEGREES WITH 30 DEGREES OF FLAPS, 30 GALLONS OF FUEL AND 3 OCCUPANTS WEIGHING A TOTAL OF 432 LBS. THE AIRPLANE LIFTED OFF AT 45 KNOTS, CLIMBED SLOWLY, WITH THE LANDING GEAR DOWN. AT 200 FEET THE AIRPLANE NOSED OVER AND STRUCK TREES.