THE ACFT COLLIDED WITH TREES ON FINAL APCH TO LAND AT A PVT AIRSTRIP. THE PLT STATED THAT ON EARLIER ATTEMPTS TO LAND HE WAS HIGH AND FAST. HE STATED HE INTENTIONALLY SLOWED THE ACFT AND USED LESS ALT IN ORDER TO NOT LAND TOO LONG ON THE AIRSTRIP. HE STATED THAT ON SHORT FINAL, THE ACFT DESCENDED BELOW THE TREE LINE BECAUSE OF A DOWNDRAFT. HE STATED HE ADDED POWER BUT WAS AFRAID THAT IF HE RAISED THE NOSE, THE ACFT WOULD STALL. THEREFORE, HE KEPT THE NOSE LEVEL AND FLEW THROUGH THE TREE TOPS. THE ACFT CONTACTED ONE LARGE TREE AND DESCENDED TO THE AIRSTRIP.