The pilot reported that he landed on the grass airstrip and while taxiing, a gust of wind from the right caused the airplane to ground loop to the left. The pilot stated that he believed the gust of wind came from a powerline clearing that was perpendicular to the runway. The airplane struck a fence during the. Initially, the damage was not believed to be substantial. Later examination of the airplane revealed that the front spar of the right wing was cracked. There were no systems anomalies with the airplane.