Upon arrival at the pilot's destination airport, the winds were calm, there was no ceiling, and the visibility was unlimited. Sunset had already occurred. Air traffic control directed the pilot to enter a left downwind for the active runway. The pilot then entered the left downwind for the runway at approximately 1,500 feet and confirmed the pattern altitude with air traffic control as there were nearby radio towers. The pilot elected to fly an extended downwind beyond the radio towers, turned left base and then final. On the turn to final, the pilot slightly overshot the runway centerline and then adjusted to align with the runway. Upon turning final, the tower controller realized the runway edge lights (MIRL) were at low intensity, advised him, and increased their intensity making the runway more visible. The runway end identifier lights (REIL) were out of service and the displaced threshold for the runway was unlighted. On final approach, the pilot heard a "thunk" sound and felt a slight jolt as if something had struck the airplane. The pilot continued the approach and landed, touching down beyond the displaced threshold and then taxied to the ramp. Post flight inspection by the pilot revealed that the right wing had a yellowish goo spattered on top of it, a large dent in the anti-ice panel on the leading edge of the outer part of the wing, a small dent in the anti-ice panel on the leading edge farther inboard on the wing, a third dent on the corner of the leading edge of the composite cap at the end of the wing, and chipped paint on the top of the wing. Examination of the airplane by a Federal Aviation Administration inspector also revealed that a piece of wood with tree bark on one side of it was wedged between the right wing tiedown ring and the wing structure. Examination of the airplane by maintenance personnel revealed that the solid laminate and sandwich structure of the wing had been substantially damaged. Examination of the surrounding area revealed that trees were present along and below the flight path for the runway. Review of the Airport Facility Directory also revealed that it advised that 88 foot tall trees were present 450 feet from the runway which took a 3:1 slope to clear.