The pilot reported that he was landing a tailwheel-equipped airplane on a remote unimproved airstrip. Before the attempted landing, he made a low pass and determined that the dirt airstrip was clear of debris, and had what appeared to be grass on either side of the landing surface. During the final approach the airplane drifted about 10 to 15 feet to the left of the pilots intended touchdown point, and was aligned with the side of the airstrip. Having determined that the vegetation along the sides of the runway was grass the pilot elected not to execute a go-around and proceeded with the landing. The pilot realized, as the airplane touched down and immediately nosed over that the vegetation alongside the airstrip was not grass but alder brush. The airplane sustained substantial damage to the wings, vertical stabilizer and left lift strut. The pilot stated that there were no preaccident mechanical anomalies with the airplane that would have precluded normal operation. In the recommendation section of the NTSB Accident/Incident Reporting Form 6120.1, the pilot stated that the accident may have been prevented if he would have aborted the landing.