Different types of changes take place in ecosystems after they experience a disturbance. From June to September 1988, 51 different wildfires started in Yellowstone Park. By the end of the summer, approximately 794,000 acres of the park were affected, including about 24 percent of the whitebark pine forest population, many lodgepole pine stands, and a variety of other plants and animals. A building in front of a wildfire. Photo by National Park Service Which type of change was seen in the ecosystems affected by the 1988 fires in Yellowstone Park