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, which included about 24 percent of the whitebark pine forest population, many lodgepole pine stands, and a variety of other plants and animals. Which type of change was seen in the ecosystems that were affected by the 1988 fires in Yellowstone Park?A. primary succession
B. secondary succession
C. a climax community
D. species extinction

Secondary succession occurs when the mature communities are removed over a specified area by a factor of change that is strong enough to affect the dominant species in the community such as a fire or human intervention (deforestation). Conversely, Primary succession can be seen where the whole community is wiped out and it has to start over from scratch, like after a volcanic eruption where all the area is covered with lava and nothing of the original community remains. A climax community forms after many years (may be hundreds of years in forests) of competition and is composed of mostly highly competitive and shade tolerant species (not pines) and is not likely to be seen after a recent event of drastic change such as a fire. Species extinction is not likely since only part of the communities were affected. So the best answer is B, secondary succession.